Search PubMed⌕ Search

Biomedical subjects

D Quaglino

Publications and source records attributed to D Quaglino.

At least 91 records · Page 5Linked to original sources
PubMed1993

Selective involvement of monocytes by acquired myeloperoxidase deficiency in a case of chronic myelomonocytic leukemia.

The authors describe a case of chronic myelomonocytic leukemia in which a myeloperoxidase (MPO) deficiency of circulating monocytes was first detected by automated differential cell counting, and subsequently confirmed by cytochemical and immunocytochemical investigations. MPO activity in neutrophil granulocytes from the same case was found to be normal. MPO deficiency in monocytes appeared to be associated with impaired phagocytic capacity and, based on the results of immunophenotypic and ultrastructural studies, was most likely attributable to a partial maturation arrest of monocytes. The present case suggests that MPO deficiency in myelodysplastic syndromes may have its origin in a number of different pathogenetic mechanisms.

Aged↗
PubMed1993

Delayed internucleosomal DNA fragmentation in programmed cell death.

DNA fragmentation was evaluated in three instances of programmed cell death, interdigital cell death in embryonic mouse limbs, and metamorphic death of both the labial glands and intersegmental muscle in the tobacco hornworm Manduca sexta. In the mouse, we evaluated both developmental cell death and expanded-range cell death induced by retinoic acid. The status of DNA was examined in several ways. Nuclei were examined by electron microscopy and Feulgen staining. Quantitative assessment of total DNA content in Feulgen-stained degenerating nuclei was made for the gland. In the labial gland, DNA content does not drop during the early phases of cell death; nor is an endonucleolytic ladder seen when DNA was examined by ethidium bromide staining or prelabeling with [3H]thymidine. Only by using end labeling of DNA could we detect DNA fragmentation at a very late stage in cell death, day 4 of the collapse of the gland. In contrast, WEHI 7.1 lymphoma cells display an early and extensive ladder after treatment with glucocorticoids. In mouse limb, for which cell death follows a more classic apoptotic morphology, a ladder is likewise not seen. We conclude that activation of an endonuclease is neither a trigger nor a necessary or defining component of the early phases of developmental programmed cell death, and that reported failure by others to find such a ladder may depend on limitations in the system that is under investigation.

Animals↗
PubMed1993

Extracellular matrix modifications in rat tissues of different ages. Correlations between elastin and collagen type I mRNA expression and lysyl-oxidase activity.

We used a rat model to correlate age, matrix gene expression and lysyl oxidase activity in three connective tissues, skin, aorta and lung. By in situ hybridization, we showed that intense collagen type I and elastin mRNA expression were limited to a brief postnatal period. Although there were some organ-specific differences, the mRNA abundance for these two scleroproteins drastically diminished with time. Thus, the majority of mesenchymal cells in young (60 days) and old (720 days) animals, appeared to be in a quiescent state, consistent with the slow turnover of these two scleroproteins. We also measured the activity of lysyl oxidase, an enzyme which plays a crucial role in the formation of crosslinks in both procollagen and tropoelastin molecules. In all the organs investigated, we observed a tissue-dependent pattern of activity. Moreover in this study we focused on the importance of gene matrix expression in evaluating lysyl oxidase activity of aging tissues.

Aging↗
PubMed1993

Anaemias and other haematological changes due to disease of the alimentary tract.

Often anaemia and other haematological changes are unrelated to primary diseases of the erythron but are secondary to gastrointestinal alterations, such as occult or overt blood loss or defective absorption of essential haemopoietic factors. This overview emphasizes, through the description of different pathological conditions, the fundamental role of the gastrointestinal tract in maintaining a normal haematological balance. This role is jeopardized in diseases related to the liver and to the various sections of the alimentary tract from the oesophagus to the rectum. Of primary importance in inducing haematological changes which may be modified by curing the primary condition are essentially the diseases of the small intestine, following malabsorption of iron, folic acid and vitamin B12, such as conditions associated with small intestine bacterial overgrowth, tropical sprue, gluten sensitive enteropathy whipple's disease and various infections with intestinal parasites. Moreover, the Authors briefly survey the other pathological conditions of the alimentary tract often associated with chronic bleeding. In this context of particular relevance are the screening procedures which may reveal the presence of occult bleeding caused by neoplastic diseases. It is important that the clinician be aware of this possibility and of the underlying physiopathological mechanism of the diseases of the alimentary tract, so that appropriate and timely therapeutic measures may be undertaken.

Anemia↗
PubMed1992

Cytogenetic findings in terminal large cell transformation in a case of Sézary syndrome.

A long-lasting case of Sézary syndrome, whose chromosomal pattern had been repeatedly investigated during a follow-up period of several years, was studied in the terminal transforming phase, which took place more than 5 years after the initial diagnosis. To the best of the authors' knowledge, this appears to be the first instance of cytogenetic studies carried out in a large cell transformation of cutaneous T-cell lymphoma. The results clearly indicate that the atypical large cells seen in the transforming phase were clonally derived from the pre-existing cerebriform cells. Newly detected relevant cytogenetic findings were: a) drop of tumor cell ploidy from hypotetraploid to hypotriploid, with striking chromosomal imbalance; b) additional structural aberrations of chromosomes 2 and 7, which had been already preferentially involved in the earlier phases, and involvement of the previously unaffected chromosomes 1, 3, and X; and c) presence in 100% of the abnormal metaphases of a large HSR on the long arm of chromosome 17.

Aged↗
PubMed1992

Role of the extracellular matrix in age-related modifications of the rat aorta. Ultrastructural, morphometric, and enzymatic evaluations.

Connective tissues such as blood vessels are known to be greatly affected by age because of impaired functional properties and increased susceptibility to diseases. With the aim of providing further information on the role of the extracellular matrix in age-related modifications, we investigated the aorta in the rat model from birth to senescence by means of morphological and morphometric observations and by evaluation of lysyl oxidase activity. Results focused on the dramatic vascular rearrangements due to progressive fibrosis of the extracellular matrix and on prominent elastin modifications. The presence of lysyl oxidase activity, even in the oldest animals, might be at least partly responsible for the increased stiffness of the aging extracellular matrix. The striking age-related remodeling of the aortic architecture and the alterations of the interactions between cellular and extracellular compartments might greatly influence the functional properties of the arterial wall in senescence, at least contributing to the consequences of some apparently age-related vascular disorders.

Aging↗
PubMed1991

Tuftsin deficiency in AIDS.

Tuftsin is an endogenous tetrapeptide that stimulates phagocytosis and is released from the Fc fragment of IgG by a splenic endocarboxypeptidase. Tuftsin activity and splenic function were measured in 21 patients with AIDS, 7 patients with AIDS-related complex (ARC), 22 patients who had undergone splenectomy, and 37 healthy volunteers. There was a significant inverse correlation between tuftsin activity and splenic function in all subjects. Tuftsin activity was significantly lower in patients with AIDS, ARC, and in those who had undergone splenectomy compared with healthy volunteers. Tuftsin deficiency may contribute to the risk of bacterial infection in symptomatic HIV-positive individuals.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Ultrastructural studies on dermis from prolidase deficient subjects.

Ultrastructural analyses were performed on clinically normal skin from forearm and/or femoral regions of five subjects, all excreting high levels of gly-pro dipeptides into the urine and exhibiting very low prolidase activity on hemolyzed erythrocytes. In both regions, the overall organization of the dermis was normal. Stereological analysis, however, showed that collagen volume density was reduced when compared to that of age-matched controls. Collagen fibrils did not show ultrastructural alterations, but they were distributed into a higher number of small bundles, and their diameters shifted towards lower values compared to age-matched controls. The elastin volume density was slightly reduced in the patients, especially in the femoral areas. In both forearm and femoral dermis, elastin fibers were significantly more numerous and smaller than in controls. Furthermore, elastin fibers were apparently normal in the forearm dermis, whereas appeared polymorphic and cribriform in the femoral skin. The results focused on the importance of efficient proline re-utilization for normal collagen and elastin synthesis and deposition. The differences between femoral and forearm skin regions from both clinical and ultrastructural points of view, may depend on mechanisms that regulate circulation and, possibly, on other factors which modulate the phenotypic expression of mesenchymal cells.

Adult↗
PubMed1991

Opposing effects of ascorbate on collagen and elastin deposition in the neonatal rat aorta.

Ascorbic acid plays an important role in connective tissue metabolism, where, among other effects, it acts as a reducing factor in the reactions catalyzed by prolyl and lysyl hydroxylases. In vitro, ascorbic acid has been shown to have a positive influence on collagen synthesis at pre- and/or post-translational levels and a negative effect on elastin production. In the present work, the effects of vitamin C on extracellular matrix deposition have been studied in vivo. Stereological analysis on electron micrographs showed, compared to age-matched controls, a 50 to 60% increase of collagen deposition in the media and in the adventitia of the aorta of rats treated for 30 days from the 18th day of life with 10% ascorbate in their drinking water. By contrast, elastin volume density was significantly reduced by the treatment at all ages examined. These morphological data were supported by in situ hybridization observations showing enhanced collagen type I mRNA and reduced elastin mRNA expression upon treatment. Although vitamin C did not inhibit lysyl oxidase activity in vivo, being only slightly higher than in controls, enzyme activity was significantly reduced, when high doses of ascorbate were added in vitro. Lysyl oxidase activity may be a function of enhanced collagen metabolism rather than a direct effect of the vitamin on the enzyme activity. These data indicate that ascorbate exerts opposite effects on the deposition of two major components of the extracellular matrix in vivo, at least during periods of rapid growth.

Animals↗
PubMed1991

Transforming growth factor-beta stimulates wound healing and modulates extracellular matrix gene expression in pig skin: incisional wound model.

Enhanced wound healing is elicited by exogenous administration of transforming growth factor- beta 1 (TGF- beta 1) in split-thickness, excisional wounds in the pig (Quaglino, Lab Invest 63:307-319, 1990). A study was designed to investigate if the selective and localized effects of TGF-beta 1 found in the previous model were dependent upon the type of wound or could be considered a more general effect of the cytokine. Transdermal, sutured incisions in the pig were evaluated by conventional histology and by in situ hybridization to reveal locally affected gene expression of collagen, elastin, fibronectin, stromelysin, TGF- beta 1, and basic fibroblast growth factor. Granulation tissue formation was markedly enhanced at 6 d by a single injection of recombinant human TGF beta 1 at the time of wound closure. Although granulation tissue was confined within the margins of the incisional wound, prominent differences in hybridization signals were observed between control and treated wounds. The stimulatory effect of TGF- beta 1 on granulation tissue formation was accompanied by a distinct enhancement in cells expressing mRNA for several different extracellular matrix proteins including collagens type I and III and elastin, whereas a single injection of human recombinant TGF beta 1 (4 micrograms) at the wound site diminished the expression of the neutral metalloprotease, stromelysin, and enhanced the frequency and intensity of cells expressing TGF- beta 1. The data reinforce the concept that TGF- beta 1 can act as a potent, auto-inductive modulator of connective tissue remodeling during the repair process.

Animals↗
PubMed1990

Modulation of vitronectin receptor binding by membrane lipid composition.

The vitronectin (Vn) receptor belongs to the integrin family of proteins and although its biochemical structure is fully characterized little is known about its binding affinity and specificity. We report here that Vn receptor binding to different matrix proteins is influenced by the surrounding lipid composition of the membrane. Human placenta affinity purified Vn receptor was inserted into liposomes of different composition: (i) phosphatidylcholine (PC); (ii) PC+phosphatidylethanolamine (PE); (iii) PC+PE+phosphatidylserine (PS) + phosphatidylinositol (PI) + cholesterol (chol). The amount of purified material that could be incorporated into the three lipid vesicle preparations was proportional to the efficiency of the vesicle formation that increased from PC (38%) to PC+PE and PC+PE+PS+PI+chol (about 50%) vesicles. Electron microscopy analysis showed that the homogeneity and size of the three liposome preparations were comparable (20-nm diameter) but their binding capacity to a series of substrates differed widely. Vn receptor inserted in PC liposomes bound only Vn, but when it was inserted in PC+PE and PC+PE+PS+PI+chol liposomes it also attached to von Willebrand factor (vWF) and fibronectin (Fn). Vn receptor had higher binding capacity for substrates when it was inserted in PC+PE+PS+PI+chol than PC+PE liposomes. Antibodies to Vn receptor blocked Vn receptor liposome binding to Vn, vWF, and Fn. The intrinsic emission fluorescence spectrum of the Vn receptor reconstituted in PC+PE+PS+PI+chol liposomes was blue-shifted in relation to PC liposomes, suggesting a conformational change of the receptor in the membranes. These data provide direct evidence that the Vn receptor is "promiscuous" and can associate with Vn, vWF and Fn. The nature of the membrane lipid composition surrounding the receptor could thus influence its binding affinity, possibly by changing its conformation or exposure or both.

Amino Acid Sequence↗
PubMed1990

Cytogenetic follow-up in a case of Sézary syndrome.

A cytogenetic follow-up study was performed for a 3-year period on a 70-year-old patient with Sézary syndrome (SS). The results showed formation of hypotetraploid cell clones with 60 to 89 chromosomes and 19 markers, some of which appeared during the period of study and stabilized thereafter. The incidence of these clonal cells increased from 29% to 85% during the follow-up study. The results confirm the presence of hypotetraploid cell clones, especially in the more advanced stages of SS. Moreover, some marker chromosomes in our patient (M2 and M3), derived from chromosome 2, were similar to those observed in SS by other investigators. According to our data and to those in the literature, SS appears to involve preferentially chromosomal regions 2p12-13, 2p21-22, 2q37, 17p13, 13q1, 9q11, 10p13, 14q11, 14q32, 7p1 and, to a lesser extent, 5q and 6q.

Aged↗
PubMed1990

Howell-Jolly body counting as a measure of splenic function. A reassessment.

Non-surgical and surgical asplenia predisposes to fatal infections; therefore, simple, non-invasive and repeatable tests for assessing splenic function are required, even in non-specialized medical institutions. Howell-Jolly bodies are the most characteristic peripheral blood abnormality after splenectomy, but their counting is not considered a reliable measure of splenic function. In this study, in a group of splenectomized subjects and of patients with non-surgical hyposplenism, we have compared counting of Howell-Jolly bodies, stained by both the May-Grünwald/Giemsa method and the Feulgen reaction, with pitted cell counting which is considered a reliable technique for the assessment of splenic hypofunction. A significant correlation has been found between Howell-Jolly body counts, stained by either technique, and pitted cell counts (P less than 0.0001). Through Howell-Jolly bodies were never detectable when pitted cell counts fell between 4 and 8%, values consistent with a very mild splenic hypofunction, for pitted cell counts above 8% their increase was always associated with increasing Howell-Jolly body counts. These data suggest that, although pitted cell counting represents a more sensitive method for evaluating splenic function, Howell-Jolly body counting may still be regarded as a simple and reliable technique for identifying and monitoring those cases associated with a real risk of overwhelming infections.

Adolescent↗
PubMed1990

Transforming growth factor-beta stimulates wound healing and modulates extracellular matrix gene expression in pig skin. I. Excisional wound model.

The effect of transforming growth factor-beta 1 (TGF-beta 1) on matrix gene expression has been investigated during the process of wound repair, where the formation of new connective tissue represents a critical step in restoring tissue integrity. Split-thickness excisional wounds in the pig were studied by in situ hybridization in order to obtain subjective findings on the activity and location of cells involved in matrix gene expression after the administration of recombinant TGF-beta 1. Data focus on the stimulatory role of this growth factor in granulation tissue formation, on the enhanced mRNA content of collagen types I and III, fibronectin, TGF-beta 1 itself, and on the reduction in stromelysin mRNA, suggesting that increased matrix formation measured after treatment with TGF-beta 1 is due to fibroplasia regulated by the abundance of mRNAs for several different structural, matrix proteins as well as inhibition of proteolytic phenomena elicited by metalloproteinases. These studies reveal elastin mRNA early in the repair process, and elastin mRNA expression is enhanced by administration of TGF-beta 1. Moreover, we show that TGF-beta 1 was auto-stimulating in wounds, accounting, at least in part, for the persistent effects of single doses of this multipotential cytokine.

Animals↗
PubMed1989

Recurrence of Hodgkin's disease after a 28-year disease-free interval. A case report.

The authors describe a case of nodular-sclerosing Hodgkin's disease, originally observed in clinical stage III B and treated by systemic chemotherapy, with relapse after a 28-year disease-free interval. As far as we know, the length of remission in this case is second only to that of a case recently described by Hung and co-workers. Therefore, although according to data in the literature relapse after a very long disease-free interval is more frequently observed in patients with stage I A and II A disease, it may occur also in cases with symptomatic, widespread disease. This phenomenon, while reflecting the complexity of relations between the different factors (histologic subtype, clinical stage, host vs tumor defenses, therapy, etc.) that variously affect the clinical course and outcome, underlines the need for cautiousness when assessing the ultimate prognosis of individual cases of Hodgkin's disease.

Aged↗
PubMed1989

Correlations between age and rat dermis modifications. Ultrastructural-morphometric evaluations and lysyl oxidase activity.

The extracellular matrix is a complex, integrated macromolecular system which plays a crucial role in the economy of each organ. In this study we focused our attention on the correlations between age and rat skin dermis. The latter was chosen as a model of the connective tissue, and was analyzed by means of electron microscopy and by measurement of the activity of lysyl oxidase, the enzyme involved in collagen and elastin crosslink formation. Ultrastructural and morphometric evaluations associated to body weight growth, showed a progressive increase in the amounts of extracellular components and a progressive reduction in the cell density. Skin from adult animals appeared characterized by a well organized matrix; by contrast, in old rats, we observed several degenerative features such as the disorganization of collagen bundles, the vacuolization of elastic fibers, and the atrophy of the mesenchimal cells. Morphometric evaluations in old animals showed a slight but significant reduction in the percentage of the total collagen measured, a fair stability in the area occupied by the elastin fibers, and an increase of the apparently non-structured matrix. The fact that lysyl oxidase activity was diminished in old rats does not corroborate the observation by several authors that increased collagen insolubility is a consequence of higher intra- and intermolecular crosslinking. This would suggest that other chemical modifications, such as crosslink oxidation or non enzymatic glycosylation, might be involved during the aging of connective tissue. The qualitative and quantitative modifications observed at all ages illustrate the correlation between connective tissue modifications and structural and/or functional properties of the skin.

Age Factors↗
PubMed1989

Localization of human placenta lysyl oxidase on human placenta, skin and aorta by immunoelectronmicroscopy.

Polyclonal antibodies to human placenta lysyl oxidase (Kuivaniemi et al., 1984) were used to localize the enzyme at ultrastructural level in human placenta, skin and aorta, by using the indirect immunogold method. The antibodies were tested on thin sections of tissues fixed and embedded in various experimental conditions. With all methods employed, the immunoreaction was always positive on collagen fibers in all tissues examined, independently of the age of the subjects. In placenta, the reaction was also slightly positive on matrix microfilaments and cells. In dermis, fibroblasts and elastin were scarcely positive in a normal 5 day-old child, in a child with skin hyperelasticity, and in two babies with osteogenesis imperfecta type II; whereas they were negative in two 16 and 40 year-old normal subjects. In aorta, the immunoreaction was always positive on collagen, scarcely positive on cells and on elastin of a 24 week-old fetus, of a normal child, and of two babies who died of complications associated with O.I. type II; on the contrary, the reaction was negative on cells and elastin fibers of a 16 week-old fetus, and of a normal 19 year-old girl. When present on elastin, gold particles were localized mostly inside the fibers. Contrary to what was observed by Kagan and coworkers on bovine aorta by using antibodies against aortic lysyl oxidase (Kagan et al., 1986), no specific localization of gold particles could be observed on or adjacent to the elastin/associated microfibrils. The results indicate that antibodies raised against placenta lysyl oxidase recognize collagen-associated as well as elastin-associated epitopes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗