PubMed Health⌕ Search

Biomedical subjects

M Willis

Publications and source records attributed to M Willis.

At least 37 records · Page 2Linked to original sources
PubMed1988

Growth of the fetal biparietal diameter in urban Cape coloured families.

Ultrasonic measurements of biparietal diameter (BPD) between the 12th week of menstrual age (MA) and delivery were taken longitudinally on a group of 98 Cape Coloured employees of Groote Schuur Hospital. The socio-economic situation of subjects was above average for the community; this was reflected in their larger body size and the increased birth weight of observed fetuses. A growth chart showing MA as a function of BPD has been constructed for clinical use. This chart can be regarded as representing a 'norm' closer to the ideal than to the average in the population.

Adult↗
PubMed1986

Effects of fructose-1,6-diphosphate, glucose, and saline on cardiac resuscitation.

Severe hypoxemia causes respiratory and cardiac arrest, in part, because severe hypoxemia decreases glycolysis and adenosine triphosphate (ATP) production by a lactic acid-induced decrease in the activity of phosphofructokinase and glyceraldehyde-3-P dehydrogenase. Fructose-1,6-diphosphate (FDP) administration increases the ATP concentration of blood. The authors hypothesized that FDP might increase the number of rabbits that could be resuscitated from hypoxemic cardiac arrest. To test this hypothesis, heart rate, arterial pressure, left ventricular end-diastolic pressure, and blood gases and pH were measured during normoxemia (FIO2 = 0.21) and again during hypoxemia (FIO2 = 0.04) in 28 adult, white, New Zealand rabbits anesthetized with pentobarbital. With the onset of hypoxemia, we gave either 40 mg/kg of 5% FDP (n = 10), 5% glucose (n = 11), or an equal volume (2.5 ml) of normal saline (n = 7) intravenously and began a continuous infusion of 2.0 mg X kg-1 X min-1 of the same sugar or 0.12 ml/min of saline. FDP-treated rabbits breathed for 20.9 +/- 4.9 (mean +/- SEM) min after initiation of hypoxemia; glucose-treated rabbits breathed for 1.4 +/- 0.2 min, and saline-treated rabbits breathed 10.3 +/- 4 min. Cardiac arrest occurred 2.5 +/- 0.5 min after the onset of respiratory arrest in FDP-treated rabbits, 4.1 +/- 0.2 min in glucose-treated rabbits, and 2.9 +/- 0.4 min in saline-treated rabbits. We could resuscitate all ten FDP-treated rabbits; two of 11 glucose-treated (FDP vs. glucose, P less than 0.001); and one of seven saline-treated rabbits (FDP vs. saline, P less than 0.001) from cardiac arrest.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMed1986

Nifedipine therapy for diffuse esophageal spasm.

Although nifedipine therapy resulted in substantial relief of dysphagia in six patients with diffuse esophageal spasm, significant side effects, particularly in young working subjects, precluded prolonged use.

Dizziness↗
PubMed1984

The effect of paralysis on oxygen consumption in normoxic children after cardiac surgery.

To determine whether paralysis reduces oxygen consumption (V02) after cardiac surgery in infants, the authors measured V02 before and after paralysis in 17 sedated infants who were ventilated mechanically after cardiac surgery. Oxygen consumption was determined as being the difference between oxygen content of inspired and expired gases. The absence or presence of "movement" (breathing or repeated movement of the extremities) before paralysis was noted. For eight infants who did not "move" before paralysis, VO2 was similar before (9.1 +/- 1.2 ml . kg-1 . min-1, mean +/- SD) and after (9.0 +/- 1.5 ml . kg-1 . min-1) paralysis (P = 0.81). However, for nine infants who did "move" before paralysis, VO2 decreased from 9.2 +/- 1.4 ml . kg-1 . min-1 before paralysis to 8.0 +/- 1.4 ml . kg-1 . min-1 after paralysis (P less than 0.05). One infant in each group had an increase in VO2 greater than 10% of the baseline value (i.e., 12% and 14%). In conclusion, if breathing or repeated movement is present before paralysis, paralysis decreases VO2 by 13% in sedated infants after cardiac surgery. If repeated or regular movement is not present before paralysis, paralysis does not decrease VO2. These data suggest that in normoxic patients, muscle paralysis does not significantly alter V02 and therefore should not be used for this purpose.

Anesthesia↗
PubMed1984

CT of the liver and spleen with EOE-13: review of 225 examinations.

EOE-13 is an experimental liver-spleen-specific computed tomographic (CT) contrast agent developed at the National Institutes of Health. Experience with this agent in 225 clinical examinations is described. On average, use of EOE-13 increases the attenuation of normal liver by 32.5 H and that of normal spleen by 52.3 H. Tumors in these organs increase only 2.6 H, making them more easily detectable. Most of the iodine in EOE-13 appears to clear from the liver and spleen by 24 hr after injection. No deaths or permanent morbidity have been observed. The complication rate is 3.6%. EOE-13 is valuable for the detection of hepatic and splenic tumors.

Adult↗
PubMed1984

Assessment of perfusion patterns during hepatic artery infusion chemotherapy: EOE-13 CT and 99mTc-MAA scintigraphy.

Hepatic perfusion patterns were evaluated in five patients receiving hepatic artery infusion chemotherapy. All patients underwent 99mTc macroaggregated albumin (99mTc-MAA) scintigraphy and CT with EOE-13. In each case, the diagnostic agent was administered through the infusion catheter at 0.66 ml/min. Hepatic perfusion patterns were identified with both imaging methods, but CT with EOE-13 yielded more precise anatomic detail and was unique in demonstrating the perfusion status of each hepatic metastasis. Further evaluation of EOE-13 for this purpose is warranted.

Adult↗
PubMed1984

Intraarterial administration of EOE-13 for the CT evaluation of hepatic artery infusion chemotherapy.

EOE-13 was infused directly into the hepatic artery through a surgically implanted hepatic artery infusion pump in a patient with liver metastases. A computed tomographic scan obtained after EOE-13 infusion accurately showed the perfusion pattern of the implanted catheter. It also demonstrated the hepatic metastases more clearly than scintigraphy with 99mTc-macroaggregated albumin. EOE-13 may prove useful for the evaluation of hepatic perfusion patterns in patients receiving hepatic artery infusion chemotherapy.

Adult↗
PubMed1983

Detection of hepatic metastases: comparison of EOE-13 computed tomography and scintigraphy.

Accurate detection of hepatic metastases is necessary to properly stage and follow many malignancies. Nineteen patients underwent computed tomographic (CT) examination with ethiodized oil emulsion 13 (EOE-CT) and liver scintigraphy within 1 month of an exploratory laparotomy. The sensitivity, specificity, and accuracy of these two imaging procedures were evaluated statistically. No differences were seen when the patients were scored as positive or negative for metastases. However, in a lesion-by-lesion analysis of 58 hepatic lesions, the sensitivity of EOE-CT was 69.0% and the sensitivity of scintigraphy was 32.8% (p less than 0.001). All lesions detected scintigraphy were also detected by EOE-CT. EOE-CT had a size threshold of 1.0-1.5 cm, while liver scintigraphy had a threshold of 2.5-3.0 cm. EOE-CT is a more sensitive examination for detection of small hepatic metastases than liver scintigraphy.

Contrast Media↗
PubMed1982

Computed tomography of the liver and spleen with intravenous lipoid contrast material: review of 60 examinations.

In 60 computed tomographic examinations of the liver and spleen in 55 patients, a new intravenous lipoid contrast material, Ethiodized Oil Emulsion 13, was used. This organ-specific contrast material, retained by the reticuloendothelial cells of the liver and spleen, caused marked increase in the attenuation of the liver and spleen, but did not appreciably change the attenuation of the tumor involving these organs, thereby significantly increasing the density differential between normal and abnormal tissue. Toxicity was considered to be well within tolerable limits with the most frequently noted untoward side effects of chills, fever, headaches, and foul metallic taste. Ethiodized Oil Emulsion 13 holds the promise to become a valuable clinical tool by which hepatic and splenic imaging may be significantly improved and lesions less than 1 cm in diameter demonstrated in the liver and spleen.

Adult↗
PubMed1978

Perfusion preservation of hearts for 6 to 9 days at room temperature.

The combination of a defined medium with single-pass perfusion has made possible long-term maintenance of beating rat hearts at 22 degrees C in vitro. The 6- to 9-day survival period appears to be the longest so far reported for hearts. This method provides a stable system which should be useful for investigating the role of single factors in myocardial preservation and evaluating the effects of exposure to pharmacological and toxicological agents.

Animals↗
PubMed1977

The effect of time of cord clamping and maternal blood pressure on placental transfusion with cesarean section.

We measured the residual placental blood volume (RPBV) of 20 infants delivered at term by cesarean section of women not in labor. In all cases, the umbilical cord was clamped within 40 seconds of birth. RPBV decreased significantly with increasing age at cord clamping. In addition, RPBV for infants with cords clamped within 20 seconds of birth correlated inversely with maternal systolic blood pressure (mean RPBV = 54.8 ml. per kilogram at 105 torr and 28.4 ml. per kilogram at 148 torr). However, RPBV did not correlate with maternal blood pressure for the whole group of 20 infants or for those with cords clamped later than 20 seconds after birth. These data indicated that in infants delivered by cesarean section placental transfusion is time related during the first 40 seconds of life and that maternal blood pressure also influences the magnitude of placental transfusion during the first 20 seconds after birth. Analysis of data from this study combined with data from a previous study shows that after 40 seconds the net flow between placenta and infant reverses and that cord clamping delayed beyond this point is accompanied by a rise in RPBV back to the level found when the cord was clamped before 20 seconds.

Blood Pressure↗