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Biomedical subjects

A Garcia

Publications and source records attributed to A Garcia.

At least 307 records · Page 17Linked to original sources
PubMed1987

Improving Falope-Ring application in laparoscopy training.

Laparoscopic Falope-Ring sterilization was performed by residents on 71 women. Immediately following application of the ring, methylene blue was injected through the cervix to assess tubal patency. Unilateral spillage of the dye was demonstrated in four patients (5.6%). In these instances a new ring was applied, or the tube was tied surgically. The high rate of tubal patency was attributed to the surgeons' inexperience. The findings suggest that the use of a patency test as an adjunct to sterilization with the Falope-Ring in training programs is likely to decrease the rate of surgical failures.

Fallopian Tube Patency Tests↗
PubMed1987

[Tooth grafts in the dog: effect at mid-term of preservation of the periodontal ligament on root and alveolar remnants].

This work was undertaken to study at middle term (5 months) the behaviour of radicular grafts implanted in newly formed sockets. In some of the grafts, the remnants of the periodontal membrane were carefully preserved in a wet medium while in the others the root surface was curetted and dried. Preservation of the periodontal tissues allowed the organization of a periodontal space. This new periodontal ligament was occasionally functional with fibres in continuity from cementum to bone. Generally it was not functional with the fibres laying parallel to cementum and bone surfaces. Early "surface resorption" of the root was prevented as well as ankylosis leading to replacement of root with bone. The extent of ankylosis was reduced. It was localized to the buccal and lingual aspects of the roots where the periodontal ligament was disorganized during the extraction procedure. In the non preserved roots, ankylosis was almost total. Roots were in part replaced with bone. At 5 months, this process was still in progress.

Alveolar Process↗
PubMed1987

Maternal serum levels of estradiol, progesterone and human chorionic gonadotropin in ectopic pregnancy and their correlation with endometrial histologic findings.

Plasma levels of estradiol 17-beta (E2), progesterone (P) and beta-human chorionic gonadotropin (b-HCG) were measured in 59 patients with ectopic pregnancy and in control patients made up of ten women with normal intrauterine pregnancies and five patients with threatened abortion. The gestational ages of the three groups were not statistically different, the means being 6.6, 6.5 and 6.7 weeks, respectively. The endometria in the patients with an ectopic pregnancy were examined histologically and the correlation with the hormonal levels was studied. Mean levels of b-HCG, E2 and P in patients with ectopic pregnancies (4,893 +/- 5,435 S.E.M. milli-international units per milliliter, 311 +/- 191 S.E.M. picograms per milliliter and 8.3 +/- 5.5 S.E.M. nanograms per milliliters, respectively) were significantly lower than those measured in normal pregnant control patients (b-HCG = 22,173 +/- 2,696 S.E.M. microunits per milliliter, p less than 0.00001; E2 = 769 +/- 81 S.E.M. picograms per milliliter, p less than 0.0001 and p = 37.8 +/- 6.1 S.E.M. nanograms per milliliter, p less than 0.0001), and in patients with threatened abortion (b-HCG = 20,310 +/- 1,688 S.E.M. milli-international units per milliliter, p less than 0.0001; E2 = 803 +/- 91 S.E.M. picograms per milliliter, p less than 0.001 and P = 29.7 +/- 2.9 S.E.M. nanograms per milliliter, p less than 0.001). Mean levels of P in ectopic pregnancies with secretory type endometria (10.4 +/- 6.0 S.E.M. nanograms per milliliter), were significantly higher than those with proliferative endometria (5.0 +/- 3.2 S.E.M. nanograms per milliliter, p less than 0.001). Data is provided not previously known, on the levels of E2 and P in ectopic pregnancy and correlation with endometrial histologic factors.

Chorionic Gonadotropin↗
PubMed1986

A human villin cDNA clone to investigate the differentiation of intestinal and kidney cells in vivo and in culture.

Villin, a Ca2+-regulated actin-binding protein is a major component of microvilli of intestinal epithelial cells and kidney proximal tubule cells. Villin expression during assembly of the brush border can be investigated using a human colon adenocarcinoma cell line HT29-18. This cell line is able to differentiate under nutritional control and develops an enterocyte-like phenotype. A cDNA library from a subclone HT29-18-C1 was constructed in an expression vector and a cDNA specific for human villin was isolated. This cDNA codes for the 110 carboxy-terminal residues of villin. Within that region, the 76 carboxy-terminal residues present 65% homology with the chicken villin 'head piece'. We show that two mRNA species 4.0 kb and 3.2 kb long hybridize with this cDNA probe in humans, whereas in rat and chicken only one mRNA species can be detected. The two villin mRNA species are co-expressed in normal human small and large intestinal mucosa and tumoral HT29-18 cells as well as in normal kidney. No villin mRNAs were detected in other normal or malignant epithelial cell types. Finally, we observed an accumulation of the two mRNA species coding for villin when HT29-18 cells become differentiated, suggesting that control of villin expression during terminal differentiation can occur at the transcription level or by RNA stabilization.

Adenocarcinoma↗
PubMed1986

Dexamethasone suppresses pituitary-adrenal but not behavioral effects of centrally administered CRF.

Intracerebral ventricular (icv) administration of corticotropin-releasing factor (CRF) significantly enhances the expression of stress-related behaviors in the rat and also activates the pituitary-adrenal system. The pituitary-adrenal response can be blocked by pretreatment of animals with dexamethasone. The behavioral effects (motor activation, increased grooming and decreased eating) on the other hand are resistant to suppression by dexamethasone. The independence of the behavioral effects from activation of the pituitary-adrenal axis suggests that stress-induced release of CRF could contribute to behavioral alterations even in the presence of high concentrations of endogenous steroids.

Adrenocorticotropic Hormone↗
PubMed1986

Unusual metastatic chondrosarcoma detected with bone scintigraphy.

A case is presented of a scapular chondrosarcoma which showed intense uptake of Tc99m MDP in the primary tumour and in pleural and osseous metastases. Additionally, there was intense visualization of the malignant pleural effusion. The bone scintigraphy correctly diagnosed the extent of the involvement. This finding is unusual because chondrosarcomas in such a disseminated state are relatively rare.

Aged↗
PubMed1986

Phase I clinical trial of an MAF-containing lymphoblastoid cell line supernatant.

A preliminary Phase I evaluation of macrophage activating factor (MAF) derived from the partially purified supernatant of human RPMI-1788 lymphoblastoid cell line was performed in 4 parts in 39 patients with advanced cancer. The first two parts used subcutaneous routes of administration and the second two parts used a 4-h intravenous infusion method. Individual doses ranged from 0.1 ml (1.7 mg protein) to 100 ml (1,700 mg protein). Subcutaneous dose was limited by the volume of administered material, and an attempt to use a concentrate of the supernatant resulted in severe local skin reactions. Larger doses given intravenously were well tolerated. Resultant toxicity was mild and consisted of transient fever and chills. One patient with malignant melanoma had a complete response of a 3-cm skin metastasis; one patient with breast cancer had disappearance of a skin nodule while visceral disease progressed; and one patient with histiocytic lymphoma had resolution of a conjunctival lesion. Treatment in many patients was associated with an increase in absolute peripheral lymphocytes. In the high-dose intravenous group, a statistically significant increase in the phagocytic index of peripheral blood leukocytes was noted. Lymphoblastoid MAF appears to be relatively safe to administer and has promise both as an antitumor agent and in the treatment of other altered immune conditions.

Adolescent↗
PubMed1985

Characterization of muscarinic receptors in human submandibular salivary glands.

We studied the binding of the muscarinic antagonist [3H]N-methyl-scopolamine [( 3H]NMS) in order to characterize muscarinic receptors located in human submandibular salivary glands obtained from intrasurgical biopsy. [3H]NMS bound with a Kd value of 1.56 nM to a single class of muscarinic receptors (Bmax 37.3 fmol/mg protein) since pirenzepine exhibited a homogeneous binding profile.

Humans↗
PubMed1985

Enterogastric reflux detection with technetium-99m IDA.

A Tc-99m IDA scan was performed in a patient with severe alkaline esophagitis subsequent to a Billroth I gastroenterostomy. The scan showed enterogastric reflux simultaneously with gastroesophageal reflux of bile. The study was recorded in a computer and the reflux quantitated.

Duodenogastric Reflux↗
PubMed1985

Studies on multiple thyroid cell membrane-directed antibodies in Graves' disease.

Immunoglobulin G was obtained from the serum of a woman who had given birth to three children with a delayed onset of hyperthyroidism; the clinical events were due to the coexistence of thyroid-stimulating antibody (TSAb) and an inhibitor of TSAb in the maternal serum. The current studies explore the possible existence of additional thyroid membrane-directed antibodies. Human thyroid slices, cells in monolayer culture, and functioning rat thyroid cells (FRTL5), with measurement of cyclic AMP concentration, were used for TSAb assays. Assays of the inhibition of binding of 125I-thyrotropin (TSH) to its receptor used human thyroid and FRTL5 cells, and human thyroid and guinea pig fat cell membranes as receptors. All activities were associated with IgG kappa. Fractions of IgG kappa obtained by adsorption to and the desorption from human thyroid and guinea pig fat cell preparations and F(ab')2 and Fab fragments of the parent IgG were tested. Results indicated that there were three activities in the IgG, namely, TSAb; an inhibitor of TSH-binding that was active in all species and preparations tested, and was effective as Fab and F(ab')2 on both particulate and solubilized thyroid membranes; and an enhancer of TSH-binding (e.g., approximately equal to 220% increase in binding) that was relatively specific for human thyroid membranes only in particulate form, was not adsorbed by fat, and was active as F(ab')2, but minimally as Fab. The concept is developed that dilution of the total IgG, experimentally in vitro or by metabolic clearance in vivo in neonates, determines the effect on either thyroid stimulation or TSH-binding. The incidence of such multiple antibodies and their interaction remains to be determined.

Adipose Tissue↗
PubMed1985

Hyperprolactinemia inhibits gonadotropin-releasing hormone (GnRH) stimulation of the number of pituitary GnRH receptors.

Gonadotropin secretion is diminished in the presence of hyperprolactinemia, and previous studies have shown that PRL can reduce GnRH secretion and impair LH responses to GnRH. To investigate the mechanisms of the inhibitory effects of PRL on the pituitary, we administered intraarterial pulse injections of GnRH (25 ng/pulse every 30 min) to castrate testosterone-implanted male rats placed in restraint cages. Serum PRL, GnRH receptor (GnRH-R), and LH responses to GnRH were measured at intervals over 72 h. In control animals which received saline pulses, serum PRL was transiently elevated to the range of 100-150 ng/ml during the first 24 h, GnRH-R remained stable (approximately 300 fmol/mg protein) and serum LH was low (less than 10 ng/ml) throughout the 72 h. GnRH pulses in castrate testosterone-implanted animals increased GnRH-R to values (approximately 600 fmol/mg) similar to those in castrate controls (no testosterone implant, saline pulses) through 48 h, but GnRH-R declined to baseline values by 72 h in both groups. Serum LH responses to GnRH pulses were only present at 24 h. Administration of bromocriptine throughout the 72 h to immobilized castrate rats or to castrate testosterone-replaced animals treated with GnRH pulses suppressed serum PRL, and GnRH-R concentrations remained elevated through 72 h. Serum LH responses to GnRH pulses were 5- to 20-fold higher in bromocriptine-treated rats, and responses were present throughout the 72 h of the experiment. Delaying the start of bromocriptine treatment until 36 h (after the spontaneous PRL peak) resulted in reduced GnRH-R and LH responses at 72 h. Similarly, administration of ovine PRL (during the first 48 h) to bromocriptine-treated rats produced low GnRH-R concentrations at 72 h. Thus, the transient elevation of PRL seen in immobilized rats can inhibit the GnRH-stimulated increase in GnRH-R and is associated with reduced LH responses to GnRH. These results indicate that PRL has a direct inhibitory effect on the gonadotrope and suggest that impaired GnRH-R responses to GnRH are one of the mechanisms involved in the diminished gonadotropin secretion seen in hyperprolactinemia.

Animals↗
PubMed1984

Transcriptionally active and inactive gene repeats within the D. melanogaster 5S RNA gene cluster.

Transcription of isolated repeat units of D. melanogaster 5S DNA in a Drosophila KcO cell extract revealed three types of template activities. 5SI DNA encodes the known 5S rRNA of D. melanogaster and has a relatively high transcription efficiency. 5SII DNA is identical to 5SI DNA except for a two-nucleotide deletion at 5S rRNA positions 28 and 29; the efficiency of transcription is approximately 40% that of 5SI DNA and because of the deletion, the primary transcript is two nucleotides shorter. 5SIII DNA does not support in vitro transcription (less than 2% 5SI DNA), but has the same sequence as 5SI DNA except for a single G to A transition at position 86. This is the first reported point-mutation in a 5S RNA gene resulting in loss of transcription function. Of approximately 23 5S rRNA gene copies in a cloned 5S DNA sub-cluster (p12D1) 19 appear to be of the transcriptionally inactive 5SIII DNA type.

Animals↗
PubMed1984

[Acute thrombosis of the superior vena cava after cardiac surgery].

One case of acute superior vena cava syndrome occurring twelve days after open-heart surgery was reported. The severity of the accompanying clinical signs led to the carrying out of an urgent superior vena cavogram. It revealed a superior vena caval obstruction by a thrombus which extended into the azygos vein; extrinsic compression was therefore ruled out. The thrombosis seemed to be due to direct trauma by the catheter or to the infusion of irritating solutions. Emergency thrombectomy was successfully carried out.

Acute Disease↗
PubMed1984

[Correction by a calcium inhibitor of a coronary spasm occurring during aortocoronary bypass].

A case of recurrent coronary artery spasm after coronary revascularization under cardiopulmonary bypass is related. The spasm, which occurred under nitroglycerin perfusion, was suspected on the ECG tracing and confirmed during immediate reoperation. It was successfully treated with bepridil, a calcium-channel blocking agent. The use of such agents after cardiac surgery is discussed.

Bepridil↗
PubMed1984

Regulation of pituitary gonadotropin-releasing hormone receptors by pulsatile gonadotropin-releasing hormone injections in male rats. Modulation by testosterone.

The pattern of the gonadotropin-releasing hormone (GnRH) stimulus is critically important in the regulation of pituitary gonadotropin secretion and continuous infusions down-regulate secretion while intermittent pulses maintain luteinizing hormone (LH) and follicle-stimulating hormone (FSH) responsiveness. We examined the effects of pulsatile GnRH administration on pituitary GnRH receptors (GnRH-R) and gonadotropin secretion in the presence of physiological concentrations of testosterone (T) to elucidate the mechanisms and sites of action of GnRH and T on the pituitary gonadotroph. Castrate male rats received one, two, or four testosterone (T) implants (serum T concentrations of 1.1, 2.4, and 5.2 ng/ml, respectively) to suppress endogenous GnRH secretion. Subsequently, intracarotid pulse injections of GnRH (5-250 ng/pulse) or saline in controls were given every 30 min for 48 h, after which gonadotropin responses and pituitary GnRH-R were measured. In control rats, the T implants prevented the rise in GnRH-R that was seen in castrates (empty implant--600 fmol/mg protein) and maintained receptors at the level that was present in intact animals (300 fmol/mg). Pulsatile GnRH administration increased GnRH-R in castrate T-implanted rats, but the response was dependent on the serum T concentration. With one T implant, increasing GnRH doses per pulse stimulated GnRH-R in a linear manner and the maximum receptor concentration (703 +/- 99 fmol/mg) was seen after the 250 ng GnRH dose. In the presence of two T implants, GnRH-R was maximal (705 +/- 45 fmol/mg) after the 25-ng dose and higher doses did not increase receptors above control values. With four T implants, GnRH doses of 5 ng induced a maximum response, 17-50 ng/pulse did not increase GnRH-R, but receptors were again increased by the 250-ng dose (633 +/- 86 fmol/mg). After 48 h of pulsatile GnRH administration there was no correlation between the number of GnRH-R and LH responses to GnRH. In rats with one or two T implants, LH responses were absent after all but the 250-ng doses. In contrast, LH responsiveness was not impaired in the presence of four implants. Thus, low dose GnRH pulses down-regulate LH secretion by an action at a post GnRH-R site, and this effect is regulated by testosterone. The results show that GnRH, given in a pulsatile manner, regulates its own receptor, and physiological increases in serum T produce a 50-fold increase in the sensitivity of GnRH-R stimulation by GnRH.

Animals↗