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At least 73 records · Page 4Linked to original sources
PubMed1985

The fetal biophysical profile in patients with premature rupture of the membranes--an early predictor of fetal infection.

A modified fetal biophysical profile (nonstress test, fetal movements, fetal breathing movements, fetal tone, amniotic fluid volume, and placental grading) was serially assessed in 73 patients who presented with premature rupture of the membranes and were not in labor. The last study before delivery was compared with the outcome of pregnancy. The relationships between individual variables and combinations of variables (biophysical scoring) and the outcome of pregnancy--as reflected by the development of chorioamnionitis and/or neonatal sepsis--were determined. These data suggest that the fetal biophysical profile is a useful tool for evaluating patients with rupture of the membranes. Rupture of the membranes by itself does not alter the biophysical scoring of the healthy fetus; however, a low biophysical score (less than or equal to 7) was a good predictor of impending fetal infection in patients with premature rupture of the membranes.

Apgar Score↗
PubMed1987

The use and misuse of the fetal biophysical profile.

The value of the fetal biophysical profile in determining fetal well-being has been well documented. The increasing clinical use of the fetal biophysical profile, however, has led to the recognition of frequent errors in the interpretation and application of this modality. These errors may result in unnecessary interventions or adverse perinatal outcome. The most frequent errors in the interpretation and application of the fetal biophysical profile are described; in an attempt to minimize the misuse of the fetal biophysical profile, an alternative protocol of antepartum fetal evaluation is suggested based upon the information obtained from the biophysical monitoring of the fetus.

Central Nervous System↗
PubMed2005

Biophysical analysis of the acute toxicity of radiotherapy in Hodgkin's lymphoma--a comparison between extended field and involved field radiotherapy based on the data of the German Hodgkin Study Group.

PURPOSE: To determine biophysical parameters from the complication probability data during and after radiotherapy of Hodgkin's lymphoma (HL), based on the number of gastrointestinal side effects that were found in the multicenter HD8 trial of the German Hodgkin Lymphoma Study Group. METHODS AND MATERIALS: Between 1993 and 1998, 1204 patients with newly diagnosed, histology-proven HL in clinical Stages I/IIA/IIB with defined risk factors and stage IIIA without risk factors were enrolled into the multicenter HD8 study. Patients were randomized to receive two cycles of COPP (cyclophosphamide, vincristine, procarbazine, prednisone) alternating with two cycles of ABVD (doxorubicin, bleomycin, vinblastine, dacarbazine) followed by radiotherapy (RT) of 30 Gy extended field plus 10 Gy to bulky disease (Arm A) or 30 Gy involved field plus 10 Gy to bulky disease (Arm B). For 910 patients, the rates of acute gastrointestinal side effects during and after RT could be determined. Comparison showed differences between Arms A and B (Grade 1-2: 16.6 vs. 3.9; Grade 3-4: 0.9 vs. 0.2; p < 0.001). From the dose-volume histograms for a "standard patient" (volume intestine 2300 cm3), we determined the normal tissue complication probability (NTCP) (V, D, m, n, TD50), the biophysical parameter TD50, and n (volume dependent) in such a manner that the observed NTCP in Arm A in cases of supradiaphragmatic involvement only and in cases of infradiaphragmatic involvement correlated with the calculated values. RESULTS: Of 1,204 patients randomized, 1,064 patients were informative for the comparison of study arms. The median observation time was 54 months. The overall survival for all eligible patients was 91%, and freedom from treatment failure was 83%. Survival rates at 5 years after start of RT revealed no differences in terms of freedom from treatment failure (85.8% in Arm A, 84.2% in Arm B) and overall survival (90.8% and 92.4%). There were also no differences between the two arms in terms of complete remission, progressive disease, relapse, death, and secondary neoplasias. In contrast, acute side effects, including leukopenia, thrombocytopenia, nausea, gastrointestinal toxicity, and pharyngeal toxicity, were more frequent in the extended field arm. Concerning gastrointestinal toxicity, the different radiation treatment volumes resulted in different NTCPs. On the basis of these findings, values of n = 0.09 and TD50 = 32 Gy were derived. However, this biophysical model is sensitive to variations of the parameters. A deviation of 1% of TD50 results in a deviation of 10% of the NTCP. CONCLUSION: Radiotherapy volume reduction from extended field to involved field after two cycles of COPP/ABVD chemotherapy gives similar results and less toxicity in patients with early-stage, unfavorable HL. Biophysical parameters could be determined from the complication probability data after RT of HL. Because of the exponential dependence, this biophysical model is unstable. It represents a "start model" until further data can be incorporated.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1987

The relationships among the fetal biophysical profile, umbilical cord pH, and Apgar scores.

The relationships among the fetal biophysical profile, umbilical cord blood pH, and Apgar scores were investigated in 124 patients undergoing cesarean section before the onset of labor. Based on a standard for the diagnosis of fetal acidosis of an umbilical cord arterial pH less than 7.20, 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 a 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 efficacy of the fetal biophysical profile to indicate fetal acidosis was found to be superior to the 1- and 5-minute Apgar scores in sensitivity and positive predictive value. These data suggest that the biophysical profile is very accurate in the identification of the fetus with acidemia. 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 new protocol of antepartum fetal evaluation is suggested based on individual biophysical components rather than the score alone.

Acidosis↗
PubMed1988

Fetal surveillance in insulin-dependent diabetic pregnancy: predictive value of the biophysical profile.

Ninety-eight insulin-dependent diabetic pregnancies underwent monitoring by means of 978 biophysical profiles from 28 weeks' gestation until parturition. Only 2.9% of the 978 tests had abnormal results (score less than or equal to 7). When performed within 2 days before birth, a normal biophysical profile predicted the 1-minute Apgar score to be normal in 92% and 5-minute Apgar score in 99%. When all biophysical profiles ever performed were included, the predictive value improved to 100%. The baby's first cry within 1 minute after birth was predicted in 95%. Furthermore, the predictive value of a normal biophysical profile regarding the absence of ominous intrapartum cardiotocographic patterns was excellent (95%). The specificity was in general good (80% to 90%), but the predictive value of abnormal test results and sensitivity were almost without exception poor. It seems that the very low rate of abnormal biophysical profiles indicates that obstetric interventions were made immediately after the occurrence of the first sign of fetal jeopardy; thus improved results were obtained.

Amniotic Fluid↗
PubMed2003

The beginnings of research on biophysics of photosynthesis and initial contributions made by Russian scientists to its development.

In contrast to the classical sciences, biophysics is difficult to define. For example, Roderick Clayton suggested that biophysics requires 'solid grounding in physics, chemistry and mathematics together with enough biology and biochemistry' [Clayton RK (1988) Photosynth Res 19: 207-224]. One may see from the proceedings of the recent biophysical congresses that their materials and ideas in a very wide sense are biological, including global geographic and ecological problems. To be recognized as biophysical, either physico-chemical methods or at least some mathematical and computer programs are usually involved in such work. One exception is the biophysics of photosynthesis, which deals with fundamental photophysical processes: the absorption of solar radiation by chlorophylls (Chls) and accessory pigments. The subsequent intermolecular transfer of singlet electronic excitation results in a primary energy conversion manifested as pairs of opposite electric charges separated in the pigment-protein complexes called reaction centers [see Clayton RK (2002) Photosynth Res 73: 63-71]. I review the initial, basic contributions in this field, and the most important accomplishments of Russian scientists in the 20th century.

Journal Article↗
PubMed1986

Fetal biophysical profile and the effect of premature rupture of the membranes.

A retrospective study of 1151 fetal biophysical profiles and scores associated with good pregnancy outcome was conducted over a three-year period in the author's institution. Normal fetal biophysical activities and scores were determined throughout gestation from 25 to 44 weeks in patients with intact membranes, and compared with profiles and scores of a group of patients with premature rupture of the membranes and good pregnancy outcome. These data suggest that although the biophysical scoring of the healthy fetus with intact membranes does not change significantly throughout gestation, some of the fetal biophysical variables (nonstress test, fetal breathing movements, amniotic fluid volume, and placental grading) do. The rupture of membranes was found to be associated with higher incidence of reactive nonstress testing, absence of fetal breathing, and reduced amniotic fluid volume in most gestational ages; however, the overall biophysical scoring of the healthy fetus was not altered throughout gestation by the presence of ruptured membranes.

Amniotic Fluid↗
PubMed1990

Randomized comparison of routine vs highly selective use of Doppler ultrasound and biophysical scoring to investigate high risk pregnancies.

OBJECTIVE: To compare routine versus highly selective use of Doppler ultrasound and biophysical scoring in higher risk pregnancy. DESIGN: A pragmatic randomized trial. SETTING: St James's University Hospital, Leeds. SUBJECTS: 500 pregnant women at high risk of intrauterine growth retardation or still birth. INTERVENTIONS: Regular monitoring with biophysical profile assessment and Doppler velocity waveform recording in umbilical and uteroplacental arteries. Results immediately available to clinicians. MAIN OUTCOME MEASURES: Gestational age at delivery, obstetric intervention rates and short-term neonatal morbidity. RESULTS: Risk factors were distributed very evenly between the 250 patients in the study and control groups respectively. A total of 902 biophysical profile and Doppler assessments were done in the 250 study group patients and only in 12 patients in the control group. In the study group, absent end-diastolic flow was found in only 2.7% of all 902 measurements. A persistently abnormal biophysical score was always associated with absence of end-diastolic flow. The mean gestational age at induction of labour was statistically and clinically similar in the two groups and there was no overall statistically significant difference in intervention rates between the two groups. There was a statistically significant lower frequency of depressed 5-min Apgar scores in the study group. Serious neonatal morbidity was also statistically significantly more common in the control group than in the study group. CONCLUSIONS: The use of Doppler ultrasound in higher risk pregnancies does not lead to an increase in iatrogenic preterm delivery. The total rate of positive tests on Doppler ultrasound is very low and persistently abnormal biophysical scores are unlikely to be found in patients where umbilical end-diastolic blood flow is present. Surrogate measures for fetal damage seem to be improved when clinicians have access to Doppler ultrasound assessments.

Adult↗
PubMed1993

Prediction of fetal acidaemia in intrauterine growth retardation: comparison of quantified fetal activity with biophysical profile score.

OBJECTIVE: To study the relation between quantified fetal movements and fetal activity assessed by the biophysical profile score and the pH in umbilical arterial blood at elective caesarean section. DESIGN: Fetal activity was assessed within 24 h prior to caesarean section for decelerative fetal heart rate patterns both by quantification (% of time spent moving) and by applying the biophysical profile score (BPS) criteria. SETTING: Department of Obstetrics, University Hospital. SUBJECTS: Nineteen growth retarded fetuses. MAIN OUTCOME MEASURES: Fetal generalised movements (FGM%), fetal breathing movements (FBM%), total fetal activity (TFA% = FGM% + FBM%); FGM, FBM and tone as assessed according the biophysical profile score (BPS); umbilical arterial pH. RESULTS: In all 11 acidaemic fetuses (pH < 7.20) TFA% was below the 10th centile for normal fetuses; nine had decreased FGM% and eight decreased FBM%. Absence of FGM or tone according to the biophysical profile score was only seen in two acidaemic fetuses. CONCLUSION: TFA% < 11.7% was a better predictor of acidaemia at birth than either reduced FGM%, FBM%, or absence of FGM, FBM and tone as defined in the biophysical profile score. The two methods of assessing FBM were identical in predicting acidaemia, suggesting that in presence of acidaemia the decrease of FBM may be an all-or-none phenomenon. Furthermore, the data indicate that reduction in body movements may precede reduction in breathing movements.

Acidosis↗
PubMed1994

Interpretation of biophysical profiles by nurses and physicians.

OBJECTIVE: To determine the agreement between nurse and physician interpretation of biophysical profile scores. DESIGN: A prospective evaluation of videotaped biophysical profiles was independently scored by four nurse and four physician interpreters and compared to that of an expert physician. SETTING: The fetal assessment center of a large tertiary-care center; study included women from public and private practices. PATIENTS: Twenty-three women with high-risk pregnancies who were regularly scheduled for a biophysical profile. Women pregnant with multiple fetuses or whose fetuses were less than 28 weeks' gestational age or had severe fetal anomalies were excluded. MAIN OUTCOME MEASURE: The proportion of agreement between the physicians and nurses and the physician expert was calculated for each biophysical profile criterion. RESULTS: The kappa statistic was used to evaluate the proportion of agreement with the "gold standard." When compared with the expert, physicians showed 60% moderate or substantial agreement, and the nurses showed 80% moderate or substantial agreement. CONCLUSIONS: Nurses' interpretations of biophysical profiles were at least as reliable as physicians' when compared with an expert reviewer.

Adolescent↗
PubMed2005

[Usefulness of fetal biophysical profile in preterm rupture of membranes with treatment].

OBJECTIVE: To evaluate the usefulness of the fetal biophysical profile as a predictor of early neonatal infection in patients with preterm rupture of membranes in conservative management. PATIENTS AND METHODS: This is a validation study of a diagnostic test. Between November, 2001 and August, 2003, 75 patients with 27 to 33 weeks of gestation and preterm rupture of membranes in conservative management were studied. Daily, a fetal biophysical profile was applied to them. Statistical analysis was done with chi square test and with a 2 x 2 contingency table that compared the biophysical score of + 8 and < or = 6 versus the presence or absence of early neonatal infection. RESULTS: The biophysical score < or = 6 was associated with early neonatal infection (p < 0.05), with sensitivity, specificity, positive and negative predictive values of 80, 85, 64 and 85%, respectively (OR 9.73, 95% CI: 2.88-34.63; p = 0.0000164). CONCLUSIONS: The biophysical score < or = 6 was significantly associated with early neonatal infection.

Adolescent↗
PubMed1989

[Prediction of fetal hypoxia using the fetal biophysical profile].

In a prospective investigation the authors assessed the diagnostic accuracy of the biophysical profile in the detection of fetal hypoxia. They made 126 tests in 104 risk pregnancies during the 33rd-42nd week of gestation. By means of a scoring system they evaluated six biophysical parameters: non-stress test, fetal breathing movements, fetal movements, fetal tone, volume of amniotic fluid and maturity of the placenta. Ninety-six patients were delivered of a baby within seven days after the test and in these patients the course of childbirth and the condition of the fetus was evaluated. In case of a pathological biophysical score the pregnancy was terminated in 83.3% by Caesarean section, whereby the weight of the fetuses was by 48% lower (1693 g) and the height by 8 cm (41.8 cm) smaller than when the biophysical score was normal. In the detection of an adverse outcome of pregnancy, under which they included an Apgar score of 7 or less during the 5th minute, the first capillary pH less than 7.20 and perinatal death, the biophysical profile had a sensitivity of 68.8%, a specificity of 97.5%, a predictive value of the positive test of 84.6% and a predictive value of the negative test of 94%.

Female↗
PubMed1987

Clinical significance of fetal tachypnea during antepartum biophysical testing.

Fetal tachypnea has been regarded as a rare finding with a poor perinatal prognosis. Eighteen cases of fetal tachypnea were noted during the biophysical tests of 200 patients. Biophysical testing consisted of concurrent ultrasound observations of fetal breathing and body movements and electronic monitoring of fetal heart rate, coupled with determinations of fetal tone and amniotic fluid volume. Fetal breathing movement frequency and rate, fetal trunkal movement frequency, and baseline fetal heart rate were analyzed on a programmed microcomputer. The mean (+/- SD) breathing rate was 68.2 +/- 6.4 breaths per minute; mean breathing frequency, 55 +/- 22.6%; mean baseline heart rate, 141 +/- 8 beats per minute; mean trunkal movement incidence, 5.5 +/- 2.6%; and mean acceleration frequency, 14.6 +/- 9.8 per hour. No fetus was apneic for more than eight minutes, and there were no significant correlations between fetal breath rates and the other biophysical parameters. There were no perinatal deaths. Seven fetuses experienced perinatal morbidity, of whom five had other abnormalities on biophysical testing. This study indicates that fetal tachypnea occurs more often than previously believed and does not generally signify fetal compromise unless other biophysical abnormalities are also present.

Female↗
PubMed1997

Fetal assessment based on the fetal biophysical profile score: relationship of last BPS result to subsequent cerebral palsy.

OBJECTIVE: The prime intent of this study was to determine the relationship if any between the last fetal biophysical profile score and the risk of cerebral palsy at age 3 years. The secondary objective was to examine the clinical characteristics of infants with cerebral palsy whose obstetric management included serial fetal biophysical profile scores. STUDY DESIGN: The incidence of a high risk pregnant population whose antenatal assessment was by serial fetal biophysical profile scoring was determined by cross-referencing two discrete data bases. The completeness and reliability of the data bases was confirmed by secondary audit. Obstetrical, neonatal and post-natal clinical records of index cases of cerebral palsy were subsequently reviewed, categorized and analyzed. RESULTS: Fetal biophysical profile scores (BPS) were recorded in 22,336 high risk pregnancies: 27 patients delivered an infant subsequently identified as having cerebral palsy (rate 1.21 per 1000). The relationship between last BPS result and cerebral palsy was inverse, exponential and highly significant (R2 = 0.987; p < 0.001). Affected infants with a last abnormal BPS result were significantly more likely to exhibit fetal distress (88.8%), acidosis (77.7%), and have neonatal seizures (88.8%). Antenatal asphyxia was the apparent cause of cerebral damage in 29.6% of cases. CONCLUSION: The last fetal biophysical profile score is a predictor of the risk of cerebral palsy.

Cerebral Palsy↗
PubMed2006

Tissue assembly guided via substrate biophysics: applications to hepatocellular engineering.

The biophysical nature of the cellular microenvironment, in combination with its biochemical properties, can critically modulate the outcome of three-dimensional (3-D) multicellular morphogenesis. This phenomenon is particularly relevant for the design of materials suitable for supporting hepatocellular cultures, where cellular morphology is known to be intimately linked to the functional output of the cells. This review summarizes recent work describing biophysical regulation of hepatocellular morphogenesis and function and focuses on the manner by which biochemical cues can concomitantly augment this responsiveness. In particular, two distinct design parameters of the substrate biophysics are examined--microtopography and mechanical compliance. Substrate microtopography, introduced in the form of increasing pore size on collagen sponges and poly(glycolic acid) (PGLA) foams, was demonstrated to restrict the evolution of cellular morphogenesis to two dimensions (subcellular and cellular void sizes) or induce 3-D cellular assembly (supercellular void size). These patterns of morphogenesis were additionally governed by the biochemical nature of the substrate and were highly correlated to resultant levels of cell function. Substrate mechanical compliance, introduced via increased chemical crosslinking of the basement membrane, Matrigel, and polyacrylamide gel substrates, also was shown to be able to induce active two-dimensional (2-D, rigid substrates) or 3-D (malleable substrates) cellular reorganization. The extent of morphogenesis and the ensuing levels of cell function were highly dependent on the biochemical nature of the cellular microenvironment, including the presence of increasing extracellular matrix (ECM) ligand and growth-factor concentrations. Collectively, these studies highlight not only the ability of substrate biophysics to control hepatocellular morphogenesis but also the ability of biochemical cues to further enhance these effects. In particular, results of these studies reveal novel means by which hepatocellular morphogenesis and assembly can be rationally manipulated leading to the strategic control of the expression of liver-specific functions for hepatic tissue-engineering applications.

Animals↗
PubMed1997

Biophysical mechanisms of stroke.

BACKGROUND: Stroke is the third leading cause of death and the leading cause of long-term disability in the United States. Although a host of genetic, biochemical, physiological, anatomic, and histological factors have been implicated, to varying degrees, in the pathogenesis of stroke, biophysical factors are believed to play a significant role in the development, diagnosis, and therapy of stroke. The purpose of this review article is to identify, describe, and illustrate these causes and biophysical and hemodynamic mechanisms predisposing a person to stroke, which often form the basis for novel methods of diagnosis and therapy. SUMMARY OF REVIEW: This mini-review begins by describing the physical principles that govern the flow of blood through normal and stenosed carotid artery bifurcations. In addition to the tortuosity, curvature, and tensile forces of the carotid artery bifurcation, the effects of biophysical phenomena from flowing blood such as viscous forces, pressure forces, velocity, kinetic energy, momentum, impulse, shear stress, and vibrational displacements exerted by the flowing blood on the vessel wall are conducive to abnormal flow behavior and patterns, degrading the vessel wall and creating the potential for stroke. CONCLUSIONS: Recent advances in the treatment of stroke are based on increasing knowledge of its underlying biophysical mechanisms, as well as on better-publicized advances in imaging instrumentation and procedures for the management and treatment of patients.

Animals↗
PubMed2001

Habituating pigs for in-pen, non-invasive biophysical skin analysis.

The purpose of this study was to develop a method for habituating pigs (Sus scrofa domestica, middle white strain) to enable non-invasive, biophysical measurements of dorsal skin to be obtained on a daily basis over a 7-week period, thus eliminating the need for anaesthesia or restraint. This was accomplished by associating measurements of transepidermal water loss (TEWL) and skin reflectance spectroscopy (SRS) with feeding times, and with positive reinforcement by allowing exercise outside the home pen. During the pig habituation period, a well-defined series of behavioural changes were observed that included dominant/ submissive leadership changes. Values of TEWL (6.29 +/- 1.25g.m(-2) x h(-1)) were in agreement with previous studies (7.56+/-2.90g.m 2 x h(-1)) obtained from unrestrained Yucatan hairless micro-pigs (Gabard et al. 1995). The coefficient of variance of TEWL and SRS measurements were comparable with those reported previously using anaesthetized pigs (Chilcott et al. 2000). These data imply that biophysical skin measurements obtained from unrestrained, conscious animals are comparable to those obtained from anaesthetized pigs and therefore, support the use of unrestrained pigs for non-invasive biophysical skin measurements. Habituating animals for in-pen, non-invasive, biophysical measurements has substantial implications for reducing and refining laboratory animal experiments in dermatological research without compromising animal welfare.

Anesthetics↗
PubMed1991

Role of umbilical Doppler velocimetry in the biophysical assessment of the growth-retarded fetus. Answers from neonatal morbidity and mortality.

We compared umbilical Doppler velocimetry with biophysical parameters, obstetrical management, and neonatal morbidity. The study of 85 pregnancies was prospective and blind both to the obstetric and pediatric staff. Our results show that under the same biophysical diagnosis, ie, abnormal fetal growth, oligohydramnios, and nonreactive cardiotocographics, the prevalence of neonatal morbidity was significantly higher in fetuses with associated abnormal umbilical pulsatility index (PI) in utero. Newborns with abnormal PI were delivered earlier, mostly for fetal indication, and were smaller and more asymmetrical than newborns with a normal PI in utero. The analysis of morbidity for homogeneous classes of weight showed that in the group of newborns between 1500 and 2500 g, newborns with normal umbilical PI did show only metabolic disturbances and one respiratory distress syndrome. On the contrary, newborns of the same gestational age and of the same weight with abnormal PI had more severe morbid episodes. In the class of weight between 1500 and 1000 g not only the severity but also the prevalence of neonatal morbidity was significantly higher in newborns with an abnormal PI in utero. None of the newborns delivered below 1000 g had a normal umbilical PI. Five died in the early neonatal period. Three suffered from mild neuromotor sequelae. Practical consequences of these findings on fetal management are the scheduled frequency of biophysical examinations, which must be closer and on an inpatient basis whenever abnormal, and the interpretation of other abnormal biophysical parameters, which must be considered as more severe whenever associated with an abnormal umbilical velocimetry.

Biophysical Phenomena↗