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Biomedical subjects

L Luciano

Publications and source records attributed to L Luciano.

At least 37 records · Page 2Linked to original sources
PubMed1999

AlphaIFN-induced hematologic and cytogenetic remission in chronic eosinophilic leukemia with t(1;5).

Chronic eosinophilic leukemia (CEL) is a myeloproliferative disease characterized by excessive eosinophilic proliferation with clonal cytogenetic abnormalities. The most frequent cytogenetic abnormality is a break in the q 31-35 region of chromosome 5, where genes encoding for IL-3, IL-5 and GM-CSF (all cytokines involved in eosinophilopoiesis) are located. We report the case of a patient with CEL with t(1;5) (q23;q31), who obtained complete hematologic and major cytogenetic response after two years of alpha-interferon (alpha-IFN) therapy. Two other cases of complete response to alpha-IFN are reported in the literature. A trial with alpha-IFN could be considered as front line treatment in this rare disease.

Adult↗
PubMed1998

Fas-mediated modulation of Bcr/Abl in chronic myelogenous leukemia results in differential effects on apoptosis.

Fas-R is expressed constitutively in CD34(+) cells of patients with chronic myelogenous leukemia (CML); Fas-R triggering results in decreased proliferation rate due to apoptosis of clonogenic cells. We have already shown that alpha-interferon (IFN-alpha) enhances Fas-R expression on CML progenitor cells, thus increasing their sensitivity to Fas-R agonists. Although it appears that IFN-alpha can prime CML cells for the effects of Fas, the response to IFN-alpha in vivo is not a constant feature in CML patients. We studied the mechanisms of Fas-mediated apoptosis in 11 patients suffering from CML in chronic phase and tried to see whether there was a correlation between in vitro inducibility of apoptosis in CD34(+) CML cells after Fas-R triggering and the clinical response to IFN-alpha. After priming with IFN-alpha, Fas triggering resulted in in vitro suppression of hematopoietic cell growth in seven of eight patients who had optimal hematologic response to IFN-alpha; in the same conditions, no inhibitory response to Fas-R agonist was observed in cells from three of three patients who proved to be poor responders to IFN-alpha. In responders to IFN-alpha, Fas-R agonist induced dose-dependent apoptosis of CD34(+) cells; this effect was associated with a decrease in the bcr/abl protein level. In cells derived from patients with a poor response to IFN-alpha, the rate of apoptosis in culture remained unchanged in the presence of Fas-R agonist and no bcr/abl downmodulation was observed. Finally, we measured bcr/abl mRNA by quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) and found that decreased bcr/abl protein after Fas triggering was not associated with decreased amounts of specific mRNA, a finding which is consistent with a posttranscriptional regulation of the bcr/abl protein expression. It appears that Fas-mediated downmodulation of p210 bcr/abl restores susceptibility to apoptosis of CML cells; in addition, in vitro studies on CML cells may predict response to IFN-alpha treatment.

Adult↗
PubMed1998

Splenectomy and risk of blast transformation in myelofibrosis with myeloid metaplasia. Italian Cooperative Study Group on Myeloid with Myeloid Metaplasia.

An unexpectedly high incidence of blast transformation after splenectomy has been reported in patients with myelofibrosis with myeloid metaplasia. However, whether this was associated with spleen removal after adjustment for risk factors was not determined. We conducted a multicenter historical cohort study of patients with myelofibrosis with myeloid metaplasia diagnosed from January 1970 through January 1994. A total of 549 patients (325 men and 224 women from 22 to 92 years of age; median age, 63 years) were included in the final data set. The Cox's proportional-hazards model was used to identify factors associated with blast transformation and death. To further adjust for factors related to spleen removal assignment, a propensity score for splenectomy was estimated using recursive-partitioning analysis. Blast transformation developed in 78 patients (14.2%). Patients who underwent splenectomy developed more blast transformations than those who were not splenectomized (23 of 87 [26.4%] v 55 of 462 [11.9%]; P < .001). The cumulative incidence of blast transformation 12 years after diagnosis was 27.0% in nonsplenectomized patients and 55.0% in splenectomized ones (P = . 01). The risk factors independently predictive of blast transformation included prior splenectomy (relative risk = 2.61), platelet count less than 100 x 10(9)/L at diagnosis (relative risk = 2.45), and the presence of blasts in peripheral blood at diagnosis (relative risk = 2.31). The relative risk of blast transformation in splenectomized patients increased from 2.2 at 48 months from diagnosis to 14.3 at 12 years. Patients with the same propensity score for splenectomy showed a higher risk for blast transformation on the basis of having undergone splenectomy (P = .02). In conclusion, the risk of blast transformation is significantly increased in subjects who underwent splenectomy and appears to be independent of factors related to spleen removal assignment.

Adult↗
PubMed1998

Diverse morphology of biliary atresia in an animal model.

BACKGROUND/AIMS: Extrahepatic biliary atresia can be simulated in Balb/c-mice which have been infected with rotavirus. Irreversible occlusion of the common bile duct is the result of an inflammatory process of the whole biliary tract. The observations in this animal model are similar to extrahepatic biliary atresia in newborn children. The present study describes the wide range of morphological findings in mice and compares the results with several classifications of extrahepatic biliary atresia in children. METHODS: Newborn Balb/c-mice were infected intraperitoneally with rhesus rotavirus; the pathological morphology of the extrahepatic bile ducts in 73 mice is described and illustrated by scanning electron microscopy. RESULTS: The extension and localisation of atresia varied from short to interrupted or long-segment atresia, with or without prestenotic dilatation. The gallbladder was small and atretic, or appeared hydropic due to atresia of the common bile duct. The wide range of pathomorphological findings is the final stage of an inflammatory process. The morphological changes of the extrahepatic bile ducts do not fit any pattern, and no classification is evident. CONCLUSIONS: Most types of extrahepatic biliary atresia in children can be mimicked in this animal model. Comparing these observations with different classifications of extrahepatic biliary atresia in children, it must be asked if any classification of the disease is justified, having regard only to pathomorphological findings in the extrahepatic biliary tract.

Animals↗
PubMed1998

CD34+-enriched donor lymphocyte infusions in a case of pure red cell aplasia and late graft failure after major ABO-incompatible bone marrow transplantation.

A variety of immunohematological complications may occur after ABO-incompatible BMT. We report a CML patient (blood group O) who received a BMT from an HLA-identical sibling (blood group AB). The transplant was followed by normal myeloid and megakaryocytic engraftment, but erythroblastopenia persisted for more than 200 days after BMT. By bone marrow culture studies, a complement-dependent serum inhibitor of hemopoiesis was detected, suggesting immunological inhibition of erythropoiesis. The patient was resistant to a number of treatments such as intravenous gamma-globulins, prednisolone and high-dose erythropoietin. Full engraftment with normal blood counts and marrow cellularity was achieved after two dose-escalating CD34+-enriched donor lymphocyte infusions (DLI). This experience suggests that CD34+-enriched DLI may be an effective treatment for patients with delayed engraftment or late graft failure due to major ABO-incompatibility.

ABO Blood-Group System↗
PubMed1997

Presence of brush cells in the mouse gallbladder.

The brush cells (BC) are the second most frequent cellular component of the epithelium of the mouse gallbladder. They have a topographical distribution, being present in large numbers toward the neck and in the fundic regions of the organ and are scattered in the body. Serial section studies demonstrate that BC have a characteristic shape consisting of a narrow apical portion, bulky body and basal cytoplasmic projections. BC are located obliquely among the principal cells. Scanning electron microscopy demonstrates that the microvilli forming the prominent brush border, after which the cell was named, have a triangular arrangement. Due to their size and stiffness, the microvilli of BC have more similarity with stereocilia of sensory cells than with conventional microvilli. Furthermore freeze-fracture replicas demonstrate that, like stereocilia, the P face of the microvilli plasma membrane of BC is smoother than the E face but several intramembranous particles form small aggregates on the microvillus tip of both P and E faces. Numerous intramembranous particles are scattered on the lateral plasma membrane. An unusual, spatially organized cytoskeleton characterizes the apical cytoplasm of BC. The use of the appropriate fixative reveals that it consists of bundles of actin filaments originating from the axis of the apical microvilli and stretching continuously up to the supranuclear region of the cell. Microtubuli, also assembled in bundles, flank in alternating manner the actin filaments over their whole course. Due to the strong parallel arrangement of both cytoskeletal structures, the apical cytoplasm of the BC assumes a typical stiffness, observable in both thin sections and freeze-fracture replicas. A variable number of vesicles of different size are aligned between the bundles of actin filaments and microtubuli; their shape is highly influenced by the fixative used. Intraluminal injection of horseradish peroxidase demonstrates that these vesicles are not resorptive as they are not filled by the tracer. The BC possess a large number of lateral microvilli. These, whether single or in pairs, are rigid cytoplasmic protrusions that leave the lateral surface of the cell in all directions and penetrate deeply into the cytoplasm of the adjacent principal cells. The bundle of actin filaments emanating from each lateral microvillus extends at different angles into the cytoplasm. A conspicuous amount of bundles of 10 nm filaments is intertwined around the nucleus and extends toward the desmosomes of the lateral plasma membrane and into the basal cellular body. Arguments are considered in support of the view that interactions between the plasma membrane with its differentiations on the one hand and the cytoskeleton elements on the other hand, play a key role in the function of BC as a receptor (sensory) cell.

Animals↗
PubMed1997

Involvement of Fas-mediated apoptosis in the inhibitory effects of interferon-alpha in chronic myelogenous leukemia.

Interferon-alpha (IFN-alpha) is an established treatment for chronic myelogenous leukemia (CML) in chronic phase, but the mechanism of its antileukemic activity is not clear. One possible mechanism of action might include the induction of apoptosis, and especially Fas-mediated cell killing may play an important role in the elimination of malignant cells. We investigated Fas receptor (Fas-R) expression and the consequences of Fas-R triggering in CML patients. Using two-color flow cytometry, we found a significantly higher number of Fas-R-expressing CD34+ cells in the bone marrow (BM) of CML patients compared with normal subjects. We have previously shown that IFN-gamma induces Fas-R expression on CD34+ cells; in this study, we investigated whether IFN-alpha induces Fas-R expression on CML progenitor cells. Dose-dependent induction of Fas-R expression was observed after IFN-alpha stimulation of CD34+ cells from CML BM. In methylcellulose culture, IFN-alpha alone at a therapeutic concentration showed only marginal antiproliferative effects on both normal and CML BM progenitors. In contrast, a Fas-R agonist, the anti-CD95 monoclonal antibody CH11, inhibited colony formation from normal progenitors, and the inhibition was even stronger on CML progenitors. When CML BM cells were cultured in the presence of IFN-alpha, Fas-R-mediated inhibition of colony growth was potentiated in a dose-dependent fashion, consistent with IFN-alpha induction of Fas-R expression. This functional effect did not require the presence of accessory cells, since similar results were obtained with purified CD34+ cells. In suspension cultures, we demonstrated that suppression of CML hematopoiesis by IFN-alpha and Fas-R agonist was exerted through Fas-R-mediated induction of apoptosis. Our findings suggest that the Fas-R/Fas-ligand system might be involved in the immunologic regulation of CML progenitor growth and that its effect can be amplified by IFN-alpha.

Antibodies, Monoclonal↗
PubMed1997

[Removal of the internal limiting membrane in macular holes. Clinical and morphological findings].

UNLABELLED: The recommended treatment for full-thickness macular holes is removal of the posterior hyaloid and sometimes the epiretinal membrane from the retina during vitrectomy in order to release the assumed intravitreous traction. We have employed a technique involving the additional removal of the membrana limitans interna (MLI) from the retina in the vicinity of the macular hole. We report on our clinical results and ultrastructural findings. MATERIALS AND METHODS: Between December 1995 and July 1996, we performed vitrectomies on 39 eyes of 37 patients with full-thickness macular hole. After removal of the attached posterior hyaloid, a specially developed forceps was used to remove a circular area of the MLI approximately three to four disc diameters in size. At the conclusion of the operation, 20% C3F8 gas was injected and the patient instructed to stay in a prone position for 8 days. RESULTS: Intraoperatively, "rhexis" of the MLI only rarely produced bleeding or recognizable retinal edema. Complete closure of the hole was observed postoperatively in 36 of the 39 eyes (92%). A visual improvement of at least two lines was achieved in 77% of eyes with successful closure. Pigment irregularities or edematous changes could not be detected either clinically or by fluorescein angiography in any of the 39 eyes. Electron microscopy was performed on 23 of the membranes. The salient feature was the MLI. Canals leading from the inner to the outer surface of the MLI contained Müller cell processes with clear signs of necrosis or degeneration. On the vitreous side, the MLI usually exhibited myofibroblasts. CONCLUSIONS: The MLI was successfully removed in all 39 eyes with a full-thickness macular hole. This procedure led to very good anatomic and functional results. It remains for future studies to determine the pathogenic significance of the necrotic processes detected by electron microscopy in the MLI canals.

Adult↗
PubMed1997

JURL-MK1 (c-kit(high)/CD30-/CD40-) and JURL-MK2 (c-kit(low)/CD30+/CD40+) cell lines: 'two-sided' model for investigating leukemic megakaryocytopoiesis.

Two novel cell lines (JURL-MK1 and JURL-MK2) have been established from the peripheral blood of a patient in the blastic phase of chronic myelogenous leukemia. The cells grow in a single cell suspension with doubling times of 48 h (JURL-MK1) and 72 h (JURL-MK2). Cytogenetic analysis has shown that JURL-MK1 is hypodiploid whereas JURL-MK2 is near triploid and that both cell lines retain t(9;22). Moreover, JURL-MK1 and JURL-MK2 have a bcr/abl-fused gene with the same junction found in the patient's fresh cells, and both cell lines express the b3/a2 type of hybrid bcr/abl mRNA. The morphology and immunophenotype of these cell lines are reminiscent of megakaryoblasts. In both lines, a limited but consistent percentage of cells expresses gpIIbIIIa (CD41a), gpIIIa (CD61) and CD36, with no expression of gplb (CD42b), glycophorin A, hemoglobin and CD34. Both cell lines are clearly positive for CD33, CD43, CD45RO and CD63, while CD13, CD44, CD54, CD30 and CD40 are specific features of JURL-MK2. Among cytokine receptors, CD117/SCF-R is strongly displayed by a large fraction of JURL-MK1 cells but is hardly detectable on about 20% JURL-MK2 cells. Both cell lines are clearly positive for CD25/IL2R alpha, while a marked expression of CD116/GM-CSF-R and CDw123/IL3R alpha is restricted to JURL-MK2. Induction of cell differentiation in vitro has demonstrated that TPA is able to modulate the JURL-MK1 phenotype, causing an increased expression of platelet-associated antigens. The JURL-MK2 phenotype is easily modulated by both TPA and DMSO, which cause an increased expression of CD41a and CD117 accompanied by a decreased expression of CD30. Proliferation studies demonstrated that JURL-MK1 cell growth is enhanced by stem cell factor, while JURL-MK2 proliferation is unaffected by this cytokine. JURL-MK1 and JURL-MK2 are two novel cell lines with divergent biological features, representing a 'two-sided' model for investigating new aspects of megakaryocytopoiesis.

Antigens, Surface↗
PubMed1997

Lack of butyrate is associated with induction of Bax and subsequent apoptosis in the proximal colon of guinea pig.

BACKGROUND & AIMS: Butyrate stimulates proliferation and suppresses differentiation in normal colonic epithelial cells. Because the involved intracellular signaling mechanisms are unclear, this study investigated certain molecular effects of butyrate. METHODS: Tissue sheets from guinea pig proximal colon were incubated in Ussing chambers in the presence and absence of butyrate. Colonic tissues were examined by scanning and transmission electron microscopy, DNA laddering, Western blots, and immunohistochemistry. RESULTS: After incubation of the colonic mucosa for 150 minutes without butyrate, morphological studies showed massive apoptosis of colonocytes. Simultaneously, these colonocytes exhibited a significant oligonucleosomal DNA fragmentation. In contrast, addition of physiological concentrations of butyrate (10 mmol/L) to colonic sheets showed no detectable DNA fragmentation within 150 minutes. Western blot analysis showed little if any difference in the level of Bcl-2 expression in colonocytes incubated with or without butyrate up to 150 minutes. In contrast, expression of Bax proteins continuously increased after 45 minutes without butyrate and reached a fivefold induction after 150 minutes compared with cells incubated in the presence of butyrate. Moreover, immunohistochemistry using an anti-Bax antibody system showed enhanced labeling of the epithelial colonocytes in the absence of butyrate. CONCLUSIONS: Removal of butyrate induces increased expression of Bax proteins paralleled by rapid apoptosis of colonocytes in vitro.

Animals↗
PubMed1996

Neutrophilic-chronic myeloid leukemia: a distinct disease with a specific molecular marker (BCR/ABL with C3/A2 junction)

Neutrophilic-chronic myeloid leukemia (CML-N) is a rare myeloproliferative disorder that runs a much more benign course than chronic myeloid leukemia, and for which no specific underlying molecular lesion has been described so far. We have analyzed the genomic DNA by Southern blotting and the BCR/ABL hybrid gene transcripts by reverse transcriptase-polymerase chain reaction in three patients with clinical findings of CML-N, who did have a t(9;22) chromosomal translocation. In all patients we have found a rare type of BCR/ABL rearrangement, with a breakpoint between exons c3 and c4 of the BCR gene (corresponding to BCR exons 19 and 20). This was confirmed by hybridization with an oligonucleotide probe spanning the c3/a2 region. This type of junction causes almost the entire BCR gene to fuse with ABL. The junction is in frame and it gives rise to a fusion protein of predicted 230 kD. Our data now provide a molecular diagnostic marker for CML-N, and they are consistent with the notion that the inclusion or exclusion of BCR exons in the fusion protein affects dramatically its capacity to derange myeloid proliferation and differentiation, leading to the appearance of different disease phenotypes.

Adult↗
PubMed1996

High-yield purification of rat monocytes by combined density gradient and immunomagnetic separation.

Satisfactory purification of rodent monocytes in suspension has not been achieved up to now because in rats and mice these cells occur as a minor population of peripheral blood leukocytes overlapping with lymphocytes in size and density. We describe a two-step procedure for the isolation of monocytes from rat blood with high yield and purity. This method permits the recovery of more than 90% of monocytes collected by perfusion of the vasculature and avoids loss of major subpopulations. Percoll density gradient centrifugation of perfusate cells is combined with subsequent indirect immunomagnetic depletion of lymphocytes using an antibody cocktail. The method described produces more than 90% pure rat monocytes.

Animals↗
PubMed1996

Withdrawal of butyrate from the colonic mucosa triggers "mass apoptosis" primarily in the G0/G1 phase of the cell cycle.

Butyrate exerts a trophic effect on the colonocytes and plays a protective role in ulcerative colitis. In the present study, we investigated the effect of butyrate withdrawal on the colonic mucosa of the guinea-pig. The samples were mounted in Ussing chambers and bathed for 45, 60, 90 and 150 min with standard Ringer solution with or without sodium butyrate. Light and electron microscopy for morphology, electrophysiological methods for testing tissue function, histochemistry using the TUNEL method for localization of apoptotic cells and flow cytometry for cell cycle analysis were applied. Morphological observations revealed that butyrate deprivation caused a time-dependent hypoplasia and a rapid triggering of massive apoptosis as substantiated by the TUNEL assay. The epithelium, however, did not show discontinuities at any time. Electrophysiological data confirmed that no leakage of the epithelium had occurred. In the control specimens, the mucosa underwent a moderate reduction in height; apoptotic epithelial cells were infrequently observed. Cell cycle analysis of colonocytes isolated from the mucosa deprived of butyrate revealed a decrease in the percentage of cells occupying each phase of the cycle, especially the G0/G1 phase. Thus, in the absence of butyrate, apoptosis was enhanced and cell renewal reduced. The trophic protective action exerted by butyrate in both physiological and pathological conditions could derive from its capacity to modulate survival and death of colonocytes.

Animals↗
PubMed1996

All-trans-retinoic acid (ATRA) responsive skin relapses of acute promyelocytic leukaemia followed by ATRA-induced pseudotumour cerebri.

A 30-year-old woman with acute promyelocytic leukaemia (APL) went into complete remission following idarubicin and cytarabine chemotherapy; 18 months later she developed repeated skin relapse, with no bone marrow involvement. DNA and RNA analysis of skin lesions revealed the presence of the PML/RAR alpha hybrid gene, which was not detected at the same time in bone marrow. The skin relapses were successfully treated by all-trans-retinoic acid (ATRA) as single agent over 2 years. However, prolonged administration of ATRA caused pseudotumour cerebri, which disappeared upon drug withdrawal. The absence of the hybrid gene in the bone marrow by RT-PCR analysis led to the patient being autografted.

Adult↗