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Biomedical subjects

E Guzman

Publications and source records attributed to E Guzman.

At least 37 records · Page 2Linked to original sources
PubMed1995

Nutritive value evaluated on rats of new cultivars of common beans (Phaseolus vulgaris) released in Chile.

Five new cultivars of common beans (Phaseolus vulgaris) recently released were analyzed for their proximate chemical composition and protein biological quality. The crude protein content in these cultivars ranged from 21.9 percent in cultivar Arroz 3 to 26.9 percent in cultivar Tórtola Diana (dry matter basis). Rats fed cultivar Tórtola INIA gained more weight, had a higher protein intake and registered higher PER and NPR than Tórtola corriente. On the other hand, rats consuming cultivars Arroz 3 and Fleetwood had lower weight gain, lower protein intake and lower PER and NPR than cultivar Coscorrón corriente. However, all these cultivars have a relatively good protein value as compared to other plant protein sources.

Analysis of Variance↗
PubMed1992

Purification and partial characterization of transglutaminase from Physarum polycephalum.

An intracellular form of calcium ion-dependent transglutaminase (R-glutaminylpeptide:amine gamma-glutaminyltransferase, EC 2.3.2.13) was purified 818-fold to apparent homogeneity from acetone powder preparations of spherules of the acellular slime mold Physarum polycephalum. The enzyme was purified by combined methods of precipitation with 15% (wt/vol) polyethylene glycol, DEAE-cellulose chromatography, and isoelectric focusing in a pH 5 to 7 gradient. The isoelectric point of the enzyme was 6.1. The molecular mass of the denatured enzyme was estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be 39.6 kDa. A molecular weight of 77,000 was found by gel filtration of the native enzyme on a Superose 12 fast protein liquid chromatography column, indicating that the native functional protein is a dimer. The purified transglutaminase catalyzed the incorporation of [14C]putrescine into protein substrates including casein, N,N'-dimethylcasein, actin purified from P. polycephalum, and actin purified from bovine muscle. Actin was the preferred substrate for the enzyme, both as a purified protein and in crude extracts prepared from P. polycephalum. With N,N'-dimethylcasein as the amine acceptor substrate, [14C]putrescine, [14C]spermidine, and [14C]spermine were all effective amine donor substrates with Km values of 49, 21.4, and 31.7 microM, respectively. All three of these polyamines demonstrated strong substrate inhibition of the enzyme activity between 100 and 200 microM. Upon starvation induced by depletion of a carbon source for growth, the specific activity of this enzyme increased sixfold during the differentiation of P. polycephalum microplasmodia to spherules. This suggests a role for transglutaminase in the construction of spherules, which have the capacity to survive starvation and dessication.

Animals↗
PubMed1992

Intrauterine resuscitation in the severely distressed fetal dog.

Severe fetal distress was produced in 16 fetal dogs by successive and/or prolonged occlusion of the maternal abdominal aorta in an acute surgical preparation, and was characterized in fetal arterial blood of 7.06 for pH, 10 mm Hg for O2, 127 mm Hg for CO2, and fetal heart rate decelerations. Five fetuses recovered spontaneously in utero and delivered normally; 3 needed maternal oxygenation before delivery; 3 suddenly died in utero; 5 fetuses were delivered while still alive in utero when the tpH reached 6.85, and eventually expired. Intrauterine recovery and resuscitation was effective in some fetuses.

Animals↗
PubMed1992

Uterine-umbilical artery Doppler velocimetry in pregnant women with systemic lupus erythematosus.

We evaluated continuous wave uterine-umbilical artery Doppler velocimetry for predicting pregnancy outcome in women with systemic lupus erythematosus (SLE). Lupus anticoagulant (LAC) and anticardiolipin (ACL) antibody status also were correlated with Doppler results and outcome. Three Doppler vascular patterns were identified in 27 pregnancies of 26 women with SLE. Patients with normal flow velocity in both vessels had normal outcomes (n = 18). Reduced flow velocity of the umbilical artery only was present in five women, whose newborn infants were of lesser gestational age and birthweight, two being small for gestational age. In four pregnancies reduced flow velocity was noted in both vessels. These cases had the poorest outcome, with three perinatal losses and all fetuses being small for gestational age. Doppler velocimetry showed 100% sensitivity and negative predictive value in the detection of the small for gestational age fetus and abnormal antepartum fetal heart rate tracing. Fourteen of 18 women with normal Doppler studies did not have preeclampsia or SLE flare-ups, whereas all nine women with abnormal Doppler studies had such complications. In all 27 pregnancies the women were screened for LAC, and 21 women also were tested for the ACL antibody. Poor correlation was found between antiphospholipid antibody status and Doppler results in three of the six pregnancies with positive antibody testing the patients had normal Doppler studies and outcomes. Thus, Doppler velocimetry may help determine when these substances will affect the outcome adversely. In this study the umbilical-placental vascular system was affected more often. Uterine-umbilical arterial Doppler velocimetry uniquely identified the fetus at risk for adverse perinatal outcome in pregnancies complicated by SLE. Thus, it is a potentially valuable tool in clarifying the pathophysiology and in the management of SLE in pregnancy.

Adult↗
PubMed1990

Value of a screening fetal heart rate tracing in the latent phase of labor.

We studied the value of a screening fetal heart rate (FHR) tracing obtained on 405 women in the latent phase of labor on presentation to the labor-and-delivery suite. All pregnancies were at term and had a cephalic presentation. Thirty-two women in the sample studied underwent a cesarean section for fetal distress. Using that end point, a screening FHR tracing in the admitting room had a sensitivity of 57%, specificity of 98%, positive predictive value of 75% and overall efficiency of 95%. One- and five-minute Apgar scores and thick meconium staining of the amniotic fluid were also examined. While no statistically significant differences were found (P less than .2 for Apgar score and less than .06 for meconium), there was a trend that might have been significant if more women had been studied. A screening FHR tracing on all women at term in the latent phase of labor will identify the majority of those who will develop fetal distress in labor. Women with an abnormal screening tracing should be admitted to the hospital and the fetal status evaluated further.

Female↗
PubMed1990

A quantitative analysis of placental vasculature in the third-trimester fetus with autosomal trisomy.

Growth disturbance in the trisomic fetus is believed to be primarily fetal in origin. There has been only sparse description of placental pathology in the third trimester in these fetuses, and therefore the placental role in their growth and development remains unexplored. We performed quantitative morphometric analysis on the placentas of 18 fetuses with trisomy and ten normal control fetuses. Doppler umbilical artery analysis was performed on ten abnormal fetuses and all controls. The placentas of trisomic fetuses exhibited a significant reduction in small muscular artery count and small muscular artery/villus ratio. Abnormal Doppler waveforms correlated closely with reduced small muscular artery counts. Undervascularization and increased vascular resistance of the placenta of trisomic fetuses may contribute to diminished fetal growth. The placenta appears to be another fetal organ whose structure and function are affected adversely by abnormal karyotype.

Arterioles↗
PubMed1989

Pregnancy surveillance with Doppler velocimetry of uterine and umbilical arteries.

Previous studies with Doppler velocimetry have demonstrated a strong correlation between abnormal waveforms and fetal-maternal disease. This study was designed to evaluate the potential role of Doppler velocimetry as a screening test in routine prenatal care. Two hundred fifty-five pregnant women had routine monthly Doppler (systolic/end-diastolic ratio) studies on the uterine and umbilical arteries starting in the twentieth week of gestation. When a cutoff value of 3 was used at 30 weeks for the umbilical arteries, there were 35 (13%) positive tests. In 20 of these values fell to less than 3 in the ensuing weeks and were considered false positive. The remaining 15 babies demonstrated positive clinical pathologic correlates. When a value of 2.6 was used at 26 weeks for uterine arteries, there were nine positive results, seven of which had clinical pathologic correlates. This study suggested an overall positivity rate of 7%; therefore it provides encouragement for a larger venture in which screening and impact on decision making are evaluated.

Adult↗
PubMed1988

Prenatal surveillance using nonstress testing and Doppler velocimetry.

One hundred forty pregnant women referred to our prenatal testing laboratory for conventional nonstress testing (NST) also had a Doppler study of the umbilical arteries. The outcomes of 88 women with abnormal testing (NST or Doppler) were compared with the outcomes of 52 women who had normal results on both tests. The results demonstrated that 50% of the fetuses with decreased flow velocity who later developed an abnormal NST were growth-retarded, 75% required a cesarean section, and 63% were admitted to the neonatal intensive care unit. Development of an abnormal NST in the presence of normal velocimetry studies occurred most frequently in the postdates pregnancy; 32% required cesarean section for fetal distress. Knowledge of the umbilical circulation through Doppler studies may be of benefit when selecting patients for NST and when interpreting results.

Blood Flow Velocity↗
PubMed1988

Uterine and umbilical artery Doppler velocimetry in postterm pregnancy.

Uterine and umbilical artery Doppler velocimetry was carried out on 149 women whose pregnancies went to 41 weeks or beyond. Flow velocity was not altered even in the presence of other signs suggestive of fetal compromise. It appears that the postdate syndrome is not associated with significant alterations in the maternal or umbilical blood flow prior to the onset of labor.

Arteries↗
PubMed1987

A classification of hypertension in pregnancy based on Doppler velocimetry.

We studied 136 pregnant women with hypertension with Doppler velocimetry of the uterine and umbilical arteries. The patients were classified into four groups according to the values of the systolic/diastolic ratios. The first group had normal ratios in both the umbilical and uterine arteries. The second group had elevated umbilical ratios and normal ratios in the uterine arteries. The third group had elevated uterine artery systolic/diastolic ratios with normal umbilical artery values, and the fourth group had elevated systolic/diastolic ratios in both vessels. Women in the group with normal ratios in both the umbilical and uterine arteries were delivered of infants with a birth weight (mean +/- SD) of 3261 +/- 522 gm and gestational age of 39 +/- 2 weeks. The values for the three groups with abnormal velocimetry were: those with elevated umbilical ratios and normal ratios in the uterine arteries: body weight = 2098 +/- 811 gm, gestational age = 35.7 +/- 3.2 weeks; those with elevated uterine artery ratios with normal umbilical artery values: 2464 +/- 722 gm, gestational age = 36.3 +/- 3 weeks; and those with elevated systolic/diastolic ratios in both vessels: body weight = 1627 +/- 697 gm, gestational age = 33.3 +/- 2.7 weeks (p less than 0.01; p less than 0.001). There were 27 small for gestational age infants delivered during this study. Doppler velocimetry studies were abnormal in 26 of them (96%). Results show that Doppler-derived vascular patterns correlate well with normal and adverse perinatal outcome. A description of the uterine and umbilical systolic/diastolic ratios should be part of the clinical evaluation of all pregnant women with hypertension. This should lead to better treatment protocols and improved clinical outcome.

Adult↗
PubMed1987

Uterine artery Doppler velocimetry: the significance of divergent systolic/diastolic ratios.

Continuous wave Doppler studies were carried out on both uterine arteries in 71 pregnant women from the twentieth week of gestation onward. Analysis of the waveform included the systolic/diastolic ratio and the presence or absence of a diastolic notch. In the current study, these ratios from 31 women with left/right systolic/diastolic difference, (between left and right uterine arteries) were compared with those of women having normal ratios. A normal left/right systolic/diastolic ratio difference of 0.3 with SD of 0.3 was found. When the left/right difference was plotted against the left/right averaged systolic/diastolic ratio, a correlation coefficient of 0.7 was noted (p less than 0.001). Significant outcome differences were noted between normal and abnormal left/right difference systolic/diastolic ratios in the perinatal parameters of gestational age at delivery, fetal weight, pregnancy-induced hypertension, proteinuria, and intrauterine growth retardation. Divergent uterine artery ratio findings are a result of one artery being the dominant supplier to the placenta. The majority of women with an elevated systolic/diastolic ratio seem to have divergent uterine blood supply to the uterus and placenta. These data suggest that errors in placentation site contribute to the development of preeclampsia and growth retardation in the fetus.

Arteries↗
PubMed1986

A new peritoneovenous shunt.

For today's most common peritoneovenous shunt catheters, the high incidence of complications (disseminated intravascular coagulation [DIC], pulmonary problems, clotting of the intravascular end, and shunt kinking) results in limited use. We have designed a new peritoneovenous shunt catheter in which we improved mechanical biocompatibility with respect to both the peritoneum and the vasculature. The device consists of: a multimicroorifice ascites filter in a double-chambered collecting device, a tubular compression pump with an intratubular check-valve, and a check-valve catheter at the intravascular end for positive exclusion of blood by reflux or back diffusion. This configuration filters the proteinaceous material from the ascites fluid, transports the filtrate into the blood stream, maintains patency, act to prevent DIC by inhibiting the creation and transport of microthrombi into the cardiovascular system, and eliminates clot formation at the intravascular end.

Aged↗