Minority ion cyclotron current drive in tokamaks.
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Journal Article↗
Biomedical subjects
L Eriksson
Publications and source records attributed to L Eriksson.
Structure of heparan sulphate from human brain, with special regard to Alzheimer's disease.
Heparan sulphate (HS) was isolated after proteolytic digestion of cerebral cortex, obtained at autopsy, of patients with Alzheimer's disease (AD) and of control subjects. Deaminative cleavage in combination with selective radiolabelling procedures showed that the N-acetylated regions in the intact polysaccharides ranged from isolated residues to approximately 10 consecutive N-acetylated disaccharide units, without any apparent difference between AD and control HS. The yield of disaccharide deamination products was slightly higher with AD than with control HS, suggesting a differential distribution of N-sulphate groups. Separation of the disaccharides by anion-exchange h.p.l.c. yielded four mono-O-sulphated and one di-O-sulphated disaccharide; these components occurred in strikingly similar proportions in all cerebral HS preparations (except polysaccharide from neonatal brain) irrespective of the age of the individual and the histopathology of the cortex specimen. No significant difference was noted between HS obtained from control and from AD tissue. By contrast, the composition of HS isolated from brain differed significantly from that of HS preparations derived from other human organs.
Acetylation↗
Brain activation induced by the perceptual maze test: a PET study of cognitive performance.
We investigated with PET the cerebral activation pattern elicited by the perceptual maze test (PMT), a neuropsychological test used to evaluate organic brain injury. The PMT examines visuospatial skill, general intelligence, visually guided motor planning, and the ability to obey rules. Eight right-handed volunteers were examined with PET using the tracer [15O]butanol. Three paradigms containing the PMT, a motor control (SHAM), and a rest condition were examined twice in a randomized order. Solving the PMT caused extensive bilateral activations in the occipital lobe extending rostrally into the parietal lobe and caudally to the posterior part of the temporal lobe. Bilateral activations were also seen in the prefrontal, medial premotor, and the anterior cingulate cortex (ACC). The premotor and primary sensory motor cortices contralateral to the performing hand were also activated. Marked activations were noted in the visual system, including areas pertaining to visuospatial decoding. The previously defined functional network (ACC, prefrontal and posterior parietal cortex) for the maintenance of visuospatial attention was activated during the PMT. Extensive bilateral deactivations were seen in frontomedial, temporal, parietal, and posterior cingulate regions. This pattern may represent relatively decreased blood flow in cortical areas pertaining to sensory modalities that were not activated in the PMT. The decreased activity in these regions could also express diminished cognitive processing in neuronal systems that might interfere with the task-related performance.
Adult↗
Monoclonal antibodies against Haemophilus ducreyi lipooligosaccharide and their diagnostic usefulness.
Monoclonal antibodies against the lipooligosaccharide of Haemophilus ducreyi were produced. Two of them, MAHD6 and MAHD7, were found to be relatively, although not absolutely, specific and reacted with nearly all strains of Haemophilus ducreyi tested: 59 of 60 and 60 of 60, respectively. The diagnostic usefulness of MAHD7 was assessed. Clinical specimens collected in Zambia from patients with genital ulcers were tested using indirect immunofluorescence (IF), enzyme immunoassay (EIA), the polymerase chain reaction (PCR) and bacterial culture. Compared with culture, IF had a sensitivity of 100%; compared with PCR, sensitivity was 89%. The corresponding figures for the EIA were 83% and 74%, respectively. The sensitivity of culture compared with PCR was 63%. The results suggest that IF on genital smears using MAHD7 might be an excellent tool for the diagnosis of chancroid in high-prevalence populations. However, further evaluation of the specificity of this test is needed.
Adolescent↗
Detection of aerolysin gene in Aeromonas strains isolated from drinking water, fish and foods by the polymerase chain reaction.
A polymerase chain reaction (PCR) technique was used to assay the presence of the aerolysin gene in a total of 89 Aeromonas hydrophila and A. sobria strains isolated from drinking water, fish and foods. These strains were also characterized for the production of virulence factors such as haemolysin, protease and cytotoxin. The primers used in the PCR targeted a 209-bp fragment of the aer gene coding for the beta-haemolysin and detected template DNA only in haemolytic A. hydrophila strains. The cell-free culture supernatants of these aerolysin-positive A. hydrophila strains were also cytotoxic to the HeLa and McCoy cells. The haemolytic A. sobria and non-haemolytic A. hydrophila were consistently negative in the PCR assay. Primer specificity was determined in the PCR by using a control haemolytic Escherichia coli, Streptococcus pyogenes and a restriction endonuclease assay. The PCR clearly identified the aerolysin-producing strains of A. hydrophila and may have application as a rapid species-specific virulence test.
Aeromonas↗
Shall red cell units stand upright, lie flat or be mixed during storage? In vitro studies of red cells collected in 0.5 CPD and stored in RAS2 (Erythrosol).
Red cells were prepared using a new anticoagulant with half the normal amount of citrate and a new additive solution (RAS2, Erythrosol) previously shown to give improved storage conditions, and stored in a highly gas permeable plastic container (PL 2209). Mixing daily and weekly resulted in lower PCO2, higher PO2 and more rapid oxygen saturation of the haemoglobin than storage unmixed in an upright position. Storage horizontally in a lying position unmixed resulted in similar blood gas values as with mixing. The haemolysis was lowest in units mixed once weekly: 0.21 +/- 0.09% after 28 days and 0.26 +/- 0.06% after 56 days. The morphology was better maintained in mixed than in unmixed units. Horizontal storage and mixing once per week seem to be optimal as judged from these in vitro studies.
Anticoagulants↗
Disk displacement and temporomandibular joint symptoms in orthognathic surgery patients.
The purpose of this study was to document the prevalence of disk displacement and temporomandibular joint symptoms in orthognathic surgery patients. Fifty-three consecutive patients with different types of dentofacial anomalies were examined clinically and with bilateral arthrography. Disk displacement unilaterally or bilaterally was found in 57% of the patients or 46% of the joints. Displacement with reduction was seen in 38 joints, and displacement without reduction was seen in 11 joints. Fifty-three percent of the patients had pain in the temporomandibular joint or masticatory muscles, 30% of the joints demonstrated clicking, and 4% had crepitation. No association was found between disk displacement and clinical symptoms except for an association between clicking and anterior disk displacement with reduction. Neither could an association between disk displacement and the type of dentofacial anomaly be appreciated. It was concluded that disk displacement was frequent in patients with dentofacial anomalies, but no relationship to temporomandibular joint symptoms and the type of dentofacial anomaly could be clearly demonstrated.
Adolescent↗
Preoperative evaluation of primary hemostasis in patients with thrombocytopenia using the Thrombostat 4000.
It is difficult to estimate the risk of hemorrhage that may follow an invasive or surgical procedure in patients with thrombocytopenia or platelet dysfunction. Conventional functional tests for the evaluation of primary hemostasis have been questioned. We have evaluated the in vitro bleeding time (IVBT) using the Thrombostat 4000 in 25 patients with thrombocytopenia in order to estimate the risk of bleeding following an invasive or surgical procedure. Using the IVBT, it was possible to suggest and evaluate preoperative treatment in order to restore primary hemostasis. All patients studied had their operations without bleeding complications. From these observations we conclude that the IVBT is a convenient and useful tool in the evaluation of primary hemostasis in these patients.
Adult↗
Buffy-coat-derived platelet concentrates prepared from half-strength citrate CPD and CPD whole-blood units. Comparison between three additive solutions: in vitro studies.
The in vitro effects of storage of platelets prepared from 4 or 6 pooled buffy coat (BC) units and stored in a platelet storage medium consisting of 30-40% of CPD plasma or alternatively half-strength citrate CPD (0.5 CPD) plasma and 60-70% of different alternative platelet additive solutions (PASs) were evaluated. Measurements of mean platelet volume, pH, pO2, pCO2, bicarbonate, glucose, lactate, ATP, total adenine nucleotide content, extracellular lactate dehydrogenase or adenylate kinase activity, as markers for disintegration of platelets, and extracellular beta-thromboglobulin, as a marker for activation of platelets, were included in the in vitro studies. Previous studies indicated that a reduction of the citrate concentration from the standard 21 to 8 mmol/l is associated with a significant reduction of the consumption of glucose and production of lactate. Alternatively, similar effects can be obtained by the addition of acetate. In a preliminary paired study, the effects of different concentrations of acetate were tested. In an additional paired study, the effects of CPD plasma in combination with either saline or a PAS containing NaCl (115.5 mmol/l), citrate (10 mmol/l), and acetate (30 mmol/l), pH 7.2 (PAS-2) were evaluated. 0.5CPD plasma in combination with either PAS-2 or a nonacetate PAS (PAS-1) were also tested. The storage of platelets in 0.5CPD plasma was used as a reference. The conclusions are: (1) A minimum acetate concentration of 30 mmol/l is needed to counteract the effects of citrate on the production of lactate. (2) pH and the bicarbonate buffering capacity are significantly better maintained in PAS-2 than in PAS-1.(ABSTRACT TRUNCATED AT 250 WORDS)
Anticoagulants↗
Early [18F]FDG positron emission tomography in infants with hypoxic-ischaemic encephalopathy shows hypermetabolism during the postasphyctic period.
Six full-term infants suffering from perinatal asphyxia and with moderate or severe hypoxic-ischaemic encephalopathy were investigated by positron emission tomography (PET). Regional cerebral metabolic rates of glucose (rCMRgl) were determined using [2-18F]2-fluoro-2-deoxy-D-glucose ([18F]FDG) PET scans at a median age of 2.5 days (range 2-5 days). Localized increases in rCMRgl were visually observed in five infants. In a subgroup of three infants, absolute values of rCMRgl in different brain regions were calculated. In all cases the results of the PET studies were in good agreement with those of the neuroradiological, neurophysiological and clinical investigations. Information indicating pathophysiological events could be extracted earlier with PET than with conventional morphological imaging techniques. We conclude that [18F]FDG-PET scans performed in critically ill, asphyxiated infants very soon after birth provide valuable information for the prediction about neurological outcome.
Asphyxia Neonatorum↗
FISH on metaphase and interphase chromosomes demonstrates the physical order of the genes for GPI, CRC, and LIPE in pigs.
The porcine genes for glucose phosphate isomerase (GPI), calcium release channel (CRC), and hormone-sensitive lipase (LIPE) map to the long arm of chromosome 6. Earlier studies, using fluorescence in situ hybridization (FISH), mapped the three loci to the same band, viz., 6q12. To ascertain the relative order of the three genes, we first conducted three double-color FISH experiments, cohybridizing two of the probes at a time. These experiments demonstrated that the gene order was cen-GPI-CRC-LIPE. This order was confirmed by cohybridizing the three probes to both metaphase and interphase chromosomes.
Animals↗
Assignment of the mouse homologue of a human MEN1 candidate gene, phospholipase C-beta 3 (Plcb3), to chromosome region 19B by FISH.
A recent study using comparative mapping analysis suggests that the proximal segment of mouse chromosome 19 contains the mouse homologs of the human multiple endocrine neoplasia type 1 (MEN1) flanking markers proximal to the locus. We have recently shown that phospholipase C-beta 3 (PLCB3) is a candidate gene for the MEN1 syndrome. In the present investigation we used fluorescence in situ hybridization with a genomic DNA clone for mouse Plcb3, and mapped the locus to chromosome region 19B. This is in agreement with the comparative mapping of the MEN1 flanking markers in mouse.
Animals↗
Brain aminobutyrate aminotransferase activity in Alzheimer's disease.
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4-Aminobutyrate Transaminase↗
[Assisted fertilization should have higher priority].
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Female↗
A toxic equivalency factor scale for polychlorinated dibenzofurans.
The ethoxyresorufin O-deethylase (EROD) induction of 20 polychlorinated dibenzofurans (PCDFs) was examined in the H4IIE rat hepatoma cell bioassay. The selection of the compounds tested was based on a multivariate chemical characterization laying the groundwork for covering the whole chemical series of PCDFs. The EROD induction potency was found to vary in ED50 values from 25 to 100,000,000 pg/mg, i.e., nearly seven orders of magnitude. The response of the bioassay was calibrated against the 2,3,7,8-tetrachlorodibenzo-p-dioxin, enabling the corresponding toxic equivalency factors (TEFs) to be calculated. In order to establish a quantitative structure-activity relationship (QSAR) for the TEF values, 37 physicochemical descriptor variables were used to chemically characterize the 87 tetra- to octachlorinated PCDFs. Using partial least-squares modeling on a training set of 10 congeners, a QSAR model with sound predictive power was obtained. The QSAR model was validated with a validation set of additional 10 congeners. The predicted TEFs indicate that a large number of congeners are potent EROD inducers.
Animals↗
PET studies of the uptake of (S)- and (R)-[11C]nicotine in the human brain: difficulties in visualizing specific receptor binding in vivo.
(S)- and (R)-[11C]nicotine were synthesized by methylation of (S)- and (R)-nornicotine using [11C]methyl iodide. Following their intravenous injection in tracer doses to smoking and nonsmoking healthy males the radioactivity in arterial blood showed a sharp peak at about 1 min followed by a plateau level for the remaining 50 min of recording. Uptake in the brain, as measured by positron emission tomography (PET), was rapid with a peak at 5 min followed by a steady decline towards the end of the measurement. The regional distribution of radioactivity followed essentially the distribution of gray matter with high uptake in the cortex, the thalamus and the basal ganglia and low uptake in the pons, cerebellum and white matter. Levels of the labelled natural enantiomer, (S)-[11C]nicotine, were higher than those of the synthetic enantiomer, (R)-[11C]nicotine, particularly in the smokers. The time-activity curves of (S)-[11C]nicotine uptake were not changed by co-administration of 1.0 mg of unlabelled nicotine with the labelled nicotine. Similarly administration of unlabelled nicotine at the peak of radioactivity, 6 min following (S)-[11C]nicotine, had no effect on the time-activity curves. Thus essential criteria for visualizing receptor binding with the PET technique could not be fulfilled. Calculation of kinetic constants using a two-compartment model gave values indicating that the brain uptake of [11C]nicotine is mainly determined by the cerebral blood flow, extraction of the tracer over the blood-brain barrier and unspecific binding. Thus 11C-labelled nicotine does not seem to be a suitable tracer for PET studies of nicotinic cholinergic receptors in the human brain.
Adult↗
No short-term difference in outcome after temporomandibular joint arthrography alone or with immediate lavage.
Thirty-three patients with an arthrographically documented anterior disk displacement without reduction were randomly assigned to be treated with upper joint space lavage or to serve as controls in an 8-week clinical trial. Pain was evaluated by the patients on a visual analog scale at rest and after chewing gum. The clinical examination followed a standardized protocol. Improvements in pain and mouth opening were found in both the lavage and control group after 8 weeks, but there were no statistically significant differences between the treatment and control groups. It was concluded that upper joint space lavage after arthrography seems to be ineffective to decrease pain and to increase mouth opening in patients with anterior disk displacement without reduction.
Adult↗
Remoxipride in the treatment of psychoses.
In Sweden the atypical neuroleptic drug remoxipride has now been used in routine treatment of psychoses for almost two years. Over 7,000 patients have been treated. During that time both advantages and problems, foreseen and unforeseen, have been encountered. This paper is based on clinical experiences and the discussion is illustrated by five short case-histories. The most important points of the discussion are: As expected, remoxipride seems to produce less extrapyramidal side-effects than traditional neuroleptics. Patients experience less, if any, impairment in cognitive functioning than with traditional neuroleptics. Patients experience less inhibition of feelings and emotions than with traditional neuroleptics, which most often is of great positive value but may also create problems when feelings and emotions get overwhelming and difficult to handle. It is very important that patients get adequate psychological support and attention from the psychiatric team when changing from a traditional neuroleptic drug to remoxipride.
Adult↗