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Biomedical subjects

J F Pedersen

Publications and source records attributed to J F Pedersen.

At least 91 records · Page 5Linked to original sources
PubMed1985

Is low temperature of the follicular fluid prior to ovulation necessary for normal oocyte development?

Because low temperature in the testis is essential to normal spermatogenesis, we speculated whether a low follicular temperature could also be of importance for the oocytes as they resume meiosis at ovulation. We measured the temperature of the follicular fluid and of the ovarian stroma in 26 follicles in 14 women. In 25 follicles (13 women) the follicular fluid was colder than the ovarian stroma. This temperature difference increases toward ovulation (maximum, 2.3 degrees C). In one case, the measurements of the follicular/stromal temperature difference showed an inverse pattern, the follicular fluid being 0.2 degree C warmer than the stroma. This woman was infertile, and oocyte evaluation for in vitro fertilization had five times shown the oocytes unable to divide in culture. The present study supports the idea that low temperature of the follicular fluid prior to ovulation may be essential for normal oocyte development.

Adult↗
PubMed1985

Left ventricular performance monitored by radionuclide cardiography during induction of anesthesia.

Radionuclide cardiography with 99mTc-labeled erythrocytes was carried out in three different studies comprising 20 female patients without heart or lung diseases. Left ventricular ejection fraction (LVEF) and other hemodynamic variables were measured immediately before and during induction of anesthesia (thiopental, N2O/O2, succinylcholine, laryngoscopy + oral intubation, halothane). In study 1, serial measurements of LVEF, left ventricular volume, and derived variables were obtained by gamma camera in seven patients using 3-min sampling periods. In Studies 2 and 3, LVEF was monitored serially in seven and six patients, respectively, by a portable, nonimaging probe (nuclear stethoscope) at 1-min intervals or less. The induction period was prolonged to last 24 min in studies 1 and 2, against 9 min in study 3. In studies 1 and 2 there was an increase in blood pressure and heart rate after thiopental and after laryngoscopy and intubation. In study 3 a similar increase was observed after intubation. In the gamma camera study LVEF decreased from 0.72 to 0.53 after thiopental, with no further decrease during intubation. This decrease was accompanied by an increase in end-systolic volume and a decrease in the ratio: systolic cuff pressure/end systolic volume, whereas end-diastolic volume and cardiac index remained unchanged. In the nuclear stethoscope studies, LVEF decreased both after thiopental and after intubation, in study 2 from 0.68 to 0.38 and from 0.53 to 0.41, respectively; in study 3 from 0.69 to 0.53 and from 0.57 to 0.44, respectively. Our observation, in healthy, female individuals, provide an impetus for further noninvasive radionuclide studies during anesthesia in patients with cardiovascular disease.

Adult↗
PubMed1985

Congenital malformations in diabetic pregnancies. Clinical viewpoints.

A consecutive series of 2,587 newborn infants of diabetic mothers treated during pregnancy and delivery in the period 1926 to 1983 has been analysed. The malformation rate was 6.6%. The series has been divided into five consecutive periods each comprising around 500 infants. During the first four periods the frequency of congenital malformations (CM) was remarkably constant also when related to the severity of the maternal diabetes. During the latest period from 1979 to 1983 a significant decrease in the frequency and severity of CM in infants of diabetic mothers was seen, most marked in the group with more severe maternal diabetes (White's classes D + F). One hundred and thirty-five insulin-dependent diabetic women with regular menstrual histories were examined by ultrasonic scanning in the 7th to 14th week of pregnancy. As judged by the crown-rump length 53 fetuses were smaller than normal. The term early growth delay is used for this phenomenon. Nine of the 135 fetuses had major CM and seven of them were smaller than normal in early pregnancy. These observations show that fetuses that are significantly smaller than normal in early pregnancy carry a higher risk of being malformed and suggest a common mechanism behind early growth delay and induction of abnormal embryogenesis.

Birth Weight↗
PubMed1985

The possibility of an early growth delay in White's class A diabetic pregnancy.

Ultrasound scanning has revealed that some fetuses of women with insulin-dependent diabetes are smaller than normal in early pregnancy as judged by the crown-rump length. This early growth delay is negatively correlated to the quality of diabetes regulation. Nine White's Class A diabetic women had fetuses that were on average 4.5 days (range, 0-11 days) smaller than expected from the menstrual history. Apparently, the expectedly modest metabolic disturbances in early pregnancy of Class A diabetic women are able to interfere with normal embryonic growth.

Diabetes Mellitus, Type 1↗
PubMed1984

Accuracy of absolute left ventricular volumes and cardiac output determined by radionuclide cardiography.

We determined left ventricular (LV) volumes and derived variables by gated equilibrium radionuclide imaging at rest and during exercise in 12 patients without valve disease or intracardiac shunts. LV volume was determined as the product of the background-corrected LV count rate and an individual attenuation correction factor divided by the count rate in peripheral blood. Attenuation correction was based on measurement of LV depth within the chest from an initial first pass study in the left lateral view and a linear attenuation coefficient of 0.156 cm-1 determined in phantom studies. The average LV depth was 8.0 cm (range 6.9-9.1) in agreement with an average depth measured by echocardiography of 8.2 cm (6.3-9.4), P much greater than 0.05. The correlation between radionuclide (RC) and simultaneous thermodilution (TD) measurements was for cardiac output (CO): r = 0.95; CO (RC) = 1.00 X CO (TD) + 0.10 1/min with a standard error of the estimate (SEE) of 0.79 1/min; for stroke volume (SV): r = 0.90; SV(RC) = 0.93 X SV (TD) + 5 ml; SEE = 8 ml; for end-diastolic volume (EDV): r = 0.96; EDV(RC) = 1.06 X EDV(TD) -14 ml; SEE = 27 ml; and for end-systolic volume (ESV): r = 0.98; ESV(RC) = 1.05 X ESV (TD) -6 ml; SEE = 20 ml. The interobserver variation, expressed as the coefficient of variation, was for cardiac output 6%, for stroke volume 6%, for end-diastolic volume 4%, and for end-systolic volume 5%. This method permits non-invasive determination of LV volume and total LV output per beat based exclusively on data obtained during radionuclide imaging.

Adult↗
PubMed1984

Three-dimensional ultrasonic scanning.

Simple experiments which form the basis for a true 3-D demonstration of sectional images are presented and a method for genuine 3-D display of dynamic ultrasound images is described. Eight ultrasound images are recorded with a slightly different angulation of the transducer. The images are extracted from the video signal from a conventional ultrasound scanner and stored in eight digital memories. After recording, each image is displayed on an oscilloscope screen, which is viewed via a fast oscillating mirror. The position of the mirror determines which of the eight images are to be displayed and thereby ensures a correct spatial relationship of the images, resulting in a true 3-D scan presentation.

Methods↗
PubMed1984

Fetal growth delay and maternal hemoglobin A1c in early diabetic pregnancy.

Forty insulin-dependent diabetic women in the first trimester of pregnancy were studied. Fetal crown-rump length was measured by ultrasound and related to maternal hemoglobin A1c. Thirty mothers with normal size fetuses had an average hemoglobin A1c level of 7.8%. Ten mothers had fetuses that were smaller than normal (equivalent to eight to 14 days less growth) and also had higher hemoglobin A1c, 8.9% (P less than .05), indicating a more poorly controlled diabetes. Careful metabolic compensation in very early diabetic pregnancy should therefore be attempted to prevent induction of early fetal growth delay.

Birth Weight↗
PubMed1984

Obstetric ultrasonography: recent observations in first trimester of pregnancy.

It is possible both to accurately measure foetal size and visualize the yolk sac and the amniotic membrane by ultrasound scanning in the first trimester of pregnancy. In threatened abortion an intrauterine haematoma or a foetal size smaller than normal are ominous signs. Likewise, too small a foetal size in early diabetic pregnancy indicates an increased risk of foetal malformation.

Abortion, Threatened↗
PubMed1983

Transperineal 125iodine seed implantation in prostatic cancer guided by transrectal ultrasonography.

A new method is described for precise transperineal insertion of radioactive 125iodine seeds in patients with prostatic cancer. The procedure is done under transrectal ultrasonography guidance using a special multichannel puncture attachment and a simple, efficient insertion technique. The advantages of the method are 1) the patients are spared the inconvenience and risk of an operation, 2) improved dose calculations are possible, and 3) seed application is easy and more precise than by the conventional operative free-hand technique.

Brachytherapy↗
PubMed1983

Ultrasound demonstration of the amniotic membrane.

Ultrasound scanning in the first trimester of pregnancy occasionally revealed a thin linear echo in the gestational sac. A total of 360 examinations, which had shown a live fetus with a crown-rump length of 7-82 mm, equivalent to a menstrual age of 6-14 weeks, were reviewed. The linear echo was seen in 51 of the examinations, at an ultrasound age of 6-12 weeks. Most frequently it was seen in the 9th week, where it was recorded in 28 of 61 (46%) of the examinations. The origin of the linear echo is believed to be the very thin amniotic membrane, which from the 8th to the 12th week is lined by fluid on both sides. Other intra-uterine membranes which all give stronger echo reflections are listed.

Extraembryonic Membranes↗