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P Braidotti

Publications and source records attributed to P Braidotti.

At least 37 records · Page 2Linked to original sources

Acute tubulo-interstitial nephritis requiring dialysis associated with intermittent rifampicin use: case report.

Rifampicin is one of the most effective antibiotics used for the treatment of tuberculosis and severe staphylococcal infections. Intermittent administration of high doses of rifampicin has been associated with frequent adverse reactions, including hepatotoxicity and nephrotoxicity, sometimes resulting in acute renal failure. We describe a case of rifampicin-associated acute renal failure, with biopsy findings of tubulointerstitial nephritis; inflammatory cells were characterized by immunohistochemistry, which showed immunoreactivity for CD3 and CD5 (T lymphocytes) and for CD68 (macrophages). The patient presented with a very rapid systemic reaction to the offending drug and rapid deterioration of renal function, which required dialysis treatment. The response to rifampicin discontinuation was excellent: no further therapy was required, as renal function began to improve within several days and returned to normal values (serum creatinine 1.17 mg/dl) seven months after the onset of symptoms. When prescribing rifampicin the physician should investigate previous use of the drug, because re-exposure is a critical factor in predicting the possibility of drug-induced acute renal failure.

Acute Disease↗

Fibrillary glomerulonephritis in Castleman's disease.

Castleman's disease is an uncommon lymph node disorder which can be associated with renal disease. In this report we describe a patient with fever, weight loss, anorexia, increase in inflammatory proteins, anemia and nephrotic syndrome. Castleman's disease, plasma cell type, was diagnosed by histologic analysis after surgical excision of a pelvic lymph node. The disease was considered localized, since further investigations did not show any other pathologic mass. After resection of the pelvic lymphoid mass, clinical remission of systemic symptoms and laboratory abnormalities was observed, with the exception of the nephrotic syndrome. Renal biopsy was performed and showed a pattern compatible with fibrillary glomerulonephritis. Progressive decline in renal function was observed, despite immunosuppressive therapy.

Castleman Disease↗

Scanning electron microscopy of human cortical bone failure surfaces.

Undecalcified samples extracted from human femoral shafts are fractured by bending and the fracture surfaces are examined with a scanning electron microscope (SEM). The investigation is performed on both dry and wet (hydrated with a saline solution) specimens. SEM micrographs show patterns in many respects similar to those observed in fractography studies of laminated fiber-reinforced synthetic composites. In particular, dry and wet samples behave like brittle and ductile matrix laminates, respectively. An analysis carried out on the basis of the mechanisms that dominate the fracture process of laminates shows that a reasonable cortical bone model is that of a laminated composite material whose matrix is composed of extracellular noncollagenous calcified proteins, and the reinforcement is constituted by the calcified collagen fiber system.

Adult↗

An elastic compound tube model for a single osteon.

A model is developed whereby the secondary osteon--the dominant microstructural component of the cortical bone tissue--is considered as an n-layered cylinder with internal stresses in linear isotropic elasticity. An exact solution is obtained for a loading condition represented by a tensile-compressive force. The lengthening, the side deformation, and the strain energy of the system are explicitly calculated. The behavior of the main elastic quantities is illustrated by graphs. In particular, the important role played by the parity of the number of lamellae is revealed.

Algorithms↗

Deposition of kappa and lambda light chains in amyloid filaments of dialysis-related amyloidosis.

beta 2-Microglobulin (beta 2m) is considered to be the amyloidogenic precursor in dialysis-related amyloidosis, although the implication of other relevant cofactors in the pathogenesis of this disease has also been hypothesized. It is conceivable that substances found in amyloid deposits might represent something more than simple codeposition, possibly playing a pathogenic role in amyloidogenesis. Along these lines, a detailed analysis of the protein composition of amyloid fibrils purified from synovial material surgically obtained from nine patients on long-term dialysis was carried out. By the use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, several other protein components, in addition to beta 2m, were found. These were characterized by NH2 amino-terminal sequencing and immunoblotting. In fibrils obtained by water extraction, which fulfill the electron microscopy criteria of highly pure amyloid material, polyclonal kappa and lambda light chains were detected with a concentration of 15 micrograms/mL in the water extraction material; the beta 2m concentration was 200 micrograms/mL. Light microscopy immunohistochemistry was performed on samples from five patients. Amyloid deposits reacted with anti-beta 2m, and anti-light (kappa, lambda), chain antibodies. The immunoreaction of amyloid filaments to anti-beta 2m, anti-lambda, and anti-kappa light chain antibodies was also tested by electron microscopy by use of the immunogold staining procedure. Amyloid filaments were labeled by the three antibodies and showed a different intensity of immunostaining apparently related to their different aggregation pattern. These observations demonstrate that polyclonal immunoglobulin light chains (kappa and lambda) are not contaminants but, together with beta 2m, represent a major constituent of amyloid deposits in dialysis-related osteoarticular amyloidosis, thus indicating their possible role in amyloidogenesis.

Adult↗

Extracellular matrix proteins, integrin receptors (VLA-beta 1, VLA-alpha 2 and VLA-alpha 5) and growth fraction in atypical macroregenerative nodules of the liver: an immunocytochemical case study.

A case of cirrhotic liver harbouring three atypical macroregenerative nodules and an hepatocellular carcinoma was immunocytochemically investigated for the expression of VLA-beta 1, VLA-alpha 2 and VLA-alpha 5 integrins and for different extracellular matrix (ECM) components (collagen I, collagen IV, laminin, fibronectin and tenascin). In addition, the proliferative activity within the nodules was evaluated, using the MIB 1 monoclonal antibody (MAb). The cirrhotic liver disclosed a continuous staining pattern of the ECM proteins investigated, as well as a "sinusoidal" immunostaining of VLA-beta 1, VLA-alpha 2 and VLA-alpha 5. The macroregenerative nodules showed a discontinued immunoreactivity for ECM proteins while maintaining a VLA-beta 1 sinusoidal immunostaining, coupled with intercellular immunostaining. VLA-alpha 2 and VLA-alpha 5 expression was lacking. The growth fraction was low in both the above pathological conditions. The hepatocellular carcinoma was devoid of any ECM immunostaining. VLA-beta 1 immunoreactivity exhibited a honeycomb pattern of staining, whereas VLA alpha subunits were absent. MIB1 expression was high, being present in 30% of neoplastic nuclei. A possible relationship between atypical macroregenerative nodules and hepatocellular carcinoma is discussed.

Carcinoma, Hepatocellular↗

Scanning electron microscopy of collagen fiber orientation in the bone lamellar system in non-decalcified human samples.

Previous studies on collagen fiber orientation have led to different interpretations and theories about the fiber arrangement in the lamellar compact bone. The purpose of this investigation was to provide new and more in-depth data on fiber arrangement in the lamellar bone system in order to explain the orientation of the fiber bundles. This was carried out by applying a simple method of preparation which permitted observation of non-decalcified samples. A previously isolated Haversian system was subjected to slow bending up to reaching the fracture point. Hence, the fracture surface was observed by SEM. The same samples were also observed by polarized light microscopy. A significant alternation of fiber orientation in the adjacent lamellae was observed. Different domains of differently oriented fibers were present within the same lamella; conjugating fibers connecting adjacent lamellae were also shown. This method avoided most of the artifacts due to chemical treatment of bone samples. The results can be easily interpreted by means of the same criteria applied in mechanics for the studying of composite materials.

Adult↗

Pancreatic (acinar) metaplasia of the gastric mucosa. Histology, ultrastructure, immunocytochemistry, and clinicopathologic correlations of 101 cases.

The occasional finding within the gastric mucosa of unidentified epithelial cells with morphological features closely resembling those of pancreatic acinar cells has prompted us to investigate a retrospective series of 8,430 consecutive gastric biopsies and of 126 surgical specimens of gastric resection and total gastrectomy. The aims of the study were to morphologically and immunocytochemically characterize these cells, to define their actual prevalence in a large series of unselected cases, and to assess the clinicopathologic correlates of their occurrence. Pancreatic acinar-like cells characterized by abundant cytoplasm, which was acidophilic and finely granular in the apical and middle portions and basophilic in the basal compartment, have been identified in 101 cases (84 gastric biopsies and 17 gastrectomies). These cells, arranged in nests or in variably sized lobules among the gastric glands, were morphologically indistinguishable from pancreatic acinar cells, both by light and by electron microscopy. Furthermore, they were consistently immunoreactive for pancreatic lipase and trypsinogen and, in 75% of the cases, for pancreatic alpha-amylase. The appearance of these cells within the gastric mucosa was correlated significantly with chronic gastritis (p = 0.032) and with the simultaneous occurrence of intestinal and pyloric types of gastric metaplasia (p = 0.021). The findings indicate that this is a previously unrecognized pancreatic (acinar) metaplasia of the gastric mucosa, clinically and morphologically distinct from pancreatic heterotopia.

Adult↗

Gastric giardiasis.

AIMS: To assess the prevalence of gastric giardiasis in patients undergoing upper gastrointestinal endoscopy, and to define the clinicopathological correlates of gastric Giardia lamblia infection. METHODS: Consecutive gastric biopsy specimens (n = 15,023) from 11,085 patients, taken at Feltre City Hospital (north eastern Italy) from January 1986 to December 1991, were histologically and immunocytochemically examined for the occurrence of G lamblia trophozoites. Three gastric biopsy specimens from patients harbouring G lamblia infection, who repeated endoscopy before treatment, were also examined electron microscopically. RESULTS: Forty one patients (0.37% of the population study) harboured gastric giardiasis. All patients underwent upper gastrointestinal endoscopy because of dyspepsia, epigastric pain, or abdominal distension. Only two patients had diarrhoea at the time of investigation. Giardiasis was clinically unsuspected in all cases, although the nine patients who also had duodenal biopsies performed had concomitant intestinal giardiasis. Gastric giardiasis was invariably associated with chronic atrophic gastritis. Intestinal metaplasia of the gastric mucosa and Helicobacter pylori infection were found in 32 and 37 of the 41 patients with gastric giardiasis, respectively. CONCLUSIONS: The invariable association of gastric giardiasis with chronic atrophic gastritis, most often showing intestinal metaplasia and H pylori infection, indicates that a decreased gastric acidity is a prerequisite for localisation of G lamblia to the gastric mucosa. Though its possible role as a gastric pathogen remains to be elucidated, these findings suggest that trophozoites should be carefully searched for when examining gastric biopsy specimens showing chronic atrophic gastritis.

Adult↗

Traumatic breakage of the ceramic head of prosthesis in total hip replacement.

The authors describe breakage of the 32 mm alumina AL2 O3 ceramic head in 3 cases of total hip replacement using two different models of prosthesis (Charnley-Müller and Mittelmeier). All three patients were of average height, weight, and activity (Brown et al., 1985; Callaghan et al., 1988), and the breakage had been caused by an accidental fall. The same mechanism of injury, in people the same age as our subjects, can cause femoral neck fractures. Reoperation was necessary in order to replace the component. The implants all appeared to be positioned correctly, and the patients had reported no symptoms. Before the trauma that caused breakage, there had been no other injuries worth noting. All patients were satisfied with their hip replacements.

Accidental Falls↗

Role of enhanced glomerular synthesis of thromboxane A2 in progressive kidney disease.

Normotensive rats of the Milan strain (MNS) spontaneously develop focal glomerulosclerosis. In order to explore the contribution of glomerular thromboxane (TX) A2 synthesis to the development of the disease, we have characterized the time course of renal functional and biochemical changes, and their modification by long-term treatment with a TX-synthase inhibitor. Oral administration (150 mg.kg-1 from 1 to 14 months of age) of FCE 22178 suppressed enhanced glomerular TXB2 production at all experimental times (mean inhibition 80%) and proteinuria (varying between 27.1 and 73.0%) while preserving renal blood flow and glomerular filtration rate. These effects of TX-synthase inhibition were seen in the absence of any statistically significant changes in systemic blood pressure. Moreover, FCE 22178 had no antihypertensive effects in hypertensive rats of the Milan strain (MHS) nor in spontaneously hypertensive rats (SHR). Treatment also prevented the age-related hypoalbuminemia and hyperlipidemia observed in control MNS and significantly (P less than 0.01) reduced glomerular histologic damage, as demonstrated by light microscopy studies and measurement of sclerotic area. We conclude that: 1) MNS rats provide an animal model of long-lasting proteinuria characterized by an age-related increase in glomerular TXB2 production paralleled by progressive loss of renal structural integrity and function and by a secondary dyslipidemia; 2) pharmacological inhibition of glomerular TX-synthase attenuates the structural as well as the functional expression of kidney disease, without a primary effect on systemic blood pressure. These data are suggestive of an important modulating role of TXA2 in the progression of MNS renal disease.

Animals↗

Multiple lumbar arachnoid cysts. Case report.

Arachnoid cysts are a rare cause of compression of the contents of the lumbar spinal canal; in the literature only about 100 cases are reported. The various methods of diagnosis are discussed in the light of a recent case observed by the authors.

Adult↗

Posterior polymorphous dystrophy of the cornea. An ultrastructural study.

A corneal button excised from a 2-month-old infant with congenital posterior polymorphous dystrophy of the cornea, a rare disease affecting Descemet's membrane and endothelium, was examined by electron microscopy. We observed irregularly arranged, sometimes multilayered cells with marked epithelial features, lining the posterior surface of the cornea in place of the endothelium, and Descemet's membrane with focal alterations sometimes involving all of its layers. We interpreted these abnormal cells as epithelial-like cells. As these findings were in a very young patient, which is unusual, we concluded that the onset of the disease may take place in the early period of intrauterine life, corresponding to the beginning of Descemet's membrane production.

Cornea↗

Ultrastructural localization of intracellular immunoglobulins in Epon-embedded human lymph nodes. An immunoelectron microscopic investigation using the immunogold staining (IGS) and the avidin-biotin-peroxidase complex (ABC) methods.

The ultrastructural localization of intracellular immunoglobulins on ultrathin sections of glutaraldehyde-fixed, postosmicated, and Epon-embedded human lymph nodes has been achieved using such highly sensitive immunocytochemical techniques as immunogold staining and avidin-biotin-peroxidase complex. These immunoelectron microscopic techniques allow the identification of intracellular immunoglobulins without affecting the ultrastructural morphology of the tissue, since they do not require any pretreatment of the sections with proteolytic enzymes or deresinating agents. Therefore, immunoglobulins can be precisely localized in the cell organelles; structures whose morphology is well preserved. The availability of a reliable postembedding staining procedure for the ultrastructural localization of immunoglobulins is of definite value for investigations on human lymphoid tissue, both normal and pathological.

Avidin↗

Immunohistochemical localization of human immunoglobulins and lysozyme in epoxy-embedded lymph nodes: effect of different fixatives and of proteolytic digestion.

The postembedding immunoperoxidase staining technique for the localization of immunoglobulins (light and heavy chains) and of lysozyme has been successfully applied to epoxy-embedded human lymph nodes, after removal of the resin. Glutaraldehyde-containing fixatives appear to be suitable for the immunohistochemical localization of human immunoglobulins and lysozyme, provided that the masked antigenicity of these proteins is recovered by proteolytic digestion of the tissue sections using 0.4% pepsin or 0.1% trypsin. Nonglutaraldehyde-containing fixatives allow the immunolocalization of human immunoglobulins without any enzymatic pretreatment. This study shows that tissues routinely fixed in glutaraldehyde and embedded for ultrastructural investigations are actually suitable for immunohistochemical studies on human immunoglobulins and lysozyme.

Female↗

Coexpression of intermediate filaments in normal and neoplastic human tissues: a reappraisal.

The current view that coexpression of intermediate filaments (IFs) must be considered a bizarre and unpredictable phenomenon, which seriously jeopardizes the use of their localization in diagnostic applications, is critically reviewed in light of the evidence so far acquired by investigations in vivo and in vitro. A less dogmatic approach, which considers IF expression the result of a series of interactions between cells and their microenvironment instead of a function of their histogenesis, not only justifies the complex variety of coexpressions observed in normal and neoplastic tissues but also confirms the usefulness of IF expression in diagnostic applications and offers new opportunities for investigations, with special regard to immunoelectron microscopy.

Cytoskeleton↗