Search PubMed⌕ Search

Biomedical subjects

J F Pedersen

Publications and source records attributed to J F Pedersen.

At least 37 records · Page 2Linked to original sources
PubMed1998

Serum levels of human placental lactogen, pregnancy-associated plasma protein A and endometrial secretory protein PP14 in first trimester of diabetic pregnancy.

OBJECTIVE: To study maternal serum levels of human placental lactogen (hPL), pregnancy-associated plasma protein A (PAPP-A) and endometrial secretory protein PP14 (PP14) in first trimester of diabetic pregnancy. METHODS: Seventy-nine insulin-dependent diabetic women and 93 normal pregnant women had a venous blood sample drawn in weeks 8-14, ultrasound age. Serum levels were measured by radioimmunoassays and expressed in multiples of the median serum value in normal pregnancy at that ultrasound age. RESULTS: Levels of hPL were significantly lower in diabetic mothers than in controls, z'= -5.502, p<0.00001. Levels of PAPP-A were also significantly lower, z' =2.263, p=0.024, but were significantly less depressed than those of hPL, z'=2.41, p=0.015. The PP14 levels did not deviate from normal. CONCLUSION: In first trimester of diabetic pregnancy there appears to be both a more general depression of trophoblast function, and also a specific depression of the hPL release.

Case-Control Studies↗
PubMed1997

Accuracy of the diagnosis of pleural effusion on supine chest X-ray.

Diagnosis of pleural effusion (PE) on supine chest X-ray (SCXR) is considered difficult. This study aimed at evaluating the accuracy of the diagnosis of PE on SCXR and was performed in two phases. At phase 1, a formula for the sonographic estimation of the volume of PE was established by correlating 24 measurements (in 7 patients in whom complete drainage was achieved) with the drained volumes. At phase two, 112 consecutive SCXRs were supplemented by sonography of the chest. The films were evaluated for the presence of PE and for the presence of different radiologic signs of PE. Sonography showed PE in 41 right and 30 left hemithoraces. The overall accuracy of the diagnosis of PE on SCXR was 82 %. Only one of the undiagnosed PEs had a volume of > 300 ml. The most accurate signs were increased density of the hemithorax, blunted costophrenic angle, and loss of the hemidiaphragm silhouette.

Adolescent↗
PubMed1997

Significant association between simple renal cysts and arterial blood pressure.

OBJECTIVE: To test the hypothesis that there is an association between simple renal cysts and arterial blood pressure (BP). PATIENTS AND METHODS: The study comprised a review of the case-notes of 115 patients (mean age 67.7 years, range 31-91) in whom renal cyst(s) was an incidental ultrasonographic finding, and 115 age- and sex-matched control patients. The notes were reviewed without knowledge of the origin or treatment. RESULTS: The systolic and diastolic BP were significantly higher in patients with a cyst(s) than in control patients (P = 0.031 and P = 0.0034; mean difference 6.9 mmHg and 5.0 mmHg, respectively). In those aged 30-70 years, the presence of one or more simple renal cysts increased the risk of having a diastolic BP > or = 95 mmHg from seven in 58 to 17 in 58 patients (P = 0.038). CONCLUSION: The association between simple renal cysts and higher arterial BP probably arises from underlying renal disease causing both. Occasionally it is possible that renal ischaemia caused by cyst expansion, and therefore increased renin release, generates the elevation in BP. If so, methods to identify such cysts should be developed.

Adult↗
PubMed1997

A simple method for relative assessment of the sound propagation velocity in breast tumors: technique and diagnostic efficacy.

OBJECTIVE: The purpose of this study was to describe and evaluate a method for assessing the sound propagation velocity in breast tumors relative to the velocity in adjacent tissue. SUBJECTS AND METHODS: Sixty-six patients with palpable breast tumors were studied. The scanning plane was aligned so that it transected the tumor and depicted the front of a rib or the pleura-lung interface behind the tumor. This contour was evaluated for distortion, and the height of the distortion and the height of the tumor were used to calculate the relative sound propagation velocity. RESULTS: A posterior reference line was revealed behind 62 of 66 tumors. Of these 62 tumors, an elevation was seen behind 49 tumors, and no distortion was seen behind 13 tumors. A depression was never observed. The median relative sound propagation velocity of 1.07 that was calculated in 42 carcinomas (range, 1.00-1.14) was insignificantly higher (p = .079) than the median relative sound propagation velocity of 1.04 obtained in 20 fibroadenomas (range, 1.00-1.15). CONCLUSION: Although assessment of relative sound propagation velocity in breast tumors was successful, the relative velocities differed only insignificantly between benign and malignant lesions.

Biopsy, Needle↗
PubMed1996

Sonographic measurement of the thymus in infants.

A new method of measuring the size of the thymus in infants less than 1 year of age is presented. The width of the thymus was measured in a transverse image while the area of the largest lobe was assessed in a longitudinal image. The thymic index was then defined as the product of these two values. Intra- and interobserver variation analysis were performed in 23 infants. Each infant was scanned alternately by both of two radiologists, and later the same day the measurements were repeated. The mean differences between the first and second measurements (intraobserver variation) were -0.25 (2 SD 7.56) and -1.13 (2 SD 10.80), respectively, for the two observers. The mean difference between the first measurements of the two observers (interobserver variation) was 1.47 (2 SD 9.39). In a postmortem study of 12 infants the thymic index measured by sonography showed an acceptable correlation to the actual volume (c = 0.80) and weight (c = 0.87) of the thymus. In conclusion, our sonographic estimate of the volume of the thymus, the thymic index, in infants under 8 months of age seems to be easy, reliable and reproducible.

Anthropometry↗
PubMed1996

Changes in the anal sphincter with age. An endosonographic study.

PURPOSE: To describe the changes in the endosonographic appearance of the anal sphincter muscles with age. MATERIAL AND METHODS: Fifty subjects (age range 22-85 years) with no history of anorectal disease or surgery were studied with anal endosonography. The thickness of the internal and external anal sphincter was registered and correlated to age. For the internal sphincter, which is often asymmetric, the maximum and minimum thicknesses were measured at any part of the circumference (except anteriorly for anatomic reasons) and also in the lateral positions. RESULTS: A significant positive correlation with age was found for all maximum, minimum, and average internal sphincter thicknesses. Moreover, the echogenicity of the internal sphincter changed with age as the sphincter muscle became more echogenic. There was no significant correlation between external sphincter thickness and age. CONCLUSION: Knowledge of the normal variation of the internal sphincter thickness with age is important since endosonography may be used to identify patients with hypertrophy of the internal sphincter. Currently, we consider maximal thicknesses above 4 mm to be abnormal in patients under 50 years of age, whereas in patients aged at least 50 years thicknesses of 5 mm or more are considered abnormal.

Adult↗
PubMed1996

Endosonography for preoperative staging of rectal tumours.

PURPOSE: The aim of this study was to evaluate the use of rectal endosonography for preoperative staging of tumour extension and lymph node involvement in rectal tumours. MATERIAL AND METHODS: Over a 4-year period 100 patients with rectal tumours were studied with sonography using 7 MHz endoprobes. Tumour spread was assessed according to the TNM classification, and the number and maximum size of perirectal lymph nodes were registered. The sonographic findings were compared with the surgical and histological findings. RESULTS: The overall accuracy of endosonography in assessing local tumour extension was 85% (76-91%; 95 percent confidence limits). T4 tumours with a large contact surface to an adjacent organ tended to be nonresectable. Lymph node assessment could be made in 81 patients who underwent radical resection: sonography showed lymph nodes in 49 patients, 30 of whom had nodal metastases; the histological examination showed lymph nodes in the remaining 32 patients, 8 of whom had nodal metastases. The number of lymph nodes at the histological examination was markedly higher than the number depicted by preoperative ultrasound. CONCLUSION: This study confirmed the use of endoluminal ultrasound in the preoperative evaluation of local tumour spread. However, endosonographic assessment of perirectal nodal involvement seems to be too unreliable to be used for the preoperative selection of patients.

Adenocarcinoma↗
PubMed1996

Can dipstick screening for hematuria identify individuals with structural renal abnormalities? A sonographic evaluation.

The present study presents data from a population study of 659 randomly selected adult volunteers. All participants had a renal sonographic examination and at the same time had their urine tested for hematuria by dipstick. Thirty participants (5%) had dipstick hematuria. Similar rats of abnormal renal findings were obtained in the hematuria-positive and hematuria-negative groups, 10% and 8%, respectively. Our results suggest that dipstick investigation for hematuria in mass-screening programs is not effective for the detection of structural renal abnormalities.

Adult↗
PubMed1995

Differential increase in the maternal serum concentrations of the placental proteins human chorionic gonadotrophin, pregnancy-specific beta 1-glycoprotein, human placental lactogen and pregnancy-associated plasma protein-A during the first half of normal pregnancy, elucidated by means of a mathematical model.

The present study was performed to compare the increase in maternal serum concentrations of four placental proteins during the first half of 240 normal pregnancies. The proteins were pregnancy-associated plasma protein-A (PAPP-A), human chorionic gonadotrophin (HCG), human placental lactogen (HPL) hormone, and pregnancy-specific beta 1-glycoprotein (PSG), all produced by trophoblast cells. The median increases were observed to be very close to exponential growth curves. Based on simple assumptions, these growth curves could be explained as being solely dependent on the growth of the placenta. The assumptions were that the proteins were produced in the placenta at a constant rate per gram of placental cell mass and secreted into the circulation shortly after synthesis. Our investigations showed that for two of the proteins, PSG and HPL, the rate constants were, in fact, close to the reported growth rate of the placenta, whereas the PAPP-A production rate constant was significantly higher than those of the others. The production curve for HCG was very different from that of the other proteins. PAPP-A and HCG must therefore have more complicated mechanisms for regulating the production. An equation was constructed that permitted estimation of the molar production of the placental proteins per gram of placental cell mass per day during the first half of normal pregnancy. The value was highest for HPL and lowest for PAPP-A.

Chorionic Gonadotropin↗
PubMed1995

Depressed serum levels of human placental lactogen in first trimester vaginal bleeding.

BACKGROUND: It has previously been shown that serum levels of pregnancy-associated plasma protein A (PAPP-A) are depressed in patients with early pregnancy bleeding and a live gestation. We examined whether human placental lactogen (hPL) levels show a similar pattern. METHOD: Prospective study in the 8th-14th gestational week comparing serum levels in 69 women with early pregnancy bleeding with those in 93 control pregnancies. RESULTS: Serum levels of hPL were significantly depressed in women with early pregnancy bleeding (p < 0.0001). CONCLUSIONS: The findings suggest a primary affection of the placenta in early pregnancy bleeding.

Female↗
PubMed1995

Serum levels of hPL, PAPP-A and PP14 in patients with early pregnancy bleeding and subchorionic hemorrhage.

OBJECTIVE: To investigate possible endocrine changes in patients with early pregnancy bleeding and subchorionic hemorrhage. DESIGN: Prospective study in first trimester of pregnancy comparing circulating levels of human placental lactogen (hPL), pregnancy-associated plasma protein A (PAPP-A) and endometrial secretory protein PP14 (PP14) in women with and without subchorionic hemorrhage. SUBJECTS: Sixty-nine women with early pregnancy bleeding, who in week 7-14 had a blood sample and an ultrasound study with both determination of fetal crown-rump length and a search for subchorionic hemorrhage. RESULTS: There was no difference between serum levels of hPL, PAPP-A and PP14 in 29 women with and 40 women without subchorionic hemorrhage, and no correlation between serum levels and the size of the hematoma. CONCLUSION: Judged from the serum levels of the studied substances there were no indications of an impaired function of the trophoblast or the decidua that could explain the development of subchorionic hemorrhage.

Adult↗
PubMed1995

Human placental lactogen and pregnancy-associated plasma protein A in first trimester and subsequent fetal growth.

OBJECTIVE: To study in an optimized design the possible relation between serum levels in weeks 8-14 of human placental lactogen and pregnancy-associated plasma protein A and fetal size at delivery. METHODS: Analysis of data from 93 normal singleton pregnancies. Gestational age was assessed from a sonographic crown-rump length measurement. Serum levels of human placental lactogen and pregnancy-associated plasma protein A were determined by radioimmunoassay, and were expressed in multiples of mean. The relative birth weight was used as an index of fetal growth. RESULTS: Serum levels of human placental lactogen and pregnancy-associated plasma protein A showed a negative correlation to gestational age at delivery (p < 0.01 and p < 0.05, respectively), and there was a positive correlation between the serum level of pregnancy-associated plasma protein A and relative birth weight (p < 0.02). CONCLUSIONS: Higher levels of human placental lactogen and pregnancy-associated plasma protein A predicted earlier delivery, maybe because of better fetal growth, and higher levels of pregnancy-associated plasma protein A predicted better fetal growth.

Birth Weight↗
PubMed1995

Brown midrib sorghum silage for midlactation dairy cows.

Brown midrib sorghum silage was compared with alfalfa, corn, and normal sorghum silages for its effect on performance, ruminal metabolism, and digestive kinetics of Holstein dairy cows in midlactation. Twelve cows averaging 90 +/- 5 DIM were assigned to one of four diets in replicated 4 x 4 Latin squares with 4-wk periods. Additionally, 3 ruminally fistulated cows (95 +/- 20 DIM) were assigned to the same diets in a 3 x 4 Youden square for measurement of ruminal characteristics. Diets were fed as isonitrogenous TMR that contained 65% silage (DM basis). The DMI was greater for the corn and brown midrib sorghum (4% of BW/d) than for the alfalfa and normal sorghum diets (3.4% of BW/d). The brown midrib sorghum supported FCM production that was similar to that of cows on corn and alfalfa diets (25.8 kg/d), but cows fed normal sorghum produced less milk and fewer milk components. Source of silage had no effect on eating time, but rumination was least for the alfalfa diet. Ruminal pH and ammonia concentrations were similar for all diets. Total VFA concentrations were greatest for the corn and brown midrib sorghum diets. The brown midrib sorghum had greater in situ extent of ruminal NDF digestion than did the normal sorghum, which agreed with in vitro data. The brown midrib sorghum used in this experiment supported FCM production similar to the corn and alfalfa silages commonly fed to dairy cows in midlactation.

Animal Nutritional Physiological Phenomena↗
PubMed1995

Intraobserver and interobserver variations in sonographic measurements of kidney size in adult volunteers. A comparison of linear measurements and volumetric estimates.

Estimation of renal size by sonography can be performed by measuring renal length, volume, cortical volume or cortical thickness. Observer variation in these measurements is an important factor, especially when repeated measurements are compared. This study was performed to examine the magnitude of intraobserver and interobserver variations for each of the above-mentioned measurements, and to find the measurement with the lowest observer variation. Sonographic measurements were performed by 3 observers on 18 adult volunteers. The standard deviation of the difference (SDD) between any 2 pairs of measurements was used as the indicator of the magnitude of the observer variation. Renal length measurement showed the lowest observer variation with a relative SDD of 4 to 5%. Measurement of cortical thickness showed the poorest reproducibility with a relative SDD of 18 to 23%, while volumetric estimations had a relative SDD of 14 to 17%. Renal length measurement should be preferred to renal volume estimation, especially when comparing repeated measurements.

Adult↗