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Biomedical subjects

I Sola

Publications and source records attributed to I Sola.

31 records · Page 2Linked to original sources
PubMed1998

Molecular features in a biphenotypic small cell sarcoma with neuroectodermal and muscle differentiation.

We report a case of a 13-year-old girl with soft tissue sarcoma of the hand, which showed muscle and neuroectodermal immunophenotypes. Molecular studies were performed on RNA collected from fine-needle aspiration (FNA) cytology and peripheral blood samples by nested reverse transcriptase-polymerase chain reaction (RT-PCR) and Southern blot analysis. This biphenotypic tumor showed simultaneous expression of EWS-FLI1 and PAX3-FKHR transcripts, specific of Ewing family tumors and alveolar rhabdomyosarcoma, respectively. Although childhood sarcomas with simultaneous muscle and neural differentiation have been described to have EWS-FLI1 transcripts, there are no reports of tumors with both transcripts. Cytological specimens are a good source of RNA for molecular studies.

Adolescent↗
PubMed1998

Engineering passive immunity in transgenic mice secreting virus-neutralizing antibodies in milk.

Protection against enteric infections can be provided by the oral administration of pathogen-neutralizing antibodies. To provide passive immunity, 18 lines of transgenic mice secreting a recombinant monoclonal antibody (Mab) neutralizing transmissible gastroenteritis coronavirus (TGEV) into the milk were generated. The genes encoding a chimeric Mab with the variable modules of the murine TGEV-specific Mab 6A.C3 and the constant modules of a human IgG, isotype Mab were expressed under the control of regulatory sequences derived from the whey acidic protein, which is an abundant milk protein. The Mab 6A.C3 binds to a highly conserved epitope present in coronaviruses of several species, which does not allow the selection of neutralization escape mutants. Antibody expression titers of 10(6) were obtained in the milk of transgenic mice that reduced TGEV infectivity 10(6)-fold. The antibody was synthesized at high levels throughout lactation. Integration of matrix attachment region sequences with the antibody genes led to a 20- to 10,000-fold increase in the antibody titer in 50% of the transgenic animals. Antibody expression levels were transgene copy number independent and related to the site of integration. The generation of transgenic animals producing virus neutralizing antibodies in milk could provide an approach to protection against neonatal infections of the enteric tract.

Animals↗
PubMed1998

CD44v6 expression is related to progression in renal epithelial tumours.

AIMS: Expression of CD44 variant isoform including exon 6 has been associated to tumour progression in several carcinomas. However, no studies have been performed to assess the prognostic value of the expression of this marker in renal cell tumours. METHODS AND RESULTS: We studied 58 renal cell tumours. All patients were followed up for at least 3 years after nephrectomy. Tumours were analysed for expression of CD44v6 assessed by two isoform-specific monoclonal antibodies. RT-PCR was performed to detect CD44 variant transcripts in 10 cases in which immunohistochemistry was negative. Twenty-two tumours showed reactivity in at least 1% cells for both antibodies with a strong membrane pattern. RT-PCR did not show CD44v6 transcripts in any of 10 studied tumours. Immunohistochemical staining was more frequent in perivascular areas or in areas of vascular invasion. In fact, CD44v6 expression correlated well with nuclear grade (P = 0.009), stage at diagnosis (P = 0.04) and appearance of metastasis after nephrectomy (P = 0.007). Although univariate survival analysis showed stage (P < 0.001), grade (P = 0.009) and CD44v6 expression (P = 0.04) to be significant predictive factors, only stage remained significant (P = 0.0013) in the multivariate analysis. CONCLUSIONS: CD44v6 expression, assessed immunohistochemically, is related to tumour progression. However, its prognostic value in renal cell tumours is dependent on tumour stage at diagnosis.

Carcinoma↗
PubMed1998

Transgenic mice secreting coronavirus neutralizing antibodies into the milk.

Ten lines of transgenic mice secreting transmissible gastroenteritis coronavirus (TGEV) neutralizing recombinant monoclonal antibodies (rMAbs) into the milk were generated. The rMAb light- and heavy-chain genes were assembled by fusing the genes encoding the variable modules of the murine MAb 6A.C3, which binds an interspecies conserved coronavirus epitope essential for virus infectivity, and a constant module from a porcine myeloma with the immunoglobulin A (IgA) isotype. The chimeric antibody led to dimer formation in the presence of J chain. The neutralization specific activity of the recombinant antibody produced in transiently or stably transformed cells was 50-fold higher than that of a monomeric rMAb with the IgG1 isotype and an identical binding site. This rMAb had titers of up to 10(4) by radioimmunoassay (RIA) and neutralized virus infectivity up to 10(4)-fold. Of 23 transgenic mice, 17 integrated both light and heavy chains, and at least 10 of them transmitted both genes to the progeny, leading to 100% of animals secreting functional TGEV neutralizing antibody during lactation. Selected mice produced milk with TGEV-specific antibody titers higher than 10(6) as determined by RIA, neutralized virus infectivity by 10(6)-fold, and produced up to 6 mg of antibody per ml. Antibody expression levels were transgene copy number independent and integration site dependent. Comicroinjection of the genomic beta-lactoglobulin gene with rMAb light- and heavy-chain genes led to the generation of transgenic mice carrying the three transgenes. The highest antibody titers were produced by transgenic mice that had integrated the antibody and beta-lactoglobulin genes, although the number of transgenic animals generated does not allow a definitive conclusion on the enhancing effect of beta-lactoglobulin cointegration. This approach may lead to the generation of transgenic animals providing lactogenic immunity to their progeny against enteric pathogens.

Amino Acid Sequence↗
PubMed1998

Preoperative chemotherapy followed by esophagectomy compared with surgery alone in the treatment of squamous cell carcinoma of the esophagus.

The aim of this study is to assess the effect of concomitant preoperative radio-chemotherapy in the treatment of epidermoid esophageal cancer. We studied a total of 45 patients, divided into two groups. Group I consisted of 20 patients diagnosed with epidermoid esophageal cancer who had been treated initially with esophagectomy. Group II consisted of 25 patients treated with preoperative radiotherapy and two cycles of chemotherapy (cisplatin and 5-fluorouracil), one at the beginning and the other at the end of the radiation treatment, on whom an esophagectomy was subsequently performed. The clinical characteristics were similar in both groups. In group II, there were 12 cases (48%) with absence of tumor in the esophageal wall, three of which had node involvement. The operative mortality was similar in both groups (10% and 8% respectively). The only significant difference found in the postoperative complications was the incidence of anastomotic leak; but this was related to the different esophagectomy techniques used rather than the type of therapy. A decrease in the number of patients with tumor recurrence was observed in Group II, especially where the local component was concerned. The best actuarial survival rate at five years was in patients with no presence of tumor after neoadjuvant treatment (44.4%). However, the radio-chemotherapy seems not to have had any benefit in cases with node involvement.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

Interference of coronavirus infection by expression of immunoglobulin G (IgG) or IgA virus-neutralizing antibodies.

Immunoglobulin gene fragments encoding the variable modules of the heavy and light chains of a transmissible gastroenteritis coronavirus (TGEV)-neutralizing monoclonal antibody (MAb) have been cloned and sequenced. The selected MAb recognizes a highly conserved viral epitope and does not lead to the selection of neutralization escape mutants. The sequences of MAb 6A.C3 kappa and gamma 1 modules were identified as subgroup V and subgroup IIIC, respectively. The chimeric immunoglobulin genes encoding the variable modules from the murine MAb and constant modules of human gamma 1 and kappa chains were constructed by reverse transcriptase PCR. Chimeric immunoglobulins were stably or transiently expressed in murine myelomas or COS cells, respectively. The secreted recombinant antibodies had radioimmunoassay titers (i.e., the highest dilution giving a threefold increase over the background) higher than 10(3) and reduced the infectious virus more than 10(4)-fold. Recombinant dimeric immunoglobulin A (IgA) showed a 50-fold enhanced neutralization of TGEV relative to a recombinant monomeric IgG1 which contained the identical antigen binding site. Stably transformed epithelial cell lines which expressed either recombinant IgG or IgA TGEV-neutralizing antibodies reduced virus production by > 10(5)-fold after infection with homologous virus, although a residual level of virus production (< 10(2) PFU/ml) remained in less than 0.1% of the cells. This low-level persistent infection was shown not to be due to the selection of neutralization escape mutants. The implications of these findings for somatic gene therapy with recombinant antibodies are discussed.

Animals↗
PubMed1997

Cardiomyocyte apoptosis and cardiac angiotensin-converting enzyme in spontaneously hypertensive rats.

Increased apoptosis has been reported in the heart of rats with spontaneous hypertension and cardiac hypertrophy. This study was designed to investigate the relationship between apoptosis and hypertrophy in cardiomyocytes from the left ventricle of spontaneously hypertensive rats (SHR). In addition, we evaluated whether the development of cardiomyocyte apoptosis is related to blood pressure or to the activity of the local angiotensin-converting enzyme (ACE) in SHR. The study was performed in 16-week-old SHR, 30-week-old untreated SHR, and 30-week-old SHR treated with quinapril (10 mg x kg[-1] x d[-1]) during 14 weeks before they were killed. Cardiomyocyte apoptosis was assessed by direct immunoperoxidase detection of digoxigenin-labeled 3'-hydroxyl ends of DNA. Nuclear polyploidization measured by DNA flow cytometry was used to assess cardiomyocyte hypertrophy. Compared with 16-week-old normotensive Wistar-Kyoto rats, 16-week-old SHR exhibited increased blood pressure (P<.001), increased rate of tetraploidy (P<.05), and similar levels of ACE activity and apoptosis. Compared with 30-week-old Wistar-Kyoto rats, 30-week-old SHR showed increased blood pressure (P<.001), increased ACE activity (P<.05), increased rate of tetraploidy (P<.01), and increased apoptosis (P<.01). Untreated 30-week-old SHR exhibited similar values of blood pressure and tetraploidy and higher ACE activity (P<.05) and apoptosis (P<.001) than 16-week-old SHR. A direct correlation (P<.01) was found between ACE activity and the apoptotic index in untreated 30-week-old SHR. The long-term administration of quinapril was associated with the normalization of ACE activity and apoptosis in treated SHR. These results suggest that the timing and mechanisms responsible for apoptosis and hypertrophy of cardiomyocytes are different in SHR. Whereas hypertrophy seems to be an earlier alteration that develops in parallel with hypertension, apoptosis develops later in association with overactivity of the local ACE. Our data suggest that cell death dysregulation may be a novel target for antihypertensive agents that interfere with the renin-angiotensin system in hypertension.

Animals↗
PubMed1992

Pathology of renal transplantation.

Renal transplantation is the most appropriate form of treatment for end-stage renal disease in all age groups. We present the experience of two hospitals in the pathology of kidney allograft. Renal biopsy is the most adequate method for the follow-up of these patients, because it permits the differential diagnosis of acute and chronic rejection, transplant glomerulopathy, recurrent and "de novo" glomerulonephritis and immunosuppression nephrotoxicity, mainly by cyclosporine A. We present the pathology features of all these entities, and study the representativity of the biopsy for diagnosis of rejection. The actuarial survival of the graft is 82% and 71% at 1 and 5 years, respectively.

Biopsy↗
PubMed1981

Persistent Müllerian structures in a genotypic male.

A case report of a male with persistent Müllerian structures is presented. The patient was 34 yr old and had a left inguinal hernia, bilateral cryptorchidism and azoospermia. His karyotype was 46 XY. At operation a uterus with vestigial Fallopian tubes and a hypoplastic testis were found inside the hernial sac. Histological studies confirmed the persistence of Müllerian structures. The clinical implications of anti-Müllerian hormone dysfunction are discussed.

Adult↗
PubMedDate not supplied

[Pathological anatomy of organ transplantation].

We review some morphological aspects shared by all allografts. The main points are: 1) The expression of antigens of histocompatibility, essentially DR, allows the diagnosis of acute rejection with a significant specificity; 2) A lesion similar to "Quilty" effect may be seen in other allografts, and it is the first manifestation of an acute rejection; 3) Fine-needle aspiration biopsy may help in the follow-up of kidney transplant but has been demonstrated ineffective in other transplants; 4) The morphology of rejection is different according to the type of immunosuppressive therapy; 5) The basic lesions of chronic rejection are vascular, but chronic rejection may be diagnosed without vessels in the biopsy specimen, by the degree of atrophy of the parenchyma; 6) For the characterization of lymphomas in transplanted patients is necessary study the clonality of tumor cells, the gene rearrangement and the lymphoid subset; 7) Molecular Pathology may help in the early diagnosis of viral infections after transplantation.

Atrophy↗