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Biomedical subjects

M T Vidal

Publications and source records attributed to M T Vidal.

At least 19 recordsLinked to original sources
PubMed2005

[Confocal microscopy of the cornea in photorefractive surgery].

OBJECTIVE: Corneal refractive surgery involves a range of techniques which have assumed a growing importance during the last few years. The advances of very different surgical methods and the early age of the majority of the patients subjected to surgery, limits our knowledge of the histopathologic changes in the operated corneas. For this reason, the development of any diagnostic tool which can permit us to improve our knowledge of the wound healing process would be of significant value. As we describe in our paper, confocal microscopy enables the assessment of the more important advantages for the study of corneal wound healing after refractive surgery: high magnification, harmless, and "in vivo", providing pathogenic information and lateral and axial definition not achievable with other exploration techniques. CONCLUSION: Confocal microscopy appears to be an essential tool for creating a global concept of quality in corneal refractive surgery.

Cicatrix↗
PubMed2003

Follicular conjunctivitis caused by Chlamydia trachomatis in an infant Saharan population: molecular and clinical diagnosis.

AIMS: To ascertain the prevalence of acute trachoma as a supposed endemic disease among infants in the Saharan refugee camps of Tindouf (Algeria) and to evaluate the efficacy of treatment with a single dose of azithromycin. METHODS: 527 children aged between 3 and 17 were evaluated in the camp schools in October 2001. All the children were clinically and microbiologically examined, including slit lamp checks of anterior segment and two conjunctival swabs, one for the detection of membrane lipopolysaccharide by quick immunoassay test Clearview Chlamydia MF and the other for the detection of specific DNA by chlamydia plasmid specific polymerase chain reaction (PCR) assay. After examination, a single dose of azithromycin was administered to each child. One month later samples from positive children and 12 random negative children by the first PCR were taken to perform a new PCR assay. RESULTS: Chlamydia trachomatis was suspected in 2.47% of the children, papillary hypertrophy being the most frequently seen clinical sign. Scarring changes secondary to trachoma were detected in 11.7% of the children. Only four cases (0.8%) were positive to the immunoassay test and 12 cases (2.27%) were positive by PCR. After treatment a second PCR was performed on positive children and they were negative of chlamydia DNA amplification. However, one child who was negative and received the treatment was positive in the second PCR assay. CONCLUSION: Acute trachoma prevalence is much lower than expected among infants in this Saharan population. The possible reasons could be the recent improvements in hygiene and health care. Cicatricial trachoma is more frequent. The Clearview immunoassay test has very low sensitivity in the detection of this disease. A single dose of azithromycin is sufficient to treat chlamydial conjunctivitis. However, a programme of improvement in hygiene and health care is necessary to prevent re-infection.

Acute Disease↗
PubMed1999

Increased expression of angiogenic factors in human colonic angiodysplasia.

OBJECTIVE: Angiodysplasia of the colon is a distinct vascular abnormality characterized by focal accumulation of ectatic vessels in the mucosa and submucosa. To investigate whether angiogenesis contributes to the pathogenesis of human colonic angiodysplasia, we examined the expression of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF), and its endothelial cell receptors flt-1 and KDR. METHODS: Immunohistochemistry was performed in sections of specimens obtained from 18 patients with colonic angiodysplasia and from eight patients with colon cancer and its adjacent, histologically normal margins of resection. We used affinity-purified rabbit polyclonal antibodies and a streptoavidin-biotin peroxidase method. RESULTS: We detected strong immunoreactivity for vascular endothelial growth factor, homogeneously distributed in the endothelial lining of blood vessels of all sizes in 16 (89%) specimens of colonic angiodysplasia and in seven (88%) patients with colon cancer. In contrast, very limited immunoreactivity was found in normal colon. Vascular staining for flt-1 was observed in eight (44%) and one (12.5%) of the colonic angiodysplasia or colon cancer specimens, respectively, but not in normal colon. Vascular immunoreactivity for basic fibroblast growth factor was observed in seven (39%) specimens from patients with colonic angiodysplasia, whereas either very limited or no immunostaining was found in sections from specimens of patients with colon cancer and its normal margins. CONCLUSIONS: In human colonic angiodysplasia, increased expression of angiogenic factors is likely to play a pathogenic role.

Adenocarcinoma↗
PubMed1998

Anticonvulsant effects of nimodipine and two novel dihydropyridines (PCA 50922 and PCA 50941) against seizures elicited by pentylenetetrazole and electroconvulsive shock in mice.

In animal models of epilepsy, calcium entry blockers have shown anticonvulsant properties. We studied the antiepileptic effects of nimodipine and two novel dihydropyridines, a calcium antagonist (PCA 50922) and a calcium agonist (PCA 50941), on pentylenetetrazole seizure and maximal electroshock seizure (MES) in mice. Anticonvulsant profile of nimodipine and PCA 50922 was similar to that of clonazepam, but markedly different from that of phenytoin. None of the doses of the PCA 50941 showed anticonvulsant effect.

Animals↗
PubMed1997

Leu-M1 immunoreactivity and phaeochromocytoma.

The aim was to evaluate Leu-M1 immunoreactivity as a prognostic factor in phaeochromocytoma. Anti-Leu-M1 monoclonal antibodies were used to determine the Leu-M1 immunoreactivity in 17 histologically confirmed phaeochromocytomas from 15 patients, using an avidin-biotin technique. Ten patients had a sporadic phaeochromocytoma, and five had multiple endocrine neoplasia type 2A (MEN 2A). Malignancy was diagnosed in three patients by the presence of metastases. Leu-M1 immunoreactivity was shown in 12 (70.5%) phaeochromocytomas. Three patterns of arrangement were observed: isolated (scattered positive cells) (n = 3); focal (aggregates of positive cells) (n = 5), and diffuse patterns (dispersed positive cells) (n = 4). Two cases of malignant phaeochromocytoma were positive (one focal and one isolated pattern). All cases of MEN 2A showed immunoreactivity, although no characteristic pattern was prevalent. A diffuse pattern was observed in all phaeochromocytomas longer than 7 cm. In conclusion, Leu-M1 expression is frequent in phaeochromocytoma. However, Leu-M1 immunoreactivity seems to be useless in predicting malignant behaviour and to be influenced mainly by tumour size.

Adrenal Gland Neoplasms↗
PubMed1995

[C-erbB-2 protein in ovarian epithelial cancer: correlation between expression in tumor tissue and blood levels].

BACKGROUND: Among 20 to 30% of the patients with ovarian cancer present overexpression of the c-erbB protein in the tumor tissue although its clinical significance has not been clearly established. In patients with a disseminated neoplasm and overexpression of c-erbB an increase in the extracellular portion of this protein may be detected in serum. The aim of this study was to determine the c-erbB protein in serum and in tumoral tissue in patients diagnosed with ovarian epithelial carcinoma. METHODS: The serum concentration of the c-erbB protein was quantified by ELISA techniques in 60 blood donor women (control group) and in 99 patients with ovarian cancer. Likewise, the expression of the c-erbB protein was determined in tumoral tissue by immunohistochemical techniques in the 99 patients with ovarian cancer. The correlation between overexpression and elevated serum values was analyzed. RESULTS: The mean c-erbB values obtained in the serum of the control group was 10.9 U/ml (SD: 2.8) with a range of 1.5-17.0. Serum determination was carried out in absence of the tumor in 49 patients being positive in 2 cases. In 7 patients the determination was performed in the presence of peritoneal implants of a diameter of less than 2 cm with none being positive. Serum determination was carried out in 43 patients in the presence of implants greater than 2 cm and 14 (32.5%) were positive. A further 153 determinations were performed during follow up of the 99 patients, 62 in tumor absence (3.2% positive), 2 in the presence of a tumor of less than 2 cm (none positive) and 89 in the presence of a tumor greater than 2 cm (34.8% positive). A correlation was found between elevated c-erbB serum values in the presence of a disseminated tumors and overexpression of tumoral tissue (p: 0.0011). CONCLUSIONS: A third of the patients with ovarian cancer and peritoneal implants of a diameter greater than 2 cm present elevated serum levels of the c-erbB.2 protein. A correlation was found between serum c-erbB positivity and overexpression of the protein in tumoral tissue.

Carcinoma↗
PubMed1995

Overexpression of c-erbB-2 in epithelial ovarian cancer. Prognostic value and relationship with response to chemotherapy.

BACKGROUND: Overexpression of the c-erbB-2 protein has been reported in tumors from approximately 25% of patients with epithelial ovarian cancer. However, its clinical significance has not been well established. METHODS: Overexpression of the c-erbB-2 protein was studied by immunohistochemistry in paraffin-embedded tumor tissue from 106 patients with ovarian cancer. RESULTS: Tumors from 23 patients (21.7%) had c-erbB-2 overexpression. The percentage of tumors with overexpression was higher in those with Stages III/IV disease (29.2%) compared with those with Stages I/II disease (5.9%) (P = 0.057), in patients with residual tumor greater than 2 cm after initial surgery (37.2%) compared with those with tumor less than 2 cm (9.5%) (P = 0.01), and in patients who failed to respond to chemotherapy with carboplatin and cyclophosphamide (75%) compared with those who responded (18.6%) (P = 0.0043). No correlation was found between c-erbB-2 expression with age, the degree of differentiation, or the histologic subtype. Median survival of the 23 patients with protein overexpression was 62 weeks, whereas 75% of the 83 patients without overexpression were alive at 123 weeks (P = 0.0000). Of the patients with advanced stage disease (III/IV), survival was also lower in those presenting with overexpression (60 weeks) compared with those without expression (75% alive at 93 weeks) (P = 0.0000). Multivariate analysis of possible prognostic factors showed that c-erbB-2 overexpression and residual tumor greater than 2 cm resulted in a worsening of survival rates. CONCLUSION: c-erbB-2 overexpression in tumors from patients with ovarian cancer resulted in a poorer prognosis than for patients whose tumors did not have overexpression.

Adult↗
PubMed1994

Right subclavian artery aneurysm and coarctation of the aorta.

A patient, diagnosed with coarctation of the aorta at the age of 59, was found to have a pulmonary mass in his right upper lobe. A chest scan and digital intravenous arteriography revealed a right artery subclavian aneurysm. Such an unusual association is described.

Aneurysm↗
PubMed1993

Adenocarcinoma in Caroli's disease treated by liver transplantation.

Caroli's disease is characterized by congenital cystic dilatation of the intrahepatic bile ducts. In 7% of cases a malignant tumor develops complicating the course of the disease. We report the case of a 25 year-old woman in whom Caroli's disease was diagnosed at the age of 11. From that time on, she had several episodes of cholangitis. In 1989, the abdominal ultrasound and CT scan showed dilatation of the intrahepatic bile ducts, intracystic lithiasis and a solid mass. FNA cytology showed a papillary adenocarcinoma. At laparotomy a tumor was found occupying both hepatic lobes, and intraoperative US showed another two nodules in the left lobe. The tumor was considered unresectable. Examination of the hilar lymph nodes was tumor-negative. Two weeks later, the patient underwent an orthotopic liver transplantation (OLT). The pathological examination confirmed Caroli's disease with adenocarcinoma. Two years after OLT, the patient is alive with normal liver function and no evidence of disease. To our knowledge this is the first case report of adenocarcinoma in Caroli's disease treated by OLT.

Adenocarcinoma, Papillary↗
PubMed1992

Cirrhotic changes in livers from children undergoing transplantation. Image analysis.

The pattern and extent of disorganization of the liver architecture were studied in 25 children undergoing orthotopic liver transplantation for cirrhosis. Image analysis techniques based on mathematical morphology were used to define seven parameters for each case, including fibrosis index (percentage of Sirius-red-stained areas), three categories of regenerative nodules (< 0.8, 0.8-1.6 and > 1.6 mm in diameter) and three categories of fibrous septa (< 0.4, 0.4-1.2 and > 1.2 mm in width). Fibrosis index ranged from 10.2% to 51.9%. Percentage of small nodules of infralobular size (< 0.8 mm in diameter) varied from 31.4% to 98.2%. Percentage of large nodules, > 1.6 mm in diameter, in only four cases was > 15%. Multivariate clustering analysis classified the cases into three main groups. One of them included only cases of cirrhosis secondary to parenchymal disease or to inborn errors of metabolism. In their pattern, tiny nodules predominated, and the percentage of slender septa, < 0.4 mm in diameter, was very high, although the overall fibrosis index was relatively low. Patients with biliary cirrhosis were classified into two groups. In one the fibrosis index was low and the size of the nodules variable, with 12% large nodules. In the other the fibrosis index was high, and small nodules, < 0.8 mm in diameter, predominated. No relationship was found with age at transplantation or previous portoenterostomy. A presumptive explanation for this divergent evolution might be the occurrence of cholangitic episodes. Overall fibrosis that the liver can sustain without failure is apparently limited.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Mathematical morphologic analysis of liver cirrhosis. Correlation with etiology, clinical score and hepatocellular carcinoma.

Remodeling of the cirrhotic liver was studied retrospectively by mathematical morphologic methods in 75 autopsy cases (40 alcoholic, 17 hepatitis B virus (HBV)-related and 18 cryptogenetic cirrhosis), including 28 hepatocellular carcinomas. The aim was to obtain objective measurements of cirrhotic patterns that could be correlated with liver function evaluated by the Pugh-Child score, establish the relationship among different morphogenetic features and evaluate the implications of an objective classification of cases by numerical taxonomy in terms of their etiology, liver function and malignant transformation. The results indicate that the Pugh-Child score was closely related to the global amount of fibrosis or to the percentage of regenerative nodules < 0.8 mm in diameter. In contrast, the higher the percentage of lobular-sized regenerative nodules (0.8-1.6 mm), the better the functional score, suggesting that they are probably residual lobules, albeit completely surrounded by fibrous tissue, rather than true regenerative pseudolobules. The four groups of cases obtained by numerical taxonomy (cluster analysis) showed different distributions for alcoholic and HBV-related cirrhosis. The pattern of the latter was practically analogous to that in classically labeled cryptogenetic cirrhosis, suggesting its viral etiology. Taxonomic classification had functional implications. The Pugh-Child score showed a definite relationship with the different clusters obtained. The incidence of malignant transformation gradually decreased from group G1 to G4, with a steeper descent between G2 and G3. These results might contribute to a more dynamic concept of morphologic changes in liver biopsies from patients with cirrhosis.

Adult↗
PubMed1990

[Megadosage of 6-methylprednisolone in systemic vasculitis with renal involvement. A prospective study].

A prospective, open and uncontrolled study of effectiveness and side effects of intravenous 6-methylprednisolone megadoses was carried out in 20 patients with systemic vasculitis with rapidly progressive renal failure. The results showed a favorable response of renal function in 80% of patients and a control of pulmonary hemorrhage in the patients in which it was present. Oliguria and the need for hemodialysis during the acute phase of the disease significantly reduced the response to treatment. Extracapillary proliferation in more than 80% of glomeruli resulted in a lesser degree of recovery of renal function. Severe side effects developed in 2 patients (10%), but they could be exclusively attributed to the 6-methylprednisolone megadose in 1 (5%). It was concluded that 6-methylprednisolone megadoses may be an effective therapeutic alternative for the treatment of these patients.

Biopsy↗
PubMed1990

[Secondary amyloidosis and rapidly progressing renal insufficiency. A clinico-pathologic study].

In the present study, 7 patients with secondary amyloidosis and renal involvement who developed rapidly progressive deterioration of renal function are reported. After the investigation of the possibly implicated clinicopathological factors a cause was found for 3 patients. In the remaining 4 patients, the rapid evolution to end stage renal disease was attributable to the rapid progression of amyloid deposits by itself. A correlation between the evolution of renal function, vascular amyloid deposits and interstitial fibrosis is reported.

Aged↗