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R Quintana

Publications and source records attributed to R Quintana.

16 recordsLinked to original sources
PubMed2001

Relationship of ovarian stimulation response with vascular endothelial growth factor and degree of granulosa cell apoptosis.

BACKGROUND: The aim of this study was to evaluate the concentration of vascular endothelial growth factor (VEGF) in follicular fluid and in granulosa cell cultures in relation to the degree of apoptosis in granulosa cells from patients with different types of ovarian response to controlled ovarian hyperstimulation. METHODS: We studied 30 women who underwent controlled ovarian hyperstimulation and oocyte retrieval. Group A comprised patients with 1-4 follicles (n = 10), group B patients with 5-14 follicles (n = 10) and group C patients with >15 follicles (n = 10). RESULTS: Mean (+/-SD) VEGF concentrations in follicular fluid were 1232 +/- 209, 813 +/- 198 and 396 +/- 103 pg/ml for groups A, B and C respectively (P > 0.01). Concentrations of VEGF in granulosa cell supernatant were 684 +/- 316, 1101 +/- 295 and 1596 +/- 227 pg/ml respectively (P < 0.05). Percentages of apoptotic cells in granulosa cells culture was 55.02 +/- 7.5, 23.98 +/- 4.4 and 14.2 +/- 2.3% respectively (A versus B, P < 0.01, A versus C, P < 0.006, B versus C, NS). CONCLUSIONS: Our findings showed that in patients with decreased ovarian response to controlled ovarian hyperstimulation, follicular fluid VEGF concentration is elevated, the concentration from granulosa cells culture supernatant is decreased and the percentage of apoptotic granulosa cells is increased, while opposite findings occurred in patients with normal or hyper-responses.

Adult↗
PubMed1998

Methylene blue dyeing of cellular nuclei during salpingoscopy, a new in-vivo method to evaluate vitality of tubal epithelium.

The Fallopian tube can be damaged by different noxious substances that may change cellular ultrastructure and function. Alteration of the cell membrane allows the passage of certain aniline dyes, which can stain the nucleus. A total of 310 Fallopian tubes from 163 patients who underwent a surgical or diagnostic laparoscopy during fertility studies was analysed by salpingoscopy. Cellular nuclei were stained by injection of 20 ml of a 10% solution of methylene blue in saline solution (NaCl 10%) through the cervical cannula prior to salpingoscopy. Evaluation of nuclear staining with methylene blue, adhesions, vascular alterations, and the flattening of folds in relation to pregnancy outcome was undertaken. Quantification of salpingoscopic findings was carried out according to a score. Flattening of folds and vascular alterations showed no difference in the pregnant and non-pregnant groups. On the other hand, adhesions and nuclear dyeing were significantly greater in the non-pregnant group (adhesions 13.6 versus 26.8%, P < 0.004, and nuclear dyeing: 25 versus 41.7%, P < 0.009, pregnant versus non-pregnant). Methylene blue dye is a new tool to evaluate in vivo cyto-histological tubal damage, and is a useful and simple method to provide a prognosis of salpingean function.

Cell Nucleus↗
PubMed1998

Multiple variables explain the variability in the decrement in VO2max during acute hypobaric hypoxia.

PURPOSE: We used multiple regression analyses to determine the relationships between the decrement in sea level (SL, 760 Torr) VO2max during hypobaric hypoxia (HH) and variables that could alter or be related to the decrement in VO2max. METHODS: HH conditions consisted of 682 Torr, 632 Torr, and 566 Torr, and the measured independent variables were SL-VO2max, SL lactate threshold (SL-LT), the change in hemoglobin saturation at VO2max between 760 and 566 Torr (delta SaO2max), lean body mass (LBM), and gender. Male (N = 14) and female (N = 14) subjects of varied fitness, training status, and residential altitude (1,640-2,460 m) completed cycle ergometry tests of VO2max at each HH condition under randomized and single-blinded conditions. RESULTS: VO2max decreased significantly from 760 Torr after 682 Torr (approximately 915 m) (3.5 +/- 0.9 to 3.4 +/- 0.8 L.min-1, P = 0.0003). Across all HH conditions, the slope of the relative decrement in VO2max (%VO2max) during HH was -9.2%/100 mm Hg (-8.1%/1000 m) with an initial decrease from 100% estimated to occur below 705 Torr (610 m). Step-wise multiple regression revealed that SL-VO2max, SL-LT, delta SaO2max, LBM, and gender each significantly combined to account for 89.03% of the variance in the decrement in VO2max (760-566 Torr) (P < 0.001). CONCLUSIONS: Individuals who have a combination of a large SL-VO2max, a small SL-LT (VO2, L.min-1), greater reductions in delta SaO2max, a large LBM, and are male have the greatest decrement in VO2max during HH. The unique variance explanation afforded by SL-LT, LBM, and gender suggests that issues pertaining to oxygen diffusion within skeletal muscle may add to the explanation of between subjects variability in the decrement in VO2max during HH.

Adult↗
PubMed1997

Accidental ovarian autograft after a laparoscopic surgery: case report.

OBJECTIVE: To report an autograft of ovarian tissue in the incision of the surgical trocar during laparoscopic surgery and to assess the potentiality of grafting of ovarian parenchyma in nonpelvic tissue in humans. DESIGN: A case report. SETTING: Instituto de Fertilidad y Ginecología de Buenos Aires (IFER), Buenos Aires, Argentina. PATIENT(S): Infertile patient undergoing surgery due to an endometriotic cyst of the left ovary. INTERVENTION(S): Laparoscopic cystectomy. Accidental retention of a portion of the capsule and adjacent ovarian tissue of the endometrioma in SC cellular tissue. Months after surgery, a SC tumor was formed under the surgical incision. It was subsequently excised. MAIN OUTCOME MEASURE(S): Observation of tumor growth during menstrual cycles and ovulation induction; anatomopathologic study of the tissue after its extirpation. RESULT(S): The tumor grew spontaneously in the periovulatory period and during treatments of ovulation induction. The anatomopathologic report of the tumor, removed 15 months after the first surgery, revealed functioning ovarian tissue with vessels of neoformation. CONCLUSION(S): This is the first description of autografted ovarian tissue in humans. We describe that the ovary can maintain its ovulatory function even in the absence of its pedicel. Also, we suggest that extirpation of surgical material through the incision of the trocar is not recommended, as the possibility of "sowing" or of autografts may occur.

Adipose Tissue↗
PubMed1997

Identification of Ser-Pro and Thr-Pro phosphorylation sites in chicken neurofilament-M tail domain.

The tail domain of the midsize chicken neurofilament polypeptide (NF-M) contains several different types of Ser-Pro and Thr-Pro putative phosphorylation sites. We determined which of these sites are actually phosphorylated in vivo. Chick sensory neuron cultures were incubated in [32P]phosphate, and the cytoskeletal fraction was mixed with a neurofilament fraction prepared from adult chicken brain. NF-M was purified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and digested with chymotrypsin, and two large fragments were isolated. These were individually cleaved with trypsin, endoprotease Lys-C, or endoprotease Glu-C, and peptides separated by two-dimensional high-voltage electrophoresis and thin-layer chromatography. 32P-labeled phosphopeptides were eluted from the cellulose plates and subjected to microsequencing and mass spectometry. We found that of 21 potential Ser-Pro and Thr-Pro phosphoacceptor sites, at least 20 are phosphorylated in vivo: all four Lys-Ser-Pro sites and at least 16 of the 17 Lys-Xaa-Xaa-Ser/Thr-Pro repeats. In addition, a novel Ser-Pro site in the extreme carboxy terminus is phosphorylated. This site, which has no proximal Lys residue, is also found in mammalian NF-M, but has not been reported to be phosphorylated. Together with three casein kinase I sites we have found recently in the acidic amino-terminal segment of the tail, a total of 24 or 25 Ser and Thr phosphoacceptor sites have now been located in the chicken NF-M tail.

Amino Acid Sequence↗
PubMed1996

A randomized, double-blind comparison of donor tolerance of 400 mL, 200 mL, and sham red cell donation.

BACKGROUND: Volume replacement could allow the safe collection of twice the normal amount of red cells in a standard donation. Studies in small numbers of donors have shown that a temporary decrease in red cell mass is well tolerated when donors give twice the usual amount (170-225 mL) of red cells in a standard 405- to 495-mL donation. Sham-donation control groups have not been included in previous studies of increased red cell donation, and perceptions of donation effects could have been biased. STUDY DESIGN AND METHODS: In the study reported here, 17 male and 13 female volunteers were randomly assigned to make a sham donation, 1-unit donation, or 2-unit donation on an automated blood cell separator. Donor tolerance was assessed by ambulatory heart rate monitoring and by a poststudy interview. Hemoglobin, hematocrit, ferritin, serum iron, total iron-binding capacity, red cell 2,3 DPG, and serum erythropoietin were measured before and after donation for comparison of the erythropoietic responses in the three study groups. RESULTS: Red cells collected totaled 206 +/- 10 mL in the 1-unit group and 414 +/- 21 mL in the 2-unit group. Changes in heart rate, systolic blood pressure, and diastolic blood pressure with donation and changes in heart rate recorded by ambulatory monitoring did not differ for the experimental groups. Postdonation changes from baseline values were evaluated on Days 2, 7, and 14. Changes in hemoglobin were significantly different between groups (p < 0.017) in all postdonation tests. There were differences between groups in erythropoietin response, red cell 2,3 DPG, ferritin levels, and hemoglobin synthesis. Hemoglobin synthesis and mean changes in 2,3 DPG, erythropoietin, ferritin, and postdonation hemoglobin were greater in the 2-unit group than in the 1-unit group. CONCLUSION: Donor tolerance of red cell donations of 414 +/- 21 mL, a volume of red cells twice that in a standard 450-mL blood donation, does not differ from donor tolerance of standard or sham donations. Physiologic adjustments and the hematopoietic response to reduced red cell mass were greater in the 2-unit group, but the donation of 1 unit or 2 units did not cause detectable symptoms of reduced oxygen-carrying capacity.

Blood Donors↗
PubMed1994

Differential sensitivity to inhibitors discriminates between two types of kinases responsible for in vivo phosphorylation of different sites in the carboxy-terminal tail of chicken neurofilament-M.

In order to characterize the phosphorylation of neurofilaments (NF) in intact neurons, we examined the ability of several protein kinase inhibitors to interfere with the incorporation 32P into individual NF polypeptides of sensory neurons in culture. We also examined their effect on the post-translational mobility shift on SDS-PAGE that accompanies phosphorylation of newly synthesized NF-M. Several agents known to inhibit cyclic nucleotide-, Ca2+/calmodulin-, and Ca2+/phospholipid-dependent protein kinases (H7, HA1004, trifluoperizine, sphingosine) had no effect on the phosphorylation of any NF polypeptide, in either assay. In contrast, two broadly active protein kinase inhibitors, staurosporine and K252a, inhibited the incorporation of 32P into NF-M by 60-70% and also blocked the post-translational mobility shift. They had no effect on NF-L. The action of staurosporine and K252a was identical to that of 25 mM LiCl. Proteolytic cleavage and phosphopeptide mapping of 32P-labeled NF-M from control and treated cultures revealed that the phosphorylation of only one subset of phosphopeptides was affected by staurosporine, K252a, and LiCl. These were contained within a single chymotryptic fragment of the NF-M tail segment, probably containing most of the 17 repeats of a KXXS/TP motif. The phosphorylation of another subset of phosphopeptides was insensitive to these inhibitors. They were contained within a different chymotryptic fragment of the tail segment which contains a KSD and four KSP potential phosphorylation sites. This differential sensitivity to protein kinase inhibitors distinguishes two different types of effector-independent kinases that phosphorylate, in vivo, different sites within the NF-M tail.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1992

Salpingoscopy: systematic use in diagnostic laparoscopy.

OBJECTIVE: To evaluate the importance of salpingoscopy together with laparoscopy in the diagnosis of tubal pathology. DESIGN: Salpingoscopy was performed as a complementary method in patients who were subjected to diagnostic laparoscopy. The relationship between the salpingoscopy and (1) the patient's previous history of tubal disease and (2) laparoscopic diagnoses was evaluated. SETTING: Private patients referred to the Instituto de Fertilidad, Buenos Aires. PATIENTS, PARTICIPANTS: Forty-two patients undergoing a diagnostic laparoscopy during the evaluation of their fertility or as a follow-up of previous therapy. MAIN OUTCOME MEASURE(S): Salpingoscopy was performed, using a colpomicrohysteroscope. We evaluated alterations in major and minor folds and their vascularization, the presence of microadhesions, and cellular nuclei dyed with methylene blue in the tubal lumen. RESULTS: Fifty percent of the patients who had no previous history of tubal disease presented with endosalpingeal alterations, and in 37% of the normal laparoscopies the salpinx had unilateral or bilateral salpingoscopic abnormalities. CONCLUSIONS: Salpingoscopy is a useful method to evaluate oviducts, before assuming their normality, and consideration of these women for assisted reproductive technology.

Abortion, Spontaneous↗
PubMedDate not supplied

Splenic, thymic, bony and lymph node metastases from orthotopic human lung carcinomas in immunocompromised mice.

In orthotopic animal models of human lung cancer, bone and lymph node metastases have been observed with high frequency after periods of a few weeks, but metastases to other organs are rare. This study evaluated development of distant metastases over a six-month period in a model of orthotopic lung carcinoma in immunocompromised mice. Human A549 lung adenocarcinoma cells were stably transfected to express high levels of green fluorescent protein. Suspensions of 1 x 10(6) cells were instilled into the lungs of athymic and SCID mice to produce orthotopic human lung carcinomas. All animals had primary tumors at termination of the experiment six months later. Splenic metastases and lymph node metastases were present in 70% of the animals and two of the three SCID mice had thymic metastases. Three animals had bony metastases. Thus, a high percentage of immunocompromised mice with orthotopic lung carcinomas ultimately develop metastases.

Adenocarcinoma↗