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Biomedical subjects

F Lopez-Rubio

Publications and source records attributed to F Lopez-Rubio.

11 recordsLinked to original sources

Antithrombin III prevents early pulmonary dysfunction after lung transplantation in the dog.

BACKGROUND: Ischemia-reperfusion injury with the resulting inflammatory response is a devastating complication of lung transplantation; much of the tissue damage could be diminished by control of the inflammatory response. Recent studies have show that antithrombin III (AT III) has an anti-inflammatory effect in addition to its established role in the regulation of blood coagulation. Thus, we hypothesized that the administration of AT III might help to prevent ischemia-reperfusion injury after lung transplantation. METHODS AND RESULTS: The study was performed in a dog model of orthotopic lung transplantation. Dogs were randomly assigned to receive either vehicle (controls) or AT III. We observed that in control dogs, during the 180-minute period after lung transplantation, the arterial O(2) partial pressure decreased and both the alveolar-arterial O(2) difference and the pulmonary vascular resistance increased. By contrast, these parameters remained unchanged in the group of dogs receiving AT III. Dogs with transplants receiving AT III did not show an increase in cell adhesion molecules, and histological examination revealed almost an absence of inflammatory response. The administration of AT III produced a marked increase in serum prostacyclin (PGI(2)) levels, whereas in control dogs, the PGI(2) levels did not change. The beneficial effect of AT III was not observed when dogs received indomethacin to prevent the stimulation of PGI(2) release by AT III. CONCLUSIONS: Our results demonstrate that AT III prevents ischemia-reperfusion injury in a dog model of lung transplantation and that this effect is conditioned by an increase in PGI(2) production.

6-Ketoprostaglandin F1 alpha↗

Interferon therapy in hemodialysis patients with chronic hepatitis C virus infection induces a high rate of long-term sustained virological and biochemical response.

AIM: The aim of the present study was to analyze the efficacy and tolerance of interferon (IFN) therapy in hemodialysis (HD) patients with chronic hepatitis C virus (HCV) infection. Specifically, we assessed whether the "normalization" of serum ALT levels was associated with the disappearance of the HCV-RNA. METHODS: Thirteen hemodialysis patients with chronic hepatitis C were treated for one year with 3 MU of alpha-IFN. The primary end point was a sustained virological response defined as the absence of HCV-RNA in the last follow-up; the secondary end points were normalization of the serum ALT levels and histological improvement. ALT was considered "normal" below 27 IU/l. RESULTS: Ten patients completed the treatment, which was discontinued in the other 3 (23%). By the end of the treatment a virological response was observed in 8 of the 10 patients (80%) who completed the one-year IFN therapy. Biochemical response was associated with a virological response in 8 of the 9 patients in whom ALT levels became normal. Three patients had a biochemical and virological relapse in the follow-up. Two of them received a further year of IFN therapy, which resulted in a sustained biochemical and virological response. In all patients who underwent a liver biopsy (n = 5), the inflammation score improved. After a median follow-up of 5 years (range 2 - 7), a sustained response was observed in 6 (46%) of the 13 patients enrolled. Two patients with a sustained response received a kidney transplant and after more than 6 years still maintain a biochemical and virological response. Side effects included flu-like syndrome (n = 8), hemoglobin decrease (n = 8), thrombocytopenia (n = 3), depression (n = 1) and seizures (n = 1). CONCLUSION: IFN treatment over a one-year period produces a high rate of long-term virological response in HD patients, associated to a biochemical response in all cases.

Adolescent↗

C1-esterase inhibitor prevents early pulmonary dysfunction after lung transplantation in the dog.

The success of lung transplantation to a large extent depends on effective protection of the graft from ischemic injury after reperfusion. Although mechanisms have not been clarified, the pathologic findings of ischemic injury after reperfusion are similar to adult respiratory distress syndrome, a condition in which the blood coagulation contact system is activated. This study evaluates the effect of C1-esterase inhibitor (C1-INH), the main inhibitor of the blood coagulation contact system, on short-term lung function in a dog model of orthotopic lung transplantation. Twelve lung transplantations were performed after 24 h of ischemic time. Dogs were randomly assigned to receive either vehicle (Control) or C1-INH. After the lung transplantation in the control group, Pao2 decreased by 84% and both the AaPO2 and the Qs/Qt% increased (340 and 530%, respectively, p < 0.01); these parameters remained unchanged in the C1-INH group. The hypoxemia observed in control animals was associated with decreased blood coagulation contact factors, complement consumption, increased expression of adhesion glycoproteins in leukocytes, and extensive intraalveolar and interstitial neutrophil infiltration. In contrast, C1-INH administration prevented hypoxemia, the decrease in blood coagulation contact factors, the activation of the complement system, the increase in expression of leukocyte adhesion molecules, and inflammatory cell infiltrate. This study has demonstrated that in a dog model of lung transplantation, the administration of C1-INH prevents early pulmonary dysfunction, and it suggests that activation of blood coagulation contact system and complement are important mechanisms causing ischemic injury after reperfusion.

Animals↗

Stereological estimates of nuclear volume in carcinoma of the ampulla of Vater.

The stereological estimate of mean nuclear volume is an objective and reproducible method of measurement of nuclear size in terms of absolute volume. We have used this method to study carcinomas of the ampulla of Vater. Our study includes 21 cases--five papillary and 16 intestinal--all treated by the same surgical procedure. The volume-weighted mean nuclear volume (nuclear nu v) and the mean nuclear area were calculated. The mean volumes of nuclear nu v were significantly different (P less than 0.01) between the papillary and intestinal carcinomas, but no differences were found between normal mucosa and papillary carcinoma. The variance was significantly larger in the intestinal group than the papillary and normal groups. The nuclear nu v showed a significant association with survival, larger nuclear nu v (greater than 150 microns 3) being associated with a lower survival rate.

Ampulla of Vater↗

[Congenital laryngeal atresia: apropos of a case].

A case of congenital laryngeal atresia in which the laryngeal lumen was obstructed by a soft, smooth protrusion is reported. Laryngeal stenosis was located at the glottic level and appeared as a protrusion reducing the laryngeal lumen to a few millimeters. The stenotic tissue consisted of striated muscle fibres cross-linked through their midlines.

Abnormalities, Multiple↗

Cytometric and histologic predictors of prognosis in ampullary carcinoma treated with pancreatico-duodenectomy.

The association between several clinical, histologic and karyometric variables and the survival rates of patients with ampullary carcinoma was examined. Cases were limited to those treated exclusively by pancreaticoduodenectomy for which follow-up data was available, eliminating those cases with deaths due to other causes. The histologic type was classified as papillary, intestinal or mixed while the differentiation was recorded as well, moderate or poor. The stroma was categorized as scanty, moderate or abundant, and the tumor stage was evaluated according to Martin's classification. High-resolution morphometric and microphotometric (DNA content) evaluation of Feulgen-stained nuclei was performed using the microTICAS system. Statistical analyses were performed to examine the relationship between these variables and survival. Neither the tumor stage nor the presence of positive lymph nodes was a significant prognostic indicator, nor was the degree of differentiation or the amount of stroma. However, the survival showed a significant association with several karyometric variables and with the histologic type. Specifically, aneuploid DNA ploidy profiles, higher mean ploidy values and larger nuclei were associated with a lower survival rate. Short-term survivors (less than five years) had a mean ploidy of 2.8N, a mean 5N exceeding rate of 8.3% and a mean nuclear area of 41 sq microns, while long-term survivors (greater than or equal to five years) had corresponding means of 1.9N, 0.6% and 26 sq microns. These differences are all significant at a two-tailed significance level of less than .05 using a separate variance estimate t-test. In addition, papillary tumors showed a better prognosis than did intestinal or mixed tumors (Breslow P less than .04 and Mantel-Cox P less than .009).

Adult↗

Renal involvement in chronic graft-versus-host disease: a report of two cases.

We report details of renal involvement during the course of chronic graft-versus-host disease (cGVHD) in two patients undergoing bone marrow transplantation as treatment for acute leukemia. In both cases, the clinical picture was primarily characterized by proteinuria without hypertension or renal failure. Electron microscopy of renal biopsy specimens revealed a similar pattern in the two cases with extensive coalescence of foot processes and intramembraneous deposition of electron-dense material. Our data suggest that the kidney may be a target organ in chronic GVHD.

Adolescent↗

Percutaneous transluminal angioplasty of stenotic ductus arteriosus.

This article describes our in vitro experience of balloon angioplasty of the ductus arteriosus (DA) in three post mortem human specimens, as well as an in vivo dilatation of a stenotic DA. The in vitro histologic observations revealed disruption of the intima and areas of pathologically fragmented and disorganized fibers at the media, with integrity of the ductal wall in all three DA. These findings led us to attempt percutaneous transluminal angioplasty (PTA) of a stenotic DA in a 2.3-kg newborn infant with hypoplastic left heart syndrome in a very deteriorated clinical condition. A Rashkind septostomy was associated with PTA of the stenotic DA. Following this, the gradients across the DA and across the atrial septum disappeared and the ductal angiographic diameter increased. Although an improved clinical condition was observed during the following hours, he died 1 day after. At necropsy, we found integrity of the ductal wall with histological changes similar to that observed in vitro. We conclude that PTA of stenotic DA could represent an alternative for palliative treatment of DA-dependent congenital heart disease.

Angioplasty, Balloon↗