PubMed Health⌕ Search

Biomedical subjects

A Palomino

Publications and source records attributed to A Palomino.

18 recordsLinked to original sources
PubMed2006

Tpk3 and Snf1 protein kinases regulate Rgt1 association with Saccharomyces cerevisiae HXK2 promoter.

Hexokinase 2 is an essential factor for signalling repression through the Saccharomyces cerevisiae high-glucose sensing pathway. The main regulatory mechanism that controls the HXK2 gene expression in yeast is mediated by the Rgt1 and Med8 transcription factors, which repress HXK2 expression in low-glucose containing media. In this study, we show that the repression activity of Rgt1 is regulated by Snf1 and Tpk3 protein kinases. Binding of Rgt1 to the HXK2 promoter requires Rgt1 phosphorylation by Snf1 or by an Snf1-dependent protein kinase. Conversely, Rgt1 hyperphosphorylation by the Tpk3 or by a Tpk3-dependent protein kinase dissociates Rgt1 from the repressor complex. Two-hybrid and chromatin immunoprecipitation experiments indicate that an Snf1-dependent interaction between Rgt1 and Med8 in the repressor complex is also essential for Rgt1 repression. The repression of HXK2 transcription by Rgt1 likely occurs through the formation of a DNA loop in the HXK2 locus, spanning the promoter and coding regions. These results suggest that a novel silent-chromatin loop is responsible for Rgt1-dependent transcriptional regulation of the HXK2 gene.

Binding Sites↗
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

Effect of nitric oxide on the expression of insulin-like growth factors and the insulin-like growth factor binding proteins throughout the lifespan of the human corpus luteum.

The presence of insulin-like growth factors (IGF), IGF binding proteins (IGFBP) and IGF receptor type 1 (IGF-IR) in the human corpus luteum was investigated by examining the expression and production of related proteins throughout the lifespan of the corpus luteum and the action of nitric oxide upon their production. The expression of proteins in corpora lutea from the early, mid-and late luteal phases was assessed by immunohisto-chemistry, evaluated by a semi-quantitative analysis and the functional study was performed in corpus luteum explants incubated with nitric oxide donors. IGF-I and -II and IGFBP-1 and -3 were measured in the culture media by specific immunoassays. The results showed that IGF-I and -II, IGFBP-1 to -6 and IGF-IR were detected in the human corpus luteum throughout the luteal phase. Moreover, the expression and production of IGF-I and IGFBP-1 increased progressively from corpora lutea from the early to late luteal phases (P < 0.05), whereas the expression and production of IGFBP-2, -4 and -5 were significantly higher in corpora lutea from the mid-luteal phase (P < 0.05). No differences were observed in the expression of IGF-II, IGFBP-3 and -6 and IGF-IR throughout the lifespan of the corpus luteum. However, functional studies showed that nitric oxide donors elicited a stimulatory action on production of IGF-I in corpora lutea from the early luteal phase (80%) and on production of IGFBP-1 in corpora lutea from the late luteal phase (50%) (P < 0.05), whereas production of IGF-II and IGFBP-3 was not affected by nitric oxide. In conclusion, the components of the IGF-IGFBP system are expressed in the human corpus luteum throughout its lifespan. Nitric oxide regulates IGF-I and IGFBP-1 production, indicating that the growth factors may serve, at least in part, as mediators of the action of nitric oxide in the human corpus luteum.

Adult↗
PubMed2001

[Prevalence of metabolic disorders among family members of patients with polycystic ovary syndrome].

BACKGROUND: About 60% of patients with polycystic ovary syndrome (PCOS) have insulin resistance, predisposing them to the premature coronary disease and type 2-diabetes mellitus. However, the history of metabolic disorders in family members of patients with PCOS has been seldom documented in the literature. AIM: To evaluate the family profile of metabolic disorders of PCOS patients and to determine their relative risk of developing one of them in comparison to a control group. PATIENTS AND METHODS: Sixty PCOS patients were evaluated. The control group were 60 normal women. The data were obtained from the clinical history and personal interview with the patients, the controls and their relatives (brothers, parents and grandparents). The metabolic disorders considered were: dyslipidemia, obesity, hypertension and diabetes. RESULTS: The ages were similar between groups (PCOS: 24.0 +/- 6.3; control group: 24.8 +/- 6.2 years). The prevalence of metabolic disorders was 62% in the relatives of the PCOS patients and 27.8% in the relatives of the control group (p < 0.005). The probability to develop a metabolic disorder within the family was 2.7 (2.2-3.3) fold higher in the PCOS group compared to the control group. The risk of developing hypertension, dyslipidemia, obesity and diabetes was 2.1 (1.5-2.9); 1.8 (1.5-2.7); 3.6 (2.6-4.9) and 2.7 (1.8-3.9), respectively, in the PCOS group compared to the control group. CONCLUSIONS: The probability of finding a metabolic disorder in the families of PCOS patients, is 2.7 fold higher than in the control group families. The metabolic disorders are more frequent in parents and grandparents of the PCOS patients than in those of normal women.

Adult↗
PubMed2001

Abnormal pattern of integrin expression at the implantation window in endometrium from fertile women treated with clomiphene citrate and users of intrauterine device.

UNLABELLED: Determine quantitative expression of endometrial integrins that reflect receptivity during implantation window in fertile women treated with clomiphene citrate (CC), and in intrauterine device users (IUD) as compared to fertile controls. Comparative study of the quantitative expression of a1, a4, av and b3 integrins in epithelial and stromal cells in mid-secretory endometrium of CC treated fertile women, IUD users and controls. All subjects included in this study had regular and ovulatory menstrual cycles. SUBJECTS: Ten women treated with a daily dose of 50 mg of CC. Six women T-Cu device users and nine fertile controls. Age ranges for all groups were similar, 29-41 years old (mean 36.3). Tissue samples were taken at the mid-secretory phase or implantation window. A histological dating of the endometrial biopsies was assessed according to Noyes criteria. Ovulation was assessed by repeated transvaginal ultrasonography. The expression of a1, a4, aV and b3 integrins in dispersions of epithelial (EEC) and stromal (ESC) cells isolated from endometrial biopsies was quantitatively determined by flow cytometry using specific monoclonal antibodies. Immunohistochemistry was also used to detect integrin expression. Biopsies from CC-treated women had a high incidence of out-of-phase endometria. Interestingly, CC-treated women over-expressed a1, aV and b3-ESC integrins and under-expressed b3-EEC subunit (P<0.05). IUD users over-expressed the a1-EEC and under-expressed a4-ESC (P<0.05) at the time of the implantation window. CC treatment in fertile women provokes a high frequency of out-of-phase endometrium and desynchronises the expression of endometrial integrins at the implantation window. The epithelial b3 integrin was under-expressed in all CC-treated patients. The T-Cu intrauterine device alters endometrial receptivity by a different mechanism independent of the expression of the epithelial b3 integrin. However, both CC and IUD use alter the expression of some epithelial and stromal integrins during the implantation window.

Adult↗
PubMed2000

A multicenter, randomized, double-blind clinical trial examining the effect of oral human recombinant epidermal growth factor on the healing of duodenal ulcers.

BACKGROUND: Our aim was to study the efficacy of oral human recombinant epidermal growth factor (EGF) in the treatment of duodenal ulcers, on the basis of its repairing actions in the gastrointestinal tract. METHODS: A placebo-controlled, multicenter, randomized, and double-blind study was conducted. Treatment groups were A) placebo solution, B) 10 microg/ml of human recombinant (hr)-EGF, and C) 50 microg/ml of hr-EGF, three times daily during 6 weeks. Patients, 15-65 years old, with a duodenal ulcer >4 mm, who gave their written informed consent to participate were eligible. Exclusion criteria were gastric ulcer and more than one duodenal ulcer, ulcer-related complications, and previous treatment with oral EGF or other specific anti-ulcer drugs in the previous 2 weeks. The main outcome variable was ulcer healing, evaluated by endoscopy after the 2nd, 4th, and 6th week. RESULTS: One hundred and three patients were included. The groups were comparable with regard to age, sex, toxic habits, antecedents of ulcerous disease, initial size and depth or the ulcer, initial symptoms, and positivity for Helicobacter pylori. The ulcers were healed in a larger proportion of patients treated with hr-EGF at the highest dose (70.6% in group C versus 40.0% and 35.3% in placebo and low-dose groups, respectively (P = 0.007)). The difference was significant from week 4 on. Groups A and B did not differ. Eighty-eight percent of group C patients were cured or improved versus 57% and 56% in groups A and B, respectively. No adverse reactions were reported. CONCLUSIONS: Oral hr-EGF was effective in the treatment of duodenal ulcer at a 50-microg/ml dose every 8 h but not at 10 microg/ml.

Administration, Oral↗
PubMed1999

A quantitative evaluation of alpha1, alpha4, alphaV and beta3 endometrial integrins of fertile and unexplained infertile women during the menstrual cycle. A flow cytometric appraisal.

The expression of integrin molecules alpha1beta1, alpha4beta1 and alphaVbeta3 within endometrial tissue has been proposed as a marker of uterine receptivity during the implantation window. The present investigation examines by flow cytometric analysis the concentrations of alpha1, alpha4, alphaV and beta3 integrin subunits in endometrial stromal (ESC) and epithelial cells (EEC) in two groups of women throughout the menstrual cycle: normal fertile women (n = 27) and women with unexplained infertility (n = 26). Integrin concentrations in endometrial cells were calculated in relative fluorescence units against a negative cellular control. The assessment of integrin subunits detected the protein in ESC and EEC from the late proliferative to the late secretory phase. In both groups of women, the alpha1 was the highest integrin expressed in ESC and EEC throughout the menstrual cycle. All women exhibited low concentrations of alpha4-EEC at the time of the implantation window. Infertile women expressed lower concentrations of the alpha4-ESC during the proliferative and early secretory phase while lower concentrations of the alpha1-ESC were seen during the late secretory phase. Interestingly, the infertile women expressed lower concentrations of beta3-EEC in the early, mid-secretory and late secretory phases (P < 0.05). Infertile women also expressed lower concentrations of alpha1-EEC and alphaV-EEC during the late secretory phase (P < 0.05). It can be concluded that the quantitative determination of beta3-EEC by flow cytometry confirmed its potential feature as a marker of endometrial receptivity at the time of the implantation window. In addition, the defective expression of the alpha1-ESC found in the late secretory phase might be associated with the poor fertility outcome of women with unexplained infertility.

Adult↗
PubMed1999

Episodic leptin release is independent of luteinizing hormone secretion.

Several studies suggest that leptin modulates hypothalamic-pituitary-gonadal axis functions. Leptin may stimulate release of gonadotrophin releasing hormone (GnRH) from the hypothalamus and of gonadotrophins from the pituitary. A synchronicity of luteinizing hormone (LH) and leptin pulses has been described in healthy women and in patients with polycystic ovarian syndrome, suggesting that leptin may modulate the episodic secretion of LH. However, it has not been established whether LH regulates the episodic secretion of leptin. To further examine LH-leptin interactions, we studied the episodic fluctuations of circulating LH and leptin in two patients with Kallmann's syndrome (KS) before and on day 7 of pulsatile GnRH administration, and compared these with those observed in the early follicular phase of 10 regularly menstruating women divided into two control groups according to the body mass index of each patient. To assess episodic hormone secretion, blood samples were collected at 10 min intervals for 6 h, before and on day 7 of GnRH administration in KS patients, and during days 3-7 of the follicular phase in normally cycling women. LH and leptin concentrations were measured in all samples. For pulse analysis, the cluster algorithm was used. Before treatment, an apulsatile pattern with no endogenous LH pulsations was observed in both KS patients. However, leptin pulses were assessed in both women. During GnRH administration, pulsatile LH activity was achieved in both patients with pulse characteristics similar to those of the respective control group. Serum leptin concentrations and leptin pulsatile patterns were not modified. These results suggest that circulating leptin is probably not modulated by pulsatile GnRH-LH secretion.

Adult↗
PubMed1999

Antisteroidogenic action of nitric oxide on human corpus luteum in vitro: mechanism of action.

To analyze the mechanism by which nitric oxide (NO) exerts its antisteroidogenic action, human luteal cells were cultured during 24 and 48 h with L-arginine (L-Arg, 1 mmol/L); 1,2(2-trifluoromethylphenyl)imidazole (TRIM) (50 micromol/L and 1 mmol/L) and cyclic guanosine monophosphate (cGMP) analog (8-Br-cGMP, 1 mmol/L). Estradiol, nitrite, and P450 AROM activity were determined in culture media. Total cGMP concentration was evaluated in the cells and culture media by radioimmunoassay, and NADPH diaphorase was used as a histochemical marker for NO synthase (NOS) activity. During the corpus luteum (CL) life-span, NO affected estradiol secretion in an age-dependent manner, with an inhibition in mid-CL (37%; p < 0.05) in agreement with our previous results, and no significant modification in early and late CL. Basal nitrite concentration in 24 and 48 h of midluteal cell cultures (42 and 93 pmol/10(6) cells, respectively) was increased by L-Arg (53% and 88%) and inhibited by the two TRIM concentrations; also, an intense diaphorase reactivity was observed in endothelial cells and luteal parenchyma. Total cGMP was not detected in cell cultures and 8-Br-cGMP did not modify estradiol secretion, whereas aromatase activity was strongly inhibited by L-Arg (70%, p < .05). These results suggest that both NOS isoforms are active in midluteal cells, and the mechanism of action for NO on in vitro estradiol secretion may be an inhibition of P450 AROM activity.

Adult↗
PubMed1998

[Analysis of the changes observed in the sleep EEG recording of patients with juvenile myoclonic epilepsy].

OBJECTIVE: The initial phases and transitional periods of sleep facilitate electroclinical manifestations of juvenile myoclonic epilepsy (JME). The period at the time of waking is identified in the different phases of sleep by cyclic electrophysiological oscillations, which in turn are synchronous with the spike-and-wave or multiple spike-and-wave activity of the electric crises seen in JME and other epileptic syndromes. This observation supports the theory of an alternating cyclical pattern (ACP) as the trigger of these discharges. PATIENTS AND METHODS: Following classical macrostructural and microstructural patterns of EEG sleep analysis, we investigated electrophysiological behavior in 13 patients diagnosed as having JME, and 5 persons of homogeneous epidemiological characteristics as controls. RESULTS: In our study we observed that both groups had similar macrostructural sleep parameters. However, in patients prone to crises, these were concentrated in the first two hours recorded and showed no differences in sleep-waking transition or ACP of phase I sleep. These were significant when both periods were compared with the remaining NREM sleep. CONCLUSION: We conclude from this study that ACP is the microstructural element of sleep which modulates and permits classification of epileptiform anomalies, mainly in studies at the time of wakening.

Child↗
PubMed1997

[Concurrence of short and long lasting episodes of nocturnal paroxysmal dystonia in an epileptic patient].

We report the case of a patient with nocturnal paroxysmal dystonia (NPD) meeting not only the diagnostic criteria described by Lugaresi et al. in 1981, but also presenting with features suggestive of underlying epilepsy as well as other differences from the diagnostic criteria originally described for NPD, such as short- and long-lasting episodes and poor response to antiepileptic drugs. The case we describe suggests a different entity, one that is unrelated to epilepsy or true NPD.

Adult↗
PubMed1990

Dose-response study of DNA and hemoglobin adduct formation by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone in F344 rats.

Levels of hemoglobin adducts and DNA adducts were measured in F344 rats after 4 consecutive daily i.p. injections of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). The dose range was from 3 to 10,000 micrograms/kg/day. [5(-3)H]NNK and [C3H3]NNK were used to measure pyridyloxobutylation and methylation, in both globin and DNA, respectively. In globin, the level of binding increased linearly with dose. Total binding of [5(-3)H] NNK to globin was 3.2 to 8900 fmol/mg and total binding of [C3H3]NNK was 3.5 to 20,000 fmol/mg. The extents of pyridyloxobutylation of both DNA and globin were determined by measuring the amounts of 4-hydroxy-1-(3-pyridyl)-1-butanone released from each, over the dose range 15-5000 micrograms/kg/day. The levels of 4-hydroxy-1-(3-pyridyl)-1-butanone released were 3.2-650 fmol/mg globin, 18-3400 fmol/mg liver DNA, and 58-2180 fmol/mg lung DNA. The extents of DNA methylation in both lung and liver were greater than pyridyloxobutylation. When the dose range was 3-5000 micrograms/kg/day, the levels of 7-methylguanine were 0.22-246 pmol/mumol guanine (149-167,000 fmol/mg) in liver DNA and 0.23-78 pmol/mumol guanine (160-53,000 fmol/mg) in lung DNA. In the lung, the ratio of methylation to pyridyloxobutylation decreased as the dose decreased. In contrast to globin adduct formation, DNA adduct formation did not increase linearly with dose; adduct formation was greater at lower doses than would have been predicted by extrapolation from higher doses. Thus the results of this study demonstrate that there was not a linear relationship between globin adduct formation, neither pyridyloxobutylation nor methylation, and DNA adduct formation in the liver or the lung of rats treated with NNK.

Animals↗
PubMedDate not supplied

[Postoperative morbidity/mortality in gastric cancer according to the rules of the Japanese Society: preliminary report].

With the purpose of evaluate the Morbi-mortality related with the kind of surgery recommended by the Japanese Research Society for Gastric Cancer (JRSGC), 13 patients treated surgically by the Rules of that Society were reviewed. Eleven patients were males and 2 females, with ages between 24 and 72 years old. Twelve of them were operated at the Hospital "Dr. Luis Gómez López" (MSAS) and one in a private clinic, both centers located in Barquisimeto, Lara State. Twelve (92.3%) of the patients had advanced Gastric Cancer and only one case was an Early Gastric Cancer. Nine patients received a Distal Gastrectomy (69.23%) and 4 a Total Gastrectomy. Eight among the 13 also underwent a combined resection of another organ(s) (Spleen; 4: Transverse Colon: 1; some kind of Pancreatic resection: 3; Gallbladder: 2). Considering the kind of Radicality (= D2: lymph Node Level Dissection, based on the JRSGC), 10 patients (76.9%) received a D2 type (the Radicality recommended by the JRSGC), being also disected another Lymph Groups (ALFA), and the Paraortics one in 6 of them. The Post-operative Stages founded were: Ia: one case; II:2 cases; IIIb: 3 cases; IV a:2 cases and IVb: 5 cases (38.46%). In relation with the Post-operative Morbidity, directly related with this kind of surgery, only one patient with a severe Desnutrion developed a Fistula, but it healed spontaneously, after a conservative treatment. Two patients received a second surgery; one during the immediate Post-operative period because a Mesentery Rotation, and the other at the 20th. Post-operative day due to an eventration plus an abdominal wall abscess. Both patients were discharge in good conditions. None of the 13 cases stayed in an Intensive or Intermediate Care Unit. There was no case of Post-operative Mortality. It is important to reassure the low risk of Post-operative Complications with this kind of Radical surgery, for Gastric Cancer patients, even in those with nutrional deficit and with a minimal hospital conditions.

Adult↗