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Biomedical subjects

I Morrison

Publications and source records attributed to I Morrison.

At least 73 records · Page 4Linked to original sources
PubMed1987

Unusual paraspinal muscle lesions in ankylosing spondylitis.

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.

Adult↗
PubMed1986

Ultrasound evaluation of amniotic fluid: outcome of pregnancies with severe oligohydramnios.

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.

Adolescent↗
PubMed1986

Fetal assessment by biophysical profile scoring: 1985 update.

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)

Amniotic Fluid↗
PubMed1985

Weight-specific stillbirths and associated causes of death: an analysis of 765 stillbirths.

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.

Birth Weight↗
PubMed1985

Cord prolapse: is antenatal diagnosis possible?

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.

Breech Presentation↗
PubMed1985

Fetal assessment based on fetal biophysical profile scoring: experience in 12,620 referred high-risk pregnancies. I. Perinatal mortality by frequency and etiology.

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.

Amniotic Fluid↗
PubMed1984

Measurement of the rotational behaviour of virus particles during adsorption to the host cell surface.

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.

Cell Membrane↗
PubMed1984

Ultrasound evaluation of amniotic fluid volume. I. The relationship of marginal and decreased amniotic fluid volumes to perinatal outcome.

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.

Amniotic Fluid↗
PubMed1984

Ultrasound evaluation of amniotic fluid volume. II. The relationship of increased amniotic fluid volume to perinatal outcome.

Qualitative amniotic fluid volume determination is a routine part of fetal biophysical profile score testing. The relationship between polyhydramnios and poor perinatal outcome has been previously documented. We have undertaken a retrospective chart review which relates qualitative amniotic fluid volume as determined at the time of last biophysical profile score assessment to perinatal outcome in 7562 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 32.9/1000 and 4.12/1000 in association with increased qualitative amniotic fluid volume, respectively. The incidences of major congenital anomaly and fetal macrosomia were significantly related to qualitative amniotic fluid volume.

Amniotic Fluid↗
PubMed1984

Treatment of the fetus in utero: evolving concepts.

The rapidly evolving ability to detect the presence of major anomalies in the developing fetus and the emerging prospect of intrauterine treatment of some of these disorders are coupled to create an exciting new frontier in care of the high-risk pregnancy. Preliminary reports suggest that in some highly selected instances perinatal death and morbidity may be prevented by intrauterine surgical procedures. The technical ability to treat the disorder as described is at hand and is unlikely to be the limiting factor in the advance of this area of fetal treatment. However, the very fact that treatment is possible cannot be considered as proof of efficacy. The physician faced with the knowledge that a potentially treatable condition is present in a given fetus may feel the necessity of instituting treatment, but the validity of such an approach is far from established. It is our opinion that efforts should be made to set at the earliest point proper controlled scientific studies from which the benefit, if any, of this surgical approach to fetal disease may be established. Such clinical studies should be conducted in concert with studies in appropriate animal models. It should be noted that fetal surgical treatment is not without potentially lethal fetal and maternal complications. Before such risks, however small, are taken, it seems reasonable to determine the long-term benefits of the surgical procedure. To this end, participation in the International Fetal Surgery Registry is encouraged.

Arnold-Chiari Malformation↗
PubMed1984

Sensitivity to retinal defocus with aspheric soft lenses--predictions and clinical validation.

The purpose of this study was to obtain a numerically accurate discrete model of the effect of front aspheric soft lenses of various asphericities on the retinal illuminance profiles within the blur circles of a model eye. A computer program was developed for a model eye based on geometrical optics. The ray density was assumed to be proportional to the flux density or illumination. Retinal illuminance profiles are calculated for several values of defocus and asphericity. These results are validated by calculations based on modulation transfer functions (MTFs), observational data from contrast sensitivity and clinical results with Cals aspheric soft lenses. The results suggest that aspheric soft lenses maximize the central illuminance of blur circles and extend the range of desensitivity to retinal defocus in the eye to 4.00 D at the largest asphericity constant investigated.

Contact Lenses, Hydrophilic↗
PubMed1984

Fetal biophysical profile score and the nonstress test: a comparative trial.

In this prospective blind study, 735 patients with high-risk pregnancies referred for antepartum testing of fetal well-being were randomly assigned to either a fetal biophysical profile scoring (375 patients) or a nonstress testing scheme (360 patients). Management was based on the results of antepartum tests, but the method of testing used was not disclosed. Fetal biophysical profile scoring resulted in a significantly higher positive predictive value in regards to low Apgar scores. Sensitivity, specificity, and accuracy, although higher with fetal biophysical profile scoring, did not demonstrate significant differences when compared with the nonstress test. The negative predictive value between the two methods was similar. All major anomalies were detected during ultrasound scanning, whereas none of these anomalies were detected by heart rate testing alone.

Apgar Score↗
PubMed1984

Circadian rhythm in bladder volumes in the term human fetus.

Circadian rhythms have been identified in a variety of maternal and fetal biophysical and endocrinologic parameters. The authors have undertaken a 24-hour study to identify the normal variation in fetal bladder volumes in the healthy, term human fetus. A significant decrease in fetal bladder volumes occurred between 2400 hours and 0600 hours when compared with other times of the day. It is suggested that this fall in fetal bladder volumes may be related to fetal cardiovascular or adrenal gland function.

Circadian Rhythm↗
PubMed1982

The correlation of ultrasonic placental grading and fetal pulmonary maturation in five hundred sixty-three pregnancies.

In a previous study, it was suggested that the presence of a grade III placenta correlates 100% with a mature lecithin/sphingomyelin (L/S) ratio and may replace amniocentesis in confirming fetal lung maturity. In this study that hypothesis was tested in 563 pregnancies. All patients underwent amniocentesis and simultaneously had placental grading. The correlations of placental grade with an L/S ration greater than or equal to 2 were: grade 0, 17%; grade I, 68%; grade II, 91%. The correlations of placental grade with the presence of phosphatidylglycerol (PG) were: grade 0, 17; grade 1, 41%; grade II, 79%; grade II, 75%. The false positive rates associated with grade III placenta were, therefore, 7% for mature L/S ratio and 25% for PG present: when combined with a biparietal diameter greater than or equal to 9.0 cm, a grade III placenta incorrectly predicted lung maturity in 8.5%. We conclude that placental grading is not accurate enough to replace amniocentesis as the standard test of fetal pulmonary maturity.

Amniocentesis↗
PubMed1982

Antepartum determination of fetal health: composite biophysical profile scoring.

Antepartum detection, classification, determination of severity, and ultimately treatment of the fetus at risk for death and damage in utero form the very basis of modern perinatal medicine. The availability of accurate methods for assessing the fetus in utero are now becoming available. In extrauterine medicine, assessment of risk is based in part on the patient's activities and response to intrinsic and extrinsic stimuli. In extrauterine medicine, differentiation of normal sleep from coma is made by assessment of multiple biophysical variables and responses. It is most likely that the same principles hold true for differentiating the normal sleeping fetus from the asphyxiated fetus. Biophysical profile scoring offers one method for differentiation. It is likely that incorporation of this principle will improve the quality of perinatal care.

False Negative Reactions↗
PubMed1981

Fetal biophysical profile scoring: a prospective study in 1,184 high-risk patients.

The results of a prospective clinical management based on fetal biophysical profile scoring method was evaluated in 1,184 referred high-risk patients. Six perinatal deaths occurred in the study group (perinatal mortality of 5.06 per 1,000); only one fetus suffered unpredictable and unpreventable death (true false negative rate 0.8 per 1,000). In addition, 13 fetuses with major congenital anomalies were detected as a result of ultrasound scanning for fetal biophysical activities. These data suggest that this method can be used effectively to screen and manage a high-risk population.

Congenital Abnormalities↗