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Biomedical subjects

L Eriksson

Publications and source records attributed to L Eriksson.

At least 181 records · Page 10Linked to original sources
PubMed1989

Secretory pattern of growth hormone regulates steroid sulfatase activity in rat liver.

Steroid sulfatase activity was quantified in liver microsomes from hypophysectomized adult female rats treated with estradiol and continuous or intermittent human growth hormone (hGH). Hypophysectomy clearly enhanced sulfatase activity as compared to intact female rats. Normal female values were completely restored by continuous infusion of hGH (1.4 i.u./kg/day). Neither the same dose of hGH given as two daily injections nor estrogen replacement therapy had any effect. It is concluded that liver microsome sulfatase activity in the non-pregnant rat is regulated by the sexually dimorphic secretory pattern of GH.

Animals↗
PubMed1989

Histologic features of the temporomandibular joint disk and posterior disk attachment: comparison of symptom-free persons with normally positioned disks and patients with internal derangement.

To gain further knowledge about the differences between normal and pathologic anatomy of the temporomandibular joint disk, we examined histologically disks obtained at autopsy from 10 symptom-free persons and compared our findings with observations involving 17 surgically removed disks. The surgical patients had internal derangement and severe long-standing temporomandibular joint pain and dysfunction. The normal disks were biconcave, whereas the surgically removed disks were deformed and thicker than the normal disks. Chondrocytes (4 joints), a surface layer of proliferative connective tissue (4 joints), vessels (2 joints), and splitting (4 joints) were seen in the surgical specimens but not in the normal specimens. The surgical specimens also showed higher maximal density of fibroblasts and vessels. It was concluded that surgically removed temporomandibular joint disks demonstrated several histologic alterations that were not seen in normal disks. These characteristics may serve as the basis for development of a histologic grading of pathologic conditions of the temporomandibular joint disk and the posterior disk attachment.

Adolescent↗
PubMed1989

Cryosectional observations of functional anatomy of the temporomandibular joint.

The anatomy and function of the temporomandibular joint are complex, and our understanding about how the retrocondylar tissues change when the condyle translates anteriorly has been incomplete. We therefore examined the sectional anatomy of 24 fresh human temporomandibular joints at different gradations of jaw opening, protrusion, and laterotrusion. We found that the tissues of the posterior disk attachment expanded in volume and occupied the space behind the condyle when the mouth was opened, protruded, or laterotruded to the contralateral side. Volumetric expansion of the tissue seemed to be due mainly to distension of the venous structures in the retrodiskal area. In the lateral region of the joint, tissue from the superior aspect of the parotid gland also seemed to contribute to the filling of the space posterior to the condyle. Thus, the retrodiskal tissue appears to have a substantial capacity to expand and fill the mandibular fossa when the condyle translates anteriorly. The possibility of a dynamic vascular physiology is suggested.

Aged↗
PubMed1989

Reliability of a negative clinical temporomandibular joint examination: prevalence of disk displacement in asymptomatic temporomandibular joints.

Unilateral temporomandibular joint arthrography was performed in 40 healthy volunteers with asymptomatic and clinically normal temporomandibular joints. Thirty-four joints (85%) showed superior disk position, and six joints (15%) were radiographically abnormal with displacement of the disk. Thus, two showed anterior displacement, one showed rotational anterolateral displacement, one showed rotational anteromedial displacement, one showed sideways lateral and one showed sideways medial displacement. Thus, a negative clinical examination for temporomandibular joint internal derangements may involve a risk of being false-negative. All but one of the joints showed normalization of disk position during opening, and it is suggested that lack of functional disturbances accounts for the freedom of symptoms.

Adolescent↗
PubMed1989

Kinetic analysis of central [11C]raclopride binding to D2-dopamine receptors studied by PET--a comparison to the equilibrium analysis.

[11C]Raclopride binding to central D2-dopamine receptors in humans has previously been examined by positron emission tomography (PET). Based on the rapid occurrence of binding equilibrium, a saturation analysis has been developed for the determination of receptor density (Bmax) and affinity (Kd). For analysis of PET measurements obtained with other ligands, a kinetic three-compartment model has been used. In the present study, the brain uptake of [11C]raclopride was analyzed further by applying both a kinetic and an equilibrium analysis to data obtained from four PET experiments in each of three healthy subjects. First regional CBV was determined. In the second and third experiment, [11C]-raclopride with high and low specific activity was used. In a fourth experiment, the [11C]raclopride enantiomer [11C]FLB472 was used to examine the concentration of free radioligand and nonspecific binding in brain. Radio-activity in arterial blood was measured using an automated blood sampling system. Bmax and Kd values for [11C]raclopride binding could be determined also with the kinetic analysis. As expected theoretically, those values were similar to those obtained with the equilibrium analysis. In addition, the kinetic analysis allowed separate determination of the association and dissociation rate constants, kon and koff, respectively. Examination of [11C]raclopride and [11C]FLB472 uptake in brain regions devoid of specific D2-dopamine receptor binding indicated a fourth compartment in which uptake was reversible, nonstereoselective, and nonsaturable in the dose range studied.

Adult↗
PubMed1989

Acute respiratory failure in anorexia nervosa with hypophosphataemia.

A 19-year-old woman with anorexia nervosa developed respiratory failure during parenteral nutrition. Serum phosphate concentration was low and the patient had several symptoms typical of hypophosphataemia. It is well known that parenteral refeeding may cause severe hypophosphataemia and this has earlier been described to cause respiratory failure in alcoholics and in patients with intestinal disease. This is, to our knowledge, however, the first reported case of respiratory failure in association with hypophosphataemia occurring in a patient with anorexia nervosa and parenteral nutrition.

Acute Disease↗
PubMed1989

Growth hormone 24-h serum profiles during pregnancy--lack of pulsatility for the secretion of the placental variant.

Serum profiles of growth hormone (GH) were recorded for 24 h in women at different stages of normal pregnancy. Two monoclonal antibodies directed against different epitopes and unaffected by human placental lactogen were used in radioimmunoassays to distinguish the pituitary 22K-GH from the placental GH variant. The 'normal' episodic peak activity of GH in non-pregnant and first trimester pregnant women was dramatically changed into a continuous very stable secretion during late pregnancy. This change was first observed at 17 weeks gestation. It is concluded that during the second half of pregnancy, serum measurements of GH reflect a major contribution from a non-episodically secreted placental GH variant and a concomitant suppression of pituitary GH. This specific signal, i.e. a continuous GH secretion, may be an important regulator of maternal liver metabolism during pregnancy.

Female↗
PubMed1989

Fluid balance and arterial blood pressure during intracarotid infusions of atrial natriuretic peptide (ANP) in water-deprived goats.

The aim of this study was to investigate if atrial natriuretic peptide (ANP) plays a role in the control of water balance in goats and whether ANP affects the increase in mean arterial blood pressure (MAP) which accompanies drinking in water-deprived animals. Bilateral intracarotid infusions were made in female adult goats deprived of water for 48 h. ANP (1.5 micrograms min-1, n = 5, or 4.75 micrograms min-1, n = 5) was infused for 40 min. In control experiments isotonic saline (n = 7) was infused. The goats got access to water 35 min after the start of the infusions. During saline infusions they drank 2.9 +/- 0.4 litres, during the low dose of ANP 1.9 +/- 0.6 litres (n.s. vs saline), and during the high dose of ANP 0.6 +/- 0.2 litres (P less than 0.01 vs saline). Plasma vasopressin concentration did not change during saline infusions until after drinking, when it decreased. The vasopressin concentration increased in one goat after infusion of the low dose of ANP and in two goats after the high dose of ANP. The low dose of ANP caused no change in MAP in four goats, but MAP dropped in the one in which vasopressin concentration increased. MAP fell in all goats infused with the high dose (P less than 0.01), with the largest changes occurring in animals showing increased vasopressin concentration. During the act of drinking a temporary increase of MAP was observed when saline or the low dose of ANP was infused, but this response was attenuated during infusions of the high dose.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Diurnal variations in thyrotropin, prolactin and cortisol during human pregnancy.

Diurnal variations in serum concentrations of thyrotropin (TSH), prolactin (PRL) and cortisol were measured in 4 women during late stages of pregnancy (gestational weeks 34-38), in 2 women at an early stage of pregnancy (gestational weeks 11 and 17) and in 2 nonpregnant women. Blood samples were obtained through a nonthrombogenic catheter using continuous withdrawal of blood by means of a portable pump changing the recipient tube at 30-min intervals. Serum TSH concentrations showed a diurnal variation in both pregnant and nonpregnant women with maximal values around midnight. Serum PRL concentrations were elevated in pregnant women but the concentrations showed marked variations indicating episodic secretion of the hormone. Serum cortisol concentrations increased in pregnant women, but the typical diurnal pattern persisted with nadir levels around midnight and marked elevations during the early morning hours. The results suggest that also during human pregnancy there is a diurnal variation in TSH and cortisol secretion, as well as an episodic secretion of PRL.

Circadian Rhythm↗
PubMed1989

Diagnosis of pulmonary embolism based upon alveolar dead space analysis.

Pulmonary embolism (PE) leads to an abnormal alveolar deadspace that is expired in synchrony with gas from normally perfused alveoli. This feature of PE separates it from pulmonary diseases affecting the airways, which are characterized by nonsynchronous emptying of compartments with an uneven ventilation/perfusion relationship. An analysis of the single breath test (SBT) for CO2, SBT-CO2, focusing on the late tidal expirate, was made in order to evaluate the feasibility to use the SBT-CO2 for the diagnosis of PE. The test was evaluated in 38 patients with suspected PE where pulmonary angiography showed that nine had PE and 29 did not. It was also tested in a reference population consisting of patients with normal lung function, obstructive lung disease and interstitial lung disease. Previously suggested gas exchange measurements for the diagnosis of PE, ie, the physiologic deadspace fraction, VDphys/VT, and the arterial-to-end-tidal CO2 gradient, P(a-E')CO2, were also evaluated in the groups. SBT-CO2 achieved a nearly complete separation between the patients with PE and those without. The other measurements, however, showed a substantial overlap between patients with PE and those with obstructive or interstitial lung disease. The SBT-CO2 is simple and potentially widely available and warrants further study as a routine technique for the diagnosis of PE.

Angiography↗
PubMed1989

Atrial natriuretic peptide in pregnant and lactating goats.

Plasma concentrations of atrial natriuretic peptide (ANP) were measured in 6 goats during pregnancy, lactation and a nonpregnant, nonlactating (= control) period before and during a rapid iv load of 0.9% NaCl. The volume of the load was 20% of blood volume. The infusions increased central venous pressure by 7 +/- 1 mmHg during pregnancy and 8 +/- 1 mmHg during lactation. Before infusions plasma ANP concentrations were 5.7 +/- 0.7 pmol/l (control period), 10.8 +/- 1.8 pmol/l (pregnancy; P less than 0.05), and 6.5 +/- 1.5 pmol/l (lactation; NS). ANP increased significantly in all periods. Maximal values were 12.5 +/- 1.5 (control period), 25.5 +/- 2.3 (pregnancy; P less than 0.01 vs control period, P less than 0.05 vs lactation), and 13.0 +/- 1.6 (lactation; NS). Renal Na excretion increased similarly during pregnancy and control period, but slightly more during lactation. In 4 of the goats iv infusions of ANP (1 microgram/min, 60 min) were given. The infusions caused natriuresis during the control period, but not during pregnancy and lactation, despite more than 10-fold increases of plasma ANP levels. In conclusion, our results indicate that although plasma ANP concentration rose to high levels during acute NaCl loading in pregnant goats, this effect was not important for the natriuresis. Instead, the natriuretic response to ANP appears attenuated during pregnancy, and also during lactation.

Aldosterone↗
PubMed1989

MR imaging of the temporomandibular joint: comparison of images of autopsy specimens made at 0.3 T and 1.5 T with anatomic cryosections.

We made MR images of 39 autopsy specimens of the temporomandibular joint at 0.3 and 1.5 T and compared the images with anatomic cryosections. Imaging time and slice thickness were the same on scans made at each field strength. The purpose was to determine which field strength provides the best scans for imaging of the joint. Additionally, we used imaging times two and four times longer on the 0.3-T scanner to assess to what extent image quality and diagnostic accuracy could be improved. The cryosections showed that 27 of the joints were normal. Twelve had disk displacements. Ten of the joints with disk displacement also had disk deformities, and seven had bony abnormalities. Investigators who analyzed the MR images had no knowledge of the findings on the cryosections. The disk position, disk configuration, and bony abnormalities were correctly diagnosed in 85%, 77%, and 100%, respectively, on 1.5-T MR images compared with 46%, 41%, and 85%, respectively, on the 0.3-T images. When the imaging time was increased by a factor of four, the accuracy rate on the 0.3-T system became comparable to that of the 1.5-T MR scanner: 73% for disk position, 67% for disk configuration. The results suggest that the diagnostic quality of MR images of the temporomandibular joint is better on scans made at 1.5 T than on those done at 0.3 T when comparable imaging times are used.

Aged↗
PubMed1989

Growth hormone in human pregnancy. Maternal 24-hour serum profiles and experimental effects of continuous GH secretion.

Growth hormone (GH) concentrations in serum were recorded in healthy women at different stages of normal pregnancy. Using a non-thrombogenic venous catheter and a portable pump, blood samples were collected at 30 min intervals for a period of 24 h. Growth hormone serum profiles were also established in non-pregnant women, women undergoing legal abortion and cesarean section and during spontaneous labor. A dramatic change in growth hormone secretion was demonstrated during late pregnancy when compared with the non-pregnant state. The pulsatile pattern, with intermittent high peaks and low or undetectable levels between peaks, characteristic of normal men and non-pregnant women, was completely suppressed. During late pregnancy, all investigated women evidenced increased, very stable serum levels of GH and there was no evidence of pulsatile activity. Two monoclonal antibodies directed against different epitopes on the GH-molecule were used in radio-immunoassays to distinguish the pituitary 22K-GH from other circulating GH variants. During the second half of pregnancy, a continuous secretion of a new placental GH variant and a concomitant suppression of the pulsatile pituitary GH secretion was demonstrated. The progressive transformation of GH secretion from a pulsatile into a stable, continuous pattern started at the end of the first trimester. After placental removal at cesarean section in late pregnancy there was a rapid fall in serum GH concentration, whereas levels were unaffected after legal abortion in the first trimester. These results and simultaneous measurements of hPL and hCG support the concept that a placental GH variant is produced during pregnancy. Studies on the diurnal variations of thyrotropin, prolactin and cortisol indicate that human pregnancy is associated with selective alterations in the secretion of pituitary hormones. The biological impact of continuous GH secretion was elucidated in two experimental systems in the rat. The pregnancy-associated murine protein-1 (PAMP-1) in rodents was previously believed to be regulated by sex steroids. However, a continuous infusion of hGH was found to increase the plasma concentration of PAMP-1 in non-pregnant, hypophysectomized female rats. On the other hand, intermittent hGH administration or estrogen treatment had no effect on this seemingly 'steroid-sensitive' protein. Steroid sulfatase activity in rat liver microsomes is another sexually differentiated function. Likewise, this system was found to be regulated by the mode of GH administration. A continuous GH secretion during human pregnancy can alter maternal liver metabolism and have important implications for the physiological adjustment to gestation.

Adolescent↗
PubMed1989

A multivariate approach to saccharide quantitative structure-activity relationships exemplified by two series of 9-hydroxyellipticine glycosides.

Multivariate saccharide quantitative structure-activity relationships (QSARs) have been developed for two series of 9-hydroxyellipticine glycosides. In order to describe the structural variation of the glycoside moieties, thirteen chromatographic variables were used. Eleven D-glycosides and seven L-glycosides were used in separate QSARs to model 9-hydroxyellipticine glycoside antitumour activity against L 1210 leukemia. The multivariate partial least squares (PLS) method was used to establish the QSARs.

Animals↗
PubMed1989

Atomic absorption spectrometric determination of selenium in human blood components.

We separated blood from five healthy blood donors into plasma, erythrocytes, platelets, and leukocytes; counted the number of cells in each fraction; and determined the selenium content of each component by hydride generation atomic absorption spectrometry. The mean (+/- SD) selenium concentrations and amounts measured were as follows: whole blood 102.3 +/- 16.1 micrograms/L, plasma 76.9 +/- 10.6 micrograms/L, erythrocytes 13.7 +/- 2.8 ag per cell, platelets 4.8 +/- 1.1 ag per cell, and leukocytes 99 +/- 26 ag per cell.

Blood Platelets↗