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Biomedical subjects

A Queizán

Publications and source records attributed to A Queizán.

15 recordsLinked to original sources
PubMed1997

Mutational analysis of the p16 gene in human neuroblastomas.

Neuroblastoma is one of the most frequent tumors in infancy. We analyzed 26 neuroblastomas, two ganglioneuromas, and a neuroblastoma metastasis for mutations and homozygous deletions of the p16 (or MTS1 or CDKN2) gene by means of the polymerase chain reaction (PCR) in combination with the single-strand conformation polymorphism (SSCP) technique and by multiplex PCR analysis. We detected mobility shifts in the SSCP gels in seven cases in the 3 half of exon 2 (named exon 2C) of the p16 gene. By PCR amplification of this particular region and SacII restriction enzyme digestion, we confirmed that those cases had a known polymorphism at codon 140 of the p16 gene. Neither mutations nor homozygous deletions were detected. Our results confirm those of Beltinger et al. (Cancer Res 55:2053-2055, 1995), which showed no p16 mutations or homozygous deletions in 18 primary neuroblastomas and nine tumor-derived cell lines. We conclude that the common pattern of p16 inactivation by homozygous deletion or mutation does not seem to be relevant to the development of neuroblastomas.

Carrier Proteins↗
PubMed1997

[Adrenocortical tumors in children].

Adrenocortical tumors are uncommon in childhood. The incidence of these tumors is about 0.3-0.4% of all the solid tumors in childhood. Because of its low incidence, there are no established protocols or uniform histological classification. Most of these endocrine tumors are hormone producing, causing virilization, Cushing's syndrome, feminization, hiperaldosteronism or hipoglicemy. Only a few of these do not produce hormones. The treatment is always surgical. The efficacy of another treatments (chemotherapy or radiotherapy) has not been demonstrated in infancy. It prognosis depends on the age and the resectability.

Adrenal Cortex Neoplasms↗
PubMed1995

[Sensibility and specificity of N-myc oncogene with respect to other prognostic factors in 15 neuroblastomas].

Several biologic features of tumor cells correlate closely with a favorable or unfavorable outcome. To aid in assessing correlation in the various number of prognostic factors including the age, stage, VMA/HVA ratios, and the serum levels of NSE and ferritin, the histopathological features, ploidy, partial monosomy for the short arm of chromosome 1, and the tumor N-myc gene copy number, are examined. We determined the sensitivity and specificity of classical markers above the amplification of the N-myc oncogene. A striking new observation is the positive correlation between genomic amplification and some prognostic factors (stage, ferritin, NSE, pathologic anatomy and 1p deletion.

Brain↗
PubMed1994

No TP53 mutations in neuroblastomas detected by PCR-SSCP analysis.

We have analysed 29 neuroblastomas for TP53 mutations in exons 5 to 8 by means of the polymerase chain reaction in combination with the single-strand conformation polymorphism technique. We could not detect any mutation. These results indicate that, in contrast to the majority of tumors so far studied, TP53 mutations do not seem to be important for the development of neuroblastomas.

DNA, Neoplasm↗
PubMed1994

[Early or late orchidopexy? An evaluation of germ cell proliferation by PCNA immune expression].

A immunocytochemical study for detection of proliferating cell nuclear antigen (PCNA) in order to quantify the number of PCNA-positive spermatogonia, and cytophotometric determination of spermatogonial DNA were performed in cryptorchid and control testes. The number of PCNA-positive spermatogonia, and the average DNA content of spermatogonia in the cryptorchid testes were altered from first years of age. These precocious spermatogonial alterations suggest that the early surgical testicular descent doesn't prevent lesions of germ cells.

Aging↗
PubMed1993

Cytophotometric DNA quantification in human spermatogonia of cryptorchid testes.

The DNA content of spermatogonia was studied by cytophotometric quantification in the testes of cryptorchid children and adults, as well as in age-matched control males. In most cases, the average DNA content of spermatogonia was significantly increased in the cryptorchid testes of children with uni- or bilateral cryptorchidism, as well as in the contralateral scrotal testes of children with unilateral cryptorchidism. In the group of adult men the average DNA content of spermatogonia in the testes was even more increased than in children. There were not significant differences between 4 and 14 years of age, between unilateral and bilateral cryptorchidism, or between cryptorchid testes and contralateral normally descended testes. The DNA content of spermatogonia in the surgically descended testes of 3 children who were re-biopsied 3-4 years after orchidopexy was similar before and after orchidopexy. These findings suggest that the spermatogonia of many cryptorchid males bear a congenital lesion.

Adolescent↗
PubMed1990

[Surgical treatment of differentiated carcinoma of the thyroid. Retrospective study].

This is a review of the surgical treatment in six patients with papillary carcinoma of the thyroid. The mean age at the time of diagnosis was eight years (range four-twelve years). Clinical presentation was: all patients had a palpable thyroid tumor, palpable lymph nodes in four and one with lung metastases. The initial surgical treatment was lobectomy and modified regional lymph nodes resection. Four patients underwent a second operation for multifocal disease, palpable lymph node or thyroid tumor. The interval from initial surgical management to the detection of recurrence ranging from one month to four years. In three patients the remaining thyroid gland was removed. Radioiodine, external irradiation and chemotherapy were given during the postoperative. The median follow-up was eight years (range one-fifteen years). All patients are alive with thyroid hormone therapy by hypothyroidism. There were no hypoparathyroidism or injuries to the recurrent laryngeal nerve. The results of this study suggest that the surgical approach in papillary carcinoma of the thyroid is total thyroidectomy because reoperation were performed in four patients.

Antineoplastic Agents↗
PubMed1986

[Digestive system duplications].

Fifteen digestive duplications, corresponding to fourteen patients, have been surgically treated in "La Paz" Pediatric Hospital between 1966 and 1984. The most common localization (40%) was the large bowel. The first choice treatment was the complete excision of lesions, with led to cure of all patients. Embryologic theories and clinical forms are also reviewed.

Esophagus↗
PubMed1985

Histologic lesions in undescended ectopic obstructed testes.

Testicular biopsies and hormone studies have been carried out on 229 children with unilateral (181) or bilateral (48) undescended ectopic obstructed testes not associated with other pathologic conditions. With regard to the histologic lesions, the obstructed testes may be classified into four types: (1) testes with minimal lesions (40.1%), showing slight reduction in both mean tubular diameter (MTD) and tubular fertility index (TFI); (2) testes with marked germinal hypoplasia (33.6%), showing slight or marked reduction in MTD and marked reduction in TFI; (3) testes with diffuse tubular hypoplasia (19.1%), showing severe reduction in MTD, marked or severe germinal hypoplasia, and normal or decreased Sertoli cell number per transverse tubular section (SCI); and (4) testes with Sertoli cell hyperplasia (7.2%), showing slightly decreased MTD, marked or severe germinal hypoplasia, and marked increased in SCI. These lesions are similar to those found in cryptorchid testes, although the proportion of testes with type III and IV lesions (the most severe) is lower than in cryptorchid testes. Hormone assays revealed normal basal gonadotropin and testosterone levels. The response of gonadotropins to gonadotropin-releasing hormone stimulation and the response of testosterone to human chorionic gonadotropin stimulation were normal or slightly reduced.

Child↗
PubMed1980

[Tolazoline in postoperative period of diaphragmatic hernia (author's transl)].

During the last ten year period, 78 newborns with congenital diaphragmatic hernia were seen at the Clinica Infantil "La Paz", Madrid. Twenty seven cases died immediately after delivery and 51 were operated. Necropsy findings showed pulmonary hypoplasia and patent ductus arteriosus. Mortality rate in operated cases was 29%. It seems that pulmonary hypoplasia increases pulmonary vascular resistance resulting in a state of fetal circulation with right-to-left shunting through ductus arteriosus. In these cases right to left shunt with umbilical and temporal artery catheters measuring pre and postductal pO2 must be demonstrated. Authors show their experience with two cases of newborns with Bockdalek hernia treated with tolazoline in postoperative period. Both survived.

Hernia, Diaphragmatic↗
PubMed1979

[Hiatal hernia following T.E.F. repair (author's transl)].

Hiatal hernia and/or gastroesophageal reflux are studied in 182 pediatric patients after surgical correction of esophageal atresia. Clinical and radiological aspects, along with postoperative complications, are reviewed. Special stress is given to late stenosis that does not cure with conventional treatment and are originated by undiagnosed reflux. Hiatal disfunction screening is proposed in following up patients of esophageal atresia in avoidance of disphagic and aspirative complications.

Esophageal Atresia↗
PubMed1976

[Tumors of the endodermal sinus (author's transl)].

Seven cases of tumors of the endodermal sinus are reviewed. This is a highly malignant germinal tumor, arisen from extraembrionary cell differentiation. It is different both biologically and pathologically from sacrocoxigeal teratoma. There are no survivors in these series. All seven patients have been surgically treated chemotherapy has been used in four, and X-ray therapy in two. It is noteworthy that alpha-phetoprotein is present in patients with this type of tumor. This fact can be used both in diagnosis of the tumor and of its recurrence.

Adenoma↗
PubMedDate not supplied

[Neonatal gastric perforation (author's transl)].

Three cases of neonatal gastric perforation of unknown etiology are presented. All three patients are female, one of them a second twin and two of them less than 2,000 g. in weight. All the patients were born under anoxic deliveries and needed resuscitative treatment. Digestive and respiratory symptoms started in all between the 2nd and the 4th days of life. Diagnosis, clinically suspected, is established radiologically. Perforations were surgically closed in all three patients. Two remain alive.

Female↗