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Biomedical subjects

M Scavuzzo

Publications and source records attributed to M Scavuzzo.

At least 19 recordsLinked to original sources
PubMed2002

The targets of nephritogenic antibodies in systemic autoimmune disorders.

In situ formation of immune complexes is a well recognized mechanism of renal injury in systemic autoimmune disorders. The identification of intrinsic renal antigens that are targets of nephritogenic antibodies is a field of active investigation. Recently, two proteins expressed in the kidney have been characterized as renal antigens. Alpha-actinin, an actin-binding protein localized in glomerular podocytes, is the major target of nephritogenic anti-DNA antibodies. Alpha-enolase, a glycolytic enzyme, is a target of nephritogenic anti-DNA and non-anti-DNA antibodies.

Actinin↗
PubMed2001

Modulation of beta2 integrin phenotype, adhesion, chemotaxis, and oxidative burst of neutrophils by cyclosporine.

Cyclosporine (CsA) is an immunosuppressive drug widely used to prevent allograft rejection, but its action on neutrophil function is not well known. Neutrophils play an important role in tissue damage during allograft rejection; chemotactic recruitment, adhesion to endothelial cells and oxidative burst of neutrophils are early events during allograft rejection. The aim of this work was to evaluate the effect of CsA on beta2 integrins' surface expression, adhesion to human umbilical endothelial cells (HUVECs), chemotaxis and oxidative burst by neutrophils. For any neutrophil function studied, data obtained from activated neutrophils exposed to CsA were compared with those derived from untreated controls. Results show that CsA does not block neutrophil chemotaxis and does not reduce surface expression of CD11 complex and HUVECs' adhesion at all concentrations tested (15, 100 and 500 ng/mL) and at incubation times of 1, 2 and 4 h as compared to controls. On the other hand, the drug affects significantly the CD18 phenotype after two hours of treatment at the maximum concentration (500 ng/mL) (P < 0.05; ANOVA) and the oxidative burst after four hours (P < 0.01; ANOVA). This study provides evidence that in addition to the well-known CsA effects on lymphocyte functions, the drug affects some neutrophil functions with dose- and time-dependent modalities.

Antibodies, Monoclonal↗
PubMed2001

Infection with Burkholderia cepacia in cystic fibrosis: outcome following lung transplantation.

As a result of concern over excessive mortality after lung transplantation, many transplant programs refuse to accept cystic fibrosis (CF) patients infected with Burkholderia cepacia. As a significant proportion of patients with CF in our community are infected with this organism, we have continued to provide lung transplantation as an option. A retrospective review was conducted of medical records of all patients with CF transplanted between March 1988 and September 1996. Fifty-six transplant procedures were performed in 53 recipients with CF between March 1988 and September 1996. Twenty-eight had B. cepacia isolated pretransplant and 25 remaining positive post-transplant. Of the 53 recipients, 19 have died (15 of 28 [54%] B. cepacia positive and 4 of 25 [16%] B. cepacia negative). B. cepacia was responsible for or involved in 14 deaths. Nine of the deaths occurred in the first 3 mo post-transplantation. One-year survival was 67% for B. cepacia positive patients and 92% for B. cepacia negative patients. Recent modifications in antimicrobial and immunosuppressive therapy since 1995 have resulted in no deaths early post-transplant in the last five patients transplanted. We conclude that early mortality in patients with CF infected with B. cepacia is significantly higher than in those not infected with B. cepacia. Modifications in post-transplant medical therapy may improve outcome.

Adult↗
PubMed2000

Surface expression of a glycolytic enzyme, alpha-enolase, recognized by autoantibodies in connective tissue disorders.

In systemic autoimmune diseases, autoantibodies specific for alpha-enolase are detected more frequently in patients with active renal involvement. To analyze the properties of anti-alpha-enolase antibodies and the distribution of the enzyme in the cell, mouse monoclonal and polyclonal antibodies were obtained from mice immunized with a glutathione-S-transferase-alpha-enolase fusion protein. Anti-alpha-enolase antibodies were purified from patient sera on enolase from human kidney. Using these antibodies, the distribution of alpha-enolase in the cell was analyzed in subcellular fractions and in the cell membrane by flow cytometry and immunoprecipitation. Plasminogen binding was studied by an immunoenzymatic assay. We observed that alpha-enolase was present in the cytosol and membrane fractions obtained from kidney and U937 cells. By flow cytometry, mouse polyclonal anti-enolase antibodies, one monoclonal and 7/9 human anti-enolase antibodies bound the membrane of U937 cells. One monoclonal antibody and mouse polyclonal anti-enolase antibodies immunoprecipitated a 48-kDa molecule from surface-labeled U937 cells and this molecule was recognized by rabbit anti-enolase antibodies. Both immunization-induced antibodies and 7/9 autoantibodies from patient sera inhibited the binding of plasminogen to alpha-enolase. The results show that alpha-enolase, an autoantigen in connective tissue diseases, is a cytoplasmic enzyme which is also expressed on the cell membrane, with which it is strongly associated. Anti-alpha-enolase autoantibodies isolated from patient sera recognize the membrane-associated form of the enzyme and/or interfere with its receptor function, thus inhibiting the binding of plasminogen. Autoantibodies specific for alpha-enolase could play a pathogenic role, either by a cytopathic effect or by interfering with membrane fibrinolytic activity.

Animals↗
PubMed1998

Return to work after lung transplantation.

The social rehabilitation of lung transplant recipients becomes increasingly important as the results of lung transplantation improve. Although return-to-work (RTW) rates have been published for recipients of other organ transplants, no such data are available after lung transplantation. The purpose of this study was to determine what factors influence RTW after lung transplantation. Of 99 lung transplant recipients (43 single, 56 bilateral) surveyed from Denver, Colorado, (n = 49) and Toronto, Ontario, Canada (n = 50), 22% (n = 22) were employed, 38% (n = 38) were unemployed but medically able to work, 29% (n = 29) were medically disabled, and 10% (n = 10) had retired. The RTW rate for those medically able to work was 37% (22/60), and it was identical at each center (n = 11). Only Canadian lung transplant recipients (36%, 4/11) secured new jobs, whereas all Colorado lung transplant recipients returned to their previous employment (100%, 11/11). A stepwise discriminant analysis revealed that (1) pretransplantation employment, (2) a diagnosis of emphysema, cystic fibrosis, or primary pulmonary hypertension, (3) a self-report of being physically able to work, (4) greater functional improvement as measured by post-lung transplantation percent predicted forced vital capacity, and (5) post-lung transplantation 6-minute walk > 550 m positively influenced RTW. This analysis accurately profiled 82% of the employed and 76% of the unemployed recipients for an overall effectiveness of 79%. The findings of this study are that (1) a 37% employment rate for those physically able was comparable to other types of organ transplant recipients, (2) employment was not determined by the type of lung transplantation procedure (single or bilateral), and (3) social factors remain employment barriers for some recipients, but their absence did not guarantee a better employment rate.

Adult↗
PubMed1997

Lack of left ventricular dysfunction associated with sustained exposure to hyperlipidemia following lung transplantation.

OBJECTIVES: Hyperlipidemia due to standard immunosuppressive agents occurs commonly following solid organ transplantation. A decision to treat hyperlipidemias would be based on the assumption that such disorders lead to accelerated atherogenesis and ultimately to cardiac dysfunction. We therefore sought to examine whether hyperlipidemias following lung transplantation were associated with a decline in left ventricular (LV) function. STUDY DESIGN: We retrospectively reviewed serial echocardiograms, radionucleotide angiograms (RNAs), and serum lipid levels following lung transplantation. Results of cardiac studies were defined as abnormal if a decline in LV grade occurred from the best result at any time postoperatively to the most recent study. PATIENTS: A total of 184 patients with transplants between November 1983 and June 1995 were reviewed. Eighty patients were excluded owing to incomplete data. One patient was excluded because of severe perioperative myocardial dysfunction. RESULTS: Approximately 80% of patients had elevated cholesterol levels and 60% had elevated low-density lipoprotein levels. Triglyceride levels were raised in 34% of patients while only 4% had an abnormal serum high-density lipoprotein level. More than 80% of patients had no evidence of LV abnormalities in either RNA or echocardiographic studies (group 1). One patient had a change in echocardiographic LV function but no change in grade of RNA (group 2). Twenty patients had a decline in grade based on RNA but no change in the echocardiogram (group 3). There were no patients with changes in both RNA and echocardiogram (group 4). All changes in LV function were from grade I to II. The mean period of follow-up exceeded 30 months for patients in groups 1 to 3. Follow-up data at 3, 4, and 5 years were available on 47, 23, and 12 patients, respectively. There were no differences between the proportions of subjects with normal and abnormal serum lipid levels in each group. CONCLUSIONS: In the initial 5 years after lung transplantation, dyslipidemias affect the majority of patients but are not associated with evidence of deteriorating LV function.

Anticholesteremic Agents↗
PubMed1997

Status of lung transplant recipients surviving beyond five years.

BACKGROUND: Prolonged survival after lung transplantation is now commonplace as a result of advances in surgical techniques and postoperative management protocols. Although 1- and 5-year functional and survival data after lung transplantation are well known, sparse information is available regarding functional status of recipients surviving beyond 5 years. METHODS: The medical records and pulmonary function study results of lung transplant recipients who had survived at least 5 years as of September 1995 were retrospectively reviewed. RESULTS: Of the 76 transplantations performed between November 1983 and September 1990, 30 (39.5%) were double lung transplantations, and 46 (60.5%) were single lung transplantations. Thirty-one recipients were alive 5 years after transplantation (12 double lung transplantations, 19 single lung transplantations). The 5-, 6-, and 7-year survival rates were 44%, 34%, and 29%, respectively. There was no association or difference in cytomegalovirus status, sex, and blood group between those who died within 5 years and those who survived beyond 5 years. The median percent predicted FEVs for single and double lung transplant recipients were as follows: 5 yrs-75%, 75%; 6 years-73%, 75%; 7 years-68%, 73%. The proportion of recipients with bronchiolitis obliterans syndrome according to published criteria was as follows: stage 0, 32%; stage I, 19%; stage II, 16%; and stage III, 19%. The functional status (i.e., active, working, disabled) 5 years after transplantation was as follows: active/working, 74%; active but not working, 13%; some limitation/independent, 10%; and disabled, 3%. CONCLUSION: Bronchiolitis obliterans syndrome is a frequent occurrence in long-term survivors. Nevertheless, in spite of this condition, most recipients have acceptable lung function, are active, and are generally working.

Activities of Daily Living↗
PubMed1997

Tacrolimus as rescue therapy for bronchiolitis obliterans syndrome.

BACKGROUND: Chronic lung allograft rejection manifested by sustained declines in lung function is the most common cause of late death after lung transplantation. Numerous strategies have shown variable results. We sought to evaluate the effect of FK506 (tacrolimus) on bronchiolitis obliterans syndrome (BOS) after lung transplantation. METHODS: A single-center open study was conducted of 15 patients whose treatment was converted to tacrolimus from cyclosporine. Of the 15, 12 patients had BOS characterized by sustained loses in lung function while receiving cyclosporine. Rate of decline of forced expiratory volume in 1 second (FEV1) for the 12 patients was calculated before and after administration of tacrolimus. Biochemical changes before and after conversion were compared for the entire group. RESULTS: Median monthly rate of decline in FEV1 was significantly reduced after administration of tacrolimus (5.3% vs 1.1%; p = 0.002). Forced vital capacity did not change significantly. No subjects experienced at least a 10% improvement in FEV1. At least a 10% further decline in FEV1 was noted in five subjects, and seven subjects had no change (i.e., within 10% of baseline). A minor nonsignificant increase in creatinine occurred after administration of tacrolimus. Blood cell count, electrolytes, and liver enzymes remained unchanged. The median change in fasting blood glucose was +0.7 mmol/L (p = 0.02). CONCLUSION: Although tacrolimus does not reverse changes in FEV1 with BOS, in this nonrandomized study it seemed to be associated with a decrease in the rate of decline in lung function and no significant sustained toxicity. Further studies are necessary to substantiate this observation.

Adult↗
PubMed1992

Unilateral donor lung dysfunction does not preclude successful contralateral single lung transplantation.

Single lung transplantation remains limited by a severe shortage of suitable donor lungs. Potential lung donors are often deemed unsuitable because accepted criteria (both lungs clear on the chest roentgenogram, arterial oxygen tension greater than 300 mm Hg with an inspired oxygen fraction of 1.0, a positive end-expiratory pressure of 5 cm H2O, and no purulent secretions) do not distinguish between unilateral and bilateral pulmonary disease. Many adequate single lung grafts may be discarded as a result of contralateral aspiration or pulmonary trauma. We have recently used intraoperative unilateral ventilation and perfusion to assess single lung function in potential donors with contralateral lung disease. In the 11-month period ending October 1, 1990, we performed 18 single lung transplants. In four of these cases (22%), the donor chest roentgenogram or bronchoscopic examination demonstrated significant unilateral lung injury. Donor arterial oxygen tension, (inspired oxygen fraction 1.0; positive end-expiratory pressure 5 cm H2O) was below the accepted level in each case (246 +/- 47 mm Hg, mean +/- standard deviation). Through the sternotomy used for multiple organ harvest, the pulmonary artery to the injured lung was clamped. A double-lumen endotracheal tube or endobronchial balloon occlusion catheter was used to permit ventilation of the uninjured lung alone. A second measurement of arterial oxygen tension (inspired oxygen fraction 1.0; positive end-expiratory pressure 5 cm H2O) revealed excellent unilateral lung function in all four cases (499.5 +/- 43 mm Hg; p less than 0.0004). These single lung grafts (three right, one left) were transplanted uneventfully into four recipients (three with pulmonary fibrosis and one with primary pulmonary hypertension). Lung function early after transplantation was adequate in all patients. Two patients were extubated within 24 hours. There were two late deaths, one caused by rejection and Aspergillus infection and the other caused by cytomegalovirus 6 months after transplantation. Two patients are alive and doing well. We conclude that assessment of unilateral lung function in potential lung donors is indicated in selected cases, may be quickly and easily performed, and may significantly increase the availability of single lung grafts.

Brain Death↗
PubMed1991

Comparison of outcomes of double and single lung transplantation for obstructive lung disease. The Toronto Lung Transplant Group.

Single lung transplantation has recently been applied with success in patients with obstructive lung disease. Such patients were previously managed by bilateral pulmonary transplantation. Between November 1986 and January 1990, 18 patients underwent transplantation for obstructive lung disease in our center. Eleven double lung transplants and seven single lung transplants were performed in patients having a mean age of 43.4 and 44.1 years, respectively. Operative death occurred in two of 11 double lung transplantations and one of seven single lung transplantations. Each patient underwent preoperative and 3-month postoperative pulmonary function tests, arterial blood gas analyses, nuclear lung scans, and 6-minute walk tests. There was no difference in the preoperative values for any of these parameters. Double lung recipients had significantly higher forced expiratory volume in 1 second and forced vital capacity than single lung recipients. However, the ratios of forced expiratory volume in 1 second to vital capacity were not different. Arterial oxygen and carbon dioxide tension were not different between the two procedures. Whereas double lung transplantations caused a slight preponderance of perfusion to the right lung, the transplanted lung in single lung recipients received a mean of 79.5% +/- 12.3% of predicted flow and only 61.6% +/- 5.0% of predicted ventilation. Three-month 6-minute walk distances were markedly improved in both groups, with double lung recipients achieving 573.0 +/- 44.7 m in comparison with the 528.0 +/- 43.0 m achieved by the single lung recipients. Single lung transplantation is a satisfactory option in patients with obstructive lung disease and might offer significant advantages to the older patient population, in which risk of double lung transplantation is high.

Adult↗