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Biomedical subjects

R Romero

Publications and source records attributed to R Romero.

At least 361 records · Page 20Linked to original sources
PubMed1992

Endothelin-1,2 levels are increased in the amniotic fluid of women with preterm labor and microbial invasion of the amniotic cavity.

The purpose of this study was to determine the effect of gestational age, labor, and microbial invasion of the amniotic cavity on amniotic fluid concentrations of endothelin-1,2. Amniotic fluid was retrieved by amniocentesis from 148 women: patients at term with and without labor, patients with preterm labor with and without intraamniotic infection, and women in the second trimester of pregnancy. Endothelin-1,2 was measured by a sensitive and specific radioimmunoassay. Immunoreactive endothelin-1,2 was detectable in all samples of human amniotic fluid. Advancing gestational age and spontaneous term labor did not result in changes in amniotic fluid concentrations of endothelin-1,2. Women with preterm labor and positive amniotic fluid cultures for microorganisms had higher amniotic fluid concentrations of endothelin-1,2 than did those without microbial invasion of the amniotic cavity (p less than 0.05). These results support a role for endothelins in the mechanisms responsible for preterm delivery associated with intraamniotic infection.

Adult↗
PubMed1992

Infection and labor. VII. Microbial invasion of the amniotic cavity in spontaneous rupture of membranes at term.

OBJECTIVE: The purpose of this study was to determine the frequency, microbiologic characteristics, and clinical significance of microbial invasion of the amniotic cavity in women with premature rupture of membranes at term. STUDY DESIGN: Amniocentesis was performed in 32 women with term premature rupture of membranes and amniotic fluid cultured for aerobic and anaerobic bacteria and Mycoplasmas. RESULTS: The prevalence of positive amniotic fluid cultures was 34.3% (11/32). The most common isolates were Ureaplasma urealyticum, Peptostreptococcus sp., Lactobacillus sp., Bacteroides fragilis, and Fusobacterium sp. Clinical chorioamnionitis occurred only in one patient with a positive amniotic fluid culture. Her neonate had ophthalmitis. Three patients (9.4%) had endometritis. Among women who were delivered vaginally, those with a positive amniotic fluid culture had a significantly higher rate of endometritis than those with a negative culture (33% [3/9] vs 0% [0/20], respectively, p = 0.023). CONCLUSIONS: These data indicate that microbial invasion of the amniotic cavity occurs in approximately one third of patients with preterm premature rupture of membranes. Microbial invasion of the amniotic cavity is a risk factor for endometritis in women with term premature rupture of membranes.

Amnion↗
PubMed1992

Comparative effects of captopril versus nifedipine on proteinuria and renal function of type 2 diabetic patients.

Our study compared the effects of an angiotensin-converting enzyme inhibitor (captopril) versus a calcium antagonist (nifedipine) on proteinuria and renal function in patients with diabetic nephropathy. A randomized follow-up study was designed. Type 2 diabetic patients, with established diabetic nephropathy (proteinuria greater than 0.5 g/24 h), were treated with nifedipine (10 patients, group A) or captopril (10 patients, group B) for 6 months. Arterial blood pressure, metabolic parameters, proteinuria and renal function were measured and compared. Mean percentage differences for glomerular filtration rate, renal plasma flow and filtration fraction between the two groups were calculated. No significant differences were observed in serum glucose, glycosylated hemoglobin (hemoglobin A1c), Na+, K+ or albumin in either group or between groups. Blood pressure decreased significantly with both treatments and mean blood pressure was significantly lower in group A compared with group B at 6 months (Mann-Whitney U-test, P = 0.03). Proteinuria was similar in both groups at randomization, but after 3 and 6 months of treatment significant reductions were observed only in the group treated with captopril (P less than 0.01). A significant decrease in filtration fraction was observed in group B with an increase in group A (Mann-Whitney U-test, P = 0.03). Multiple regression analysis identified the therapeutic agent administered as an independent variable for decrease in proteinuria. It is concluded that antihypertensive treatment with captopril, but not with nifedipine, reduced proteinuria in patients with diabetic nephropathy, although a better mean blood pressure was obtained with nifedipine.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Glucose↗
PubMed1992

The natural interleukin-1 receptor antagonist in term and preterm parturition.

OBJECTIVE: Interleukin-1 has been implicated in the mechanisms responsible for preterm labor in the setting of infection. The interleukin-1 receptor antagonist is a new member of the interleukin-1 gene family that inhibits the biologic effects of interleukin-1 by blocking its receptors. Reduction of interleukin-1-induced prostaglandin production by intrauterine tissues may have potential value in the treatment of preterm labor associated with infection. The purpose of these studies was (1) to determine interleukin-1 receptor antagonist levels in the amniotic fluid of women with term and preterm labor (with and without infection) and (2) to study the effects of interleukin-1 receptor antagonist on interleukin-1-induced prostaglandin biosynthesis by human amnion and chorion. STUDY DESIGN: Amniotic fluid was obtained from women in the midtrimester of pregnancy (n = 20), at term pregnancy (with and without labor, n = 69), and in preterm labor (n = 47). Fluid was cultured for aerobic and anaerobic bacteria and Mycoplasmas. Interleukin-1 alpha, interleukin-1 beta, and interleukin-1 receptor antagonist concentrations were measured by immunoassays previously validated for human amniotic fluid. The effect of interleukin-1 receptor antagonist on interleukin-1-induced prostaglandin production by amnion and chorion was studied with primary cultures. Cells were incubated with interleukin-1 receptor antagonist and interleukin-1 alpha or interleukin-1 beta for 16 hours. Prostaglandin E2 released into the media was assayed by immunoassay. RESULTS: (1) Interleukin-1 receptor antagonist was present in all amniotic fluid samples; (2) amniotic fluid contains the highest interleukin-1 receptor antagonist concentrations detected in any biologic fluid to date; (3) amniotic fluid interleukin-1 receptor antagonist concentrations were not increased in women with preterm labor and intraamniotic infection in spite of dramatically elevated concentrations of interleukin-1 alpha and interleukin-1 beta in the same fluid (median 22 ng/ml and range 0.16 to 70 for preterm labor with negative amniotic fluid culture vs median 30 ng/ml and range 6 to 70 for preterm labor with positive amniotic fluid culture; p > 0.05); (4) interleukin-1 receptor antagonist reduced interleukin-1 beta-induced prostaglandin E2 production by amnion and chorion in a dose-dependent manner; (5) interleukin-1 receptor antagonist by itself did not stimulate prostaglandin E2 release by amnion and chorion when used in concentrations ranging from 0.1 to 1000 ng/ml. CONCLUSIONS: (1) Interleukin-1 receptor antagonist is a physiologic component of amniotic fluid; (2) the release of interleukin-1 alpha and interleukin-1 beta into the amniotic fluid in women with preterm labor is not associated with an increase in interleukin-1 receptor antagonist levels in amniotic fluid; (3) interleukin-1 receptor antagonist reduces interleukin-1-induced prostaglandin production by amnion and chorion; (4) exogenous anticytokine agents may be of value in the treatment of preterm labor.

Adult↗
PubMed1992

The natural interleukin-1 receptor antagonist prevents interleukin-1-induced preterm delivery in mice.

OBJECTIVES: Interleukin-1 has been implicated in the mechanisms responsible for preterm parturition in the setting of intrauterine infection. This cytokine is produced by human decidua, stimulates prostaglandin production by intrauterine tissues, and induces preterm parturition in mice. The purpose of this study was to determine whether pretreatment with the natural interleukin-1 receptor antagonist can block interleukin-1-induced preterm parturition in mice. STUDY DESIGN: Balb/CJ female mice impregnated by B6D2 F-1 male mice were randomly allocated to one of the following treatment groups: (1) saline solution (n = 15), (2) human recombinant interleukin-1 alpha or human recombinant interleukin-1 beta (n = 12), (3) human recombinant interleukin-1 receptor antagonist (n = 13), and (4) human recombinant interleukin-1 receptor antagonist plus human recombinant interleukin-1 (n = 24). RESULTS: An interleukin-1 dose of 10 micrograms per mouse induced preterm parturition in all cases. Pretreatment with interleukin-1 receptor antagonist (dose 1 mg per animal) prevented interleukin-1-induced preterm parturition. Interleukin-1 receptor antagonist administration was not associated with demonstrable side effects including behavioral changes, vaginal bleeding, duration of pregnancy, and pregnancy outcome. CONCLUSION: Our results suggest that interleukin-1-induced preterm delivery in mice is mediated by the interleukin-1 receptor.

Animals↗
PubMed1992

Infection and labor. VIII. Microbial invasion of the amniotic cavity in patients with suspected cervical incompetence: prevalence and clinical significance.

OBJECTIVE: The purpose of this study was to determine the prevalence and clinical significance of microbial invasion of the amniotic cavity in patients presenting with cervical dilatation in the midtrimester of pregnancy. STUDY DESIGN: Amniocentesis for microbial studies was performed in women admitted with cervical dilatation > or = 2 cm, intact membranes, and without active labor between 14 and 24 weeks of gestation. Amniotic fluid was cultured for aerobic and anaerobic bacteria, as well as for mycoplasmas. Gram stain was performed on all samples. RESULTS: The prevalence of microbial invasion of the amniotic cavity was 51.5% (17/33). The most common microbial isolates were Ureaplasma urealyticum, Gardnerella vaginalis, Candida albicans, and Fusobacterium sp. All patients with microbial invasion of the amniotic cavity had complications. Patients who underwent cervical cerclage in the presence of a positive amniotic fluid culture had rupture of membranes, clinical chorioamnionitis, or pregnancy loss. On the other hand, the prognosis of patients with a negative amniotic fluid culture was better than that of patients with a positive culture. Of 16 patients with a negative amniotic culture, nine were delivered at > 34 weeks. CONCLUSIONS: (1) Microbial invasion of the amniotic cavity occurs frequently in women presenting with cervical dilatation in the midtrimester; (2) the microbiologic state of the amniotic cavity is an important prognostic factor for pregnancy outcome; (3) amniocentesis to determine the microbiologic characteristics of the amniotic cavity should be considered before a cerclage is placed in women presenting with cervical dilatation in the midtrimester.

Abortion, Spontaneous↗
PubMed1992

Lipoprotein abnormalities in hyperlipidemic and normolipidemic men on hemodialysis with chronic renal failure.

Lipids, lipoproteins, apolipoproteins (apo) and apo E polymorphism were determined in 101 men with chronic renal failure (CRF) were were on hemodialysis and 101 healthy controls matched for age and sex. Patients with CRF on hemodialysis had significantly higher levels of serum triglycerides, very-low-density lipoprotein (VLDL) cholesterol, intermediate-density lipoproteins (IDL), and lower levels of low- and high-density lipoproteins (LDL and HDL, respectively) than controls. Regarding apolipoproteins, serum apo B concentrations were decreased. Apo C-III concentrations in sera and in VLDL and HDL fractions were significantly increased in 35 hemodialysis patients compared with 32 controls. Seventy-eight of the 101 CRF patients had normal serum cholesterol and triglycerides (less than 5.2 mmol/liter and less than 2.3 mmol/liter, respectively). However, this subgroup also showed a significant increase in VLDL-triglycerides and serum apo E concentration in addition to changes observed in the group as a whole. Apo E polymorphism in our study population did not differ from that reported for other European populations. According to the different apo E phenotypes, lipids and lipoprotein composition showed no significant differences in controls or patients. We conclude that accumulation of triglyceride-rich lipoproteins in patients with CRF on hemodialysis may thus be at least in part related to the enrichment of apo C-III in VLDL and HDL fractions. Lipoprotein profile in hemodialysis patients, including those with normal serum cholesterol and triglyceride levels, is consistent with high cardiovascular risk.

Adult↗
PubMed1992

Effect of bezafibrate on lipoprotein (a) and triglyceride-rich lipoproteins, including intermediate-density lipoproteins, in patients with chronic renal failure receiving haemodialysis.

The effect of bezafibrate, at doses of 200 mg three times weekly throughout a period of 10 weeks, on lipoprotein (a) and triglyceride-rich lipoproteins including intermediate-density lipoproteins (IDL) has been studied in 12 patients with chronic renal failure receiving haemodialysis. No side-effects were observed, and serum creatine phosphate kinase values remained within normal limits throughout the duration of the study. Serum cholesterol, triglycerides and apoprotein (apo) B significantly decreased after bezafibrate, whereas apo A-I increased significantly. Serum lipoprotein (a) decreased after bezafibrate, although differences reached no statistical significance. The very-low-density lipoproteins (VLDL) cholesterol and the VLDL triglycerides decreased from 0.93 +/- 0.45 mmol/l (Mean +/- SD) to 0.54 +/- 0.27 mmol/l (P less than 0.05) and from 1.50 +/- 0.58 mmol/l to 0.91 +/- 0.35 mmol/l (P less than 0.01) respectively. The IDL cholesterol and IDL triglycerides decreased from 0.44 +/- 0.35 mmol/l to 0.20 +/- 0.18 mmol/l (P = NS) and from 0.46 +/- 0.35 mmol/l to 0.17 +/- 0.12 mmol/l (P less than 0.05) respectively. These data, with a substantial improvement of the lipoprotein profile in patients with chronic renal failure on haemodialysis after treatment with bezafibrate, suggest a decrease in the coronary heart disease risk.

Adult↗
PubMed1992

Aromatase activity and estradiol in human breast cancer: its relationship to estradiol and epidermal growth factor receptors and to tumor-node-metastasis staging.

PURPOSE: The present report attempts to clarify whether there is a relationship between aromatase activity (ARAC) and estradiol (E2), hormonal receptors, E2 receptor (ER), and epidermal growth factor receptor (EGFR), as well as with tumor stage and histopathology in human breast cancers. MATERIALS AND METHODS: We studied 225 breast carcinomas, 67 of which were premenopausal and 158 postmenopausal. In each sample, ARAC, EGFR, ER, and E2 were quantified. ARAC was quantified by Thompson and Siiterii's method, EGFR was quantified with a two-point assay method using radioactive iodine (125I)-EGF as ligand, and ER was measured by the Scatchard method using 3H-E2. E2 was quantified by radioimmunoassay in the diethylether tumor extract. RESULTS: ARAC was found in 64% of the cancers studied. There is a strong direct association between ARAC and tumor size in postmenopausal patients (P = .001). In the postmenopausal group, the proportion of ARAC-positive (ARAC+) tumors is significantly higher among ER-positive (ER+) than ER-negative (ER-) ones (P less than .001). ER+ tumors also have significantly higher levels of E2 than do ER- ones (P less than .0001); similarly, ARAC+ tumors have significantly higher levels of E2 than do ARAC- ones (P less than .0001). There is a significant multiple linear correlation between the log of the levels of ARAC, ER, and EGFR and the log of tumor E2 (P less than .0001). The correlation coefficients obtained show that ARAC and ER have a positive effect on tumor E2. CONCLUSION: The results obtained suggest the importance of tumor ARAC in the tumoral levels of E2 and reinforce the possible biologic significance of tumor ARAC, especially in postmenopausal breast carcinoma patients.

Adult↗
PubMed1992

Effect of social class and nutrient intake on height and plasma insulin-like growth factor in Andean Equadorian children.

The purpose of this study was to assess the validity of insulin-like growth factor (IGFI) determination as an index of nutritional status and growth in Equadorian schoolboys. Plasma IGFI was measured in 144 healthy boys, 9 years old, who were classified by their social class in four groups: 1 (n = 29); 2 (n = 49); 3 (n = 28); 4 (n = 8). Children in groups 1 and 2, of the lower socio-economic class, had significantly reduced caloric and protein intakes compared to children in groups 3 and 4 (P less than 0.01). Mean heights were significantly lower in groups 1 and 2 (P less than 0.001 and less than 0.05, respectively). The mean plasma IGFI in group 1 was 561 +/- 64 mU/ml and significantly lower than that in groups 2-4 (872 +/- 75, 986 +/- 94, and 1238 +/- 190 mU/ml in groups 2, 3 and 4, respectively) (P less than 0.01). The effect of caloric and nitrogen supplementation was studied in 36 children taken from groups 1 and 2 combined, and divided into three subgroups; they were given (1) an animal protein supplement of 18 g/day with 860 kcal/day (n = 12), (2) a vegetable protein supplement of 17.8 g/day based on a traditional Andean food with 862 kcal/day (n = 12), and (3) a placebo (n = 12). The IGFI levels increased significantly after 7 and 14 days in both subgroups 1 and 2. These results demonstrate that plasma IGFI reflects the nutritional status and responds to a short-term diet supplementation. It may provide a reliable means of assessing the effect of nutritional programs intended to improve the growth of children in underdeveloped countries.

Body Height↗
PubMed1991

Human decidua: a source of cachectin-tumor necrosis factor.

Cachectin-tumor necrosis factor (TNF-alpha) has been implicated as a possible signal for the initiation of human parturition in the setting of infection. These studies were conducted to determine whether human decidua can produce TNF-alpha in response to bacterial lipopolysaccharide (LPS). Decidual explants from women undergoing elective cesarean sections were incubated with and without Escherichia coli LPS (25 ng/ml) for 20 h. TNF-alpha concentration in the conditioned media was measured with an enzyme-linked immunoassay and bioassay (L929 bioassay). While conditioned media from unstimulated decidual explants contained either undetectable or low levels of TNF-alpha, conditioned media from LPS stimulated decidua contained TNF-alpha (mean = 2.6 pmol/mg protein per 20 hours, SEM +/- 1.03). There was a strong correlation between the immunoreactive and bioactive TNF-alpha (Spearman rank correlation r = 0.76, P less than 0.001). We conclude that human decidua in vitro can produce TNF-alpha in response to LPS.

Decidua↗
PubMed1991

Comparison of total fetal activity measurement with the biophysical profile in predicting intra-amniotic infection in preterm premature rupture of membranes.

A comparison was made between measurement of total fetal activity and biophysical profile as predictors of infection in preterm premature rupture of membranes. Sixty-four patients with premature rupture of membranes, not in labor, between 24 and 34 weeks' gestation were studied. All patients had an amniocentesis and 25 patients were diagnosed as having intra-amniotic infection. The sensitivities of the tests were 96% and 92%, respectively, with specificities of 82% and 59%. Measurement of the total fetal activity had significantly better specificity.

Journal Article↗
PubMed1991

Oxytocin secretion and human parturition: pulse frequency and duration increase during spontaneous labor in women.

The secretory pattern of oxytocin was determined in blood samples taken at 1-minute intervals for 30 minutes from 32 parturient women. The samples were collected in a manner that minimized degradation by plasma oxytocinase, and a highly specific antibody was used for the radioimmunoassay. The results indicated that oxytocin is secreted in discrete pulses of short duration. The frequency of the pulses was significantly higher during spontaneous labor than before the onset of labor. The mean pulse frequencies per 30 minutes were 1.2 +/- 0.54 before labor, 4.2 +/- 0.45 during the first stage, and 6.7 +/- 0.49 during the second and third stages of labor. The mean pulse durations in these three groups were 1.2 +/- 0.20, 1.9 +/- 0.28, and 2.0 +/- 0.26 minutes, respectively. The amplitude of the pulses was variable with no significant differences between the groups, the majority being around 1.0 microU/ml. The spontaneous pulses were of similar magnitude as those measured in 18 women after intravenous injections of 4 to 16 mU of oxytocin, which doses stimulated uterine contractions. We therefore conclude that the pulses of oxytocin observed at increasing frequency during spontaneous labor are of physiologic significance and provide evidence for the participation of oxytocin in the onset and maintenance of spontaneous labor.

Analysis of Variance↗