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Biomedical subjects

R Gomez

Publications and source records attributed to R Gomez.

At least 109 records · Page 6Linked to original sources

Cystic hygroma of the arm: a case report and review of the literature.

Cystic hygromas arising outside of the cervicofacial, thoracic, and abdominal areas are extremely rare. Detailed descriptions of this lesions along with its MRI findings, in the extremities are lacking in the literature. The following case report describes such a lesion occurring in the arm.

Adult↗

Serum C-reactive protein, white blood cell count, and amniotic fluid white blood cell count in women with preterm premature rupture of membranes.

OBJECTIVE: To compare the diagnostic performance of maternal blood C-reactive protein, white blood cell count (WBC), and amniotic fluid (AF) WBC in the identification of positive AF culture, histologic and clinical chorioamnionitis, and neonatal morbidity in women with preterm premature rupture of membranes (PROM). METHODS: Maternal blood was collected for the determination of C-reactive protein and WBC at the time of amniocentesis from 90 women with preterm PROM. Amniotic fluid was cultured for aerobic and anaerobic bacteria as well as mycoplasmas. Amniotic fluid WBC was determined for research purposes. Receiver operating characteristic curve and logistic regression were used for statistical analysis. RESULTS: The prevalence of positive AF culture was 28% (25 of 90). Women with positive AF culture and clinical chorioamnionitis had significantly higher median C-reactive protein, WBC, and AF WBC than did women without these conditions (P < .05), whereas women with histologic chorioamnionitis and significant neonatal morbidity had higher median C-reactive protein and AF WBC, but not WBC, than those without the conditions (P < .05). An AF WBC of at least 20 cells per mm3 had a greater sensitivity than C-reactive protein (cutoff, 0.7 mg/dL) and WBC (cutoff, 13,000 cells per mm3) in the detection of positive AF culture and histologic chorioamnionitis. Logistic regression analysis indicated that among AF WBC, C-reactive protein, and WBC, AF WBC was the best predictor of positive AF culture (odds ratio [OR] 24.2, 95% confidence interval [CI] 6.0, 97.5, P < .001), histologic (OR 74.0, 95% CI 7.4, 736.3, P < .001) and clinical chorioamnionitis (OR 8.9, 95% CI 0.9, 85.6, P = .057), and neonatal morbidity (OR 4.3, 95% CI 1.1, 16.6, P < .05). CONCLUSION: Amniotic fluid WBC performs better than C-reactive protein and maternal blood WBC in the diagnosis of positive AF culture, histologic and clinical chorioamnionitis, and neonatal morbidity in women with preterm PROM.

Adult↗

Increase in prostaglandin bioavailability precedes the onset of human parturition.

The traditional paradigm that prostaglandins (PGS) are of central importance in the initiation of labor has been challenged. A group of investigators has recently reported that the amniotic fluid concentrations of PGE(2) and PGF(2 alpha) increase only late in the course of labor implying that "the accumulation of prostaglandins in amniotic fluid is an after-effect of labor and not indicative of a role of these compounds in the initiation of human parturition." The present study was conducted to determine whether amniotic fluid prostaglandin concentrations increase prior to the onset of human labor, the central question in this controversy. Three amniocenteses were performed in 17 women with intrahepatic cholestasis of pregnancy -- the first two prior to the onset of labor and the third during early spontaneous labor. PGE(2) and PGF(2 alpha) were measured with sensitive and specific radioimmunoassays. Amniotic fluid concentrations of PGE(2) and PGF(2 alpha) increased prior to the onset of spontaneous labor. An additional increase in the concentrations of PGE(2) and PGF(2 alpha) was found in samples obtained in early labor. We conclude that an increase in prostaglandin bioavailability precedes the onset of spontaneous human parturition.

Amniocentesis↗

Colocalization of glucagon-like peptide-1 (GLP-1) receptors, glucose transporter GLUT-2, and glucokinase mRNAs in rat hypothalamic cells: evidence for a role of GLP-1 receptor agonists as an inhibitory signal for food and water intake.

This study was designed to determine the possible role of brain glucagon-like peptide-1 (GLP-1) receptors in feeding behavior. In situ hybridization showed colocalization of the mRNAs for GLP-1 receptors, glucokinase, and GLUT-2 in the third ventricle wall and adjacent arcuate nucleus, median eminence, and supraoptic nucleus. These brain areas are considered to contain glucose-sensitive neurons mediating feeding behavior. Because GLP-1 receptors, GLUT-2, and glucokinase are proteins involved in the multistep process of glucose sensing in pancreatic beta cells, the colocalization of specific GLP-1 receptors and glucose sensing-related proteins in hypothalamic neurons supports a role of this peptide in the hypothalamic regulation of macronutrient and water intake. This hypothesis was confirmed by analyzing the effects of both systemic and central administration of GLP-1 receptor ligands. Acute or subchronic intraperitoneal administration of GLP-1 (7-36) amide did not modify food and water intake, although a dose-dependent loss of body weight gain was observed 24 h after acute administration of the higher dose of the peptide. By contrast, the intracerebroventricular (i.c.v.) administration of GLP-1 (7-36) amide produced a biphasic effect on food intake characterized by an increase in the amount of food intake after acute i.c.v. delivery of 100 ng of the peptide. There was a marked reduction of food ingestion with the 1,000 and 2,000 ng doses of the peptide, which also produced a significant decrease of water intake. These effects seemed to be specific because i.c.v. administration of GLP-1 (1-37), a peptide with lower biological activity than GLP-1 (7-36) amide, did not change feeding behavior in food-deprived animals. Exendin-4, when given by i.c.v. administration in a broad range of doses (0.2, 1, 5, 25, 100, and 500 ng), proved to be a potent agonist of GLP-1 (7-36) amide. It decreased, in a dose-dependent manner, both food and water intake, starting at the dose of 25 ng per injection. Pretreatment with an i.c.v. dose of a GLP-1 receptor antagonist [exendin (9-39); 2,500 ng] reversed the inhibitory effects of GLP-1 (7-36) amide (1,000 ng dose) and exendin-4 (25 ng dose) on food and water ingestion. These findings suggest that GLP-1 (7-36) amide may modulate both food and drink intake in the rat through a central mechanism.

Animals↗

GRO alpha in the fetomaternal and amniotic fluid compartments during pregnancy and parturition.

PROBLEM: GRO alpha/MGSA is a new member of the chemokine superfamily CXC(alpha) and is produced by a variety of cells including macrophages, fibroblasts, epithelial, and endothelial cells, and keratinocytes. This chemokine has chemoattractant activity and may participate in neutrophil recruitment and activation during the course of intrauterine infection. This study was conducted to investigate the effect of labor and microbial invasion of the amniotic cavity (MIAC) on amniotic fluid, fetal, and maternal plasma GRO alpha concentrations. METHOD: A cross-sectional study was designed using parameters that included gestational age, results of amniotic fluid (AF) cultures, and labor status at the time of amniocentesis. Fluid was retrieved by transabdominal amniocentesis. MIAC was defined as a positive amniotic fluid culture for bacteria. Umbilical cord blood was retrieved at the time of delivery. Amniotic fluid, maternal and fetal plasma GRO alpha concentrations were measured with a sensitive and specific ELISA (Quantikine, R&D Systems, Minneapolis, MN). RESULTS: 1) GRO alpha was detectable in amniotic fluid, umbilical cord, and maternal plasma samples; 2) GRO alpha concentrations in amniotic fluid increased with advancing gestational age; 3) Both term and preterm gestations with MIAC were associated with higher amniotic fluid GRO alpha concentrations than those with sterile amniotic fluid, independent of the labor status (term, MIAC, labor: median 2.7 ng/ml, range 1.4-12.7 vs. term, no MIAC, labor: median 2.1 ng/ml, range 0.7-3.4, vs term, no MIAC, no labor: median 1.9 ng/ml, range 1.8-4.2; P < 0.005; preterm: MIAC median 5 ng/ml, range 0.6-47.9 vs. no MIAC: median 2.3 ng/ml, range 0.5-10; P < 0.008); 4) A strong correlation was found between umbilical cord plasma GRO alpha concentrations and neonatal neutrophil count, and between GRO alpha concentrations and white blood cell count in the amniotic fluid (r = 0.67, P < 0.0005 and r = 0.38, P < 0.001, respectively). CONCLUSION: GRO alpha is a physiologic constituent of amniotic fluid and cord blood. Amniotic fluid GRO alpha concentrations increase with gestational age. Intrauterine infection both preterm and at term is associated with an increase in GRO alpha concentrations of amniotic fluid, suggesting that GRO alpha may play an important role in recruitment of neutrophils into the amniotic cavity.

Amniotic Fluid↗

Liver transplantation in patients with Budd-Chiari syndrome.

Patients with Budd-Chiari syndrome (obstruction of the hepatic veins) and associated hepatic insufficiency may be candidates for orthotopic liver transplantation (OLT). In our series of 405 OLT patients, 3 were transplanted due to Budd-Chiari syndrome (0.7%). The indication for liver transplantation in these patients was severe hepatic insufficiency (chronic in two and acute in the third one). Morphologic study of the obstructions revealed apparently different causes, including thrombi, membranous webs in hepatic veins, and hydatid cyst compression. The surgical technique employed in these transplantations was similar to that for other etiologies. Due to its implications for the future course of OLT, it is important to determine the exact etiology of Budd-Chiari syndrome in the pretransplant period and to treat the patients with early and long-term anticoagulant therapy to avoid syndrome recurrence.

Adolescent↗

Amniotic fluid interleukin-6: a sensitive test for antenatal diagnosis of acute inflammatory lesions of preterm placenta and prediction of perinatal morbidity.

OBJECTIVE: Our purpose was to determine whether amniotic fluid concentrations of interleukin-6 are of value in the antenatal diagnosis of acute inflammatory lesions (histologic chorioamnionitis) of preterm placenta and in the prediction of perinatal morbidity and mortality. STUDY DESIGN: The relation among placental histologic findings, perinatal outcome, and amniotic fluid interleukin-6 concentrations was examined in 50 consecutive patients who delivered preterm neonates within 72 hours after amniocentesis. Interleukin-6 was determined by enzyme-linked immunosorbent assays. Receiver-operator characteristic curve was used for analysis. RESULTS: Patients with acute histologic chorioamnionitis had significantly higher median amniotic fluid interleukin-6 concentrations than patients without histologic chorioamnionitis (median 70.8 ng/ml, range 0.7 to 499.2 ng/ml vs median 2.9 ng/ml, range 0.8 to 16.0 ng/ml, respectively; p < 0.00001). An amniotic fluid interleukin-6 concentration > 17 ng/ml had a sensitivity of 79% (23/29) and a specificity of 100% (21/21) in the diagnosis of acute histologic chorioamnionitis and a sensitivity of 69% (18/26) and a specificity of 79% (19/24) in the prediction of significant neonatal morbidity (defined as neonatal sepsis, respiratory distress syndrome, pneumonia, intraventricular hemorrhage, bronchopulmonary dysplasia, or necrotizing enterocolitis) and mortality. These sensitivities were significantly higher than those of amniotic fluid culture (79% vs 38%, p < 0.005; 69% vs 27%, p < 0.01, respectively). CONCLUSIONS: Amniotic fluid interleukin-6 is a sensitive test for the prospective diagnosis of acute histologic chorioamnionitis and the identification of neonates at risk for significant morbidity and mortality.

Amniotic Fluid↗

Amniotic fluid interleukin-6: correlation with upper genital tract microbial colonization and gestational age in women delivered after spontaneous labor versus indicated delivery.

OBJECTIVE: Our purpose was to determine whether amniotic fluid interleukin-6 is increased and inversely proportional to gestational age in women with chorioamnion colonization and spontaneous labor versus women delivered for medical or obstetric indications. STUDY DESIGN: The chorioamnion and amniotic fluid were cultured at cesarean delivery for aerobic and anaerobic bacteria, fungi, mycoplasmas, Chlamydia trachomatis and Trichomonas vaginalis in 269 women with singleton gestations with intact membranes. The amniotic fluid interleukin-6 concentration was also determined. RESULTS: Amniotic fluid interleukin-6 levels were (1) higher in women with spontaneous labor versus those with indicated deliveries (15.8 +/- 5.0 vs 2.2 +/- 0.2 ng/ml, p = 0.01), (2) inversely proportional to gestational age in women with spontaneous labor (< 34 weeks: 47.4 +/- 18.0 ng/ml vs > or = 34 weeks: 8.7 +/- 4.1 ng/ml, p = 0.001) but not in women with indicated deliveries (1.5 +/- 0.4 vs 2.4 +/- 0.3 ng/ml), (3) higher in women with a positive versus a negative chorioamnion (15.1 +/- 4.8 vs 3.0 +/- 0.8 ng/ml, p < 0.001) or amniotic fluid (17.4 +/- 7.7 vs 3.8 +/- 0.9 ng/ml, p < 0.001) culture, and (4) higher in women with a negative amniotic fluid but positive chorioamnion culture compared with women in whom both cultures were negative (10.0 +/- 4.4 vs 3.0 +/- 0.9 ng/ml, p = 0.002). CONCLUSIONS: Amniotic fluid interleukin-6 levels are (1) higher and inversely proportional to gestational age in women with intact membranes and spontaneous labor versus indicated deliveries, (2) higher in women with one or more microorganisms in the chorioamnion or amniotic fluid, and (3) reflective of chorioamnion microbial colonization, even when the amniotic fluid culture is negative, and may be a useful clinical marker for infection-mediated preterm labor.

Amnion↗

Premature parturition is characterized by in utero activation of the fetal immune system.

OBJECTIVE: At birth the fetus emerges from a sterile environment into a nonsterile one. This process is associated with activation of the fetal immune system which protects the fetus against infection in the newborn period. We conducted this study to determine whether activation of the monocyte-neutrophil system occurs in fetuses before premature birth. STUDY DESIGN: Forty patients in premature labor with intact membranes underwent cordocentesis for research purposes. Fetal blood was analyzed with the use of flow cytometry to measure the cell surface markers CD11c, CD13, CD15, and CD67, which are associated with monocyte and neutrophil activation, and CD14 and CD63, which were used as controls. RESULTS: Twenty-eight percent (11/40) of the infants were delivered prematurely within 72 hours of entering the study while the remainder were delivered at term. Our data clearly indicate that premature infants delivered within 72 hours had a higher percentage of CD11c, CD13, CD15, and CD67 than those delivered at term. In contrast, there were no significant differences in the percentages of CD14 and CD63. CONCLUSION: Activation of the monocyte-neutrophil system exists in fetuses destined for premature delivery. These findings indicate that premature parturition is associated with in utero immune system activation.

Adolescent↗

Doppler velocimetry of the fetal middle cerebral artery in patients with preterm labor and intact membranes.

A prospective cohort study was conducted to determine whether preterm labor is associated with changes in the impedance to blood flow of the fetal middle cerebral artery. Doppler velocimetry studies were performed in 194 consecutive patients with preterm labor and intact membranes. Pulsatility indices of the middle cerebral artery and umbilical artery were determined on admission. Results were expressed as ratio of the observed pulsatility index to mean value for gestational age expressed as delta MCA PI and delta UA PI, respectively. The prevalence of preterm delivery (< 37 weeks) and delivery within 24 hours of admission was 55.2% (107/194) and 15.5% (30/194), respectively. Patients with an examination-to-delivery interval within 24 hours had significantly lower mean delta MCA PI than that of patients delivered at > or = 37 weeks and > or = 4 weeks after the examination (P < 0.01). Fetuses with a delta MCA PI at or below 0.88 had a relative risk of 2 (95% confidence interval, 1.32 to 2.9) who were delivered within 24 hours compared to controls (sensitivity 76.7%, specificity 62.8%, positive predictive value 26.7%, negative predictive value 93.5%). Stepwise logistic regression analysis indicated that the relationship between delta MCA PI and examination-to-delivery interval remained statistically significant after correcting for cervical dilatation (P < 0.001). Our data indicate that preterm parturition is associated with a decrease in the impedance to flow in the fetal cerebral circulation.

Adult↗

[Liver transplantation using grafts from donors over 65].

OBJECTIVE: Donors age 50 years was an exclusion criteria in past decades. The increase of patients in the waiting list has determined the acceptance of older donors (over 65 years old). We analyze our results in liver transplantation using donors over 65 years. PATIENTS: From 1986 to may 1994, we performed 381 OLT. In five cases (1.3%) the OLT was performed using donors over 65 years of age (66, 67, 68, 70 and 71). The selection criteria for donors and recipients were similar to the other transplanted patients. Immunosuppression included cyclosporine or FK-506, prednisone and azathioprine. RESULTS: There were no primary graft failures and preservation damage, biochemical and clinical evolution were not different to the procedures using younger donors. Three grafts presented non-corticoresistant acute rejection. After a follow-up of 11.6 mo (range 4-37 mo) only one graft was lost (Kaposi's sarcoma in the liver). Four grafts and four patients are in excellent biochemical and clinical condition. CONCLUSIONS: Donor age should not be an exclusion criteria. Grafts from older donors (over 65 years old) may be considered safe and will permit to increase the number of OLT.

Adult↗

Adrenergic and non-adrenergic spinal projections of a cardiovascular-active pressor area of medulla oblongata: quantitative topographic analysis.

A cardiovascular-active pressor area of medullary reticular formation was defined by mapping changes in arterial blood pressure produced by microinjections of the neuroexcitatory amino acid, L-Glutamate (L-Glu). Sites where L-Glu provoked pressor responses larger than 10 mmHg were localized to a rostral longitudinal cell column of the nucleus reticularis rostroventrolateralis (n.RVL) extending 450 microns posteriorly to the facial nucleus. Spinal projections from the ventrolateral medulla were studied with a dual retrograde transport-immunocytochemical method. A striking correspondence was observed between the ventrolateral pressor area (VLPA) of n.RVL and rostrocaudal distribution of a circumscribed population of thoracic reticulospinal neurons containing tyrosine hydroxylase (TH)- or phenylethanolamine N-methyltransferase (PNMT)_immunoreactivity. Quantitative analysis revealed that 72% of the total number of retrogradely labeled neurons within the active area were immunocytochemically positive for TH; 28% of the reticulospinal projection cells were immunonegative. Deposits of L-Glu and dye through the same micropipettes verified a consistent correlation of vasopressor sites and the rostral subset of catecholaminergic neurons. Since comparable numbers of cell bodies in the VLPA contain TH and PNMT all are presumed to be adrenergic. At levels of n.RVL immediately adjacent to the VLPA commencing at a level 450 microns caudal to the facial nucleus, sites were unresponsive to Glu-stimulation or vasodepressor. At these levels, only non-adrenergic reticulospinal neurons project to cervical or thoracic spinal segments. We conclude that the VLPA is highly restricted to a narrow column of n.RVL < 0.5 mm in length and corresponds precisely with a population of predominantly adrenergic thoracic reticulospinal neurons that project exclusively to sympathoadrenal preganglionic motoneurons [cf 46]. These findings corroborate the idea that an adrenergic-spinal pathway may play a role in controlling sympathetic outflow.

Animals↗

Is oligohydramnios a risk factor for infection in term premature rupture of membranes?

Our objective was to determine if a reduced volume of amniotic fluid is a risk factor for microbial invasion of the amniotic cavity in women with rupture of membranes at term. Transabdominal amniocentesis under ultrasound guidance was used to evaluate the microbiological state of the amniotic cavity in 53 patients with term premature rupture of membranes before vaginal examination. Amniotic fluid index was measured prior to the procedure in all cases. The prevalence of microbial invasion of the amniotic cavity was 32.1% (17/53). Women with microbial invasion of the amniotic cavity had a significantly lower median amniotic fluid index than did women without evidence of infection (median 4.4 cm, range 1.0-8.1 vs. median 7.8 cm, range 1.3-14.4, respectively; p < 0.001). An amniotic fluid index of < 5 cm had a sensitivity of 71% (12/17) a specificity of 89% (32/36), a positive predictive value of 75% (12/16) and a negative predictive value of 87% (32/37) in the prediction of microbial invasion of the amniotic cavity. Among women who delivered vaginally, those with an amniotic fluid index of < 5 cm had a higher rate of endometritis than those with an amniotic fluid index of >or= 5 cm (19% (3/16) vs. 0% (0/26), respectively; p < 0.05). We conclude that women with term premature rupture of membranes and an amniotic fluid index of < 5 cm are at an increased risk for microbial invasion of the amniotic cavity and puerperal infection after a vaginal delivery.

Journal Article↗

Regulation of protein kinase C by transforming growth factor beta 1 in rat costochondral chondrocyte cultures.

Transforming growth factor beta (TGF-beta) regulates the proliferation and differentiation of chondrocytes; however, the mechanism of TGF-beta signal transduction remains unclear. We examined whether the response to TGF-beta is mediated by protein kinase C activity in chondrocytes at different stages of maturation. The aims were to examine the effect of recombinant human TGF-beta 1 (rhTGF-beta 1) on protein kinase C in rat costochondral chondrocyte cultures; determine the major isoform present; assess the involvement of phospholipase C or tyrosine kinases; determine whether genomic or nongenomic pathways are involved; and test whether these mechanisms differ as a function of the stage of cell maturation. Dose-dependent increases in protein kinase C activity were observed in confluent, fourth-passage cultures of rat costochondral growth zone and resting zone chondrocytes treated with rhTGF-beta 1. In growth zone cells, elevated activity was observed at 12 h and decreased markedly by 24 h. In resting zone cells, elevated activity was observed at 9 h, maximum stimulation occurred at 12 h, and activity returned to baseline levels after 48 h. Immunoprecipitation studies showed protein kinase C alpha is the major isoform present in both untreated and treated cells. Neither the phospholipase C inhibitor, U73122, nor the tyrosine kinase inhibitor, genistein, significantly reduced the protein kinase C response to rhTGF-beta 1. Actinomycin D and cycloheximide, inhibitors of transcription and translation, produced dose-dependent inhibition of rhTGF-beta 1 stimulated protein kinase C activity in both resting zone and growth zone chondrocytes. The time course of activation and insensitivity to U73122 suggest that phospholipase C-mediated events are not involved in rhTGF-beta 1 stimulation of protein kinase C in costochondral chondrocytes. Similarly, because genistein had no effect, tyrosine kinases are not implicated. Rather, the reduction in protein kinase C activity observed when rhTGF-beta 1 is administered along with actinomycin D or cycloheximide indicates that new gene expression and protein synthesis are required for the response. These results indicate that the effect of rhTGF-beta 1 is mediated by protein kinase C; however, it is very slow and may require new protein kinase C production, perhaps via a cytokine cascade. Moreover, the classic mechanism of activation of protein kinase C by phospholipase C was not found, suggesting a novel mechanism of activation. Finally, the effects of rhTGF-beta 1 on protein kinase C are dependent on the state of cell maturation with respect to onset and duration of response.

Animals↗