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Biomedical subjects

A Fernandez

Publications and source records attributed to A Fernandez.

At least 217 records · Page 12Linked to original sources
PubMed1989

Mucinous metaplasia to neoplastic lesions in endometrial samples with cytohistologic correlation.

Seven cases of endometrial mucinous metaplasia and five of well-differentiated mucinous adenocarcinoma of the endometrium were studied. Cytologic specimens were obtained by Isaacs endometrial sampler, avoiding endocervical contamination. The histologic diagnosis between the intermediate type of mucinous metaplasia and the well-differentiated mucinous adenocarcinoma posed no problems. DNA analyses of the histologic samples showed a euploid pattern in benign and intermediate types of metaplasia, while well-differentiated mucinous adenocarcinoma showed a hyperdiploid pattern. The cytologic diagnosis of benign mucinous metaplasia should be suggested in the presence of abundant mucinous cells in endometrial samples in the absence of nuclear abnormalities.

Adenocarcinoma, Mucinous↗
PubMed1989

The beta-carboline derivatives ZK 93426 and FG 7142 fail to precipitate abstinence signs in diazepam-dependent cats.

The aim of the present study was to investigate the ability of different benzodiazepine recognition site antagonists (Ro 15-1788 and ZK 93426) and inverse agonists (Ro 15-4513, FG 7142 and CGS 8216) to induce abstinence signs in diazepam-dependent cats. Different groups of cats were challenged with each of the benzodiazepine recognition site ligands under investigation 24 hours after the last dose of chronic treatment with diazepam (7 mg/kg, IP at 8.00 a.m. and 8.00 p.m. for 21 consecutive days). The benzodiazepine derivatives Ro 15-4513 and Ro 15-1788 precipitated an abstinence syndrome within minutes after IP administration. The pyrazoloquinoline derivative CGS 8216 also induced withdrawal signs that were less severe and had a longer latency than those elicited by Ro 15-4513 and Ro 15-1788. Abstinence signs included tremors, increased muscle tone, irritability, fear, arched-back posture, pupillary dilation and vocalizations. On the other hand, the beta-carboline derivatives ZK 93426 and FG 7142 failed to precipitate abstinence signs in diazepam-dependent cats when given at doses that prevented the acute effects of diazepam. Our results demonstrate that the ability to induce withdrawal signs in diazepam-dependent cats depends on the chemical structure of the challenge drug (i.e., benzodiazepine or pyrazoloquinoline), since beta-carboline antagonists like ZK 93426 and partial inverse agonists like FG 7142 lack this property.

Animals↗
PubMed1989

Modulation of vimentin containing intermediate filament distribution and phosphorylation in living fibroblasts by the cAMP-dependent protein kinase.

Microinjection of the purified catalytic subunit of the cAMP-dependent protein kinase (A-kinase) into living rat embryo fibroblasts leads to dramatic changes in vimentin intermediate filament (IF) organization, involving the collapse of the filaments into tight bundles. In some cell types, this rearrangement of the IF proceeds further, leading to an apparent loss of filament integrity, resulting in a punctate staining pattern throughout the cytoplasm. Both these types of IF rearrangement are fully reversible, and similar to structural changes previously described for IF during mitosis. As shown by electron microscopy, in rat embryo fibroblasts these changes in IF structure do not involve the loss of the 10-nM filament structure but instead correspond to the bundling together of 25 or more individual filaments. Metabolic pulse labeling of injected cells reveals that accompanying these changes in IF organization is a dramatic increase in vimentin phosphorylation which appears maximal when the IF are fully rearranged. However, this increase in IF phosphorylation is not accompanied by any significant increase in soluble vimentin. Analysis of the sites of phosphorylation on vimentin from injected cells by either V8 protease cleavage, or two-dimensional tryptic peptide mapping, revealed increased de novo phosphorylation of two vimentin phosphopeptides after microinjection of A-kinase. These data strongly suggest that the site-specific phosphorylation of vimentin by A-kinase is responsible for the dynamic changes in IF organization observed after injection of the kinase into living cells, and may be involved in similar rearrangement of the IF previously described during mitosis or after heat shock.

Animals↗
PubMed1989

A combined therapeutic protocol for aseptic nonunion of the humeral shaft: a report of 25 cases.

Twenty-five patients with aseptic nonunion of the humeral shaft, treated by a combined therapeutic procedure, are reported. The initial treatment of these 21 closed and four open fractures had been nonoperative in 21 patients and surgical in four. Seven further open procedures had been performed in four of these patients, also undergoing failure. The time period between the fracture and our treatment averaged 13 months (range, 6-46 months). A uniform therapeutic protocol, consisting of decortication, internal fixation with a broad, straight DCP ASIF plate and autologous cancellous bone grafting, was performed in all cases, supplemented with the use of surgical cement in one. Radiologic healing was achieved primarily in 24 patients in periods averaging 6 months and after renewal of the protocol in one patient. Followup averaged 35 months (range, 8-69 months): results were good in 21 patients.

Adolescent↗
PubMed1989

Demonstration of sugar residues in the ultimobranchial tubule and thyroid C-cells of the rat using peroxidase labelled lectins.

The distribution of various sugars, that contribute to the composition of the carbohydrate components of the glycoprotein in the ultimobranchial tubule and the thyroid C-cells has been studied, using eight peroxidase-labelled lectins (Dolichos biblorus, Glycine max, Bauhinia purpurea, Helix pomatia, Arachis hipogaea, Ulex europaeus I, Limax flavus and Sophora japonica). The results obtained seem to show that there are receptors for Dolichos biflorus, Glycine max, Bauhinia purpurea, Helix pomatia, Arachis hipogaea, Ulex europaeus I and Limax flavus in the ultimobranchial tubule, suggesting the existence of N-acetylgalactosamine, galactose, L-fucose and sialic acid. However, the C-cells show only a positive reaction with Ulex europaeus I indicating the existence of fucosyl residues in those cells. All these findings support the contention that the ultimobranchial body might contribute decisively not only to the formation of C-cells but also, partially, to the constitution of certain follicular cells.

Animals↗
PubMed1989

Combination of selegiline and controlled release levodopa in the treatment of fluctuations of clinical disability in parkinsonian patients.

Thirteen parkinsonians with a long duration of the disease and long-term dopa therapy, seven of them showing severe on-off oscillations and 6 an "end-of-dose impairment", were treated with a controlled release (HBS) preparation of L-DOPA/benserazide for more than 3 years. Thereafter, selegiline was added in a progressively increasing dosage up to a maximum of 10 mg/day during 4 months, with the aim of a) further improving the long-term results and b) reducing the doses of the new formula of L-DOPA. A significant decrease of early morning parkinsonism and reduction of motor disability throughout the day were observed; "wearing-off" cases showed better results compared with those presenting "on-off" oscillations. A mean reduction of 20% in the doses of levodopa was achieved. Likewise, a mild reduction of dyskinesias and a mild-moderate enhancement of dystonias were recorded. Only one patient did not tolerate selegiline and two others received lower doses due to side-effects. Selegiline was capable of enhancing the antiparkinsonian effect of the new formula of L-DOPA, while allowing a reduction of the doses administered. It must also be emphasized that such improvement was achieved in complicated patients, most of whom showed some deterioration of response in the late stages of long-term sustained-release levodopa treatment.

Adult↗
PubMed1989

Percutaneous transluminal angioplasty as best treatment in stenosis of vascular access for hemodialysis.

We show the results of treatment with percutaneous transluminal angioplasty on 38 occasions for vascular access for hemodialysis. Our study includes 22 patients with A-V internal fistulas (Cimino type), 1 autologous saphenous vein shunt and 7 synthetic polytetrafluoro-ethylene shunts. Twenty patients have had a follow-up period over 24 months. Four patients required a second and 2 of them a third transluminal dilatation. Only on two occasions were complications related to the technique. The microscopic findings of the venous wall after percutaneous transluminal angioplasty are shown.

Adult↗
PubMed1989

Alexithymic characteristics in rheumatoid arthritis: a controlled study.

Forty rheumatoid arthritis (RA) patients diagnosed by rigid criteria were evaluated for alexithymic characteristics using the Beth Israel Hospital Psychosomatic Questionnaire (BIQ) and the Toronto Alexithymia Scale (TAS). 40 healthy subjects matched with RA patients on sociodemographic variables served as controls. RA patients scored significantly higher on the BIQ and TAS compared to controls. The two scales correlated in the expected direction. Using the TAS cutoff score of 74 and above, 11 RA patients (27.5%) were identified as alexithymic. RA patients with greater functional impairment showed significantly higher alexithymia scores.

Adult↗
PubMed1989

Viral antigen distribution in the central nervous system of cattle persistently infected with bovine viral diarrhea virus.

Distribution of viral antigens in the central nervous system of 25 cattle with a persistent bovine viral diarrhea virus (BVDV) infection was studied. Using a polyclonal antiserum produced in pigs and the direct immunofluorescence and immunoperoxidase technique, BVDV antigen was located exclusively in neurons. Predilection sites for viral persistence were cerebral cortex and hippocampus; in other areas of brain and spinal cord, viral antigens were in single neurons or small groups of neurons. There was no morphological evidence of cellular alteration due to viral persistence. Perivascular lymphocytic infiltrations were in affected nervous tissue. It is concluded that the central nervous system is an important location for persistence of BVDV.

Animals↗
PubMed1988

Neonatal rat brain astroglial dipeptidyl peptidase II activity regulation by cations and anions.

Astrocytic glial cells from neonatal rat brains were grown in primary culture. Dipeptidyl peptidase II (DPP-II) enzyme activity was measured in cells disrupted by nonionic detergent. The rate of enzyme activity was measured in the presence of various ions, under isosmotic conditions adjusted using mannitol and NaCl. DPP-II activity was not affected by the candidate metal co-factors (2 mM) Co2+, Mg2+, and Mn2+, nor by the metal chelators EDTA and o-phenanthroline. However, selected cations (50 mM Cl- salts) significantly inhibited DPP-II activity compared to Na+ control; the relative inhibition ranking was Rb+ less than K+ less than Zn2+ less than Hg2+. Many test anions (50 mM Na+ salts) also inhibited DPP-II activity compared to Cl- control: SO4(2-) less than NO3- less than F- less than SO3(2-). Surprisingly, the anion S2O3(2-) was the only test agent which strongly stimulated activity. The data are consistent with the concept that specific ion species interact with the glial DPP-II enzyme to affect catalytic activity.

Animals↗
PubMed1988

Human intestinal brush border angiotensin-converting enzyme activity and its inhibition by antihypertensive Ramipril.

Angiotensin-converting enzyme (ACE) has been identified as a prominent brush border membrane-bound enzyme of human jejunum. In this study, we purified brush border membrane vesicles enriched in ACE, and characterized the ACE with regard to (a) its stability in the membrane, (b) substrate hydrolysis kinetics compared with pulmonary endothelial ACE, and (c) pharmacologic interaction with Ramipril. These investigations resulted in the following findings. The uninhibited enzyme is stable in native membranes in vitro, with a half-life of 195 +/- 7 h. Kinetic analysis of ACE hydrolysis activity revealed the presence of a single enzyme species, which yielded a high Vmax and displayed a Km similar to purified ACE from lung endothelium. Brush border ACE was inhibited by Ramipril, one of the most specific and potent orally administered ACE inhibitors indicated for hypertension. We determined the brush border ACE value of IC50 = 3 X 10(-9) M Ramipril-diacid, which is the same value for serum and lung ACE. Brush border ACE remains 100% inhibited by 10 microM Ramipril during at least 8 days in vitro. The data indicate that ACE is a prominent jejunal brush border enzyme that behaves pharmacologically and kinetically like its peripheral circulation counterpart. This study suggests that high doses of orally administered ACE inhibitors may affect intestinal epithelial function.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1988

Ramipril inhibition of rabbit (Oryctolagus cuniculus) small intestinal brush border membrane angiotensin converting enzyme.

1. Rabbit small intestinal brush border membranes possessed prominent angiotensin converting enzyme (ACE) activity. 2. Intestinal ACE was located on the lumen surface, as verified by ACE co-enrichment with brush border membrane marker enzymes. 3. Hydrolysis kinetics of rabbit intestinal ACE were comparable to the lung, utilizing the substrate (N-[3-(2-furyl)acryloyl]-L-phenylalanylglycylglycine; the Vmax = 543 +/- 51 mumol/min/g and Km = 0.62 +/- 0.09 mmol/l. 4. Intestinal brush border ACE activity was strongly inhibited by the antihypertensive drug Ramipril, which yielded an IC50 value of 5 nmol/l; the ACE activity remained completely inhibited during 15 days after a single dose of 10 mumol/l Ramipril.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1988

Lymphorrhea as postoperative complication of living donor nephrectomy: a case report.

We report a case of lymphorrhea after living donor nephrectomy. Clinically the donor presented with an increased flow of a liquid characteristic of lymph, which was treated successfully with iodinated povidone. The possible pathogenic mechanisms implicated in the development of lymphocele following renal transplantation are discussed.

Drainage↗
PubMed1988

Evidence for auditory temporal distinctiveness: modality effects in order and frequency judgments.

Two new, long-lasting phenomena involving modality of stimulus presentation are documented. In one series of experiments we investigated effects of modality of presentation on order judgments. Order judgments for auditory words were more accurate than order judgments for visual words at both the beginning and the end of lists, and the auditory advantage increased with the temporal separation of the successive items. A second series of experiments investigated effects of modality on estimates of presentation frequency. Frequency estimates of repeated auditory words exceeded frequency estimates of repeated visual words. The auditory advantage increased with frequency of presentation, and this advantage was not affected by the retention interval. These various effects were taken as support for a temporal coding assumption, that auditory presentation produces a more accurate encoding of time of presentation than does visual presentation.

Adult↗
PubMed1988

Regulation of actin microfilament integrity in living nonmuscle cells by the cAMP-dependent protein kinase and the myosin light chain kinase.

Microinjection of the catalytic subunit of cAMP-dependent protein kinase (A-kinase) into living fibroblasts or the treatment of these cells with agents that elevate the intracellular cAMP level caused marked alterations in cell morphology including a rounded phenotype and a complete loss of actin microfilament bundles. These effects were transient and fully reversible. Two-dimensional gel electrophoresis was used to analyze the changes in phosphoproteins from cells injected with A-kinase. These experiments showed that accompanying the disassembly of actin microfilaments, phosphorylation of myosin light chain kinase (MLCK) increased and concomitantly, the phosphorylation of myosin P-light chain decreased. Moreover, inhibiting MLCK activity via microinjection of affinity-purified antibodies specific to native MLCK caused a complete loss of microfilament bundle integrity and a decrease in myosin P-light chain phosphorylation, similar to that seen after injection of A-kinase. These data support the idea that A-kinase may regulate microfilament integrity through the phosphorylation and inhibition of MLCK activity in nonmuscle cells.

Actin Cytoskeleton↗