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Biomedical subjects

M Vega

Publications and source records attributed to M Vega.

At least 19 recordsLinked to original sources
PubMed2006

Androgen and estrogen receptors and co-regulators levels in endometria from patients with polycystic ovarian syndrome with and without endometrial hyperplasia.

OBJECTIVE: To study if the endocrinological status of PCOS women affects the endometrial sensitivity to steroids by evaluating the expression of androgen receptor (AR), estrogen receptor alpha (ERalpha), estrogen receptor beta (ERbeta), co-activators AIB1 and ARA70, and co-repressor NCoR. METHODS: Gene and/or protein expression of steroid receptors and co-regulators was measured in 17 samples of normal endometrium (NE), 23 PCOS endometrium without treatment (PCOSE), 11 endometria from PCOS women and with endometrial hyperplasia (HPCOSE), and 10 endometria from patients with endometrial hyperplasia (HE), using RT-PCR and/or immunohistochemistry and Western blot. RESULTS: Gene and protein expression of AR was relatively elevated in PCOSE and HPCOSE compared with NE. A significant increase in ERalpha protein expression was observed in PCOSE, preferentially in the nucleus of endometrial cells, whereas ERbeta gene and protein expression increased gradually from PCOSE to HPCOSE and HE, mainly in the epithelial compartment. Importantly, we found a gradual increase in the ERbeta/ERalpha gene and protein expression ratio in endometria from the four groups of women. AIB1 showed increased nuclear protein expression in PCOSE compared to NE, in the presence of a high expression of ARA70 in all groups. High expression of ARA70 together with a normal expression level of AIB1 was observed in HPCOSE. The cytoplasmic immunostaining of NCoR was similar between the four groups of patients. CONCLUSION: The PCOS endometrium exhibits a higher sensitivity to steroid action. We can inferred that these alterations could deregulate the transcription of genes involved in the cell cycle, which may lead to the development of endometrial hyperplasia in PCOS women.

Adult↗
PubMed2006

Nerve growth factor-dependent activation of trkA receptors in the human ovary results in synthesis of follicle-stimulating hormone receptors and estrogen secretion.

CONTEXT: Previous studies showed that nerve growth factor (NGF) induces the expression of functional FSH receptors (FSHR) in preantral follicles of the developing rat ovary. OBJECTIVE: The objective of this study was to determine whether NGF can affect granulosa cell (GC) function in human periovulatory follicles using intact human ovaries and isolated human GCs. PATIENTS AND INTERVENTIONS: Human GCs were obtained from in vitro fertilization patients and normal ovaries from women with elective pelvic surgery for nonovarian indications. RESULTS: In normal ovaries, NGF and trkA (NGF's high-affinity receptor) were detected by immunohistochemistry in GCs of preantral and antral follicles. NGF and trkA are also present in thecal cells of antral follicles. Both freshly collected and cultured GCs contained immunoreactive NGF and trkA in addition to their respective mRNAs. Human GCs respond to NGF with increased estradiol (E(2)) secretion and a reduction in progesterone output. Exposure of human GCs to NGF increased FSHR mRNA content within 18 h of treatment, and this effect was blocked by the trk tyrosine kinase blocker K-252a. Also, cells preexposed to NGF released significantly more E(2) in response to hFSH than cells not pretreated with the neurotropin, showing that the NGF-induced increase in FSHR gene expression results in the formation of functional FSHRs. CONCLUSIONS: These results suggest that one of the functions of NGF in the preovulatory human ovary is to increase the secretion of E(2) while preventing early luteinization via an inhibitory effect on progesterone secretion. NGF stimulates E(2) secretion both directly and by increasing the formation of FSHRs.

Estradiol↗
PubMed2006

Diffuse basal ganglia or thalamus hyperechogenicity in preterm infants.

OBJECTIVE: To determine the incidence and factors associated with diffuse basal ganglia or thalamus hyperechogenicity (BGTH) in preterm infants. STUDY DESIGN: (1) Review of serial neurosonograms among neonates with gestational age (GA) <34 weeks born at Weiler Hospital during a 21-month period; (2) Color Doppler flow imaging; (3) Case-control study using GA group-matched controls; and (4) Blind reading of CT scans or MRIs in patients with BGTH. RESULTS: Among 289 infants, 24 (8.3%) had diffuse BGTH. Color Doppler flow imaging was normal in nine patients. The incidence of diffuse BGTH was inversely related to GA (P<0.01). Logistic regression (n=96) showed that diffuse BGTH was significantly associated with requirement of high-frequency oscillation (HFO) (P=0.031), severe intraventricular hemorrhage (IVH) (P=0.004), hypotension requiring vasopressors (P=0.040), hypoglycemia (P=0.031) and male gender (P=0.014). Most patients with diffuse BGTH had normal basal ganglia and thalamus on CT/MRI, one had a hemorrhage, and one had an ischemic infarction. CONCLUSIONS: In our series, diffuse BGTH occurred in 8.3%, and was associated with factors similar to those previously reported. In contrast, several series have reported almost exclusively linear or punctuate hyperechoic foci, corresponding to hyperechogenicity of the lenticulostriate vessels. Our data provide further evidence to suggest that diffuse BGTH and hyperechogenicity of the lenticulostriate vessels are two different entities. Additional studies are required to determine the long-term significance of diffuse BGTH.

Basal Ganglia↗
PubMed2004

Treatment of type II endoleaks after endovascular repair of abdominal aortic aneurysms: translumbar puncture and injection of thrombin into the aneurysm sac.

OBJECTIVES: The aim of this article is to report our experience in the use of a new technique for the treatment of type II endoleaks which appear after the endovascular treatment of abdominal aortic aneurysms. MATERIALS AND METHODS: In three patients with secondary type II endoleaks, we performed a translumbar puncture, introducing a 22-Gauge needle into the aneurysm sac under CT guidance. Once intrasac pressure had been registered, 1000U (2 ml) of human thrombin were slowly injected into the sac. RESULTS: Complete sealing of the endoleak was achieved in all three patients, confirmed by the lack of contrast filling of the sac in the CT scans performed 5 min and 24 h after the procedure. Initial intrasac pressure was equal to systolic arterial pressure in the three patients. After the procedure, the pressure decreased by 30-40 mmHg. There were no complications during the procedure, which lasted 45-90 min. No endoleak recurrence has been observed in any of the three cases 6 months later. CONCLUSIONS: We present an alternative method of treating type II endoleaks, which could become the treatment of choice if and when a wider experience confirms our initial good results.

Aortic Aneurysm, Abdominal↗
PubMed2004

Interleukin-1beta up-regulates nitrite production: effects on ovarian function.

We have previously reported that Interleukin-1beta (IL-1beta) affects ovarian function in the rat, modulating prostaglandin and progesterone (P) production. As IL-1beta effects were associated to nitric oxide (NO) synthesis, in the present work we have further examined the role of ovarian NOS-system, in IL-1beta antisteroidogenic action. Mid-luteal explants from rats were incubated for 4 h in the presence of IL-1beta (1-35 ng/ml)-alone or in combination with NOS-inhibitors-and then assayed for P and nitrite production. IL-1beta treatment reduced P levels in a dose-dependent manner, returning to basal levels at 35 ng/ml. This reduction in steroid synthesis was paralleled by a dose-dependent increase in nitrite levels, reaching a maximum at 25 ng/ml but without effect at 35 ng/ml. L-Arginine (1 and 2 mM) was able to mimic IL-1beta actions and the NOS blocker L-Nitro-Arginin-Methyl Ester reverted these effects. Moreover, the selective iNOS inhibitor, 1400 W, completely abolished IL-1beta antisteroidogenic effect, therefore confirming the dependence of IL-1beta action upon iNOS activation. Finally, IL-1beta did not affect eNOS expression but up-regulated iNOS mRNA and protein levels. Our results suggest an interaction between IL-1beta and the NOS-system. Thus, we may conclude that in the rat iNOS-derived NO production, induced by IL-1beta, affects ovarian P biosynthesis and hence NO may be a major effector molecule of ovarian IL-1 system.

Animals↗
PubMed2003

Operative repair of popliteal aneurysms: effect of factors related to the bypass procedure on outcome.

The objective of this study was to compare patency rates following the repair of popliteal aneurysms according to the site of inflow, material of bypass graft and quality of distal runoff. Seventy bypasses were performed over an 11-year period. Autogenous saphenous vein was used in 53 procedures (75.7%) and prosthetic material was used in 17 (24.3%). Early mortality was 2.8%. Early primary and secondary patency rates were 95.7% and 97.1%, respectively. Autogenous vein showed better 10-year patency than prosthetic material (86% vs. 57%; p = 0.02). No significant differences in patency were observed according to the inflow site (87.8% groin vs. 74.7% supragenicular). Bypasses that originated in the groin showed improved patency when a saphenous vein was used (84.8% vs. 43.7%; p = 0.01). However, no influence of the graft material was noted in supragenicular bypasses (90.4% vs. 84.8%; p = 0.6). Bypasses in extremities with good runoff showed better patency than those in limbs showing poor runoff (86% vs. 55%; p = 0.003). The use of saphenous vein for the repair of popliteal aneurysms showed better results than those with prosthetic material, although in bypasses originating from the distal superficial femoral or above-knee popliteal artery, no significant differences in patency were observed. Good distal runoff was associated with improved overall outcome.

Adult↗
PubMed2003

[Purtscher's retinopathy: a rare complication of acute non-alcoholic pancreatitis].

Purtscher's retinopathy is a rare complication of acute alcoholic pancreatitis that is characterized by the development of cotton-wool exudates and retinal hemorrhages located around the optic disk. Its development is due to ischemic phenomena in the posterior pole of the retina due to microemboli in the retinal arterioles and capillaries. This complication is not related to a poorer prognosis of acute pancreatitis and the retinopathy usually has a favorable outcome with disappearance of the ophthalmic lesions and restoration of visual acuity after 4-6 weeks in most cases. However, some patients may show residual lesions, especially if optical atrophy occurs. We present a 40-year-old woman with loss of visual acuity due to Purtscher's retinopathy during the course of mild acute idiopathic pancreatitis.

Acute Disease↗
PubMed2003

Endoscopic follow-up of patients after curative surgery for colorectal cancer: results of a medical assistance protocol.

AIMS: To evaluate the results of an endoscopic follow-up assistance protocol for colorectal cancer (CRC) after curative surgery. PATIENTS AND METHODS: Between 1994 and 1996, 205 patients with CRC were submitted to curative surgery in our hospital. An endoscopic follow-up was proposed to the patients based on an endoscopy six months following surgery, in the case they did not have a complete endoscopy prior to surgery, or one year after surgery if they did, another one two years later, and a third endoscopy between the third and fifth year. We retrospectively analyzed the follow-up outcome and endoscopic findings. RESULTS: 155 patients were submitted to follow-up, of which 74,2% completed the protocol. 3 synchronous tumours, 4 anastomosis relapses and 2 metachronous tumours were detected. Curative surgery was performed on 100% of the synchronous tumours, 50% of the relapses and 50% of the metachronous tumours. 48.3% and 20.6% of the patients had synchronous and metachronous polyps, respectively. 14.7% of the polyps were larger than 1 cm, 21.7% and 4.8% were tubulovillous and villous, respectively, and 3.7% had severe dysplasia. Finally, patients with synchronous polyps had higher risk of developing metachronous polyps (RR 7.1, CI 95% 2.3; 22.2, p<0.0001). CONCLUSIONS: The rate of adenomatous polyps with high risk of malignant degeneration, metachronous tumours or relapses detected by colonoscopy is low in our series. On the other hand, the detection of polyps during follow-up was related to the presence of synchronous polyps.

Aged↗
PubMed2002

Altered proteinogram in short term portal vein stenosed rats.

The electrophoretic pattern of serum proteins has been studied in short-term prehepatic portal hypertensive rats since atrophy is produced in the liver, which is the main origin of most of these proteins, during this postoperative period. After 28 days of evolution, rats (n = 9) with triple stenosing ligated portal vein showed hypoalbuminemia, hypo-alpha-globulinemia, hyper-alpha2-globulinemia and hyper-gamma-globulinemia, the albumin/globulin ratio decreased with respect to the control animals (n = 8). These alterations are associated with hepatic atrophy, portosystemic and portohepatic (44.4%) collateral circulation. The proteinogram alterations found in rats with short-term prehepatic portal hypertension suggest that hepatic failure exists in spite of potential portohepatic revascularization which is frequently originated by the development of portohepatic collateral circulation.

Animals↗
PubMed2002

Regulation of steroid synthesis and apoptosis by insulin-like growth factor I and insulin-like growth factor binding protein 3 in human corpus luteum during the midluteal phase.

The aim of the present study was to investigate the action of insulin-like growth factor I (IGF-I) and insulin-like growth factor-binding protein 3 (IGFBP-3) on steroidogenesis and apoptosis in human corpus luteum during the midluteal phase. Slices from corpora lutea were incubated for 4 h with IGF-I or IGFBP-3. Progesterone, oestradiol, androstenedione and testosterone concentrations were determined by radioimmunoassay; caspase 3 expression was assessed by immunohistochemistry; bcl-2, bax and P(450arom) expression were assessed by RT-PCR; and apoptosis was detected by in situ terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling. The results showed that addition of IGF-I stimulated progesterone production (150%, P < 0.01), oestradiol production (65%, P < 0.05) and bcl-2 gene expression (approximately 200%, P < 0.05), but decreased apoptosis (P < 0.05). In contrast, IGFBP-3 reduced steroid production and increased bax gene expression and the percentage of apoptotic cells (P < 0.05). Neither IGF-I nor IGFBP-3 had an effect on P(450arom) expression or on the concentrations of its substrates. However, maximum expression of caspase 3 was detected in corpus luteum during the midluteal phase. In conclusion, these results indicate that IGF-I and IGFBP-3 act as regulatory peptides of the function of the human corpus luteum during the midluteal phase. This action may be direct or mediated by steroid production or by bcl-2-bax expression.

Adult↗
PubMed2001

Two intermediates in the synthesis of decahydroisoquinolines with NMDA and AMPA receptor antagonist activity.

In 6-methyl-N-(4-nitrobenzoyl)-5,6-dihydropyridin-2(1H)-one, C(13)H(12)N(2)O(4), (I), the piperidone ring is in a distorted half-chair conformation. In 8-methoxy-3-methyl-N-(4-nitrobenzoyl)-1,2,3,4,5,6,7,8-octahydroisoquinoline-1,6-dione, C(18)H(20)N(2)O(6), (II), the heterocyclic ring is in a slightly distorted half-boat conformation, while the other six-membered ring is in a distorted chair conformation. Compound (II) presents a strong intramolecular C-H...O hydrogen bond. In both (I) and (II), the molecules interact through C-H...O interactions.

Crystallography, X-Ray↗
PubMed2001

Two polycyclic compounds derived from a Diels-Alder reaction.

In both 9,10-dimethoxy-11-oxatricyclo[6.2.1.0(2,7)]undeca-4,9-diene-3,6-diol, C(12)H(16)O(5), (I), and 5,6-dimethoxy-3,7-dioxatetracyclo[6.4.0.0(2,6).0(4,12)]dodec-9-en-11-ol, C(12)H(16)O(5), (II), the hetero-oxygen-containing five-membered rings have an envelope conformation. The six-membered rings are in a boat conformation in compound (I), and in (II), one is in a half-boat and the other is in a slightly distorted boat conformation. The molecules in both compounds interact through classical hydrogen bonds and C-H.O contacts.

Crystallography, X-Ray↗
PubMed2001

Reversed-phase high-performance liquid chromatography versus spectrophotometric assay for thimerosal in Cuban recombinant hepatitis B vaccine.

A reversed-phase liquid chromatographic method was applied to study the stability of thimerosal in Cuban recombinant hepatitis B vaccine samples stored under different temperature conditions. Salicylic acid was used as internal standard, it allowed one to determine the thimerosal in the presence of its degradation products. Good stability of the preservative was demonstrated in vaccine samples for as long as 6 years. The same results were obtained when the vaccine samples were incubated at 37 and 45 degrees C during 30 days. The results were in compliance with the microbiological test for determining the effectiveness of antimicrobial preservative in these samples.

Anti-Infective Agents↗
PubMed2001

Results of salvage surgery for local or regional recurrence after larynx preservation with induction chemotherapy and radiotherapy.

BACKGROUND: After treatment of locally advanced laryngeal carcinomas with induction chemotherapy and radiotherapy, some patients suffer a local or regional failure of the tumor, and salvage surgery is required. The aim of this study was to review the results of such salvage surgery in this group of patients. METHODS: A retrospective study of a cohort of 110 patients diagnosed between 1989 and 1996 with a locally advanced laryngeal carcinoma (T3-T4) treated with induction chemotherapy and radiotherapy was performed. The results of salvage surgery in patients with a local and/or regional failure of the treatment were analyzed. RESULTS: Forty-two patients presented a local and/or a regional recurrence of the tumor: 26 patients in the larynx, eight in the neck, and a further eight in both in the larynx and the neck. Salvage surgery was carried out in 28 patients (67%), consisting of total laryngectomies with neck dissections (24 cases), endoscopic resection of the tumor (one case), and radical neck dissections (three cases). Five-year adjusted survival for the 42 patients was 38%. Five-year survival for the 28 patients treated with salvage surgery was 57%. Five patients had postoperative complications: four had pharyngo-cutaneous fistulas and one had wound infection. CONCLUSIONS: After a local and/or regional recurrence, 67% of patients with advanced laryngeal carcinoma treated with induction chemotherapy and radiotherapy were candidates to salvage surgery. Five-year adjusted survival for this group of patients was 57%.

Cohort Studies↗