Electronic and optical properties of ultrathin Si/Ge (001) superlattices.
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Biomedical subjects
Publications and source records attributed to I Morrison.
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The fetal biophysical profile score was modified by selective use of the nonstress test. In 2712 study patients (7851 tests) the incidence of nonstress test was reduced to 2.7% with no measurable effect or test accuracy. The nonstress test was most useful in evaluation of abnormal ultrasound monitored variables.
The incidence of false-negative fetal death, which is defined as stillbirth unrelated to major anomaly or alloimmunization occurring after a last normal fetal biophysical score, was determined in 19,221 referred high-risk pregnancies. The calculated rate of fetal death after a last normal test was 0.726/1000 (14 deaths), which remained relatively constant despite a progressive increase in tests and patients studied. We conclude that a normal fetal biophysical profile score confers a high probability of perinatal survival.
In the art of medicine we have always known that establishing an accurate diagnosis of health or disease is essential. An active search for the physical signs, both the time honoured and newly discovered, are a crucial step in achieving diagnostic accuracy, in monitoring disease progression, and in assigning prognosis. In extrauterine medicine it is common practice to gather together sets of biophysical data in order to determine immediate health, to monitor condition, and to estimate prognosis: witness the use of vital signs, and, in the newborn, the Apgar score. The providers of perinatal care have known since biblical days that fetal biophysical activities were a reflection of fetal condition (Luke: Chapter 1, Verses 44-45), yet lacked the ability to categorize these activities in an objective and complete manner. The introduction of dynamic ultrasound imaging methods to perinatal medicine at last create the window through which the principles of extrauterine medicine may now be applied to the intrauterine patient--the fetus. Fetal biophysical profile scoring is a method that utilizes this new wealth of information to differentiate the normal fetus from the fetus at risk for death or damage in utero. The method is based on the concept that the discrimination of fetal health and disease improves as more variables are considered. The now extensive clinical experience with the method, in which both overall (gross) and selected (corrected) perinatal death are reduced, while maintaining a remarkably low false negative predictive error, indicate the validity of the concept. Comparative studies lead us to believe that reliance upon single biophysical variables, such as fetal movement counts, or antepartum fetal heart rate monitoring, is no longer of sufficient accuracy to support its use as a sole measure of fetal condition. Looking forward, we anticipate that while the concept on which fetal biophysical profile scoring is based will remain unchanged, inclusion of additional variables is likely to occur. It seems likely that addition of new variables, as may be now measured using high-resolution dynamic ultrasound methods, both B-mode and Doppler, will improve diagnostic accuracy even more. We believe that the application of the current and future modified methods of composite fetal risk assessment will render the occurrence of the tragedy of perinatal loss even more infrequent. While the goal of complete elimination of perinatal deaths remain elusive, this method may be one step towards this goal.
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Minicore, multicore, core-targetoid and other ultrastructural lesions were found in the paraspinal muscles of patients with AS. The 10 patients studied, all men with AS, showed varying degrees of muscle fibre atrophy, Z band streaming, rod body formation, minicores, multicores and core-targetoid fibres. Central core disease, rod body myopathy, minicore and multicore diseases are recognized clinical entities within the congenital group of structural myopathies. Target fibres are believed to be a feature of reinnervation. It is also known that experimental tenotomy causes core-targetoid changes, rod bodies, minicores and multicores. Therefore, it seems possible that tension is a necessary stimulus for the correct programming of synthetic muscle enzymes, and without this disorganization occurs. It may also be assumed, but in this case for genetic reasons, that similar biochemical systems are disturbed in the group of congenital myopathies.
Severe oligohydramnios, defined as a condition in which the largest pocket of amniotic fluid measures less than 1 cm in its vertical axis as determined by an ultrasound method, was observed in 113 patients in a population of 15,431 referred high-risk patients (0.7%). In all cases, intervention took place unless there was a recognized structural anomaly or extreme prematurity. Overall gross perinatal mortality was 132.7/1000, and the incidence of major anomaly was 13.3%. With intervention the corrected perinatal mortality rate was 17.7/1000, a rate not significantly different from that observed in the entire population. All end points of perinatal mortality were significantly increased in patients with severe oligohydramnios, in comparison with randomly selected control subjects with normal amniotic fluid. These findings are interpreted to indicate that severe oligohydramnios in a structurally normal fetus is an indication for delivery.
In extrauterine medicine, physicians have come to rely upon sampling of multiple biophysical variables as a means of differentiating states of well-being and compromise. This basic tenet of medicine is expressed by obtaining an Apgar score or some variant in the newborn and as a measure of vital signs in later life. Few, if any, decisions regarding well-being are ever based on a single-variable assessment and, conversely, definition of compromise is rarely based upon a single variable. Through the use of dynamic ultrasound imaging it now becomes possible to visualize the fetus and its biophysical responses in health and disease. Through such visualization it becomes possible to bring to bear some of the basic principles that sustain extrauterine medicine on the intrauterine patient, the fetus. Fetal biophysical profile scoring describes a method that encompasses this concept. The results obtained by application of this method are promising. We would argue that consideration of multiple fetal biophysical variables will, in most instances, yield superior results to single-variable monitoring alone. Hence we have abandoned antepartum fetal heart rate testing as the sole method of fetal risk assessment and used the tool only in conjunction with others of the many variables that may be monitored by dynamic ultrasound methods. This concept of multiple-variable analysis as the superior method for fetal assessment seems clear and well-justified. It is our opinion, however, that the concept of fetal bioprofile scoring may be more important than the method itself in its original description.(ABSTRACT TRUNCATED AT 250 WORDS)
An analysis of 765 consecutive stillbirths associated with 98,927 pregnancies during a 6-year interval showed significant differences for cause of death at specific weight categories. In addition, 57% of stillbirths occurred at infant weights of greater than or equal to 1500 gm. Hypoxia accounted for 43% of all stillbirths. The implications with respect to preventability and for changes in routine prenatal care through the incorporation of the several methods of fetal assessment currently available are discussed.
Cord presentation was diagnosed antenatally in nine patients at term referred for fetal ultrasound assessment (incidence of 0.61%). Seven patients were delivered by cesarean section; cord position was confirmed in four and suspected in three patients. There were two vaginal deliveries, one following spontaneous version and the other a stillbirth associated with cord prolapse.
Fetal biophysical profile scoring was used as a method for antepartum fetal risk assessment in 12,620 high-risk patients referred in a 55-month interval. A total of 26,257 tests were performed on these patients (range, one to 18 tests per patient). Ninety-three perinatal deaths occurred (gross perinatal mortality rate, 7.37 per 1000) of which 62 (66.6%) were due to a major anomaly, seven were due to Rh disease (7.5%), and the remaining 24 deaths (25.8%) occurred in structurally normal fetuses. The corrected perinatal mortality rate was 1.90 per 1000. Eight structurally normal fetuses died within 1 week of a normal test result (corrected false negative rate, 0.634 per 1000). These data suggest fetal biophysical profile scoring is an accurate method for identification of the fetus at risk for perinatal death.
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The rotational diffusion of bacteriophage epsilon 15 was measured before and after virus adsorption to outer membrane vesicles of the host Salmonella anatum. The virus capsid was labeled with eosin isothiocyanate, and the decay of transient dichroism following dye excitation by pulses of plane-polarized light was measured. From the data, the rotational diffusion constant of the unadsorbed virion and its hydrodynamic diameter were estimated and found to be consistent with electron microscopic measurements of the capsid dimensions. Addition of outer membrane vesicles of S. anatum to the virus suspension revealed the immobilization of the virus particles on the membrane surface.
Qualitative amniotic fluid volume determination is a routine part of fetal biophysical profile score testing. The relationship between oligohydramnios and poor perinatal outcome has been previously documented. We have undertaken a retrospective chart review relating qualitative amniotic fluid volume as determined at the time of last biophysical profile score assessment to perinatal outcome in 7582 referred high-risk obstetric patients. Gross and corrected perinatal mortality in association with normal qualitative amniotic fluid volume ranged from 4.65/1000 and 1.97/1000, respectively, to 187.5/1000 and 109.4/1000 in association with decreased qualitative amniotic fluid volume, respectively. The incidences of major congenital anomaly and intrauterine growth retardation were significantly related to qualitative amniotic fluid volume.