Octa-O-acetyl-beta,beta-thiotrehalose.
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Carbohydrate Sequence↗
Biomedical subjects
L Eriksson
Publications and source records attributed to L Eriksson.
Rectangular solid domains in ceramide-cholesterol monolayers - 2D crystals.
Very small rectangular domains were observed by atomic force microscopy in binary monolayers of synthetic ceramides and cholesterol. When the cholesterol content is increased the domains are bigger although the rectangular shape is retained. The almost perfect shape of the domains indicates two-dimensional single ceramide crystals. Lipid domains in monolayers of this particular shape and size have to our knowledge not been reported in the literature previously.
Ceramides↗
Expression of interleukin-6 in human dorsal root ganglion cells.
The expression of Interleukin-6 (IL-6) was studied in normal dorsal root ganglia (DRG) of juvenile and foetal humans, using immunohistochemistry and in situ hybridization techniques. There was an expression of IL-6-like immunoreactivity in more than 75% out of neuronal cells in the juvenile ganglia with a peripheral localization, and also an expression in the foetal ganglion cells. There was a co-localization of IL-6 with substance P (SP) and calcitonin gene-related peptide (CGRP) in more than 60% of the DRG cells, respectively. By in situ hybridization 0.9% of the cells in the juvenile ganglia and 1.1% of the cells in the foetal ganglia showed a positive signal for IL-6. In addition, expression of IL-6 was found in juvenile medulla spinalis, preferentially in the white matter.
Calcitonin Gene-Related Peptide↗
Determination of molecular geometry by high-order multiple-quantum evolution in solid-state NMR.
The principles of molecular geometry determination by high-quantum heteronuclear local field spectroscopy in solid-state NMR are discussed. The extreme multiple-quantum coherences in a cluster of nuclear spins are allowed to evolve in the presence of heteronuclear through-space couplings to two spins of a different type. The multiple-quantum dephasing curve is independent of the homonuclear spin-spin couplings and may be described in terms of geometric parameters. The triple-quantum version of the experiment is demonstrated by determining the psi torsion angle in a [(15)N(2), (13)C(3)]-labeled sample of the peptide ala-ala-gly. Two regions of torsion angle space fit the experimental data, one in the neighborhood of -152 degrees and one in the neighborhood of +161 degrees. The latter determination is in excellent agreement with the X-ray estimate of +160.5 degrees.
Magnetic Resonance Spectroscopy↗
The skin barrier from a lipid perspective.
This contribution summarises the results from a number of investigations undertaken in the spirit of the Domain Mosaic Model proposed by Forslind in 1994. Atomic Force Microscopy (AFM) studies on the two-dimensional phase behaviour of some stratum corneum lipids revealed phase separation of the lipids in the typical case and the ability of cholesterol to reduce the line tension between phases. A theoretical model was developed describing the response of an oriented stack of polar lipid bilayers in the presence of a gradient in water chemical potential (water solution to humid air). The gradient gives rise to an inhomogeneous water swelling, and presumably to a liquid crystal-to-gel transition in the lamellar region closest to humid air. Skin penetration enhancers such as Azone and oleic acid cause phase transformations in lipid bilayer systems which may be relevant in the context of skin permeation.
Air↗
Methyl 4-O-beta-L-fucopyranosyl alpha-D-glucopyranoside hemihydrate. lerik@struc.su.se.
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Carbohydrate Sequence↗
Is histamine involved in milk ejection in goats?
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Animals↗
Osteonecrosis of the temporomandibular joint: correlation of magnetic resonance imaging and histology.
PURPOSE: The aims of this study were to investigate whether osteonecrosis affects the mandibular condyle and to determine whether this condition could be diagnosed with magnetic resonance imaging (MRI). MATERIALS AND METHODS: The study was based on 50 temporomandibular joints in 44 patients in whom MRI and surgery were performed for painful internal derangements. At the time of surgery, a core biopsy specimen was obtained from the marrow of the mandibular condyles, and the histological observations were correlated to T1-(proton density) and T2-weighted MR images. RESULTS: Histological evidence of osteonecrosis was found in nine joints (18%). Bone marrow edema, which may be a precursor of osteonecrosis, was found in nine other joints. The MRI was 78% sensitive and 84% specific for the diagnosis of osteonecrosis of the mandibular condyle. However, the positive predictive value was only 54% because of a number of false-positive MRI diagnoses. CONCLUSION: Osteonecrosis can affect the mandibular condyle, and this condition can be diagnosed with MRI. A combination of edema and sclerosis of the bone marrow was the most reliable MRI sign of osteonecrosis. The cause, its clinical significance, and the need for treatment are unknown.
Adult↗
Metoprine-induced thirst and diuresis in Wistar rats.
In the present study, the renal responses to metoprine, a histamine-N-methyltransferase inhibitor, were studied in conscious rats. Metoprine (10-20 mg kg(-1)) or vehicle were administered i.p. to male Wistar rats and the effects were followed for the subsequent 24 h. It was found that as early as 3 h after the drug administration metoprine 20 mg kg(-1) had increased water consumption and urine flow approximately 6-8-fold. The treatment decreased urine osmolality and increased free water clearance, but caused no change in plasma renin activity or plasma vasopressin concentration. In addition, a metoprine-induced elevation in the systolic blood pressure was observed during the first few hours of the experiment. During the nocturnal period of the study, glomerular filtration rate and the excretion of electrolytes did not increase in metoprine-treated rats as they did in control rats. A decrease in the release of atrial natriuretic peptide was also found. The present results show that inhibition of histamine catabolism by metoprine causes massive changes in renal functions. It seems to promote water excretion by the kidneys but, on the other hand, to reduce the excretion of electrolytes. Although the exact mechanisms, especially the role of increased blood pressure and nocturnal suppression of atrial natriuretic peptide, require further clarification, the present data suggest that renin-angiotensin system and vasopressin were not involved in these renal responses to metoprine.
Animals↗
Sudden unexpected cardiac deaths among young Swedish orienteers--morphological changes in hearts and other organs.
During the years 1979-1992 an accumulation of sudden unexpected cardiac deaths (SUD) occurred among young Swedish orienteers. A reevaluation of material saved from 16 autopsies was undertaken. Myocarditis was most frequent. It was found in different stages in the majority of cases, indicating subacute or chronic disease with ongoing reparative processes. There were severe morphological changes in all cases. All but one showed a picture of fibrosis and unspecific hypertrophy and/or degenerative changes in myocytes. The hearts were classified into three groups (A-C), based on the morphological picture of the retrieved heart tissue and the macroscopic description. Group A comprised five cases in which areas with active myocarditis combined with areas of healing or healed myocarditis widely distributed in the left ventricle were the only morphological changes found. Group B comprised four cases demonstrating foci of myocarditis in different stages in the left ventricle and changes resembling those found in arrhythmogenic right ventricular dysplasia (ARVD), including degenerative changes with fibrosis and fatty infiltration located in either ventricle. Group C comprised the remaining seven cases. In none of the cases were coronary artery or valvular anomalies present, nor significant coronary sclerosis or changes outside the heart that could cause SUD.
Adolescent↗
Interstitial cells of Cajal in the human fetal small bowel as shown by c-kit immunohistochemistry.
BACKGROUND: Interstitial cells of Cajal (ICCs) express the tyrosine kinase receptor c-kit, which is required for their development and spontaneous pacemaker activity in the bowel. From murine models it has been proposed that ICCs do not develop until after birth, but more recent findings indicate that c-kit is expressed early in the embryonic period. The temporal development of ICCs in the human gut remains unknown. AIM: To investigate ICCs in the human fetal small bowel using c-kit immunohistochemistry. SUBJECTS: Small bowel specimens were obtained at post mortem examination of 16 fetuses and nine neonates, eight of whom were premature, born at gestational ages of 13 to 41 weeks, without gastrointestinal disorders. METHODS: Immunohistochemical analysis was performed on material fixed in formalin and embedded in paraffin. The specimens were exposed to antibodies raised against c-kit (an ICC marker) and neurone specific enolase (a general neuronal marker). The ABC complex method was used to visualise binding of antibodies to the corresponding antigens. RESULTS: c-kit immunoreactive cells were visualised from 13 weeks of gestation. The immunoreactivity was mainly localised in association with the myenteric plexus. From about 17-18 weeks of gestation, the ICCs formed a layer along the myenteric plexus, whereas this layer appeared to be disrupted at 13-16 weeks of gestation. CONCLUSIONS ICCs are c-kit immunoreactive at least from a gestational age of 13 weeks in the human fetal small intestine. From 17-18 weeks of gestation until birth, they form a continuous layer around the myenteric ganglia.
Embryonic and Fetal Development↗
Second trimester ultrasound screening performed by midwives; sensitivity for detection of fetal anomalies.
BACKGROUND: To assess the sensitivity for detection of fetal anomalies by a second trimester ultrasound screening program performed in a way representative of a majority of Swedish obstetrical departments. The examinations were performed at the ultrasound division of the Department of Obstetrics and Gynecology at the University Hospital of Uppsala, Sweden. METHOD: A prospective study covering a two-year period. Eight thousand two hundred and twenty-eight unselected, consecutive pregnant women (8345 fetuses) were examined. The ultrasound scans were performed at a gestational age of 15-22 weeks by specially trained midwives. All fetal anomalies suspected at the ultrasound screening were recorded. Follow-up of all scanned fetuses was done through neonatal reports, records from the pediatric department, a national malformation registry and autopsies. All live-born infants were followed one year after birth. Main outcome measures were sensitivity, specificity, and positive predictive value for detection of fetal anomalies and prevalence of fetal anomalies. RESULTS: In all 145 fetuses/infants with confirmed anomalies were identified (prevalence 1.7%). Thirty-two were detected by second trimester ultrasound screening (sensitivity 22.1%). Twenty false positive cases were identified, of which fifteen were ruled out on the same day the suspicion arose and five were transient findings. The specificity was 99.8% and the positive predictive value 61.5% CONCLUSIONS: When performing a second trimester ultrasound screening program, prenatal diagnosis of fetal anomalies will be part of the procedure whether this is a primary aim or not. It is therefore of great importance that the pregnant women receive adequate information and that the voluntariness of participation is stressed. In this study the sensitivity was low. Standardizing the scanning procedure (check-list for fetal anatomy) and improving the education of the operators are feasible ways to increase the sensitivity.
Adult↗
New chemical descriptors relevant for the design of biologically active peptides. A multivariate characterization of 87 amino acids.
In this study 87 amino acids (AA.s) have been characterized by 26 physicochemical descriptor variables. These descriptor variables include experimentally determined retention values in seven thin-layer chromatography (TLC) systems, three nuclear magnetic resonance (NMR) shift variables, and 16 calculated variables, namely six semiempirical molecular orbital indices, total, polar, and nonpolar surface area, van der Waals volume of the side chain, log P, molecular weight, and four indicator variables describing hydrogen bond donor and acceptor properties, and side chain charge. In the present study, the data from a previous characterization of 55 AA.s from our laboratory have been extended with data for 32 additional AA.s and 14 new descriptor variables. The new 32 AA.s were selected to represent both intermediate and more extreme physicochemical properties, compared to the 20 coded AA.s. The new extended and updated principal property scales, the z-scales, were calculated and aligned to previously reported z(old)-scales. The appropriateness of the extended z-scales were validated by the use in quantitative sequence-activity modeling (QSAM) of 89 elastase substrate analogues and in a QSAM of 29 neurotensin analogues.
Amino Acids↗
Cerebral effects of nicotine during cognition in smokers and non-smokers.
For the smoker, nicotine has a positive effect on attention, cognition and mood. Conversely, nicotine abstinence is characterized by uncomfortable psychological effects such as impaired attention, but also irritability. We postulated that nicotine exerts an effect on cerebral areas important for attention and mood. Regional cerebral blood flow (rCBF), as an index for cerebral activity, was measured in both smokers and non-smokers. They were scanned during performance of a psychometric task with and without i.v. infusion of nicotine (1-methyl-2-[3-pyridyll] pyrrolidine). Nicotine induced rCBF decreases in the anterior cingulate cortex and the cerebellum, and concomitant increases in the occipital cortex. The changes were similar in nature and magnitude in smokers and non-smokers. Thus, specific changes were induced in areas pertaining to the anterior attention system and to higher order visual cortex. We conclude that these effects on cerebral activity provide insights into the desired positive effects of nicotine on cognition as well as the negative effects experienced during nicotine abstinence.
Adult↗
Pharmacokinetics of meropenem in patients with cystic fibrosis.
The pharmacokinetics of meropenem were studied after single i.v. infusions of 15 mg meropenem/kg body weight in eight subjects with cystic fibrosis (CF) and eight healthy volunteers matched for age, sex, and weight. Significantly shorter terminal half-lives (mean, 0.74 h vs. 0.99 h) and mean residence times (mean, 1.09 h vs. 1.39 h) were noted in CF subjects. Plasma and renal clearances tended to be higher and distribution volumes smaller among the patients, but differences were not statistically significant. The results are consistent with the findings for many other beta-lactam agents used in CF patients. Assuming a MIC90 of 4 mg/l for meropenem against Pseudomonas aeruginosa, the time above the MIC was less than 3.3 h in six of the eight CF patients. This finding should be kept in mind when designing treatment regimens with meropenem in CF subjects.
Adult↗
XY sex reversal in the wood lemming is associated with deletion of Xp21-23 as revealed by chromosome microdissection and fluorescence in situ hybridization.
In the wood lemming (Myopus schisticolor), XY sex reversal occurs naturally because of the presence of an X chromosome variant designated X*. The two types of X chromosome, X and X*, can be distinguished by G-banding, and analyses have demonstrated complex rearrangements of the short arm of X*. Here, chromosomal microdissection, degenerate oligonucleotide-primed polymerase chain reaction (DOP-PCR) and fluorescence in situ hybridization (FISH) techniques have been used to generate and map DNA probes for different parts of the X and X* chromosomes. The results showed that the region of Xp21-23 is deleted from the X* and some of the deleted DNA sequences are homologous to the mouse gamma-satellite. The deletion must be associated with the sex reversal in this species. FISH experiments with dissected probes of X and distal half of Xq provided evidence for presence of homologous sequences between large regions of the X and Y chromosomes, including euchromatic and heterochromatic parts of the sex chromosomes. The findings of this study will be of significance for further cloning of important candidate gene(s) responsible for the XY sex reversal.
Animals↗
Lung transplantation at the University of Lund 1990-1995. Analysis of the first 39 consecutive patients.
Between 1990 and 1995 39 patients were lung transplanted at the University Hospital in Lund. This is a retrospective review of survival and lung function in these patients. There were 17 single-lung transplants (SLT), 21 double-lung transplants (DLT) and 1 heart-lung transplant (HLT). Seven patients died during the period, giving an overall survival of 82%. One-year survival according to Kaplan-Meier survival analysis was 87%, and 2-year survival was 83%. Vital capacity and forced expiratory volume in 1 s (FEV1) 1 year after transplantation were 91% and 100% of predicted, respectively, in the DLT group and 60% and 50% in the SLT group. Bronchiolitis obliterans syndrome (BOS) developed in 11 of the 35 patients (31%) surviving more than 6 months, 2/21 in the DLT group and 8/13 in the SLT group and in the patient with HLT. The median time until detection of BOS was 11 months after the operation (range 6-18 months). Working capacity 1 year after transplantation was 60% of predicted in the DLT group and 47% of predicted in the SLT group. Ventilatory capacity was no longer function limiting. Lung transplantation today is a therapeutic option with a good medium-term survival and good functional results in selected patients with severe lung disease.
Adolescent↗
Lung hyaluronan and water content in preterm and term rabbit pups exposed to oxygen or air.
Rabbit pups were delivered by cesarean section 1 or 2 d before term, or vaginally around term, and then reared in room air or exposed to intermittent or continuous hyperoxia (> 85%) for up to 9 d. Pups were killed at different ages, and lung hyaluronan (HA; microgram/g of dry lung weight) and lung water content, measured as wet/dry lung weight, were determined. Compared with the day of birth, the lung HA concentration did not change significantly on succeeding days in pups kept in air delivered 2 d (-2 d) or 1 d (-1 d) before term, whereas the water content decreased significantly. Continuous exposure to hyperoxia resulted in a significantly raised lung HA concentration 6 d postterm in both -2 d and -1 d pups, and intermittent exposure to hyperoxia resulted in a significantly raised HA concentration 6 d postterm in -1 d pups, compared with the groups exposed to room air. These increases were accompanied by significantly elevated wet/dry lung weight ratios. Microscopic examination revealed significantly increased HA staining scores in alveoli, arterioles, and bronchioli in both hyperoxia-exposed groups of -2 d pups 6 d postterm, and nonsignificantly higher scores in -1 d and vaginally delivered pups of comparable age, compared with the scores at birth. The results indicate that oxygen exposure neonatally may result in an increase in lung HA accompanied by an increase in lung water content. The increase in lung HA concentration in our study may be an effect of oxygen free radicals or of oxygen-induced stimulation of inflammatory mediators.
Air↗