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L Roque

Publications and source records attributed to L Roque.

31 records · Page 2Linked to original sources
PubMed1996

Malignant salivary gland neoplasms: a cytogenetic study of 19 cases.

A group of 19 malignant salivary gland neoplasms of various histological types (mucoepidermoid carcinoma, acinic cell carcinoma, adenoid cystic carcinoma, epithelial-myoepithelial carcinoma, myoepithelial carcinoma, basal cell adenocarcinoma, carcinoma ex-pleomorphic adenoma, ductal carcinoma, adenocarcinoma not otherwise specified and undifferentiated carcinoma) were cytogenetically investigated. Previous karyotypic information revealed deletion of the long arm of chromosome 6, loss of chromosome Y and the gain of chromosome 8 as the most recurrent deviations found in these neoplasms. Clonal chromosome aberrations were detected in 11 cases of this series. In 7 of them there were only numerical deviations (gain of chromosomes 2, 7, 8, 10 and X and loss of chromosomes 18, 21 and Y) without concomitant structural anomalies. Structural rearrangements such as t(2;7), t(6;16), t(6;9) and t(1;1) translocations were found in two mucoepidermoid carcinomas, one adenoid cystic carcinoma and one ductal carcinoma, respectively. The wide spectrum of changes found in this group of neoplasms may reflect the diversity in their histogenesis and differentiation phenotypes.

Adolescent↗
PubMed1995

Cytogenetic findings in 31 papillary thyroid carcinomas.

Chromosome studies performed on 31 papillary thyroid carcinomas (PTCs) revealed clonal numerical and structural abnormalities in 12 tumors. The numerical clonal aberrations found were trisomy 2, trisomy 7, and loss of the Y chromosome. A nonrandom telomeric association, tas(15;16)(p13;p13), was observed in one carcinoma. Structural alterations with a breakpoint at 10q11.2 were detected in two tumors. Other chromosomes involved in rearrangements were chromosomes 1, 2, 3, 5, 7, 9, 11, 12, and 14. The observation of clonal changes of chromosome 2 [i(2)(q10) and trisomy 2] in two tumors, which were both histologically classified as tall-cell PTC variants, suggests that gain of 2q may be important in the development of this morphological variant.

Adolescent↗
PubMed1995

Benign salivary gland tumors: a cytogenetic study of 21 cases.

Cytogenic findings of 21 benign salivary gland tumors, including 14 pleomorphic adenomas, 5 Warthin's tumors, 1 myoepithelioma, and 1 cystadenoma, are reported. The present study confirms that pleomorphic adenomas characteristically have highly specific rearrangements involving only a few chromosome regions (3p21, 8q12 and 12q13-15) which suggests their specific role in the mixed tumor genesis. Warthin's tumors also show non-random numerical and structural alterations that were concurrent in one of the cases studied. To our knowledge no cytogenetic data are available in myoepitheliomas and cystadenomas. The former reveals a normal karyotype and the latter shows only clonal numerical alterations (gain of chromosomes 2 and 18).

Adenolymphoma↗
PubMed1994

Amplification of chromosome subregion 12p11.2-p12.1 in a metastasis of an i(12p)-negative seminoma: relationship to tumor progression?

Cytogenetic analysis of a metastasis of a human testicular germ cell tumor (seminoma) revealed multiple numerical and structural anomalies, including an abnormally banding region (ABR) present on the short arm of one of the chromosome 12 homologs. Fluorescence in situ- and comparative genomic hybridization experiments revealed that the ABR results from the amplification of 12p11.2-p12.1 derived sequences. We speculate that this particular region may harbor gene(s) relevant for testicular germ cell tumor progression.

Adult↗
PubMed1994

Calcitonin-producing insulinoma: clinical, immunocytochemical and cytogenetical study.

The case of a patient with a large goitre associated with hypercalcitoninaemia and fasting hypoglycaemia is reported. Pentagastrin (PG) test was negative. Repeated measurements of fasting glycaemia, insulin and C peptide established the diagnosis of insulinoma. After localization by endoscopic ultrasonography, a distal pancreatectomy was performed and a small insulinoma was recovered. Glycaemia and calcitonin (CT) became normal. The tumour cells displayed a strong immunoreactivity for insulin and CT. Cytogenetical evaluation of the tumour revealed a translocation t(1;9) (p13;p22).

Aged↗
PubMed1994

Effects of eggshell quality and broiler breeder age on hatchability.

The effects of eggshell quality and breeder age were assessed on egg weight loss during incubation, fertility, hatchability, and embryonic mortality. The trials involved hatching eggs from three commercial broiler breeder flocks of the same strain but of different ages. The eggs were divided according to specific gravity into two groups, thin-shelled (< or = 1.080) and thick-shelled (> 1.080). Thin-shelled eggs displayed a greater increase in weight with breeder age and greater weight loss during incubation. Thick-shelled eggs showed an increased hatchability as a result of greater fertility and lower intermediate and late embryonic mortalities. Percentage of culls, pips, and rots were not related to shell thickness. Eggs from the younger flock had a higher weight loss during incubation irrespective of shell thickness. Hatchability and viability (hatchability of fertile eggs) were lower in the younger flock due to increased early and late embryonic mortalities. Fertility, culls, and pips were not affected by breeder age. The data may indicate the extent to which recent innovations in breeder management and in incubation technology have changed patterns of fertility and embryonic mortality.

Age Factors↗
PubMed1993

Deletion of 3p25-->pter in a primary follicular thyroid carcinoma and its metastasis.

We report the cytogenetic analysis of a follicular thyroid carcinoma and its bone metastasis. Both lesions had identical chromosomal abnormalities, with a der(3)t(2;3)(q13;p25) as the most likely primary clonal alteration. Our findings corroborate previous observations of frequent 3p deletions in thyroid follicular carcinomas and suggest that the minimal chromosomal region of loss in these tumors is 3p25-->pter.

Adenocarcinoma, Follicular↗
PubMed1993

Cytogenetic findings in 18 follicular thyroid adenomas.

Cytogenetic study of 18 follicular thyroid adenomas showed clonal chromosome changes in 12 tumors. These results suggest the existence of at least three cytogenetically distinct subgroups: a hyperploid group characterized by the presence of a cluster of numerical changes including +5, +7, and +12 as the most frequent anomalies and, less frequently, +4, +9, +14, +16, and +17; a pseudo- or near-diploid group characterized by simple karyotypic aberrations; and a cytogenetically normal group.

Adenoma↗
PubMed1993

Thyroid nodular hyperplasia: chromosomal studies in 14 cases.

Cytogenetic study of 14 thyroid nodular hyperplasias revealed a hyperdiploid karyotype in two cases (14%) and a normal chromosomal complement in the remaining cases. Some of the numerical alterations found were identical to the ones considered characteristic of a subset of thyroid adenomas (+5, +7, +9, +12, +14, and +16). Our findings suggest that the cytogenetic events involved in the pathogenesis of thyroid hyperplastic lesions and benign tumors may be closely related, which supports the hypothesis of a biologic "continuum" between these two types of lesions.

Adult↗