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Biomedical subjects

L Vitale

Publications and source records attributed to L Vitale.

At least 37 records · Page 2Linked to original sources
PubMed1994

[Vesico-vaginal fistula after abdominal hysterectomy. Use of the Legueu technique].

Vesicovaginal fistulas are commonly seen as a complication of abdominal (or vaginal) Hysterectomy. The signs and symptoms of a vesicovaginal fistula depend upon its size and location. Identification of a vesicovaginal fistula includes an intravenous urogram; cystoscopy may be performed in order to evaluate the possibility of immediate or delayed repair. Case report. Principles of surgical repair. The principles of surgical closure are similar: 1) total separation of the tissues comprising the wall of the vagina and the wall of the bladder; 2) sharp excision of the fistulous tract between to two structures; 3) closure of the defects with non-overlapping suture lines; 4) where possible, interposition of alternative tissue between the two suture lines. The intervention proposed by Legueu allows an abdominal transperitoneal approach to the fistula and is comprehensive of these principles. With such a procedure we have treated successfully two cases which required surgical closure. CONCLUSIONS. In patients who develop vesicovaginal fistulas as a complication of abdominal hysterectomy, we have applied the intervention proposed be Legueu, which allows closure of the fistula via a transperitoneal route. Preliminar diagnostic evaluation and following of the foundamental principles of correct surgical closure are indispensable to accomplish a successful intervention.

Adult↗
PubMed1994

[Retroperitoneal abscesses: clinical and therapeutical aspects].

The authors explain the clinical and anatomical features of retroperitoneal abscesses, which occur less commonly than peritoneal infections. Retroperitoneal abscesses arise chiefly from injuries in adjacent structures, but they may be primary when caused by hematogenous bacterial spread. The pyogenic bacteria have replaced Mycobacterium tuberculosis as the major causative organism. Retroperitoneal abscesses may be symptomless, but fever and abdominal pain are prominent features. The differential diagnosis includes retroperitoneal tumors and hematomas. These lesions are best delimited by CT scanning which localizes them accurately. The treatment consists in a prompt and adequate drainage and systemic antibiotics therapy. Drainage by catheter, however, has a lower success rate than the surgical approach. The surgical mortality rate is about 25%.

Abscess↗
PubMed1994

[Postoperative pulmonary thromboembolism].

The authors report their finding concerning the frequency of postoperative pulmonary thromboembolism in an autopsy series of subjects who had died with 15 days of surgery. In all cases the relationship was evaluated between death and age, sex, the underlying pathology and the type of surgery.

Adolescent↗
PubMed1994

[Use of ultrasonic surgery in laparoscopic cholecystectomy].

INTRODUCTION: Laparoscopic cholecystectomy now represents a valid alternative to traditional surgery in the treatment of gallstone diseases. For the past twenty years laparotomic cholecystectomy has represented the golden standard of gallstone treatment given its extremely low mortality rate (0.5%) and equally acceptable morbidity rate. Laparoscopic cholecystectomy now appears to have taken over the position of elective treatment. Sophisticated techniques, such as ultrasound scalpels make this form of surgery particularly safe. MATERIALS AND METHODS: The authors report a series of 50 patients who underwent laparoscopic cholecystectomy in which ultrasound surgery was used in 40 cases using the CUSA system. The gallbladder hilus is prepared using ultrasound manipulation following the secure identification, respect and clipping of the cystic artery and duct. DISCUSSION AND CONCLUSIONS: Laparoscopic cholecystectomy appears to be the ideal treatment for gallstone diseases. In the series reported here the use of the ultrasound scalpel allowed the gallbladder hilus to be reach skeletization, preserving the main structures and keeping the operating field clean and blood-free, without increasing operating times. The possibility of severe accidents, such as vascular lesions to the hepatic artery or vena portae, or damage to the common bile duct or other abdominal organs are reduced using this technique.

Adult↗
PubMed1993

[A bleeding jejunal schwannoma. The complications of a rare neoplasm of the small intestine].

The authors report a rare case of jejunal Schwannoma which appeared as hematemesis and melaena. No preoperative test, even selective angiography, enabled a correct clinical diagnosis to be made. Only after explorative laparotomy and careful palpation of the small intestine was the bleeding lesion located. Resection and termino-terminal anastomosis were then performed. The preparation of immunohistochemical reactions now allow forms which were previously diagnosed in different terms to be precisely classified.

Adult↗
PubMed1993

M-07e cell bioassay detects stromal cell production of granulocyte-macrophage colony stimulating factor and stem cell factor in normal and in Diamond-Blackfan anemia bone marrow.

Ten healthy donors and four patients with Diamond-Blackfan anemia (DBA) have been investigated for granulocyte-macrophage colony stimulating factor (GM-CSF) and stem cell factor (SCF) production by bone marrow-enriched fibroblasts (BMEF) in a highly sensitive biological assay on growth factor-dependent M-07e cells. M-07e cells detected active soluble kit-ligand from normal bone marrow fibroblasts as well as from DBA BMEF which produce constitutively significant amounts of SCF. Interleukin 1 beta (IL-1 beta) induced a significant increase of soluble SCF from both normal and DBA BMEF. GM-CSF was undetectable in unstimulated cultures, while its production by bone marrow microenvironmental cells was documented for both normal and DBA patients after IL-1 beta stimulation in vitro.

Adult↗
PubMed1993

Immunotoxic effects of mercuric compounds on human lymphocytes and monocytes. III. Alterations in B-cell function and viability.

The major goal of the study was to determine the effects of high and low levels of mercury on human B-cells. Following treatment of B-cells with HgCl2 (0-1000 ng) and MeHgCl2 (0-100 ng), their activation by mitogens was evaluated. Both forms of mercury caused a dose dependent reduction in B-cell proliferation in the presence or absence of monocytes. MeHgCl was approximately 10 times more potent than HgCl2. Mercury also inhibited the ability of these cells to synthesize IgM and IgG. Analysis of the expression of activation markers indicated that CD69, an early marker of cell activation, was not effected by mercury. In comparison, B-cell expression of the low affinity IgE receptor and the transferrin receptor were significantly reduced. Of particular interest, cells activated by mitogen for 48 hr became refractory to the immunotoxic effects of mercury. When exposed to high levels of HgCl2 (0.5-10 micrograms/ml) and MeHgCl (0.05-1 micrograms/ml), there was minimal reduction in B-cell viability at 1-4 hr, however, after exposure to mercury for 24 hr, cell death was apparent. MeHgCl was approximately 5-10 times more potent than HgCl2. Electron microscopic analysis revealed early nuclear alterations characterized by hyperchromaticity, nuclear fragmentation and condensation of nucleoplasm. Both forms of mercury caused a rapid and sustained elevation in the intracellular levels of Ca++. The results of this investigation clearly show that mercury-containing compounds are immunomodulatory; moreover, the decrease in B-cell function indicates that this metal is immunotoxic at very low exposure levels. Furthermore, the cytotoxic events are consistent with the notion that mercury initiates changes associated with programmed cell death.

B-Lymphocytes↗
PubMed1993

[Study of the cell cycle using flow cytometry in drug allergy].

Drug allergy has been studied by flow cytometry with the technique of cellular cycle, of which the principle is based on cellular activity. There were four groups of patients in the study: The first reference groups (A:20 patients) gave evaluation of phase S + G2-M without antigenic stimulation of monodisperse lymphocyte cultures. This was 4%. The second group (B:15 patients) presented a phase S + G2-M of 14.1% with PHA compared with the reference response significant at 2.5%. The third group (C) was composed of 5 wasp venom allergic subjects with cellular activity phase of 17.3% and 5 nonallergic subjects with an almost identical response of around 15%. The fourth group was 5 subjects who were allergic to drugs with clinical history that strongly indicated an allergy. The response to stimulation in these subjects was much greater for each of the drugs than that of a reference subject who was taking the same drug without problem. Wasp venom seems to behave like PHA, as a mitogen. In contrast, the subjects who were objectively and clinically sensitive to drugs, had an overall greater response to them than those shown by references. It is important to have a control for each drug used.

Adolescent↗
PubMed1992

Extracellular alpha-amylase from Streptomyces rimosus.

A purification procedure for an extracellular alpha-amylase from Streptomyces rimosus, oxytetracycline-producing strain, is described. The enzyme obtained was shown to be an acidic (pI 4.75) monomer with a relative molecular mass (M(r)) of 43,000, containing three cysteines involved in the catalytic activity of the enzyme. Its amino-terminal part has 57-67% homology with amylases from other Streptomyces species. S. rimosus alpha-amylase is sensitive to higher temperatures, and partially stabilized by Ca2+ ions. It hydrolyses starch (optimum at pH 5.0-6.0) in an endohydrolase manner giving rise to maltotriose, maltotetraose and higher oligosaccharides. Starch granules, except those from rice, were not significantly affected by the isolated alpha-amylase.

Amino Acid Sequence↗
PubMed1992

Basic amino acids preferring broad specificity aminopeptidase from human erythrocytes.

An aminopeptidase hydrolyzing 2-naphthylamides of Lys, Arg, Leu, Met, Phe and Tyr, as well as different di- to tridecapeptides, was purified from the cytosol of human erythrocytes. The enzyme showed preference for Lys and Arg at N-terminus, as proline and D-amino acids were nonpermissive at P1' site. Higher affinity for oligopeptides than for aminoacyl naphthylamides was observed. Among the substrates were Lys-bradykinin, angiotensin III, thymopentin and enkephalins. Aminopeptidase was shown to be a monomeric protein of M(r) approximately 110000 and of pI approximately 4.8, activated by Co2+ and inhibited by EDTA, pHMB, amastatin, bestatin and puromycin. The isolated enzyme could be classified as cytosolic, Lys(Arg) preferring, broad specificity aminopeptidase.

Amino Acid Sequence↗
PubMed1992

Immunotoxic effects of mercuric compounds on human lymphocytes and monocytes. I. Suppression of T-cell activation.

Considerable attention has been directed at defining the health deficits associated with exposure to mercurial compounds. While numerous studies have been conducted, the findings have been somewhat contradictory and have led to a confused understanding of the immunotoxicology of mercury. It is becoming clear, however, that the immunotoxic effects of heavy metals in general, and mercury in particular, are dependent upon the assays and source of cells. The major goal of our study was to assess whether low level mercury exposure modulates human T-cell function. Following treatment of T-cells with HgCl2 (0-1000 ng) and MeHgCl (0-100 ng), their activation by mitogens was evaluated. Both forms of mercury caused a dose dependent reduction in T cell proliferation, however, the effect was dependent upon the presence of monocytes. Moreover, in the absence of monocytes, HgCl2 enhance PMA induced T-cell proliferation. MeHgCl was approximately 5-10 times more potent than HgCl2. Mercury also inhibited the ability of these cells to synthesize and secrete IL-1. Analysis of the expression of activation markers on the cell surface indicated that one of the earliest markers of lymphocyte activation, CD69, was not effected by mercury. In comparison, T-cell expression of IL-2R and the transferrin receptor was impaired. Of particular interest, cells activated by mitogen for 24 hr became refractory to the immunotoxic effects of mercury. The results of this investigation clearly show that mercury-containing compounds are immunomodulatory; moreover, the decrease in T-cell function following exposure to mercury indicates that this metal is immunotoxic at very low exposure levels.

Antigens, CD↗
PubMed1992

Immunotoxic effects of mercuric compounds on human lymphocytes and monocytes. II. Alterations in cell viability.

The major goal of this investigation was to examine the cytotoxic properties of both HgCl2 and MeHgCl, in terms of their ability to alter human T-cell and monocyte viability. Following treatment with HgCl2 (0-20 micrograms/ml) or MeHgCl (0-2 micrograms/ml), there was minimal reduction in lymphocyte viability at 1-4 hr. However, after exposure to mercury for 24 hr, cell death was apparent. In comparison, monocytes exhibited significant loss of viability during the early exposure periods. MeHgCl was approximately 5-10 times more potent than HgCl2. Other indicators of cell death were also determined. Measurement of the energy charge ratio indicated profound changes in cellular energy conservation. Electron microscopic analysis of cells treated with mercury revealed early nuclear alterations characterized by hyperchromaticity, nuclear fragmentation and condensation of nucleoplasm. In concert with these nuclear changes, there was destruction of cytoplasmic organelles with loss of membrane integrity. Studies of phospholipid synthesis by mercury treated cells confirmed that there were alterations in membrane structure. Thus, there was a decrease in total phosphatide synthesis by treated cells. Moreover, monocyte phospholipid synthesis appeared to be more sensitive to the presence of mercury then lymphocytes. Finally, both forms of mercury caused a rapid and sustained elevation in the intracellular levels of Ca++. These morphological and biochemical changes are consistent with the notion that mercury initiates cytotoxic changes associated with programmed cell death.

Animals↗
PubMed1992

Prevalence of the primitive megakaryocyte progenitors (BFU-meg) in adult human peripheral blood.

The in vitro growth of early (megakaryocyte burst-forming units, BFU-meg) and late (megakaryocyte colony-forming units, CFU-meg) megakaryocyte (meg) progenitors has been evaluated in normal adult human peripheral blood (PB). All the experiments were carried out using CD34+ cells, which were assayed in a serum-free fibrinclot assay. PB BFU-meg were morphologically characterized as plurifocal aggregates containing greater than 50 cells/colony, distinct from unifocal CFU-meg, in a limiting dilution assay. At variance with PB CFU-meg, PB BFU-meg were unaffected by the complement-mediated cytotoxicity with anti-HLA-DR. The optimal source of colony-stimulating activity for PB BFU-meg growth was recombinant human interleukin 3 (rhIL-3; 100 U/ml), which supported a significantly higher number of BFU-meg in comparison with recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF; 200 U/ml, p = 0.043). Combinations of rhIL-3 (100 U/ml) plus rhGM-CSF (200 U/ml), rhIL-3 plus recombinant human interleukin 6 (rhIL-6; 100 U plus 100 U/ml) or rhIL-3 plus rhGM-CSF plus rhIL-6 (100 U plus 200 U/ml plus 100 U/ml) failed to further increase the number of PB BFU-meg with respect to rhIL-3 (100 U/ml) alone. Both PB BFU-meg and CFU-meg were markedly inhibited, in a dose-dependent fashion, by increasing doses of human purified transforming growth factor-beta 1 (TGF-beta 1) (from 0.001 to 10 ng/ml). Finally, the CFU-meg/BFU-meg ratio in PB (0.52) was significantly different from that of normal bone marrow (2.3), clearly indicating that adult human peripheral blood predominantly carries primitive megakaryocytic progenitors.

Adult↗
PubMed1991

In vitro growth and regulation of bone marrow enriched CD34+ hematopoietic progenitors in Diamond-Blackfan anemia.

Diamond-Blackfan anemia (DBA) is a congenital red blood cell aplasia. No clear explanation has been given of its defective erythropoiesis, although different humoral or cellular inhibitory factors have been proposed. To clarify the nature of this defect we studied the effect of several human recombinant growth factors on an enriched CD34+ population obtained from the bone marrow of 10 DBA patients. We observed a defect underlying the early erythroid progenitors, which were unresponsive to several growth factors (erythropoietin, interleukin-3 [IL-3], IL-6, granulocyte-macrophage colony-stimulating factor [GM-CSF], erythroid potentiating activity), either alone or in association. The production of cytokines was not impaired, and high levels of IL-3 and GM-CSF were found in phytohemagglutinin-leukocyte-conditioned medium (PHA-LCM) when tested with a sensitive biologic assay on the M-07E cell line. Hematopoietic stem cells in DBA patients may be induced to differentiate to the granulocyte megakaryocyte, but not the erythroid compartment, as shown after CD34+ cell preincubation with IL-3. Addition of the stem cell factor to IL-3 and erythropoietin induces a dramatic in vitro increase in both the number and the size of BFU-E, which also display a normal morphologic terminal differentiation.

Antigens, CD↗
PubMed1991

Essential thrombocythemia: impaired regulation of megakaryocyte progenitors.

In this paper, the in vitro growth of bone marrow early (megakaryocyte burst-forming units, BFU-meg) and late (megakaryocyte colony-forming units, CFU-meg) progenitors was evaluated in 18 essential thrombocythemia (ET) patients and 22 normal control subjects. BFU-meg clonality was demonstrated both in normal and ET bone marrows, cultivating these primitive progenitors at limiting dilutions in plasma clot assay: 1 to 7 BFU-meg/2.5 x 10(4) mononuclear non-adherent cells were observed, with a strong correlation in ET [r = 0.955 stimulated by recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) plus recombinant human interleukin (rhIL) 3], as well as in normal controls (r = 0.969). In order to clearly elucidate the in vitro response of ET megakaryocyte (meg) progenitors to recombinant growth factors, the interference of accessory cells (i.e., monocytes, T lymphocytes, and natural killer cells) and human serum were avoided by performing experiments on CD34+ cells in a serum-free fibrin clot assay. The number of both early and late meg progenitors in ET was significantly increased in response to rhIL-3, rhIL-3 plus rhIL-6, and rhIL-3 plus rhGM-CSF, but not in response to rhGM-CSF alone. Furthermore, both meg progenitors were investigated for their response to rh transfer growth factor (TGF)-beta 1, tested at concentrations from 0.01 to 10 ng/ml. rhTGF-beta 1 was able to inhibit CFU-meg and BFU-meg in a dose-response manner normal, whereas ET CFU-meg appeared less sensitive to the lower doses investigated (p less than 0.05) and ET BFU-meg were slightly reduced in number only at the higher concentrations of rhTGF-beta 1 (p less than 0.01). Our data suggest that the increased thrombopoiesis in ET may depend on an increased sensitivity of meg progenitors to some of the physiological growth factors and to a disrupted sensitivity to at least one negative regulator of megakaryocytopoiesis. Since these abnormalities involve both meg progenitors, this can be considered a demonstration that the neoplastic event hits the most primitive hemopoietic progenitors.

Cell Division↗