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Biomedical subjects

E L Salazar

Publications and source records attributed to E L Salazar.

At least 19 recordsLinked to original sources
PubMed2001

The evidence for an etiological relationship between oral contraceptive use and dysplastic change in cervical tissue.

A case-control study of 112 patients with cervical intraepithelial neoplasia (CIN) and 131 control subjects was conducted. Estradiol receptor levels were determined in the total (cytosolic-nucleosolic) fraction of the neoplastic cervical specimens taken during the late proliferative phase of their cycle from 58 premenopausal patients who had been oral contraceptive (OC) users for at least 2 years and from 54 premenopausal women who had not been OC users. All specimens contained variable amount of estradiol receptor (from 7.6 to 53.0 fmol estradiol/mg protein and 7.2 to 29.3 fmol estradiol/mg protein in patients who were OC users and non-users, respectively). A significant correlation was found between estradiol receptor concentration and histological grading in both groups, likewise higher levels of estradiol receptor were observed in the low-grade CIN group tissue from patients who were OC users (p < 0.05). At the same time 17 beta-estradiol and progesterone levels were also determined in the serum of all women who had not used an OC for at least 12 months. The mean +/- SD estradiol serum levels in non-users of OC with CIN (0.189 +/- 0.08 ng/ml, follicular phase) were greater than the mean +/- SD (1.163 +/- 0.33 ng/ml, luteal phase) progesterone serum concentration. Serum estradiol levels were significantly higher (p < 0.05) in OC users, whereas progesterone levels were not (p > 0.05). OC users had an increased risk (odds ratio = 1.31, 95% CI 1.0-2.3) of cervical neoplasia.

Adult↗
PubMed2001

Relationship between estradiol 16 alpha-hydroxylation and human papillomavirus infection in cervical cell transformation.

The ovarian steroid hormone estradiol and its metabolite estrone were examined in 45 normal women and 127 premenopausal women with precancerous cervical lesions. Interviews, colposcopy and cervical scrapings were performed. The mean +/- SD values for estradiol and estrone were 0.07 +/- 0.08 ng/ml and 0.06 +/- 0.02 ng/ml, respectively in normal subjects. Corresponding data in patients with cervical intraepithelial neoplasia alone or in association with human papillomavirus (HPV) infection were 0.074 +/- 0.03 ng/ml and 0.076 +/- 0.03 ng/ml or 0.080 +/- 0.03 ng/ml and 0.148 +/- 0.02 ng/ml, respectively, which revealed a significantly greater extent of estrogenic action in the latter population (p < 0.05). We considered that the presence of HPV infection probably increased 16 alpha-hydroxylation of estradiol, providing a possible link between the viral and hormonal elements, possibly having a bearing on the etiology of the disease.

Adolescent↗
PubMed2000

[Effect of oral contraceptive administration on the frequency of estrogen receptor and cervical intraepithelial neoplasia].

A study of 56 sexual active women with cervical intraepithelial neoplasia (CIN) was conducted in Mexico City, to determine wether the risk for this condition is altered by using oral contraceptives. Responses of a standardized questionnaire compared 29 patients under oral contraceptive (OC) treatment and 27 control subjects selected from the same screening program, though which the cases were detected. Estrogen receptor (ER) levels were determined in each hyperplastic tissue. The ER frequency was approximately the same in women under oral contraceptive (OC) treatment and in women without it. (P > 0.05). Among other risk factors, first intercourse at an early age, first pregnancy age, number of pregnancies and multiple sexual partners were consistently no significant (p > 0.05) when both groups were compared. In this study, we have found no evidence of an etiologic relationship between neither oral contraceptive usage or non usage and CIN.

Adolescent↗
PubMed1998

[Risk factors and correlations with some tumor markers in the incidence of breast cancer in pre- and post-menopausal patients].

Between January and November 1992, forty eight women with benign disorders of the breast were studied and compared with one hundred fifty two patients with malignant disease of the breast. The content of alkaline phosphatase (ALP) levels was measured in the serum of premenopausal and postmenopausal patients. In all of them clinical history was taken, weight size and corporal mass index (CMI) (weight/size2). When the patients were grouped according to type of breast lesions, it appeared that plasmatic ALP levels, were higher in the groups with infiltrating carcinoma than in the women with benign disorders of the breast. The physiological status of the enzyme in this study, relate probably the activity of the tissue in either benign or malignant tissue, through fibroadenoma had less activity than adenocarcinoma. Status ALP (> or = 90 UI/L), CMI, menstrual state and histological type were compared. We found a significant correlation between these parameters.

Adenocarcinoma↗
PubMed1996

[Receptor (ER, PgR) levels as prognostic factors in the endocrine therapy of pre- and post-menopausal patients with stage III infiltrative ductal and lobular cancer of the breast].

Receptors group (ER+, PgR+) in post-menopausal and pre-menopausal patients with ductal and lobular infiltrating mammary cancer clinical stage III and poorly differentiated histological assessment was studied. Levels of (ER+, PgR+) were correlated to endocrine therapy response (Tamoxifen) after 5 years of its administration. Both pre and post-menopausal patients with infiltrating ductal carcinoma, the (RE+, RPg+) tumour content, the mean values were 52 +/- 8, 53 +/- 11 fmol/mg protein and 111 +/- 20, 36 +/- 7 fmol/mg protein, respectively. With regard to lobular carcinoma, the (RE+, RPg+) tumour content, the mean value was 109 +/- 28, 46 +/- 12 fmol/mg protein in pre-menopausal patients, whereas it was 287 +/- 60, 66 +/- 18 fmol/mg protein in post-menopausal patients. The tumour was considered (ER+, PgR+) when specific binding was than 10 fmol/mg protein. In both ductal and lobular carcinoma the mean (ER+) concentrations are significantly different between the post and pre-menopausal patients, while the mean (PgR+) concentrations are significantly different in post-menopausal women. After five years of treatment with tamoxifen, survival analysis of patients with ductal infiltrating and lobular infiltrating carcinoma revealed a very strong correlation between levels of receptor group (ER+, PgR+) and their response to endocrine therapy.

Adult↗
PubMed1992

[Determination of estradiol-17 beta concentration in the saliva of fertile women during the menstrual cycle by an ELISA-type immunoenzymatic, competitive method].

In accordance with the lipophilic properties that are presented by steroidal molecules and the easy of their diffusion and ultrafiltration across serum to saliva, a competitive immunoenzymatic method based on the solid phase system (ELISA) is here in described, it aims to evaluate 17B oestradiol during menstrual cycle using saliva as the biological fluid. In order to apply this competitive system, the requirements are: as antigen 17B oestradiol immobilized on a solid phase, anti 17B oestradiol sheep serum, (1er. Ab) rabbit-globulin anti sheep serum (2o. Ab). The latter when it's conjugated to an enzyme will reveal and will evaluate the presence of 17B oestradiol-antibody reaction. This ELISA method offers acceptable results within a quality control program, indicating with respect to sensibility, a minimum detection level of 2.5 pg/ml. The specificity, which depends on the antibody used and its interaction with the structurally related steroids was not significative with oestrone (1.32%) and oestradiol, (2.46%). The recovery of 17B E2 was adequate (90-95%). In the standard curve the interassay coefficient of variation ranged between 3.0-4.8%; in the saliva samples, the intra assay and inter assay coefficient of variation were 7.2-9.4 and 4.8-12.1% respectively. With respect to the biological fluid used, we can say that saliva is one of the most accessible fluids in the human body and it can be obtained daily without problem. One additional advantage is that 17B E2 values showed excellent correlation with the menstrual cycle phases. So, because the safety, low cost and simplicity we think this ELISA method appears to be very convenient in order to measure oestradiol in normal and pathological conditions.

Enzyme-Linked Immunosorbent Assay↗
PubMed1992

[Cholesterol and phospholipids in human seminal plasma before and after vasectomy].

Before and 2.6 months after vasectomy the alterations of secretory capacity and physiologic damage of the accessory genital glands, were evaluated by means of chemical analyses of certain constituents of seminal plasma such as free cholesterol, esterified cholesterol and phospholipids. The results of these studies showed that the ratio between the concentration of free cholesterol and esterified cholesterol is constant six months after vasectomy and the concentration of phospholipids decreases two months after vasectomy. These results are significant and may be important to know the alterations of secretory capacity of the human genital glands after vasectomy.

Cholesterol↗
PubMed1991

[The role of hyperpolarization and depolarization of the membrane of the human spermatozoon].

The electric potential across the membrane (psi) is evaluated through the accumulation of the lipophilic, radiolabelled, triphenylmethylphosphonium (3H-TPMP+), cation on membrane human sperm. The washed sperm cells, were incubated in presence of 3H-TPMP+ in low-K+ medium or high-K+ and allowed to take up the cation to steady-state (ie; 20 min at 37 degrees C). By using this differential, the value obtained was inserted in the Nernst equation, this value yielded a psi of -69 +/- 2 mV. The presence of divalent cations Zn++ and Mg++ in the incubation medium both induced a hyperpolarization of 10% and 8.6%, respectively. The addition of specific reagents such as p-chloromercuribenzene-sulfonate and ethylene-diamine-tetraacetic acid sodium salt both decreased the psi 35% and 58% respectively. The agents to act upon the components of the sperm cell membrane such as the dithiothreitol and progesterone induced hyperpolarization and depolarization of the membrane 16% and 40%, respectively. The presence of propranolol and L-alpha-lysophosphatidylcholine, which affect the ionic gradients present across the plasma membrane, both induced a depolarization from 43% and 92% respectively. Finally, the addition of tetraphenylboron (TPB-) on the incubation medium, enhanced the value of the psi 75%. These studies are transcendent because with the utilization of agents depolarizing, or hyperpolarizing we obtain changes in the psi from -80 +/- 0.6 mV, until -6 +/- 0.6 mV changes of 74 +/- 1.5 mV across of the sperm cell membrane.

Cell Membrane↗
PubMed1991

[Profile of the membrane potential of mammalian sperm during maturation, ejaculation and capacitation].

The accumulation of lipophilic cation radiolabeled tri-phenylmethyl phosphonium (TPMP+) was utilized to determine the resting membrane potential across the plasma membrane psi. Washed sperm of mammalian was suspended and incubated in low-K+ and high-K+ medium and allowed to take up the cation to a steady-state (20 min at 37 degrees C). By using this differential, the value obtained was transformed at value concentration using the intracellular volume and with these values inserted in the Nernst equation, we obtained the psi. During the maturation process the psi obtained in sperm cells of caput of the epididymis of New Zealand white rabbits was -75(+/-)-3 mV, in sperm cells of corpus and cauda, the psi obtained were -60(+/-)-5 and -52 +/- 3.5 mV, respectively. In the ejaculated spermatozoa the psi obtained was -69 +/- 2 mV. Finally, during the capacitation of human spermatozoa induced by the addition of calcium ions and the ionophore A23187 the psi obtained was -35 +/- 4 mV. These changes in the psi are significant because when the mammalian sperm cells are under different physiological conditions the membrane polarity is modified for the hyperpolarization and depolarization observed.

Animals↗
PubMed1991

[Sialyltransferase activity in the spermatic membrane and its relation to human fertility and sterility].

Sialyltransferase activity was determined on normospermic men sperm cells (greater than 80 x 10(6) sperm/ml and 75% motility) and oligospermic infertile sperm cells (less than 20 x 10(6) sperm/ml and less than 20% motility) and asthenospermic (greater than 40 x 10(6) sperm/ml and less than 10% motility). Sialytransferase activity is quantified by means of the transference of radioactivity of CMP-3H-sialic acid toward the exogenous acceptor (asialofetuin). The enzyme substrate complexes formed in presence of phosphotungstic acid result precipitated insoluble, which was retained on glass fiber filter. The sialyltransferase activity decrease in oligospermic sperm cells 62 +/- 3% and in the asthenospermic decreased 57 +/- 4% with respect normospermic sperm cells. The decrement on sialyltransferase activity in the infertile sperm, permits to assume that this enzyme probably participates as a direct cause of its pathology with detrimental structural and functional integrity of the plasma membrane.

Cell Membrane↗
PubMedDate not supplied

Hyperplastic changes and receptor status in the breast tissue of bodybuilders under anabolic-androgenic steroid stimulation.

Anabolic androgenic steroids (AAS) are misused by athletes to improve their physical performance. AAS with similar groups and configuration indicate that testosterone is the base of this ability to stimulate anabolic activity. The effect of these compounds on the breast tissue of males that consume them is a confirmation of its metabolic pathway. To confirm its hormonal effects, the status of estradiol and progesterone receptors (ER, PgR) status was determined in cytoplasmic and nuclear fractions (HRc, HRn) of 8 premalignant breast tissues from 8 bodybuilders (aged 21 to 45 years) under AAS stimulation. The control group included 5 males with benign disorders of the breast, but not due to AAS administration. The concentrations of ERc and ERn were significantly higher (p < .05) in males under AAS stimulation than in males without these. The concentrations of PgRc and PgRn do not differ between these two groups (p > .05) The benign breast disease is remarkably similar in female and male patients, suggesting a common origin. In the same way, the measurement of both HRc and HRn is necessary to accurately report receptor concentration.

Adult↗
PubMedDate not supplied

Estradiol/androgen receptors during aging: microsomal distribution in human benign prostatic hypertrophy.

Estradiol and androgen receptor levels were determined in benign prostatic hypertrophy tissue by means of dextran-coated charcoal method. 80% of the cases contained estrogen receptor, whereas 85% of cases contained the androgen receptor. In 50 year old patients, nuclear estradiol and androgen receptors were 48% and 34% higher than the cytosolic values, respectively, whereas in 70 year old patients, the levels of nuclear estradiol and androgen receptors were 6% and 57% higher than the cytosolic values, respectively. Nuclear androgen receptor in 50 year old patients was 34% higher than the estradiol receptor, and in 70 year old patients, androgen receptor was 23% higher than the estradiol receptor. Cytosolic values of estrogen receptor in 50 year old patients were diminished 50%, whereas in 70 year old patients, the ER value was increased 40% with regard to androgen receptor. On the other hand, estradiol receptor values measured in microsomal fractions, and were higher when compared to androgen receptor levels (mean percentage +/- 50%). These findings suggest that the biological effects due to the subcellular distribution of AR or ER and that their microsomal distribution would constitute a reserve mechanism and activation of receptors for the continued growth of benign prostatic hypertrophy.

Aging↗
PubMedDate not supplied

Hyperpolarization/depolarization on human spermatozoa.

The accumulation of the lipophilic cation radiolabeled triphenylmethylphosphonium (TPMP+) was utilized to determine the resting membrane potential across the plasma membrane (psi) of human sperm. Washed sperm were suspended and incubated in low-K+ and high-K+ medium and allowed to take up the cation to a steady state (20 min at 37 degrees C). By using this differential, the value obtained was inserted in the Nernst equation and the value yielded a psi of -69 +/- 2 mV. When the Na+ or K+ concentration is high in the medium, the accumulation of TPMP+ in the membrane sperm cells was increased or decreased, respectively, inducing hyperpolarization and depolarization of the membrane 20% and 85%, respectively. The presence of divalent cations Zn++ and Mg++ in the incubation medium both induced a hyperpolarization of 10% and 8.6%, respectively. The addition of specific reagents such as p-chloromercuribenzenosulfonate and ethylenediaminetetraacetic acid sodium salt both decreased the psi 35% and 58%, respectively. The agents acting on the sperm cell membrane, such as dithiothreitol and progesterone, both induced hyperpolarization and depolarization of the membrane 16% and 40%, respectively. The presence of propranolol and L-alpha-lysophosphatidylcholine, which affect the ionic gradients present across the plasma membrane, both induced a depolarization from 43% and 92%, respectively. Finally the psi was glucose-dependent. The result of these studies was that, by the use of agents causing hyperpolarization or depolarization, we obtained changes in the psi of -83.4 +/- 2.2 mV, until -6 +/- 0.6 mV changes of -76.8 +/- 2 mV translated across the sperm cell membrane.

Cations↗
PubMedDate not supplied

Action of cholinergic drugs on accumulation of TPMP+ on human spermatozoa.

Neurotransmitters or antagonists with nicotinic- or acetylcholine-type receptors were utilized to measure the accumulation of the radiolabeled lipophilic cation triphenylmethylphosphonium (TPMP+) on the plasma membrane of human sperm. Washed sperm incubated in the presence of TPMP+ in a low-K+ or high-K+ medium were allowed to take up the cation to a steady state (i.e., 20 min at 37 degrees C). The difference between TPMP+ in each incubation medium was inserted in the Nernst equation yielding a resting membrane potential of -69 +/- 2 mV. The addition of nicotine or acetylcholine to the low-K+ and high-K+ medium induced a hyperpolarization of 17% and 20%, respectively. In the presence of propranolol the membrane potential decreased by 44%. The association of nicotinic or acetylcholine receptor on human sperm or adrenergic beta-receptor blocking agent may alter the ionic permeability of the membrane, possibly due to hyperpolarization or depolarization.

Acetylcholine↗
PubMedDate not supplied

Presence and chemical composition of glycoproteic layer on human spermatozoa.

Studies from electronic microscopy disclosed the presence of an electrodense stranded and branch-like electrodense layer that extends toward extracellular space. Chemical composition of this glycoproteic layer showed that protein and total sugar content is similar (0.98 microgram/microgram protein). As for the total sugar content of this glycoproteic constituent, sialic acid accounts for 40%, hexosamines 27%, and fucose 30%. Electrophoresis characterization of this constituent showed the presence of 6 different motility bands. Risen levels of sialic acid indicate the contribution of sialic residue in the net charge of the sperm membrane, its role during capacitation, and its possible participation in the formation of binding bridges between sperm membrane and ovum.

Cell Membrane↗