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Biomedical subjects

D Quaglino

Publications and source records attributed to D Quaglino.

At least 109 records · Page 6Linked to original sources
PubMed1989

Diamine oxidase plasma activities after treatment with heparin and jejunal morphometry in untreated coeliac disease.

Diamine oxidase plasma concentrations after treatment with heparin were measured and compared with the surface to volume ratio of jejunal biopsy samples assessed by a morphometric technique in patients with untreated and treated coeliac disease and in biopsied controls. As expected, enzyme activity was significantly lower in patients with untreated coeliac disease than in patients on a gluten-free diet and in biopsied controls. No difference was found between treated patients and biopsied controls. There was a significant overall correlation between plasma enzyme activity and surface to volume ratio of jejunal mucosa, although two untreated patients without an overt malabsorption syndrome but with a very low surface to volume ratio had normal enzyme activity. This study shows that in coeliac disease plasma diamine oxidase activity after treatment with heparin does not always mirror the extent of the jejunal lesions, particularly in those patients with minimal or unrelated symptoms who would benefit most from a valid screening test to identify their condition.

Adult↗
PubMed1989

Terminal cisternae of denervated rabbit skeletal muscle: alterations of functional properties of Ca2+ release channels.

Terminal cisternae (TC) of skeletal muscle represent the specialized compartment from which Ca2+ is released into the myoplasm after a propagated action potential. In this study we have investigated the morphology, protein composition, and Ca2+ release properties of TC isolated from rabbit gastrocnemius muscle 2 wk after nerve sectioning. Thin-section electron microscopy showed that TC vesicles from denervated muscle were enriched in calsequestrin (CS) and contained a larger fraction of the junctional sarcoplasmic reticulum (SR), as judged by membrane profiles with morphologically intact feet structures. Accordingly, the yield of junctional SR from denervated muscle was twice that of control muscle, and the protein pattern of TC vesicles exhibited an increase in junctional protein components, e.g., CS and the 350-kDa protein. The larger content of the 350-kDa protein, or ryanodine receptor (F.A. Lai, H. Erickson, E. Rousseau, Q.-Y. Liu, and G. Meissner, Nature Lond. 331: 315-319, 1988; T. Imagawa, J. S. Smith, R. Coronado, and K. P. Campbell. J. Biol. Chem. 262: 10636-10643, 1987; L. Hymel, M. Inui, S. Fleischer, and H. Schindler, Proc. Natl. Acad. Sci. USA 85:441-445, 1988) was paralleled by an increased binding site density (Bmax) for ryanodine binding in denervated muscle TC. The effects of ruthenium red, a Ca2+ release blocker, on Ca2+ loading rate and Ca2+-ATPase activity suggested that TC from denervated muscle were less permeable to Ca2+. After active Ca2+ loading, both doxorubicin and caffeine induced Ca2+ release from isolated TC, yet Ca2+ release rates were reduced in denervated muscle TC.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMed1989

Dipeptidyl amino peptidase IV cytochemistry in circulating lymphocytes from HIV-I-seropositive subjects.

In order to assess whether changes in the relative proportions of cells pertaining to different T-lymphocyte subsets correlate with dipeptidyl amino peptidase IV (DAP IV) activity, the enzyme was cytochemically investigated in circulating lymphocytes from 20 HIV-I-seropositive drug addicts. Although on the average, a significant reduction of lymphocyte DAP IV activity was found in comparison with healthy control subjects, wide variations between individual cases were observed, and no obvious relationship emerged between DAP IV staining on one hand, immunocytological findings and Walter Reed staging on the other. Therefore, in view of the preliminary results reported, the variations of lymphocyte DAP IV activity in the course of HIV I infection seem to deserve further investigation, in order to clarify both the biological significance of this reaction and its possible clinical relevance.

Adolescent↗
PubMed1989

Dermal alterations in patients with Wilson's disease treated with D-penicillamine.

Wilson's disease is characterized by accumulation of copper and D-penicillamine favors its elimination. However, penicillamine binds to precursors of intermolecular crosslinks both in collagen and elastin, and could lead to alterations of these two fibrous proteins. In the present report skin biopsies from patients with Wilson's disease, treated with 900 mg/day of D-penicillamine, for 5, 9, 58 and 60 months, were studied by electron microscopy and compared with findings obtained from skin biopsies of age-matched normal subjects. Clinically, the elasticity and consistency of the skin of Wilson's patients was not modified by D-penicillamine treatment. The ultrastructural organization of collagen fibrils appeared normal in the adults treated with D-penicillamine for 5-9 months. In a 15-year-old girl, treated for 48 months, a high number of collagen fibrils were swollen and unreeved. Elastin fibers were altered in all patients. The alterations were mostly pronounced in the reticular dermis, were proportional to the time of treatment, and consisted of polymorphous aggregates of elastin connected to apparently normal elastin fibers. A stereological analysis, on EM pictures from the patient treated for 60 months, and from an age-matched control, showed a significant decrease in the percentage of collagen and of the mean area occupied by each collagen bundle in the reticular dermis of the patient compared to control; on the contrary, the number of elastin fibers per unit area increased significantly, and the mean area of each elastin fiber decreased. The volume density of elastin was similar to control. The results indicate that prolonged administration of penicillamine to humans induces alterations in the deposition of dermal collagen and elastin.

Adolescent↗
PubMed1988

Postnatal transformations of alveolar surfactant in the rabbit: changes in pool size, pool morphology and isoforms of the 32-38 kDa apolipoprotein.

To clarify perinatal transformations of surfactant we performed lung lavage in term fetuses and in 0-24-h-old newborn rabbits. Lavage fluid was separated into three pools, namely lavage pellet, lavage supernatant and cells. We found that at birth the pellet contains 94.1 +/- 1.4% (S.E.) saturated phosphatidylcholine, while the supernatant and cells contain traces of it. At birth the pellet contains secreted lamellar bodies while the supernatant lacks any recognizable structure. After birth, the alveolar saturated phosphatidylcholine level increases 5.1-times in 24 h, the proportions between pools reaching adult values in 90 min (pellet = 75.9 + 4.8%, supernatant = 22.7 +/- 4.9%), and small vesicles appear in the supernatant, probably originating from the turnover of alveolar surfactant during breathing. The saturated phosphatidylcholine associated with cells remains unchanged. At birth, the 32-38 kDa surfactant apolipoprotein appears to be less extensively sialylated than in adult life.

Age Factors↗
PubMed1988

Denervation-induced proliferative changes of triads in rabbit skeletal muscle.

Protein compositional and functional differences exist between longitudinal and junctional sarcoplasmic reticulum (SR) in relation to Ca transport and to Ca release. In light of this knowledge, we have reinvestigated the effects of denervation on SR of rabbit gastrocnemius, a predominantly fast muscle. Electron microscopy of 2-weeks denervated muscle showed proliferation of transverse tubules (TT), forming junctional contacts with SR terminal cisternae (TC). At coincident periods, the yield of muscle microsomes was increased, and their fractionation by sucrose-density centrifugation demonstrated a relative increase of heavy vesicles. Thin-section electron microscopy of heavy SR from denervated muscle showed an increased number of vesicles containing calsequestrin (CS) as compared with control muscle. Electrophoretic analysis confirmed the relative decrease of Ca-ATPase protein and the striking increase of CS both in total microsomes and in heavy SR vesicles. Calcium loading and Ca-ATPase activity as well as the density of Ca-ATPase protein were decreased to a similar extent (20-30%) in denervated muscle microsomes. Stimulation of Ca-ATPase activity by Ca-ionophore A23187 showed that the vesicles were tightly sealed. When probed by competitive ELISA with antibody to SR Ca-ATPase from pure fast muscle, the Ca-ATPase of denervated microsomes was found to be highly cross reactive. Cleveland's peptide maps of the Ca-ATPase protein after partial digestion with S. aureus V8 protease also showed no significant change after denervation. Changes in cholesterol content and in the ratio of Mg-ATPase to Ca-ATPase activity of denervated muscle microsomes indicated a 4-fold increase of TT protein, i.e., from about 3% to not more than 12% of total protein, at 2 weeks after denervation. All these changes were totally reversed upon reinnervation of muscle fibers, and the consequent muscle recovery, as obtained by nerve crushing instead of nerve sectioning. From these results, we conclude that denervated adult fast muscle, similarly to immature fast muscle, contains more junctional SR. However, the molecular and catalytic properties of the Ca-ATPase are unaffected by denervation.

Animals↗
PubMed1988

Mitochondrial oculoskeletal myopathy: case report.

We report a case of oculoskeletal myopathy with abnormal mitochondria in which the chief clinical feature was ophthalmoplegia. Muscle weakness was mild and there were no retinal or cerebellar abnormalities, no deafness and no cardiac defects. The muscle biopsy specimen revealed subsarcolemmal mitochondrial aggregates and ragged red fibers. Electronmicroscopy showed that the aggregates were made up of mitochondria of variable size with structural abnormalities of the cristae and crystalloid inclusions. We believe that this oculoskeletal myopathy is distinct from Kearn-Sayre syndrome.

Adult↗
PubMed1987

Burkitt-like lymphoid malignancy presenting as a breast tumor.

The authors describe a case of a female patient, who presented with a rapidly expanding mass of the right breast as the first clinical sign of a Burkitt-like lymphoproliferative disorder. Massive bone marrow infiltration with leukemic spillover and limited lymph node involvement were subsequently detected. The difficulties encountered in classifying, according to current schemes, the observed lymphoid neoplasm are emphasized. Moreover, an evaluation of the true rarity of mammary localizations at the onset of lymphoid malignancies, based on a review of the literature, suggests, especially for the most malignant varieties, a higher frequency than supposed.

Bone Marrow↗
PubMed1987

Lysyl oxidase activity and elastin/glycosaminoglycan interactions in growing chick and rat aortas.

Hydrophobic tropoelastin molecules aggregate in vitro in physiological conditions and form fibers very similar to natural ones (Bressan, G. M., I. Pasquali Ronchetti, C. Fornieri, F. Mattioli, I. Castellani, and D. Volpin, 1986, J. Ultrastruct. Molec. Struct. Res., 94:209-216). Similar hydrophobic interactions might be operative in in vivo fibrogenesis. Data are presented suggesting that matrix glycosaminoglycans (GAGs) prevent spontaneous tropoelastin aggregation in vivo, at least up to the deamination of lysine residues on tropoelastin by matrix lysyl oxidase. Lysyl oxidase inhibitors beta-aminopropionitrile, aminoacetonitrile, semicarbazide, and isonicotinic acid hydrazide were given to newborn chicks, to chick embryos, and to newborn rats, and the ultrastructural alterations of the aortic elastic fibers were analyzed and compared with the extent of the enzyme inhibition. When inhibition was greater than 65% all chemicals induced alterations of elastic fibers in the form of lateral aggregates of elastin, which were always permeated by cytochemically and immunologically recognizable GAGs. The number and size of the abnormal elastin/GAGs aggregates were proportional to the extent of lysyl oxidase inhibition. The phenomenon was independent of the animal species. All data suggest that, upon inhibition of lysyl oxidase, matrix GAGs remain among elastin molecules during fibrogenesis by binding to positively charged amino groups on elastin. Newly synthesized and secreted tropoelastin has the highest number of free epsilon amino groups, and, therefore, the highest capability of binding to GAGs. These polyanions, by virtue of their great hydration and dispersing power, could prevent random spontaneous aggregation of hydrophobic tropoelastin in the extracellular space.

Amino Acid Oxidoreductases↗
PubMed1987

Familial Ehlers-Danlos syndrome type II: abnormal fibrillogenesis of dermal collagen.

We examined a father and son affected by Ehlers-Danlos syndrome type II. Both patients had micrognathia together with ligament and skin hyperlaxity. The son exhibited complete cleft palate. Ultrastructural studies revealed abnormal collagen fibrils in the dermis of both patients. In the child the most striking alterations consisted of lateral fusion of an enormous number of collagen fibrils giving rise to huge polymorphic collagen masses. In the father's dermis the great majority of collagen fibrils appeared normal; however, lateral fusion of fibrils together with local abnormal collagen aggregation were occasionally seen. In both patients the dermal elastic network was well developed and elastic fibers appeared normal.

Adult↗
PubMed1987

Relationships between different cytobiological aspects of myeloid leukaemias.

The present survey deals with the various cytobiological techniques, including the classical morphological and cytochemical approach, as well as the more recently introduced methods of study which may be employed for the characterization of malignant myeloid cells and the identification of particular leukaemic variants. The authors discuss in turn the advantages and limitations of the various approaches and draw attention to the possible relationships which may be detected using combined techniques between different cytobiological aspects, such as the expression of surface markers on the one hand and different degrees of proliferative activity on the other, and the presence of specific cytogenetic alterations as well as the existence of peculiar morphological and cytochemical patterns.

Cell Division↗
PubMed1986

Follicular lymphomas with predominant splenic involvement: report of two cases.

The authors describe the results of histological, cytomorphological, cytochemical and immunological studies carried out in two cases of follicular lymphoma characterized at onset by an exceptional degree of splenomegaly. Although several different histological types seem to be capable of giving rise to prominent splenic involvement, the authors, on the basis of the reported findings, suggest the possibility that some cases of follicular lymphoma presenting with conspicuous splenomegaly and which at present are classified in the group of the so-called intermediate lymphocytic lymphoma, might be an expression of proliferation of a cell type normally recognizable in the marginal zone of the splenic follicles.

Aged↗
PubMed1986

Aortic elastin abnormalities in osteogenesis imperfecta type II.

Skin and aortic samples from two patients who died by lethal perinatal Osteogenesis Imperfecta (O.I.) were studied by optical and electron microscopy and compared with similar samples from two normal human fetuses and one newborn child. No significant abnormalities were observed in the dermis of O.I. patients apart from small differences in the diameter of reticular collagen fibrils. On the contrary, in the aortas of both patients collagen fibrils were significantly smaller than in the controls; moreover, elastin lamellae were deeply altered and consisted of roundish aggregates of elastin, massively permeated by cytochemically recognizable glycosaminoglycans. As identical features were described in experimental lathyrism by using inhibitors of the enzyme lysyl oxidase (Pasquali Ronchetti et al., 1984), the conclusion is reached that in the two cases of lethal perinatal O.I. examined, a severe lysyl oxidase deficiency could account for the observed ultrastructural abnormalities of elastin and that, besides defects of collagen type I, additional alterations of cellular metabolism might be responsible for the clinical heterogeneity of the disease.

Aorta↗
PubMed1986

Effect of DL-penicillamine on the aorta of growing chickens. Ultrastructural and biochemical studies.

The effect of DL-penicillamine on the architecture of the aortic wall of growing chickens was studied, with particular attention to elastin and collagen. Penicillamine was added to the diet (0.2% and 0.4%, in the presence or not of 10 mg/kg CuSO4 and 100 mg/kg vitamin B6) from hatching, for periods from 7 days up to 2 months. The same regions of the thoracic aortas were examined and compared in all the different experimental conditions. The results showed that penicillamine induced relevant modifications in the process of elastin fibrogenesis. The alterations consisted of an increase of elastin in the extracellular space, associated with an increase in the number of elastin fibers per unit area, and a decrease of the mean profile area of the fibers. Interestingly, penicillamine induced the formation of numerous bundles of microfibrils associated or not with elastin fibers. After prolonged treatment, elastin tended to diminish and the fibers tended to fuse into polymorphic syncytia. Collagen fibrils were larger, showed more heterogeneous cross diameters, were less numerous, and were more spread out within the tissue. All the other components of the aortic wall appeared not to be altered by the chemical. Penicillamine did not modify the copper content of chick aortas, whereas it induced a 40-50% reduction of the activity of both salt and 4 M urea-soluble peptidyl lysyl oxidases in the same tissue. These data may help in understanding some of the pathologic manifestations in human beings during D-penicillamine treatment.

Animals↗
PubMed1985

Alterations of elastin fibrogenesis by inhibition of the formation of desmosine crosslinks. Comparison between the effect of beta-aminopropionitrile (beta-APN) and penicillamine.

Experimental lathyrism was induced by feeding newborn chicks a diet containing 0.2 and 0.4% DL-Penicillamine, with or without CuSO4 (10 mg/Kg diet) and Vitamin B6 (100 mg/Kg diet), or 0.015 and 0.1% beta-aminopropionitrile fumarate (beta-APN). After 7, 15, 25 and 55 days of treatment the animals were killed, the aortas removed and processed for electron microscopy in the presence of markers for proteoglycans, and the elastic fibers were carefully examined. Penicillamine, which prevents the formation of desmosine crosslinks by binding to precursors, induced the production of numerous new elastin fibers which appeared normal from the ultrastructural point of view. It seems, therefore, that at least in chick aortas, desmosine crosslinks are not necessary for the aggregation of tropoelastin molecules into structurally normal fibers. On the contrary, beta-APN, a classical inhibitor of lysyl oxidase, induced the tropoelastin molecules to aggregate into abnormal protuberances on the old fibers. Moreover, the elastin deposited during beta-APN treatment was always permeated by cytochemically revealed proteoglycans, which were never observed after penicillamine treatment. It is speculated that, at least in the system under study, the epsilon-amino groups of tropoelastin molecules may offer the binding sites for matrix proteoglycans until they are removed by lysyl oxidase, and that matrix proteoglycans might play a role in elastin fibrogenesis by preventing spontaneous tropoelastin aggregation in areas far from growing elastin fibers.

Amino Acids↗