PubMed Health⌕ Search

Biomedical subjects

F Sanchez

Publications and source records attributed to F Sanchez.

At least 73 records · Page 4Linked to original sources
PubMed1986

Differential diagnosis between follicular adenoma and follicular carcinoma of the thyroid by marker features.

Morphometric features descriptive of nuclear morphology, nuclear chromatin texture and nuclear staining density were studied in tissues from encapsulated follicular carcinoma and follicular adenoma of the thyroid, whose differentiation is one of the most difficult tasks in thyroid pathology. Measurements were made on nuclei in both tumorous and normal-appearing areas in the same section from six patients with each diagnosis, as well as on nuclei in sections from six normal individuals. The average nuclear optical density (OD) was significantly lower in the follicular carcinomas than in the follicular adenomas while the nuclear area was significantly increased in the carcinomas. The variance of the nuclear OD values was higher in both tumor and normal-appearing areas in the sections from the follicular adenomas than in the follicular carcinomas; this variance was lowest in tumor areas from the follicular carcinomas. There were also significant differences in another chromatin feature (the average difference in OD values between adjacent pixels) between nuclei from follicular carcinomas and those from follicular adenomas, whether comparing measurements between the tumor areas or between the histologically normal-appearing areas of the sections. These results suggest that the high-resolution study of marker features, such as nuclear chromatin and staining density, may help in the differentiation between follicular adenoma and encapsulated follicular carcinoma of the thyroid.

Adenocarcinoma↗
PubMed1985

Computed tomography evaluation of pheochromocytoma in pregnancy.

Two cases representative of the spectrum of the problem of pheochromocytoma in pregnancy are presented. One patient was typical of many cases of pheochromocytoma not diagnosed until delivery, with resultant maternal and fetal death. Computed tomography accurately preoperatively localized a pheochromocytoma involving the organ of Zuckerkandl in the second patient, with subsequent uncomplicated removal of the tumor during a cesarean delivery. A discussion of pheochromocytomas in pregnancy and the relative risk and benefits of preoperative localization with computed tomography are presented.

Adrenal Gland Neoplasms↗
PubMed1983

In vitro transcription of Drosophila actin and 70,000-dalton heat shock protein genes.

Drosophila genomic DNAs containing a chromosomal locus 87C1 70,000-dalton heat shock protein gene, the locus 79B actin gene, and the 88F actin gene have been used as templates in an in vitro HeLa transcription system. RNA polymerase II-dependent transcription initiates from specific sites on the heat shock protein gene and the 79B actin gene. The locations of the transcription start sites were determined by two types of experiments: sizing of RNA runoff transcripts and S1 nuclease mapping of the 5' terminus of the in vitro transcripts. Transcription initiates at or near the in vivo initiation site of the heat shock protein gene and initiates at or near a site 14 nucleotides downstream of the in vivo start site of the 79B actin gene. The addition of the 79B actin, 88F actin, or heat shock protein templates to a HeLa extract transcription reaction precluded the transcription of a second template subsequently added. The exclusion occurs rapidly, within 15 s, is not dependent on transcription, and is only partially resistant to high concentrations of the second added template. We propose that stable protein-promoter complexes play an important role in maintaining exclusive transcription of the first template added in vitro.

Actins↗
PubMed1983

Two Drosophila actin genes in detail. Gene structure, protein structure and transcription during development.

DNA fragments representing the six Drosophila actin genes have been isolated by recombinant DNA techniques. We have compared the transcriptional characteristics of the actin genes at the cytological loci 79B and 88F. The activity of each gene in vivo was examined using gene-specific probes from transcribed, but non-translated 3' regions of each gene. The genes show similar patterns of transcriptional activity during development until the pupal stage, with two periods showing RNA accumulation at two to three hours and 12 to 15 hours during embryonic development, followed by large increases in the proportion of message from each gene in first and second instar larvae. During pupal development, the 88F gene apparently produces a larger proportion of transcripts than at any other developmental stage, while the transcripts of the 79B gene are reduced to a level lower than in first and second instar larvae. The 5' end of each messenger RNA in larvae has been mapped by nuclease S1 digestion of hybrids between restriction fragments of genes and homologous mRNAs. The two genes display widely differing capacities to serve as templates for transcription in vitro in HeLa cell extracts. The complete DNA sequences of both genes including the flanking regions immediately 3' and 5' to the gene are presented. These data permit comparison of the DNA sequences of these Drosophila actin genes with each other and with the DNA sequence and protein sequence information available for the actins of Drosophila and other organisms. These two genes share the common structural feature of an intervening sequence at amino acid 307, though the sequences within each intron differ greatly. This may be a reflection of a duplication event, followed by divergence of the intervening sequences. We discuss possible correlations between the DNA sequences of each 5' flanking region and the differences in transcriptional characteristics of these two distinct but closely related genes.

Actins↗
PubMed1982

Self-retaining ureteral stent catheters in the management of urologic complications of gynecologic malignancies.

Fifteen patients with ureteral obstruction secondary to advanced and/or recurrent gynecologic malignancies underwent endoscopic (3) or surgical transvesical (12) insertion of Gibbons (12) or Double "J" (3) stent catheters. Renal function improvement was noted in all but one patient who had renal parenchymal disease. No complication attributable to the insertion procedure was recorded. This approach to the treatment of ureteral occlusion in patients with gynecologic cancer is discussed and recommended.

Adult↗
PubMed1978

[Anastomosis between carotis externa and carotis interna circulation (indication and results) (author's transl)].

An extra-intracranial anastomosis operation was carried out in 60 stroke patients in order to bypass the occlusion or severe stenosis in the internal carotid or middle cerebral artery. Postoperative angiographical follow-up studies showed a well functioning extra-intracranial bypass in more than 90 % of the patients. In many cases repeat angiography done weeks or months following surgery revealed an enlargement of the caliber of the extracranial artery used for constructing the bypass and also of the cerebral arteries that were irrigated by the bypass. Furthermore we noted that the new collateral channel was able to fill a steadely increasing part of the cerebral circulation and that it was also found to irrigate territories of the brain that were previously well perfused by leptomeningeal anastomosis or retrograd flow through the ophthalmic artery etc. resulting in a reversal of the direction of blood flow in these collaterals. The neurological follow-up examinations revealed that the increase in cerebral blood supply following the extra-intracranial anastomosis operation resulted in a considerable improvement of the post-stroke neurological deficits.

Carotid Arteries↗
PubMed1977

Idiopathic rupture of the iliac vein.

Idiopathic rupture of large veins is very rare. There has been one report in the Portugese literature of such an instance involving the iliac vein. Our patient was an elderly woman in whom evidence of intra-abdominal hemorrhage developed. There was no clinical evidence of trauma. At laparotomy a large retroperitoneal hematoma secondary to an 8-mm tear in the left common iliac vein was found. The tear occurred adjacent to where the right common iliac artery passes over the vein. Repair was followed by uneventful recovery. Results of the pathological examination showed nonspecific information.

Aged↗
PubMed1977

[Not Available].

Explore the source record for details and available documents.

History of Pharmacy↗
PubMed1976

Clinical use of the LH-RH in assessing gonadotropic reserve in children with idiopathic precocious puberty, premature thelarche and premature adrenarche.

Serum LH and FSH were assayed in 31 girls with normal pre puberty, precocious puberty, premature thelarche, and premature adrenarche, aged 2 to 9 years. The effect of synthetic luteinizing hormone-releasing hormone (LH-RH) on serum gonadotropins was evaluated in eleven of them. In all girls with precocious puberty, serum LH was increased up to high levels. The mean releasable LH in two girls with idiopathic precocious puberty was significantly greater than in normal prepubertal or pubertal children. Basal FSH in children with precocious puberty was within the limits of normal prepuberal children, and FSH secretion in response to LH-RH was not significantly greater than in the group of normal prepubertal and pubertal girls. In children with premature thelarche and premature adrenarche, basal levels of LH and FSH, as well as gonadotropin response to LH-RH were in the prepubertal range. These preliminary results show that the LH-RH test might be of clinical value in differenitating abnormal puberal development.

Age Factors↗
PubMed1976

Inhibition of complement-dependent lymphocyte rosette formation by sera of patients with chronic glomerulonephritis.

It has been demonstrated that activated C3 products might bind to lymphocyte C3 receptors and inhibit subsequent complement-dependent lymphocyte rosette formation. Sera from patients with various types of chronic glomerulonephritis (GN) have been tested in a complement-dependent rosette inhibition assay using normal donors' lymphocytes as reacting cells. Control subjects consisted of healthy donors and patients with miscellaneous renal and general diseases. Most sera of membranoproliferative GN and of systemic lupus erythematosus, and two-thirds sera of focal glomerolosclerosis patients, significantly inhibited rosette formation. Only 15-40 percent sera of patients with other types of GN were inhibitory. Serum inhibiting activity usually correlated with low serum C3 level (P less than 0.0005), although inhibition could be observed with normal serum C3. However, no correlation was found between a patient's own complement-dependent lymphocyte rosette count and his serum inhibitory activity. These results extend previous findings and suggest that the complement-dependent rosette inhibition assay can be used routinely to detect serum activated complement components either free or bound to immune complexes.

Chronic Disease↗
PubMed1975

Myocardial ultrastructural changes during extracorporeal circulation wtih anoxic cardiac arrest and its prevention by coronary perfusion. Experimental study.

This experimental work has been carried out with the aim of studying the ultrastructural myocardial changes caused by prolonged anoxic cardiac arrest during cardiopulmonary bypass, and their prevention by means of two different techniques of coronary perfusion--systemic-pressure continuous and low-pressure intermittent perfusion. After 30 minutes of cardiac anoxia, the ultrastructural changes of the myocardial cell were reverted to normal by coronary perfusion; when anoxic cardiac arrest was prolonged up to 60 minutes there was severe myocardial damage, with marked mitochondrial changes and dehiscence of intercalated discs, which persisted in spite of restoring coronary flow. These morphological data were in accordance with the fact that no dog which underwent anoxic cardiac arrest for 60 minutes recovered. Both intermittent and continuous coronary perfusion were effective in preventing anoxic damage; cardiac muscle cells were better preserved by low-pressure intermittent perfusion than by systemic-pressure continuous perfusion, which caused intracellular and intramitochondrial oedema.

Animals↗