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At least 181 records · Page 10Linked to original sources
PubMed2006

Biophysical profile scores and resistance indices of the umbilical artery as seen in patients with pregnancy induced hypertension.

OBJECTIVE: The role of Biophysical Profile Score and resistive index of the umbilical artery for monitoring pre-eclampsia patients. DESIGN: Descriptive prospective study. SETTING: Kenyatta National Hospital and Mater Hospital, Nairobi, Kenya. SUBJECTS: One hundred and ten cases during a three month period. RESULTS: Normal biophysical profile scores were found in 93 (84.5%), and 17 (17.5%) cases had abnormal scores ranging from mild to severe foetal distress. Resistive index of umbilical artery (RI-UA) were normal in 72 (66.1%) and high resistive index accounted for 33.9%. Intra-Uterine Growth Restriction (IUGR) was a prominent finding accounting for 30.5%. A positive relationship was shown to exist between IUGR and RI-UA and also with severity of hypertension with P-values < 0.05. Resistive index of umbilical artery was positively related to the duration of illness confirming its dependence on chronicity (P = 0.004). Resistive index of umbilical artery proved to be an earlier indicator of foetal compromise before any foetal distress becomes obvious. CONCLUSION: Regular obstetrical ultra sound foetal surveillance in pre-eclampsia patients is important for foetal wellbeing. Doppler evaluation of high risk patients is more sensitive test than the biophysical profile score.

Adolescent↗
PubMed1996

Comparison of umbilical Doppler velocimetry, nonstress testing, and biophysical profile in pregnancies complicated by diabetes.

The purpose of this study was to determine which test is best for predicting adverse outcomes in pregnancies complicated by diabetes: the nonstress test, biophysical profile, or umbilical artery velocimetry. We evaluated 207 singleton pregnancies complicated by diabetes within 1 week of delivery using the afore-mentioned pregnancy surveillance tests. Adverse pregnancy outcome was defined as delivery before 37 weeks of gestation or the occurrence of fetal growth restriction, hypocalcemia, hypoglycemia, hyperbilirubinemia, respiratory distress syndrome, or fetal risk requiring cesarean delivery. The prognostic value of each of the three tests was assessed, after controlling for the mothers' White classification and third trimester glycosylated hemoglobin value. Among the 207 pregnancies, 75 (36.2%) had an adverse outcome. In pregnancies in which the umbilical artery systolic to diastolic ratio was > or = 3.0, the relative risk of adverse outcome was 2.6 (95% confidence interval: 1.9-3.5, P < 0.001). For those with a biophysical profile < or = 6 the relative risk was 1.7 (95% confidence interval: 0.9-2.9, P = 0.109). Patients with a nonreactive nonstress test had a relative risk of 1.7 (95% confidence interval: 1.2-2.5, P = 0.009). Umbilical artery Doppler velocimetry was superior to either the nonstress test or the biophysical profile in identifying the subgroup of pregnancies complicated by diabetes that resulted in an adverse outcome.

Female↗
PubMed1999

The effect of betamethasone and dexamethasone on fetal heart rate patterns and biophysical activities. A prospective randomized trial.

UNLABELLED: BACKGROUND; Contradictory findings on the effect of betamethasone versus dexamethasone on antenatal tests of fetal well-being have been reported. The purpose of this study was to compare the effects of these steroid compounds on fetal heart rate patterns and biophysical activities in a prospective. randomized trial. STUDY DESIGN: Forty-six pregnant women (gestational age range 27-34 weeks) at risk for preterm delivery were randomized to receive betamethasone or dexamethasone for enhancement of fetal lung maturity. Fetal heart rate was recorded for 60 minutes and analyzed with the Sonicaid System 8000 before (0 hours), and 48 hours and 96 hours after steroid administration. Subsequently, fetal limb, body and breathing movements were sonographically observed and quantified for 30 minutes. To account for fetal circadian rhythms, all examinations were performed between 1 p.m. and 5 p.m., at least one hour after maternal meals. RESULTS: Fetal heart rate accelerations (p<0.001; p<0.01), short-term variation (p<0.0001; p<0.05), long-term variation (p<0.01; p=NS), duration of high episodes (p<0.001; p<0.05), total movement count (p<0.001; p<0.05), and duration of breathing time (p<0.0001; p<0.0001) were substantially reduced 48 h after betamethasone and dexamethasone administration, respectively, with percent reduction being larger for the betamethasone group, except for breathing movements (p<0.05; p<0.001; p<0.001; p<0.005; p<0.05; p=NS; respectively). In 68.2%( and 45.5% of fetuses, less than 30 seconds of continuous breathing movements were found in the betamethasone and dexamethasone groups, respectively. In 71.8% and 12.5%, of fetuses, respectively, less than 2 body/limb movements were observed. Therefore five and two fetuses in the betamethasone and dexamethasone study group, respectively, had both nonreactive fetal heart rate monitors for 60 minutes and biophysical profiles of < or =4/10. All parameters returned to baseline values at 96 h. Baseline fetal heart rate and numbers of decelerations remained unchanged (p=NS). CONCLUSIONS: Both betamethasone and dexamethasone induce a profound, albeit transient, suppression of fetal heart rate characteristics and biophysical activities in the preterm fetus. However, the effect of betamethasone is more pronounced. Awareness of these phenomena might prevent unwarranted iatrogenic delivery of preterm fetuses.

Adult↗
PubMed2002

[Effect of hormonal replacement therapy on cutaneous biophysical properties of menopausal women].

PURPOSE: The aim of this analysis was to study the possible effect of hormonal replacement therapy on some biophysical properties of the skin of menopausal women. SUBJECTS AND METHODS: A study was carried out on 106 menopausal, phototype I to IV women with clinically healthy skin. During the medical evaluation, the menopausal status, duration of the menopause, and, possible use of hormone replacement therapy and its duration were collected. A series of biophysical skin parameters in controlled environmental conditions was assessed on the face: sebum casual level, skin surface pH, skin colour, transepidermal water loss, capacitance, conductance, skin relief and temperature. The same parameters except for sebum were assessed on the forearm. Three sub-samples were defined according to the duration of the menopause and of hormone replacement therapy. RESULTS: The skin colour parameters revealed a greater red intensity value in menopausal women who had been treated for at least one year. In menopausal women who had been treated for at least 5 or 10 years, the biophysical measurements were significantly higher for the parameters evaluating hydration and sebum secretion, associated with higher values for the yellow intensity parameter and the skin relief parameters on the forehead. CONCLUSION: These results support the subjective impression and the clinical evaluation according to which hormonal replacement therapy could modify the development and the severity of some properties associated with skin ageing after the onset of menopause.

Aging↗
PubMed2003

Radiation dosimetry and biophysical models of space radiation effects.

Estimating the biological risks from space radiation remains a difficult problem because of the many radiation types including protons, heavy ions, and secondary neutrons, and the absence of epidemiology data for these radiation types. Developing useful biophysical parameters or models that relate energy deposition by space particles to the probabilities of biological outcomes is a complex problem. Physical measurements of space radiation include the absorbed dose, dose equivalent, and linear energy transfer (LET) spectra. In contrast to conventional dosimetric methods, models of radiation track structure provide descriptions of energy deposition events in biomolecules, cells, or tissues, which can be used to develop biophysical models of radiation risks. In this paper, we address the biophysical description of heavy particle tracks in the context of the interpretation of both space radiation dosimetry and radiobiology data, which may provide insights into new approaches to these problems.

Astronauts↗
PubMed2005

[Correlation analysis between biochemical and biophysical markers of endothelium damage in children with diabetes type 1].

UNLABELLED: Endothelial damage is one of the earliest stages in the atherosclerosis process. Adhesion molecules, secreted from dysfunctional endothelial cells are considered as early markers of atherosclerotic disease. Ultrasonographic evaluation of brachial arteries serves to detect biophysical changes in endothelial function, and evaluation of carotid arteries intima-media thickness allows to evaluate the earliest structural changes in the vessels. The aim of the study was to the evaluate levels of selected adhesion molecules (sICAM-1, sVCAM-1, sE-selectin, sP-selectin) and endothelial function with use of brachial artery dilatation study (flow mediated dilation--FMD, nitroglycerine mediated dilation--NTGMD) and IMT in carotid arteries in children and adolescents with diabetes type 1, as well as the correlation analysis between biochemical and biophysical markers of endothelial dysfunction. MATERIAL AND METHODS: We studied 76 children and adolescents, with mean age--15.6+/-2.5 years, suffering from diabetes mean 7.8+/-2.8 years, mean HbA1c--8.4+/-1.5%. Control group consisted of 33 healthy children age and gender matched. Adhesion molecules levels were estimated with the use of immunoenzymatic methods (R&D Systems). Endothelial function was evaluated by study of brachial arteries dilation--FMD, NTGMD, with ultrasonographic evaluation (Hewlett Packard Sonos 4500) after Celermajer method, and IMT after Pignoli method. RESULTS: In the study group we found elevated levels of sICAM-1: 309.54+/-64 vs. 277.85+/-52 ng/ml in the control group (p<00.05) and elevated level of sE-selectin: 87.81+/-35 vs. 66.21+/-22 ng/ml (p<00.05). We found significantly impaired FMD in brachial arteries in the study group--7.51+/-4.52 vs. 12.61+/-4.65% (p<00.05) and significantly higher IMT value: 0.51+/-0.07 vs. 0.42+/-0.05 mm (p<00.001). Correlation analysis revealed a significant negative correlation between sE-selectin and FMD - r=-0.33 (p=0.004), and a positive correlation between E-selectin and IMT: r=0.32 (p=0.005). CONCLUSIONS: 1. In children and adolescents with diabetes type 1 we found elevated levels of adhesion molecules sICAM-1 and sE-selectin, what can confirm an endothelial dysfunction in these patients. 2. Significant negative correlation between sE-selectin level and FMD, and positive correlation between sE-selectin and IMT were found. 3. Biophysical proof of this damage is impaired brachial artery dilatation--FMD, and increased IMT values provide information about structural changes in the vessels.

Adolescent↗
PubMed1990

[Biophysical profile in prolonged pregnancy. Another alternative of fetal surveillance].

The value of the biophysical profile scoring to predict occur-rate perinatal outcome in prolonged pregnancy, was assessed. 60 patients with the diagnosis of prolonged pregnancy were included in this prospective clinical trial. A fetal biophysical profile score, described by Manning and modified by Johnson, was recorded in all these patients. There were 40 cases (66%) with normal profile scoring 3 of which had a feature considered as perinatal morbidity (specificity 94.8%). In contrast, from 20 cases with abnormal profile scores, 18 (90%) had abnormal perinatal findings (sensitivity 85.7%). The false positive and negative rates were low, 10 and 7.5% respectively, and the global predictive value of this test was 90%. In our study the amniotic fluid volume was the profile variable most able to identify a compromised fetus and the second with the highest specificity. Although we had a high cesarean section rate, (71%), we suggest that with normal profile scores (greater than or equal to 8) and normal amniotic fluid volume, the fetal biophysical profile may be an accurate test in the evaluation of the fetal condition in this obstetric complication.

Female↗
PubMed1990

Clinical chorioamnionitis is not predicted by an ultrasonic biophysical profile in patients with premature rupture of membranes.

A modified biophysical profile was assessed serially in 47 patients with premature rupture of membranes who were not in labor. This profile included fetal movement, fetal tone, fetal breathing, amniotic fluid volume, and placental grade. The most recent study, obtained within 2 days of delivery, was compared with pregnancy outcome as reflected by the development of chorioamnionitis and/or neonatal sepsis. No study patient received antibiotics, steroids, or tocolytics before labor. Neither the composite biophysical profile nor any of its components were found to be different between patients with and without clinical chorioamnionitis. Neonatal sepsis was not observed. These data do not support the use of the biophysical profile as a predictor of maternal infection.

Birth Weight↗
PubMed1990

[Biophysical profile in prolonged pregnancy. Another alternative to fetal monitoring].

The value of the biophysical profile scoring to predict accurate perinatal outcome in prolonged pregnancy, was assessed. 60 patients with the diagnosis of prolonged pregnancy were included in this prospective clinical trial. A fetal biophysical profile score, described by Manning and modified by Johnson, was recorded in all these patients. There were 40 cases (66%) with normal profile scoring 3 of which had a feature considered as perinatal morbidity (specificity 94.8%). In contrast, from 20 cases with abnormal profile scores, 18 (90%) had abnormal perinatal findings (sensitivity 85.7%). The false positive and negative rates were low, 10 and 7.5% respectively, and the global predictive value of this test was 90%. In our study the amniotic fluid volume was the profile variable most able to identify a compromised fetus and the second with the highest specificity. Although we had a high cesarean section rate, (71%), we suggest that with normal profile scores (greater than or equal to 8) and normal amniotic fluid volume, the fetal biophysical profile may be an accurate test in the evaluation of the fetal condition in this obstetric complication.

Female↗
PubMed1989

Fetal biophysical profile scoring: current status.

The fetal biophysical profile may assist the clinician to ascertain the fetal condition at the time of testing (acute markers), the degree of fetal compromise (gradual hypoxia concept), the presence of chronic fetal stress or possibility of in utero death due to cord accident (oligohydramnios), intrapartum complications such as abnormal heart rate patterns and abruptio (grade III) placenta, and impending fetal infection in patients with PROM (if performed daily). In addition it may identify major congenital anomalies which may drastically alter obstetric management. It remains to be seen if the use of computer-assisted systems for concurrent observation of the biophysical activities, or the addition of more biophysical variables, will further improve the accuracy of this testing method.

Female↗
PubMed1987

Fetal biophysical testing. The effects of prolonged maternal fasting and the oral glucose tolerance test.

Fetal biophysical testing incorporates observations of the fetal heart rate (FHR), fetal breathing movements (FBMs) and fetal trunkal movements (FTMs). These parameters were examined during maternal fasting and glucose loading. Thirty normal term gravidas were studied during a 210-minute session, of which the first 30 minutes served as a fasting control period, following which 20 (group G) received 100 g oral glucose, while 10 (group F) continued fasting. Serum glucose levels in both groups were determined every 30 minutes. FHR, FBMs and FTMs were recorded concurrently using abdominal electrocardiography and real-time ultrasonography and entered on line into a microcomputer. Offline data analysis provided mean 30-minute baseline FHRs, acceleration counts, FBM incidences, FBM rates and FTM incidences. Both groups were similar for gestational age, birth weight and perinatal outcomes. Mean 30-minute FHR baseline was unchanged and similar in both groups. Mean 30-minute FHR acceleration counts and FTM incidences were significantly higher in group F, while FBM incidences and rates were significantly higher in group G. While biophysical testing can be conducted under either set of maternal conditions, different normal standards must be employed, test length must be sufficient to account for normal biologic variations, and biophysical parameters must be monitored concurrently.

Electrocardiography↗
PubMed1987

The relationship between fetal biophysical profile and cord pH in patients undergoing cesarean section before the onset of labor.

In a prospective study of 124 patients undergoing cesarean section before the onset of labor, the fetal biophysical profile was found to have a significant relationship with umbilical cord blood pH (artery and vein). Using cord arterial pH less than 7.20 as a standard for the diagnosis of fetal acidosis, the sensitivity, specificity, and positive and negative predictive values of the fetal biophysical profile score were 90, 96, 82, and 98%, respectively. When the combination of nonreactive nonstress test and absent fetal breathing was used as the "abnormal test," the sensitivity, specificity, and positive and negative predictive values were 100, 92, 71, and 100%, respectively. The first manifestations of fetal acidosis are nonreactive nonstress testing and loss of fetal breathing; in advanced acidemia, fetal movements and fetal tone are compromised. A protocol of antepartum fetal evaluation is suggested based upon the individual biophysical components rather than the score alone.

Acidosis↗
PubMed1986

Fetal biophysical profile versus amniocentesis in predicting infection in preterm premature rupture of the membranes.

A comparison between daily fetal biophysical profile determinations and amniocentesis (for Gram stain and culture) was studied prospectively in 58 patients who presented with preterm premature rupture of the membranes and no apparent infection or labor. The efficacy of these two methods in predicting infection outcome--as reflected by the development of clinical amnionitis and/or neonatal sepsis--was determined. These data suggest that daily fetal biophysical profile assessment is superior to amniocentesis in predicting infection outcome in these patients. The use of frequent biophysical profile determinations should replace amniocentesis in selecting those patients with premature rupture of the membranes who are more likely to develop infection with associated fetal/neonatal sepsis.

Amniocentesis↗
PubMed1994

[Biophysical profile in twin pregnancy: prospective study].

The biophysical profile is an excellent test for assessment of the fetoplacental unit, for analyze is value in twin gestation, we study prospectively 81 multiple gestations. The fetuses were examined weekly antepartum. We use the modified profile of Manning which include only the sonographic criteria: the figures for predict stillborn were: sensitivity of 66.7%, specificity of 98.8%, positive predictive value of 50% and negative predictive value of 99.4% and predict between distressed and healthy fetus of a pair; 94.6% of fetus perform good biophysical profile score twenty minutes. We conclude that the fetal biophysical profile is the elective tool in the assessment of twin gestations.

Adolescent↗
PubMed1994

Can fetal biophysical observations anticipate outcome in preterm labor or preterm rupture of membranes?

OBJECTIVE: To evaluate fetal biophysical testing as a predictor of preterm delivery after preterm labor or preterm rupture of the membranes (PROM). METHODS: We studied 50 women with suspected preterm labor and intact membranes and 25 women with PROM but not in labor between 28 and 36 weeks' gestation. Before treatment, each subject had cervical Bishop scoring and 1-hour ultrasound observation of fetal heart rate, breathing, body movements, and flexion-extensions. Data were compared with t tests, chi 2 tests, or receiver operating curves. RESULTS: The mean gestational age at entry was similar in both groups. Twenty (80%) PROM and ten (18%) preterm labor patients delivered within 72 hours of admission; two (8%) PROM and 38 (76%) preterm labor patients delivered more than 7 days after admission. Absent breathing and body movements had high positive predictive values (100%) but moderate sensitivities (less than 55%) for predicting delivery within 72 hours or 7 days in the PROM and preterm labor groups. These sensitivities increased to nearly 70% with the addition of Bishop scores. The optimal diagnostic cutoffs for delivery within 72 hours or 7 days were a breathing incidence below 1% for the PROM group and a body movement incidence below 1% for the preterm labor group, and a breathing incidence of at most 5%. CONCLUSIONS: Complete absence of one biophysical variable confers limited sensitivity but high positive predictive value for early delivery in patients with preterm labor or PROM. The use of cutoff percentages for the incidence of individual variables improved sensitivity for both conditions. Cervical scoring added to biophysical monitoring by improving the sensitivity for early delivery of patients in preterm labor.

Chi-Square Distribution↗
PubMed1997

Biophysical studies of lipopeptide-membrane interactions.

There are a number of naturally occurring motifs for lipidation of peptides and proteins. In cases in which this involves adding a single hydrocarbon chain to the peptide, it is either a fatty acid or an isoprenyl group. Lipopeptides will partition between membrane and aqueous phases. When only one hydrocarbon chain is attached to the peptide, the affinity of the lipopeptide for the membrane is only marginally increased over that of the free peptide. The resulting partitioning is largely determined by the extent of the interaction of the peptide moiety with the membrane. In contrast, lipidation involving two hydrocarbon chains, either as two single chains attached at distinct locations of the peptide or a double-chain lipid anchor, firmly attaches the lipopeptide to the membrane. This can allow the placement of specific binding sites on a membrane surface. Such a strategy can be used, for example, to place specific antibodies on the surface of drug-carrying liposomes for the purpose of targeting drug delivery. In addition, lipopeptides will alter the physical properties of membranes. One of these effects is to increase the bilayer to hexagonal phase transition temperature. Substances having this property may also alter functional properties of membranes. While it is unlikely that these changes in the biophysical properties of the membranes. While it is unlikely that these changes in the biophysical properties of the membrane are responsible for specific functions of lipopeptides, such changes may be used to modulate certain properties of a membrane, such as the rate of viral fusion.

Biophysical Phenomena↗
PubMed2000

Linking the fields--the interplay of organic synthesis, biophysical chemistry, and cell biology in the chemical biology of protein lipidation.

Research in the biological sciences has undergone a fundamental and dramatic change during the last decades. Whereas biology was more phenomenologically oriented for a long time, today many biological processes are investigated and understood in molecular detail. It has become evident that all biological phenomena have a chemical basis: Biology is based on chemical principles. In the past, this insight had led to the development of biochemistry, molecular biology, and modern pharmacology. Today it increasingly determines the manner in which various biological phenomena are studied. The tools provided by classical biological techniques often are not sufficient to address the prevailing issues in precise molecular detail. Instead, the strengths of both chemical and biological methodology have to be used. Several recent research projects have proven that combining the power of organic synthesis with cell biology may open up entirely new and alternative opportunities for the study of biological problems. In this review we summarize the successful interplay between three disciplines-organic synthesis, biophysics, and cell biology-in the study of protein lipidation and its relevance to targeting of proteins to the plasma membrane of cells in precise molecular detail. This interplay is highlighted by using the Ras protein as a representative example. The development of methods for the synthesis of Ras-derived peptides and fully functional Ras proteins, the determination of their biophysical properties, in particular the ability to bind to model membranes, and finally the use of synthetic Ras peptides and Ras proteins in cell biological experiments are addressed. The successful combination of these three disciplines has led to a better understanding of the factors governing the selective targeting of Ras and related lipid-modified proteins to the plasma membrane.

Biophysical Phenomena↗
PubMed2007

Tumor-derived factors impaired motility and immune functions of dendritic cells through derangement of biophysical characteristics and reorganization of cytoskeleton.

The generation and progress of tumors are accompanied with a marked suppression of human immune system. To explore the mechanisms by which tumors escape from immune recognition, we studied the influences of tumor microenvironment on differentiation of dendritic cells (DCs), which play an important role in tumor immunology, by biophysical and immunological methods. It was found that the cytokines derived from tumors caused an increase in osmotic fragility and a decrease in membrane fluidity of DCs, disordering and elevated expression levels of cytoskeleton, and changes of the gene transcriptional levels and energy status of the cells. Moreover, IL-12 production and the expression levels of some surface-marker molecules were also suppressed. These changes led to impaired capabilities of antigen uptake, cell motility and naïve T cell activation; the abnormal biophysical characteristics of DCs may be one aspect of the immune escape mechanism of tumor. These results provide insights into the importance of the reconstruction of tumor microenvironment for immunotherapy based on the anti-cancer activities of DCs.

Actins↗