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Biomedical subjects

W M Moore

Publications and source records attributed to W M Moore.

At least 19 recordsLinked to original sources
PubMed1992

Prediction of birthweight by fetal ultrasound biometry.

A total of 104 women with singleton pregnancies who were delivered between 37 and 42 weeks gestation had ultrasound scans during the fortnight before delivery. The biparietal diameter (BPD), abdominal circumference (AC) and femur length (FL) were measured in all cases. Estimation of fetal weight (EFW) was done by four different methods: using AC alone, AC/BPD, AC/FL and AC/BPD/FL. Results were compared with values of actual birthweights at delivery. There was no significant difference between the mean birthweights of the 47 boy and 57 girl fetuses studied. The EFW(Shepard) method showed the least bias overall: mean percentage error 1.7%, standard deviation (SD) 10.6%. The other three methods significantly underestimated birthweights on average: EFW(Deter), mean error 2.2%, SD 9.3%, p < 0.02; EFW(Campbell), mean error 5.4%, SD 9.5%, p < 0.001; EFW(Hadlock), mean error 5.6%, SD 9.3%, p < 0.001. The percentage error in each group was significantly negatively correlated (p < 0.001) with the scan-delivery interval. Two new equations were generated which gave more accurate predictions for the cases under study using AC, BPD and FL as a combination and also in addition to scan-delivery interval (SDI) in days.

Abdomen↗
PubMed1991

Phosphoramidon blocks the pressor activity of porcine big endothelin-1-(1-39) in vivo and conversion of big endothelin-1-(1-39) to endothelin-1-(1-21) in vitro.

In porcine aortic endothelial cells, the 21-amino acid peptide endothelin-1 (ET-1) is formed from a 39-amino acid intermediate called "big endothelin-1" (big ET-1) by a putative ET-converting enzyme (ECE) that cleaves the 39-mer at the bond between Trp-21 and Val-22. Since big ET-1 has only 1/100-1/150th the contractile activity of ET-1, inhibition of ECE should effectively block the biological effects of ET-1. Big ET-1 injected intravenously into anesthetized rats produces a sustained pressor response that presumably is due to conversion of big ET-1 into ET-1 by ECE. We determined the type of protease activity responsible for this conversion by evaluating the effectiveness of protease inhibitors in blocking the pressor response to big ET-1 in ganglion-blocked anesthetized rats. The serine protease inhibitor leupeptin, the cysteinyl protease inhibitor E-64, and the metalloprotease inhibitors captopril and kelatorphan were all ineffective at blocking the pressor response to big ET-1. However, the metalloprotease inhibitors phosphoramidon and thiorphan dose-dependently inhibited the pressor response to big ET-1, although phosphoramidon was substantially more potent than thiorphan. None of the inhibitors blocked the pressor response to ET-1 and none had any effect on mean arterial pressure when administered alone. In a rabbit lung membrane preparation, ECE activity was identified that was blocked by the metalloprotease inhibitors phosphoramidon and 1,10-phenanthroline in a concentration-dependent manner. This enzyme converted big ET-1 to a species of ET that comigrated on HPLC with ET-1 and produced an ET-like contraction in isolated rat aortic rings. Our results suggest that the physiologically relevant ECE is a metalloprotease.

Animals↗
PubMed1991

The influence of severity of spinal cord ischemia in the etiology of delayed-onset paraplegia.

To clarify the cause of delayed-onset paraplegia, the authors evaluated the neurologic outcome after temporary (10 to 30 minutes) spinal cord ischemia in the awake rabbit. Loss of motor function occurred in less than 2 minutes in all animals. Restoration of flow within 16 minutes always resulted in full return of function, whereas with occlusion times of greater than 27 minutes all animals remained paralyzed. After temporary occlusion of 20 to 21 minutes, however, 71% of animals returned to normal neurologic function but developed delayed-onset paraplegia 14 to 48 hours later. This appears to be a reliable method for the creation of a model of delayed-onset paraplegia in the awake animal, and will facilitate more detailed studies of the pathophysiology of ischemia-induced paraplegia.

Animals↗
PubMed1991

Phosphoramidon blocks the pressor activity of big endothelin[1-39] and lowers blood pressure in spontaneously hypertensive rats.

In porcine aortic endothelial cells, the 21-amino acid peptide endothelin-1 (ET-1) is formed from a 39-amino acid intermediate big endothelin (big ET) by a putative endothelin-converting enzyme (ECE) that cleaves the 39-mer at the Trp21-Val22 bond. Because big ET has less than 1% of the contractile activity of ET-1, inhibition of ECE should effectively block the biological effects of big ET. Big ET injected intravenously into anesthetized rats produces a sustained pressor response that presumably is due to conversion of big ET to ET-1 by ECE. We determined the type of protease activity responsible for this conversion by evaluating the effectiveness of protease inhibitors in blocking the pressor response to big ET in ganglion-blocked anesthetized rats. The serine protease inhibitor leupeptin, the cysteinyl protease inhibitor E-64, and the metalloprotease inhibitors captopril and kelatorphan were ineffective at blocking the pressor response to big ET. However, the metalloprotease inhibitors phosphoramidon and thiorphan both dose-dependently inhibited the pressor response to big ET, although phosphoramidon was substantially more potent than thiorphan. None of the inhibitors blocked the pressor response to ET-1 and none had any effect on blood pressure when administered alone as an i.v. bolus to the ganglion-blocked anesthetized rat. However, phosphoramidon infused intravenously at 20 mg/kg/h for 4 h lowered the mean arterial pressure (MAP) in conscious spontaneously hypertensive rats (SHRs) whereas kelatorphan at the same dose did not. Our results suggest that ECE is a novel metalloprotease and that ECE inhibitors could have therapeutic potential for the treatment of hypertension.

Animals↗
PubMed1991

Superior vena cava and central venous reconstruction.

Partial or complete obstruction of the superior vena cava and its major tributaries occassionally results in incapacitating venous hypertension of the upper extremities and/or head and neck. Factors intrinsic and extrinsic to the central veins play a role in the pathogenesis. The more common causes include mechanically and chemically induced intimal injury with resultant fibrosis, sclerosis, or thrombosis and neoplastic masses with external compression or direct extension in the central venous structures. Medical therapy is indicated in the acute situation and generally allows the time necessary for development of collateral drainage routes. Persistent or progressive symptomatic venous hypertension develops in 5% to 40% of these patients, and approximately 10% of the patients will remain incapacitated. Presented here is a series of 10 patients who underwent reconstruction of the superior vena cava or central veins for incapacitating venous hypertension of the upper extremities and/or head and neck. Reconstruction was accomplished by venous transposition (three patients), externally reinforced ePTFE (six patients), and reversed saphenous vein graft (one patient). No perioperative deaths occurred; however, two late deaths occurred at 3 and 9 months after reconstruction from causes unrelated to the operative procedure. One patient experienced early postoperative graft thrombosis requiring thrombectomy, after which the graft remained patent. All patients had patent grafts and were asymptomatic with respect to their venous disease at the time of preparation of this manuscript, with a mean follow-up period of 30 months. Specific details concerning these 10 cases are discussed and integrated with a focused review of the literature and the historic development of the intraoperative techniques and postoperative care that facilitate the successful management of patients with symptomatic central venous occlusion.

Blood Vessel Prosthesis↗
PubMed1991

Mesenteric artery occlusive disease.

The age and advanced stage of atherosclerosis in this patient population require careful preoperative evaluation and attention to detail in the perioperative period in an effort to avoid complications in other organ systems resulting from diffuse occlusive disease. The keys to accurate diagnosis and successful management of patients with acute or chronic mesenteric ischemia include a detailed history, focusing on the quality and temporal relation of the symptoms; an accurate vascular assessment on physical examination, with attention directed to ruling out nonvascular causes of the symptoms; a high index of suspicion of vascular origin for otherwise unexplainable abdominal pain in the patient population at risk; an aggressive diagnostic approach with a low threshold for obtaining mesenteric angiography; CT of the abdomen to rule out occult pancreatic carcinoma; expeditious correction of metabolic and electrolyte abnormalities and optimization of cardiac function; and early surgical intervention, with directed revascularization in an effort to minimize loss of bowel from infarction.

Acute Disease↗
PubMed1990

Sleep in the first year of life.

The sleep patterns of 174 infants were recorded on one typical day at six, 13, 26 and 52 weeks of age, using a 24-hour log. During the first year of life the number of episodes of sleep was reduced by about 50 per cent, but total sleep time was reduced by only two hours. A circadian rhythm was established by six weeks of age. Smaller infants slept more than larger ones in the first months of life. Sex or birth-order of the child did not affect the duration or number of sleep episodes, but sleep pattern related significantly to whether or not mothers found their infants difficult to feed. Introduction of weaning food at an early stage reduced the number of sleep episodes, but increased the average length of each episode. Socio-economic status showed no significant relationship with number of episodes or total length of sleep.

Circadian Rhythm↗
PubMed1989

In vitro and in vivo activity of chymotrypsin-activated big endothelin (porcine 1-40).

We investigated whether big endothelin (porcine 1-40) had contractile activity in isolated rat aorta or pressor activity when injected intravenously into the anesthetized rat. When isolated rat aorta was exposed to a 100 nM concentration of big endothelin, 4.8% of a maximal KCl contraction was observed, compared to 131% of KClmax when paired aortic rings were exposed to an equivalent concentration of synthetic endothelin. Likewise, big endothelin had very weak pressor activity when injected intravenously into anesthetized, ganglion-blocked rats at 10 nmol/kg. When big endothelin was incubated with chymotrypsin, native endothelin and other peptide fragments were formed. Chymotrypsin-treated big endothelin produced an endothelin-like contraction when applied to isolated rat aortic rings, and a characteristic endothelin-like effect on blood pressure in vivo. Our results indicate that the biological activity of endothelin could be effectively blocked by inhibiting the enzyme which converts big endothelin to endothelin.

Amino Acid Sequence↗
PubMed1989

Weight and recumbent length from 1 to 12 mo of age: reference data for 1-mo increments.

Serial data from 504 infants were used to develop reference data for 1-mo increments in weight and recumbent length by fitting a family of three-parameter mathematical functions to the serial data for each individual. The percentiles for status and for increments tended to be larger for the boys than for the girls except for the lower percentiles of increments for weight after 9-10 mo and for recumbent length after 8-9 mo. These data can be used to assess growth in white or black infants whether they are breast-fed or formula-fed. These new data will allow earlier evaluation of growth velocity than the reference data for 3- and 6-mo increments that were available previously. This can lead to the earlier initiation of diagnostic procedures and treatment. The present data should be useful also in research studies.

Body Height↗
PubMed1988

Reference data for head circumference and 1-month increments from 1 to 12 months of age.

Serial head circumference measurements in 462 participants in the Fels Longitudinal Study were used to develop reference data for ages 1 to 12 months. We used a three-parameter mathematical function to model the serial head circumference data for each individual and estimated head circumference at 1-month intervals. Reference data for selected percentiles of head circumference status and 1-month increments were calculated from the estimated head circumferences. These reference data are presented in tables and charts for use in testing hypotheses about group differences or to monitor changes within individuals.

Cephalometry↗
PubMed1988

Sex difference in fetal head growth.

Growth of the fetal biparietal diameter (BPD) throughout the second and third trimesters was measured in a prospective longitudinal study. Linear-cubic equations were fitted to the data of individual fetuses and from these equations mean growth curves were produced for males and females. The head growth trajectories of males and females were significantly different. The study illustrates why the practice of dating pregnancies by ultrasonic fetal BPD measurement at about 16 weeks gestation can lead to error.

Cephalometry↗
PubMed1988

Assessment of transmural force during application of vascular occlusive devices.

An in vivo system was established whereby the transmural forces exerted across the arterial wall during vascular occlusion were directly measured. Evaluation of various currently available vascular occlusive devices was conducted and transmural force transmission data were recorded. The clamps were classified according to their mechanical design characteristics. The magnitude of force required to obtain cessation of distal flow varied significantly among devices of differing mechanical design but correlated well when compared with clamps of similar design. This information was then compared with graded analysis of the degree of intimal injury created by these specific devices as assessed with scanning electron microscopy. The amount of transmural force exerted by each individual device correlated with the grade of intimal injury created by that device. We conclude that fundamental clamp design dictates the magnitude of applied transmural force, that force and the vectors of the application of that force are directly responsible for the degree of resultant intimal injury, and that the intima appears to possess an injury threshold of approximately 5 x 10(4) dynes/cm2. Intimal injury may determine success or failure of vascular surgical procedures; therefore it is prudent to seek the least traumatic means of vascular occlusion.

Animals↗
PubMed1987

Traumatic hemipelvectomy.

Management of patients who have suffered traumatic hemipelvectomy is one of the most difficult challenges to confront a trauma surgeon. We present a case of a female survivor of traumatic hemipelvectomy and factors in the care of these patients that can lead to a successful outcome.

Accidents, Traffic↗
PubMed1987

The changing incidence of caesarean section in the health district of Central Manchester.

The caesarean section rate in England and Wales has practically doubled from 5.6% in 1974 to 10.6% in 1982. Because most statistical reports are based on the practice of individual hospitals and do not reflect what is occurring in a particular community, a retrospective study of the incidence of, and reasons for, caesarean section performed in residents of the geographically defined Health District of Central Manchester was carried out for 1974 and 1982. The caesarean section rate in this community increased from 7% in 1974 to 16% in 1982. Caesarean sections performed for failure to progress in labour, previous caesarean section and preterm fetal compromise before labour accounted for three quarters of the increase. Breech presentation was not a significant contributor to the increase. The reasons for the increase in caesarean sections performed for failure to progress in the first stage of labour were not clarified in the records, and is the subject of prospective investigation.

Adolescent↗
PubMed1987

Head circumference reference data: birth to 18 years.

Highly reliable data from a sample of 888 white US children, measured serially in a single study, have been used to provide reference data for head circumference from birth to 18 years of age. The present data differ little from those already available for the age range from birth to 36 months of age, but they are considerably higher (about 0.5 cm) at older ages for boys and tend to be slightly higher for girls. These new reference data are smoother across age than those used currently for screening and evaluation. Percentiles for 6-month increments from birth to 6 years have been provided.

Cephalometry↗
PubMed1986

Production of interleukin 1 by SK hepatoma tumor cells.

SK hepatoma cells and SK hepatoma conditioned media contain an 18,000-dalton factor which is pyrogenic, stimulates collagenase and prostaglandin production in skin and synovial fibroblasts, induces bone resorption, and stimulates the proliferation of murine thymocytes. These results are consistent with the finding that this tumor cell line produces interleukin 1 [Doyle, M. V., Brindley, L., Kawasaki, E., & Larrick, J. (1985) Biochem. Biophys. Res. Commun. 130, 768-773] since all these activities have been associated with this cytokine. Greater than 80% of the cellular activity has a molecular weight of 30,000, while in contrast, greater than 80% of the activity in the tumor-conditioned media has a molecular weight of 18,000. When active material from the cells is incubated with trypsin, this high molecular weight material is completely converted into an active 18,000 molecular weight species. The isoelectric point of all active material is always between pI 4.0 and 5.1, regardless of molecular weight. All of these results are consistent with the hypothesis that active, high molecular weight interleukin 1 alpha is first synthesized and stored by the tumor cell. This cytokine is then cleaved by a trypsin-like protease to an active, lower molecular weight species which can be secreted into the media.

Animals↗