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Biomedical subjects

G Sacchi

Publications and source records attributed to G Sacchi.

At least 55 records · Page 3Linked to original sources
PubMed1990

Autologous implant of peritoneal mesothelium in rabbits and man.

With the purpose of studying peritoneal physiology, original biopsy methods were devised and human and rabbit peritoneal mesothelial cells cultured and characterized. It was then decided to verify whether these cells could be implanted autologously during peritoneal dialysis in cases of acute loss of mesothelial surface. Staphylococcal peritonitis was induced in 12 rabbits and after 4 days of antibiotics, 6 of them were autoimplanted with cultured mesothelial cells, previously marked in 3 cases with thymidine (H3TdR). Implanted rabbits sacrificed after 3 and 6 days showed taking of the new mesothelial cells both by direct morphological observation and by autoradiography. Four uremic CAPD patients recovering from severe peritonitis were implanted with 300 million of their own peritoneal mesothelial cells, previously cultured and frozen. Morphological signs of taking were evident by laparoscopy and from peritoneal biopsies performed 3 and 6 days after implant. The fact that such implants are possible may have interesting applications in medicine and surgery.

Adult↗
PubMed1989

Peritoneal vascular changes in continuous ambulatory peritoneal dialysis (CAPD): an in vivo model for the study of diabetic microangiopathy.

Replication of the basement membrane of the peritoneal capillaries and the mesothelium is observed in all uremic patients after a period of continuous ambulatory peritoneal dialysis (CAPD). Biopsy specimens of the parietal peritoneum were taken in diabetic and non-diabetic patients on insertion or repositioning of the CAPD catheter. The basement membrane of the capillaries and mesothelium was normal in non-diabetics on insertion of the catheter, but after 2 to 66 months of CAPD, multiple replication was found. In nearly all the diabetics there was already replication of the basement membrane of the peritoneal capillaries before CAPD was begun but the basement membrane of the mesothelium was intact. After several months of CAPD thickening of the basement membrane of the capillaries was found in 36% of diabetics, sometimes to the point of occlusion. After CAPD, replication of the basement membrane of the mesothelium has been observed in both diabetics and non-diabetics although it is initially perfectly normal in both. CAPD is proposed as an experimental model for diabetic microangiopathy in man.

Basement Membrane↗
PubMed1989

Implant of autologous mesothelial cells in animals and a peritoneal dialysis patient.

Success in culturing human and animal peritoneal mesothelial cells for the purpose of study, led us to determine whether these cells could be autoimplanted in animals and man during peritoneal dialysis in cases of acute and extensive loss of mesothelial surface area. Using an original biopsy technique, we were able to cultivate and characterize from the structural and caryological point of view, human and rabbit peritoneal mesothelial cells. Staphylococcal peritonitis was provoked in 12 rabbits with in-dwelling peritoneal catheters and after 4 days of antibiotic therapy, 6 of them were autoimplanted with cultured mesothelial cells. In the animals sacrificed on the third and sixth days, direct morphological observation and autoradiographic techniques showed that the transplanted cells had taken and revealed a different picture from that in the non-transplanted rabbits. In a 56 year old female diabetic patient, upon insertion of the first peritoneal catheter, a specimen of mesothelial cells was cultured and then frozen. Seven months later after an episode of peritonitis from candida which dictated removal of the peritoneal catheter, since there was a sufficient number of cultured mesothelial cells and the patient consented, the implant was performed. Peritoneal biopsy by laparoscopy three and six days later showed that the cells had taken. The purpose of the study was merely to show that autoimplant of mesothelium in man and animals is possible.

Animals↗
PubMed1989

Neuroendocrine tumour of the uterine cervix. Cytomorphologic, histochemical and immunohistochemical aspects.

We report a case of neuroendocrine tumour of the uterine cervix (carcinoid) with spread to the corpus and adnexa, and hepatic metastases. Carcinoid represents a rare entity among tumours of the uterine cervix, and is now included among the APUD system-derived tumours (apudomas). Gross examination revealed an enlarged uterus (11 x 7 cm) with neoplastic infiltration of the endocervical canal and uterine corpus, and yellowish-white nodules in both ovaries. Microscopic features were those of a malignant trabecular carcinoid (Morson's type I-II). Morphological, histochemical, immunohistochemical and ultrastructural studies were performed. Grimelius stain and antisera to NSE and bombesin yielded positive reactions. Focal positivity was seen with EMA, and probably expressed an epidermoid component. On the basis of a review of the literature, we classify our case within the differentiated neuroectodermic tumours, despite the extremely aggressive biologic behavior already present at surgery. Combined use of histochemical, immunohistochemical and ultrastructural techniques is the correct approach to the histopathologic diagnosis of malignancies with rare and difficult features.

Carcinoid Tumor↗
PubMed1989

Pattern of double glomerulopathies: a clinicopathologic study of superimposed glomerulonephritis on diabetic glomerulosclerosis.

Among 1715 renal biopsies investigated by means of light microscopy, immunofluorescence, and/or electron microscopy, 20 cases of various glomerulopathies (GP) were found to be superimposed on diabetic glomerulosclerosis (DGS). The most frequently superimposed GPs were acute GN (nine cases) and cryoglobulinemic GN (six cases). Although the former association is known to occur, the latter has not so far been reported. In the other patients DGS was associated with crescentic GN (two cases), membranoproliferative GN, membranous GN, and IgA nephropathy (one case each). Morphologic clues allowing the identification of the superimposed GP and the diagnostic relevance of the available morphologic methods were stressed. In particular, light microscopy was sufficient to identify the superimposed crescentic GN, whereas immunofluorescence and/or electron microscopy were needed in the other cases in order to show the composition and the seat of the deposits, respectively. In addition, electron microscopy was useful in identifying some peculiar features such as humps, mesangial cell interposition, and organized deposits in cryoglobulinemic GN. The actual frequency of superimposed GPs is difficult to assess: either under or overestimation is possible. Pathologists must be aware that this miscalculation is not an episodic event and that the estimation must be carefully sought whenever clinical data are equivocal and not fully fitting with DGS alone. The duration of the diabetes seems to favor the superimposition of GN on DGS. In these patients the prognosis is poor, not only when it could be expected to be, as in the cases with superimposition of crescentic or membranoproliferative GN, but also when DGS is associated with acute GN, whose prognosis is generally favorable.

Adult↗
PubMed1988

Monoclonals and allergy. A review, with experimental contribution.

The role of monoclonal antibodies in allergy has been explored. First the status of art of monoclonal research in general is reviewed, by outlining a monoclonals identikit and the relevant technologies employed for their development. The attention is then focused on the present impact of monoclonals in the allergological field, first considering a general outline, and then the important steps of standardization of monoclonal antibodies. A comprehensive hint is made concerning the monitoring of immunotherapy, with future extrapolations on developing anti-idiotype vaccines, of which same examples can already be found in the infectious field, thus leaving the way open in allergy as well. A second section deals with the experimental contribution of the Authors, with the description of the preparation of the allergenic extracts of D.F., with details of the relevant steps (rabbit immunization; extract characterization; techniques used for monoclonal screening and characterization). The results obtained are discussed in relation to the techniques employed, weighing the reciprocal advantages and drawbacks.

Animals↗
PubMed1987

Ultrastructural renal findings in allografted kidneys of patients treated with ciclosporin A.

22 renal biopsies of 22 patients with 6-month-old transplants have been examined at the light- and electron-microscopic level to demonstrate the toxic effects induced by ciclosporin A (CS). These patients presented stable renal function and were exempt from acute rejection symptoms or nephrotoxicity. Interstitial fibrosis, tubular atrophy and interstitial lymphocytic infiltration were the lesions most often observed by light microscopy. In a single case an arteriolar lesion suggestive of arteriolopathy due to Cs was seen. Ultrastructural observations of renal tubular cells showed a tendency of rough and smooth endoplasmic reticulum to microdilate and microvacuolize. In 4 out of 22 cases there were mitochondrial alterations with giant mitochondria. In only 1 case, clusters of cilia were seen. Clinical histological correlations show that interstitial fibrosis is directly proportional to CS blood level. CS higher blood levels suggest a higher risk of nephrotoxicity.

Basement Membrane↗
PubMed1986

Superimposed nephritis: a separate entity among glomerular diseases?

The concomitant occurrence of two glomerular diseases in the same patient was diagnosed in seven out of 105 patients undergoing renal biopsy for suspected glomerulopathy. The most frequently associated disease was a membranous type glomerulopathy. The follow-up was characterized by a rapid deterioration of renal function and two patients were required to start a chronic hemodialysis program soon after the diagnosis. It is suggested that the observed coexisting patterns of glomerular injury do not occur on the basis of chance alone and should be considered as a separate entity in glomerular pathology. In all cases, clinical and pathologic findings were strongly suggestive for two consecutive distinct pathologic processes, thus justifying the use of the term superimposed nephritis. It is reasonable to assume that the mechanisms responsible for glomerular damage and for the evolution of the disease in superimposed nephritis are different from those regulating the corresponding glomerulonephritis when occurring alone. The high prevalence of membranous pattern in superimposed nephritis indicates that pre-existing glomerular alterations might favor an immune reaction in the subepithelial space.

Adult↗
PubMed1986

Adriamycin-induced glomerulosclerosis in the rat.

To evaluate long-term effect of sustained proteinuria induced by a single injection of adriamycin (ADR) on occurrence of focal segmental glomerulosclerosis (FSG), we treated 50 Sprague-Dawley (SD) rats, weighing 250 g with 5 mg/kg body weight of ADR. After six months of heavy proteinuria, 40% of ADR-treated rats did not develop FSG. In the remaining 60% of animals, a mild FSG was observed associated with the presence of large tubular casts and interstitial inflammation. Glomerulosclerosis was never observed in absence of tubulointerstitial lesions. Nine months after ADR, all rats exhibited FSG with renal insufficiency but the severest changes were restricted to the tubulointerstitial level. Our results indicate that chronic proteinuria induced by ADR is a relatively good model of glomerular sclerosis, however, the cause of glomerular sclerosis is probably different from that operating in other experimental models of FSG. Both sclerotic changes and progression of disease seem to be dependent on formation of tubular casts with consequent interstitial changes. This study raises the question of the relative role of tubulointerstitial changes in the subsequent development of FSG.

Animals↗
PubMed1986

Morphology of the peritoneal membrane during continuous ambulatory peritoneal dialysis.

In the last 3 years we performed 52 peritoneal biopsies (PB) in 31 patients on continuous ambulatory peritoneal dialysis (CAPD). Samples of the parietal peritoneum were obtained either during insertion of the catheter or while it was being repositioned or removed. PB was performed in 13 patients before initiating CAPD and in 27 after 7-49 months of CAPD while 7 had PB during peritonitis, and, again, in 5 of these cases, PB was repeated after 1-4 months for light, electron transmission, and scanning electron microscopy. BP after CAPD showed that mesothelial cells were irregularly spaced, and at times we observed alterations in the cellular structure. Rarely were these cells degenerating, while rarefaction and in many cases complete absence of microvilli were observed. In some cases the submesothelial layers showed rarefaction of the connective tissue and sclerosis. During peritonitis, PB showed more alterations with marked degeneration and in some cases necrosis of the mesothelium and alterations of connective tissue. PB performed some months after peritonitis showed only a partial regression of these alterations and sclerotic patches, and no microvilli were noted in the mesothelium.

Ascitic Fluid↗
PubMed1986

Specific immunotherapy with allergoids in atopic subjects, hyporeactive to other vaccines.

Allergoids comply with the therapeutic requirement to reach high doses of the injected allergen, since the modifications of the allergens cause a loss of allergenicity, though the immunogenicity is being retained. Considering that it is possible to use a starting dose 40 times higher in comparison with retard vaccines, we thought it very expedient to treat with allergoids 18 patients allergic to parietaria, and 12 patients allergic to grass pollen, who had shown no clinical improvement after immunotherapy, lasting for at least three years with retard vaccines. The therapeutic results obtained are the following: improvement in 66% of the parietaria allergic patients after the first year, and of the 72% in the second year, of the 75% of the grass pollen allergic patients after the first year and of the 83% in the second year. They can be interpreted as due to the fact that such patients are always poorly reactive to the doses of allergens commonly present in retard vaccines. On the contrary, they do react to allergoids, both due to the high amount of allergen administered, and to the fact that polymerization brings about a stronger epitopic expression matched by a higher immunogenic activity. Moreover, the data are also indicative for a good relationship between the antibody titer of antigen-specific blocking IgG and the clinical effectiveness valued by means of symptom and medication scores.

Humans↗
PubMed1985

Acquired C1 inhibitor deficiency with angioedema symptoms in a patient infected with Echinococcus granulosus.

A patient with echinococcosis, acquired deficiency of the inhibitor of the activated first component of complement and angioedema symptoms has been studied. These symptoms started 7 months after the surgical removal of an echinococcus liver cyst. Eight years later, when the complement was investigated, a marked deficiency of the C1 inhibitor, C1, C4 and CH50 was present. The patient was therefore successfully treated with tranexamic acid. After 4 years, the woman needed another operation because of a relapse of echinococcosis; afterwards she was symptom-free without medications, while the complement profile remained unchanged. Circulating immune complexes were detected by the conglutinin method. The patient's serum was demonstrated to possess an anticomplementary activity without affecting the C1 inhibitor when incubated with normal human serum at 37 degrees C. At present, 16 years after the onset of the symptoms, there are no signs of lymphoproliferative disease.

Angioedema↗
PubMed1984

Localization of dopamine receptors in the rabbit renal artery: a histoautoradiographic study.

The localization of dopamine receptors within rabbit renal artery was studied using 3H-spiroperidol as a label for dopamine receptors and a histoautoradiographic technique. Preliminary radioreceptor binding studies showed that 3H-spiroperidol was bound to sections of renal artery in a manner consistent with the existence of dopamine receptors. In fact the binding was found to be saturable, stereospecific and of high affinity, with a Bmax approximately of 158.3 fmol/mg protein and a Kd of 13.5 nmol/l. The microscopic examination of sections processed for the histoautoradiographic demonstration of 3'-spiroperidol binding sites showed that the distribution of dopamine receptors in the renal artery was widespread. The highest concentration of dopamine receptors was found primarily in the smooth muscle cells of the media and then, in the following order, in endothelial cells of the intima and in fibrous and connective cells of the adventitia. The direct demonstration of dopamine receptors in the media of rabbit renal artery strongly supports the hypothesis that these receptors may be involved in the relaxation of the artery caused by infusion or application of dopamine.

Animals↗
PubMed1984

Immunoelectron microscopy of human renal biopsies: prerequisites and limitations.

The traditional diagnostic approach to immunologically mediated glomerulonephritis is based on the morphological (both in light and electron microscopy) and immunofluorescence examinations of different samples of the same renal biopsy. A major disadvantage of this composite procedure is represented by the inability to precisely correlate the immunocytochemical data with the presence and distribution of electron-dense deposits. Immunoelectron-microscopic techniques could therefore represent a more useful tool for immunomorphological investigations into these glomerulopathies. In order to overcome the significant limitations of preembedding staining procedures, we introduce two postembedding staining techniques (using peroxidase or colloidal gold as markers of the immunoreaction) which result in a precise immunolocalization of immunoglobulins in the dense deposits of glutaraldehyde-fixed, postosmicated and Epon-embedded renal biopsies, while adequately preserving the ultrastructural morphology of the tissue sections.

Biopsy↗
PubMed1984

In vivo and in vitro study of antigens and allergens in pollen extracts of Graminaceae.

The standardization of the diagnostic and immunotherapeutic products plays an even more definite role in allergology. The investigations performed in the last few years allowed to attain the purification and characterization of the allergenic extracts, both from the allergenic and antigenic viewpoint, implementing the most sophisticated techniques. The identification of the allergens in the extracts is of primary importance in the standardization and purification of the allergens themselves. The allergenic activity may be determined both in vitro and in vivo and the combination of the two techniques allows reaching a higher reliability in the assay. The Authors thought it very timely to verify the reliability of the in vivo and in vitro assays by employing four allergenic extracts of Graminaceae pollens, due to their importance in the allergological field. Phleum, Lolium, Cynodon, Anthoxanthum, were selected for the investigations. The extracts were also characterized by immunoprecipitation techniques. The results allowed to state that good results may be obtained by the in vivo assay (prick test) of allergenic extracts, with a precision comparable to that obtainable with the RAST inhibition, even using a restricted sample of allergic patients. It was ascertained that it is possible to express the allergenic activity versus a reference extract (Phleum). The three extracts (Anthoxanthum, Cynodon, Lolium), for which good antisera were obtained, were antigenically characterized, by means of CRIE and CIE, and the major allergens were identified.

Adult↗
PubMed1984

Steroids and Adriamycin nephrosis.

Adriamycin induces a nephrotic syndrome in rats characterized by severe ultrastructural changes of visceral epithelial cells similar to those observed in puromycin aminonucleoside (PA) nephrosis and in human 'minimal changes' glomerulopathy. Since steroids have been shown to be effective in human 'minimal changes' glomerulopathy and in PA nephrosis, we undertook the present study to assess whether steroids had a therapeutic effect on adriamycin nephrosis. Groups of rats injected with different doses of adriamycin were subsequently treated with prednisolone. No significant differences were observed in proteinuria and in ultrastructural findings between the control and the steroid-injected animals. This study suggests that the mechanism underlying adriamycin-induced nephrotic syndrome might be different from that responsible for PA nephrosis or human 'minimal changes' glomerulopathy.

Animals↗