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Biomedical subjects

R Expósito

Publications and source records attributed to R Expósito.

6 recordsLinked to original sources
PubMed2002

Determination of zinc (II) in pharmaceuticals based on a flow-through bulk optode.

A method based on flow injection (FI), was applied for the determination of Zn (II) using a flow-through bulk optode membrane that incorporates 1-(2-pyridylazo)-2-naphthol in a plasticized poly (vinyl chloride) membrane entrapped in a cellulose support. The calibration graph plotting the reflectance at 562 nm versus [Zn (II)] was linear in the range 0.16-3.27 mgl(-1) (2.5 x 10(-6)-5 x 10(-5) M) with a detection limit of 0.10 mgl(-1). The variation coefficients of the sensor response for 0.33 mgl(-1) of Zn (II) were +/-0.11% for consecutive measurements (n=10), +/-0.19% between days (n=5) and +/-0.22% between different membranes (n=6). The sensor can be readily regenerated with the same acetic/acetate carrier of pH 3.9. The FI method proposed was applied to the determination of zinc (II) in pharmaceuticals.

Flow Injection Analysis↗
PubMed1999

Oocyte donor selection from 554 candidates.

Oocyte donation is a technique in full expansion in the field of human reproduction. The main problem with this technique is the shortage of oocytes. In our programme, prospective donors are selected from anonymous, well-informed university students over 18 years of age, who give their informed consent in writing. Before being accepted as donors, the candidates' personal and family medical histories were taken and they were given a gynaecological examination, genital ultrasonography, and analysed for syphilis, acquired immune deficiency syndrome, hepatitis B and C, coagulation factor VIII, fetal haemoglobin and karyotype. The donors received economic compensation of about 750 euros. Over the last 6 years, 554 medical histories have been taken. Fifty-eight candidates (10.5%) were rejected because of previous family or personal pathologies. Only 243 out of 496 (49%) continued the study. Sixteen candidates (7%) were rejected as a result of gynaecological problems and ultrasonographic results; and 12 (4.9%) as a result of their blood test results; 215 donors were accepted (38.8% of the original population). Other options for recruiting oocyte donors are commented on and we argue that the methodology described here is the most suitable one.

Adult↗
PubMed1999

Triplet pregnancy achieved through intracytoplasmic sperm injection with spermatozoa obtained by prostatic massage of a paraplegic patient: case report.

Spinal cord-injured men with ejaculation disorders can have children thanks to assisted reproduction techniques. Spermatozoa from these patients are usually obtained through vibratory stimulation, electroejaculation or by puncturing the seminal duct or the testicle. We present the first published case, as far as we are aware, of spermatozoa obtained through prostatic massage of a paraplegic patient. Penile vibratory stimulation was unsuccessful in this patient. In-vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI) with spermatozoa obtained through electroejaculation was performed at another centre but pregnancy was not achieved. Through prostatic massage, we obtained a total semen volume of 6 ml containing a total count of 12.32x10(6) spermatozoa (6.24x10(6) with tails), 8% of which had motility (graded + and ++); and 16% of which had normal morphology. The spermatozoa obtained were then used to perform IVF with ICSI and a triplet pregnancy was achieved. Prostatic massage appears to be an easy, non-traumatic and risk-free method to obtain spermatozoa from paraplegic patients.

Adult↗
PubMed1998

Human immunodeficiency virus type 1--serodiscordant couples can bear healthy children after undergoing intrauterine insemination.

OBJECTIVE: To use semen from men who were seropositive for human immunodeficiency virus type 1 (HIV-1) to inseminate their partners without infecting them. DESIGN: Prospective study. SETTING: Private practice. PATIENT(S): Sixty-three HIV-1-seropositive men and their HIV-1-seronegative female partners. INTERVENTION(S): The men provided 107 semen samples that were prepared with the use of the Percoll and swim-up techniques. The presence of HIV-1 was determined in the fraction of motile spermatozoa obtained after washing. If HIV-1 was not detected. IUI was performed in stimulated cycles. MAIN OUTCOME MEASURE(S): Human immunodeficiency virus type 1 RNA and DNA were detected with the use of the polymerase chain reaction technique modified for spermatozoa. RESULT(S): One hundred seven semen samples were washed. Human immunodeficiency virus type 1 was not detected in 101 samples (94.4%) and was detected in 6 samples (5.6%). In the latter cases, IUI was not performed. One hundred one IUI procedures were performed in 63 women. Thirty-one pregnancies resulted, for a pregnancy rate of 30.7% per cycle and 49.2% per inseminated woman. Thirty-seven healthy children were born. The results of tests for the detection of HIV-1 and antibodies to HIV-1 in the inseminated women were negative. CONCLUSION(S): On the basis of these results, testing for HIV-1 with the use of the polymerase chain reaction technique on the semen fraction obtained after washing appears to prevent infection in the inseminated woman. This method makes it possible to help HIV-1-seropositive men to have children without infecting their female partners.

Adult↗
PubMed1998

Pregnancy following intracytoplasmic sperm injection from an HIV-1-seropositive man.

The first pregnancy achieved in a seronegative woman following in-vitro fecundation through intracytoplasmic sperm (ICSI) injection from a man with autoimmune deficiency syndrome (AIDS; HIV-1 carrier) is reported. The semen was prepared by PureSperm and swim-up techniques. Some of the motile spermatozoa obtained were used to detect the presence of HIV-1 using the polymerase chain reaction technique. HIV-1 in DNA or RNA form was not detected using this technique. The remaining spermatozoa were frozen. Ovarian stimulation in the woman was performed with long-protocol analogues and gonadotrophins. Thirteen mature oocytes were recovered, into which the thawed spermatozoa were microinjected. Nine embryos were obtained. Four were frozen, four transferred and one discarded. The woman became pregnant. Analyses for HIV-1 in the woman, performed in the first and third months of pregnancy, gave negative results. This case provides further experience with washed semen of sufficient quality for performing artificial insemination in HIV-1-serodiscordant couples (101 inseminations, 31 pregnancies, 28 deliveries, 37 babies, all healthy). In women with obstructed Fallopian tubes, or when the semen is not of sufficient quality for artificial insemination techniques to be performed, ICSI can be carried out using frozen, HIV-1-free semen.

Acquired Immunodeficiency Syndrome↗