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Biomedical subjects

A Tosoni

Publications and source records attributed to A Tosoni.

32 records · Page 2Linked to original sources
PubMed1999

BK virus renal infection in a patient with the acquired immunodeficiency syndrome.

BACKGROUND: We describe herein a patient with the acquired immunodeficiency syndrome and renal failure due to biopsy-proven BK virus (BKV) infection. Three months after the diagnosis of the renal viral infection, his condition remained unchanged. Although BKV has previously been shown to be associated with ureteral stenosis and renal damage in renal transplant patients, to our knowledge, the literature contains only 3 cases describing the presence of BKV lesions in the kidneys of immunosuppressed patients who had not undergone transplantation. METHODS: The presence of BKV infection was demonstrated by means of histology, immunohistochemistry with polyclonal anti-SV40 antibody, immunoelectron microscopy, polymerase chain reaction, and enzymatic cleavage with BamHI. RESULTS: Histologic examination revealed interstitial inflammatory infiltrates and tubules with enlarged and eosinophilic nuclei. CONCLUSIONS: The high frequency of latent BKV infection and its reactivation during immunosuppression suggest that the possibility of its involvement in renal damage should be considered in immunocompromised patients.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Renal Encephalitozoon (Septata) intestinalis infection in a patient with AIDS. Post-mortem identification by means of transmission electron microscopy and PCR.

We describe the occurrence of renal Encephalitozoon (Septata) intestinalis infection in a 35-year-old AIDS patient who died with disseminated tuberculosis. The patient did not complain of specific symptoms involving the kidney or lower urinary tract during life, but at autopsy, light microscopic examination of the kidney revealed numerous small round or oval bodies in the tubules and tubular cell cytoplasm that were interpreted as intracellular protozoa. Transmission electron microscopy of tissue retrieved from paraffin-embedded samples identified these organisms as microsporidia belonging to the Encephalitozoonidae family, but did not allow definitive identification of the species of infecting parasite. This was made possible only by means of Southern blot hybridization after the polymerase chain reaction, which recognized the micro-organism as E. intestinalis.

AIDS-Related Opportunistic Infections↗
PubMed1998

PCR detection of JC virus DNA in the brain tissue of a 9-year-old child with pleomorphic xanthoastrocytoma.

Pleomorphic xanthoastrocytoma (PXA) is a rare cerebral tumor of young adults with a slow growth and a good prognosis. Due to its peculiar histopathological findings, the tumor resemble to the lytic phase of progressive multifocal leukoencephalopathy (PML), a JC Virus (JCV) induced disease. For these reasons, the presence of JCV genoma and viral particles were searched for by means of nested polymerase chain reaction (nPCR) and electron microscopy (EM) in a 9-year-old child with PXA. Although EM did not reveal any viral particles, nPCR did reveal genomic sequences of the LT, R, and VP1 regions of JCV. Sequence analysis showed that the R region was mutated with respect to the archetypal form thus yielding the Mad 4 variant of JCV previously reported as being oncogenic in animals. We suggest that JCV may have played a role in the development of this tumor.

Astrocytoma↗
PubMed1997

Neuropathology in cats experimentally infected with feline immunodeficiency virus: a morphological, immunocytochemical and morphometric study.

Neuropathological changes have been described associated with feline immunodeficiency virus (FIV) infection. The objective of our study was to characterize the lesions found in the brain and spinal cord of experimentally FIV-infected cats and to quantify, by morphometric analysis, the intensity of gliosis found in these subjects at different time post infection (pi). The brains and spinal cords appeared grossly normal. Gray matter of cortical and subcortical structures showed a moderate to pronounced gliosis particularly in all cerebral cortex and hippocampus. Morphometric analysis demonstrated that GFAP immunoreactivity was markedly higher in infected animals. Gliosis was present 15 days pi and did not appear to progress during the infection, whereas neuronal changes when present were observed only in long-term infected animals (15-23 months pi). In a large proportion of infected cats a diffuse gliosis of white matter and vacuolar myelinopathy was also present. Despite some discrepancies observed between neuropathological changes in FIV-infected animals and HIV-infected individuals, the presence in the cerebral cortex of cats with FIV infection of alterations similar to those observed in AIDS patients demonstrates that FIV is an interesting animal model particularly that may be useful for clarifying the pathogenesis of neuropathological changes associated with HIV infection.

Animals↗
PubMed1996

Intracellular protozoan infection in small intestinal biopsies of patients with AIDS. Light and electron microscopic evaluation.

Small intestinal biopsies of 21 patients with acquired immunodeficiency syndrome (AIDS) with light microscopic findings diagnostic or suspicious for parasite infection were investigated by transmission electron microscopy (TEM). TEM allowed us to identify and specify the genus and species of involved parasites in 16 out of the 21 cases: 7 Cryptosporidium parvum, 5 Enterocytozoon bieneusi and 4 Isospora belli. Cryptosporidium was easily identified on light microscopy (LM), and only slightly influenced by parasite burden in all the 7 cases; TEM confirmed LM diagnosis and made it possible to characterize the parasites as C. parvum. The identification of Microsporidium on LM in our cases was related to the burden of parasite; its presence was certainty identified in 2 cases and suspected in 3. TEM allowed to identify these parasites as E. bieneusi. Intracytoplasmic coccidia could be detected with certainly in semithin sections in all 4 cases, but TEM was always needed to specify the infectious agent as I. belli. In 5 cases the suspicious of protozoan infection on LM (3 microsporidia, 1 intracytoplasmic coccidia and 1 Cryptosporidium) was not confirmed by TEM. Our data suggest that TEM is an appropriate diagnostic tool in this field of pathology and necessary in most of the cases.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Ultrastructural evidence of thyroid damage in amiodarone-induced thyrotoxicosis.

Amiodarone-induced thyrotoxicosis occurs in 2-12.1% of patients on chronic amiodarone treatment. In most cases its pathogenesis is related to iodine overload in the presence of preexisting thyroid abnormalities, such as multinodular or diffuse goiter or autonomous nodule. A minority of patients show apparently normal glands or pictures of non-autoimmune thyroiditis. However, there is recent evidence of a direct toxic effect of amiodarone, with consequent release of iodothyronines into the circulation. We report a patient with amiodarone-induced thyrotoxicosis with toxic thyroid effects demonstrated by electron microscopy in a fine-needle aspiration biopsy. There were three main pathologic findings: multilamellar lysosomal inclusions, intramitchondrial glycogen inclusions--both ultrastructural findings indicating thyroid cell damage--and a microscopic morphological pattern of thyroid cell hyperfunction. No inflammatory changes were found. Plasma thyroglobulin levels were high. The patient proved to be a non responder to simultaneous administration of methimazole (starting dose 30 mg/day) and potassium perchlorate (1000 mg/day for 40 days), while still taking amiodarone, thus providing evidence against a possible pathogenetic role of iodine overload. Dexamethasone (starting dose 3 mg/day) was added to methimazole. After three months euthyroidism had been restored and plasma thyroglobulin level substantially decreased. Subsequent subclinical hypothyroidism developed, which persisted after stopping antithyroid treatment and required substitution treatment with levothyroxine. In view of the primary role of lysosome function in the proteolysis of thyroglobulin molecules and of the energy-requiring carrier-mediated transport of monoiodotyrosine across the lysosomal membrane for iodine salvage and reutilization, we suggest that the pathological lysosomal and mitochondrial changes observed could be an ultrastructural marker for subsequent hypothyroidism in amiodarone-induced thyrotoxicosis. Our observations suggest the usefulness of ultrastructural thyroid evaluation and serial plasma thyroglobulin determinations to thoroughly evaluate the underlying pathogenetic mechanisms in amiodarone-associated thyrotoxicosis with apparently normal thyroid glands. Moreover, more knowledge of its pathogenesis could improve both prognostic stratification and treatment guides.

Aged↗
PubMed1993

University of Wisconsin solution and human saphenous vein graft preservation: preliminary anatomic report.

Endothelial damage of human saphenous vein (HSV) during the preparation for bypass grafting could affect graft patency. Improving the preservation of HSV could provide a longer and better patency of coronary artery bypass grafts. An electron microscopic comparative analysis of the effects of three different preservatives on HSV morphology was carried on in order to determine the best method to prevent or minimize possible endothelial damage. Distal segments of HSVs were harvested from 15 patients with a "no-touch" technique. Each segment was divided into seven specimens after a low pressure distension with saline solution. The first of them was fixed immediately after harvesting with 2.5% glutaraldehyde solution, for basal evaluation. Three were fixed after 30 min and three after 5 h preservation at 4 degrees C in a) autologous, oxygenated, and heparinized blood (AOHB), b) heparinized saline solution with papaverine (HSSP) and c) University of Wisconsin solution (UWS). The specimens preserved in AOHB showed marked endothelial cell detachment and endothelial cell loss after both preservation times (30 min and 5 h). The specimens preserved in HSSP for 30 min showed no alteration in endothelium in 12 cases, while a partial endothelial detachment with intracellular edema was present in the last 3 cases; all 5 h specimens showed only a few remnants of endothelial cells. The specimens preserved in UWS for 30 min showed a morphology comparable to specimens preserved in the saline solution for the same time; in the 5 h specimens a well preserved endothelium was found in 11 cases and partial endothelial detachment and subendothelial edema in the other 4.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗
PubMed1993

Ultrastructural changes in the duodenal mucosa of HIV-infected children.

We studied the ultrastructure of duodenal biopsy specimens from six HIV-infected children with chronic gastrointestinal symptoms. A monomorphic pattern of microvillar damage (short and irregular microvilli, joined at their bases) was seen in all cases, even when the mucosa was normal on conventional histology. Among nine HIV antibody negative children, a similar pattern was seen only in three out of four celiac children with severely atrophic mucosa. No viral, bacterial, or protozoan pathogen was found. In HIV-infected children tubuloreticular inclusions were also seen in endothelial cells. These ultrastructural changes could help to account for the gastrointestinal symptoms in HIV-infected children.

Biopsy↗
PubMedDate not supplied

Ultrastructural study of renal involvement in two females with Anderson-Fabry disease.

Anderson-Fabry disease (AFD) is a rare X-linked lipid storage disorder due to a deficient lysosomal a-galactosidase A (a-Gal) activity. In males with the classic form of the disease the enzymatic defect leads to progressive accumulation of glycosphingolipids (GL) in different organs, mainly in the kidney, heart, and brain, causing severe multisystem failure. AFD is usually mild in heterozygous females, but severe cerebrovascular, renal, and cardiac manifestations have been rarely described. The aim of this study is to describe renal involvement of mild symptomatic female carriers by ultrastructural analysis focusing to microvascular lesions, considered to be one of the major causes of systemic disease in AFD. Resin-embedded renal biopsies from 2 sisters with isolated mild proteinuria and belonging to a family group with AFD were observed by light and electron microscopy. In spite of the mild clinical symptoms, diffuse GL storages were demonstrated in all types of glomerular cells and in interstitial endothelial cells. Moreover, platelets were frequently observed in glomerular vassels, a feature coherent with a possible role of prothrombotic state, and platelet activation, in early glomerular lesions.

Fabry Disease↗
PubMedDate not supplied

Ultrastructural studies in the lytic phase of progressive multifocal leukoencephalopathy in AIDS patients.

Brain fragments from eight cases (four autopsies and four biopsies) of patients with acquired immune deficiency syndrome (AIDS) with JC virus (JCV) lytic infections were examined ultrastructurally. Particular efforts were made to look for virions and their subcellular distribution in cells not usually involved by papovavirus infection. The cellular and subcellular distribution of virions was investigated with emphasis on cell types not normally associated with papovavirus infection. The pattern of JCV infection was as follows: 1) oligodendrocytes; nucleus only, 7 cases; cytoplasm only, no cases; 2) astrocytes (normal and "bizarre"); nucleus and cytoplasm, two cases; cytoplasm only, four cases; 3) macrophages; nucleus and cytoplasm, one case; cytoplasm only, four cases; and 4) neurons; nucleus and cytoplasm, two cases; cytoplasm only, three cases. Perivascular, endothelial, ependymal, and microglial cells were never infected. Our ultrastructural data indicate that cell types other than oligodendrocytes can be involved productively by JCV in the lytic phase of progressive multifocal leukoencephalopathy (PML) in AIDS patients. Neuronal cells, especially, can be infected productively by the JCV, and this should be considered in clinical interpretation of cortical symptoms and signs in suspected or proven cases of PML.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

Continuous intra-arterial blood gas monitoring. A clinical experience.

Miniaturized sensors, based upon the principles of optical fluorescence, can measure in vivo the pH, pCO2 value and pO2 value of blood. In this report we studied continuous intra-arterial blood gas monitoring in 27 patients undergoing cardiac surgery (no. 16 coronary artery by-pass grafting, no. 2 valvular surgery) and major vascular surgery (no. 9 abdominal aortic aneurysms). Total duration of continuous intra-arterial blood gas monitoring was 677 hours, with a ratio of 25.0 +/- 14.8 hours/patient (range 4-96 hours). The in vitro values of pH, pCO2 and pO2 were compared to simultaneous records from the fiberoptic sensor for each of the 283 arterial blood gas samples obtained, by means of linear regression and Bland-Altman method, in order to test the correlation and the agreement between the two methods of measuring. For pH average bias was -0.023 and intersensor precision was 0.028, with a strong correlation (R = 0.92; p < 0.001) and agreement. For pCO2 the average bias was 0.91 and the inter-sensor precision was 2.65, with a slight decrease in correlation (R = 0.89; p < 0.001) and agreement. For pO2 average bias was -2.69 and the intersensor precision was 12.16, with a strong correlation (R = 0.97; p < 0.001) and agreement. In addition, we tested the reliability of the system for values of pO2 above 100 mmHg and we found a strong correlation (R = 0.96; p20.001) and agreement even for these clinical conditions, largely out of physiologic parameters. This study demonstrates the feasibility and reliability of continuous intra-arterial three-component PB 3300 (Puritan Bennett) blood gas monitoring.

Aged↗
PubMedDate not supplied

[The effectiveness of enoximone in patients with serious left ventricular dysfunction submitted for aorto-coronary bypass].

BACKGROUND: The purpose of this study was to investigate whether the combined positive inotropic and vasodilating properties of enoximone have a short-term benefit when used in patients who underwent open heart surgery. METHODS: From 7/1994 to 1/1995 twenty-six patients with severe myocardial dysfunction (ejection fraction < 35%) were enrolled into a prospective trial before undergoing coronary artery bypass graft. They were randomly selected into two study groups: the first treated with enoximone (group E) and the other one with dopamine (group D). Anaesthesia was the same for both groups using high-dose fentanyl. Buckberg cardioplegia was used. All patients were followed by: conventional monitoring, Swan-Ganz catheter and transesophageal echocardiography. measurements (hemodynamic parameters, end-systolic and diastolic area and left ventricular wall motion) were recorded: after induction of anesthesia, after loading-dose and an intensive care unit. Enoximone- and dopamine infusions were started during weaning from cardiopulmonary bypass and tailored to hemodynamic parameters (cardiac index > 2.8 l/min, wedge pressure < 16 mmHg, mixed venous blood saturation > 65%). Major events were defined as: endotracheal intubation > 36 h, using intraortic balloon pump or centrifugal pump, intensive care timer > 48 h, in hospital cardiac death. Prices, were established by DRG-tables (diagnosis related groups). Statistical analysis were performed by X and "t" Student tests. RESULTS: Cardiac index increased more significantly in group E (CI 1.9-->3.9 vs 2.3-->3.3; p 0.05) thanks to a higher reduction of vascular systemic (SVRI 2889-->1447 vs 2536 -->1565; p 0.005) and pulmonary resistances (PVRI 271-->193 vs 288-->218; p 0.05). Fewer major cumulative events and intensive care costs were observed in group E rather than group D. CONCLUSIONS: Enoximone administer immediately after open heart surgery had more beneficial hemodynamic and clinical effects than dopamine in patients with severe left ventricular dysfunction.

Cardiotonic Agents↗