[Complex partial epileptic seizures with focal EEG changes during benzodiazepine withdrawal].
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Adult↗
Biomedical subjects
A Persson
Publications and source records attributed to A Persson.
Purification of plasma membranes by aqueous two-phase affinity partitioning.
A rapid method for purifying rat liver plasma membranes of high purity and yield is described. Squashed liver was homogenized in an aqueous polyethylene glycol-dextran two-phase system. After phase separation and reextraction of the bottom phase with fresh top phase, the combined polyethylene glycol-rich top phases were affinity partitioned in the presence of borate buffer with new bottom phase containing dextran-linked wheat-germ agglutinin. Under these conditions the lectin selectively pulled plasma membranes into the dextran-rich bottom phase, while other membranes preferentially distributed in the top phase. The lectin-containing bottom phase was reextracted with fresh top phase before collecting the purified plasma membranes by centrifugation. This protocol resulted in a preparation that was 30- to 40-fold enriched compared to the homogenate in plasma membrane markers for both the apical and basolateral domains and had yields of 55-70%. The contamination by other membranes was low. The entire procedure was completed within 90 min. The method should be useful for purifying plasma membranes also from other sources.
Animals↗
Surfactant protein D: subcellular localization in nonciliated bronchiolar epithelial cells.
Surfactant protein D (SP-D, CP4) is a collagenous surfactant-associated carbohydrate binding protein that was initially characterized as a biosynthetic product of type II pneumocytes. Immunoperoxidase studies of formaldehyde solution-fixed and paraffin-embedded rat lung demonstrated staining for SP-D in the cytoplasm of a subpopulation of bronchiolar epithelial cells as well as type II cells. Accordingly, immunogold-labeling techniques were used to further examine the cellular distribution and subcellular localization of SP-D in the small airways. Lung tissues were fixed with 0.5% glutaraldehyde-3% paraformaldehyde and embedded in LR White resin. Sections were reacted with affinity purified polyclonal antibodies to SP-D, and sites of antibody binding were demonstrated using a biotinylated secondary antibody-streptavidin-gold detection system. Anti-SP-D selectively decorated secretory compartments of nonciliated bronchiolar cells (Clara cells) with strong and specific labeling of apical electron-dense secretory granules. Almost all of the granules in nonciliated columnar cells were labeled; however, labeling was typically nonuniform, with preferential decoration of the periphery of the granule. The largest numbers of immunoreactive epithelial cells were observed in the distal membranous bronchioles, with progressively smaller numbers of cells in more proximal bronchioles. There was no detectable labeling of cells lining the large cartilagenous airways or trachea. These studies provide evidence that SP-D is a secretory product of nonciliated bronchiolar cells. We suggest that Clara cell-derived SP-D is a component of bronchiolar lining material, consistent with our hypothesis that SP-D contributes to surfactant metabolism and/or host defense within small airways.
Animals↗
Improvement of nerve conduction in diabetic neuropathy. A follow-up study 4 yr after combined pancreatic and renal transplantation.
Eighteen patients with long-standing insulin-dependent (type 1) diabetes mellitus and polyneuropathy were studied after combined pancreatic and renal transplantation. Repeated tests were performed on peripheral nerve function (electroneurography) and on autonomic function (R-R test) 6 mo and 1, 2, and 4 yr after the transplantation. Eighteen diabetic patients with only a kidney graft served as controls. After initial improvement of nerve conduction in both groups, probably caused by the elimination of uremia, further improvement was seen only in the euglycemic pancreas-graft recipients. Improvement of autonomic (parasympathetic) function was slight after 48 mo and was similar in both groups.
Adult↗
Diabetic neuropathy four years after pancreas transplantation.
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Diabetes Mellitus, Type 1↗
Liquid chromatographic separation of the enantiomers of metoprolol and its alpha-hydroxy metabolite on Chiralcel OD for determination in plasma and urine.
The two enantiomers of metoprolol and the four enantiomeric forms of alpha-hydroxymetoprolol were separated by liquid chromatography on a Chiralcel OD column containing a cellulose tris(3,5-dimethyl-phenylcarbamate) chiral stationary phase. The column efficiency was strongly dependent on the flow-rate and the enantioselectivity was influenced by temperature. Of utmost importance for the chiral separation was the water content of the mobile organic phase. The separation system was used for the separation and determination of the enantiomers in plasma and urine samples. The metoprolol enantiomers could be determined by fluorescence down to 10 nmol/l of each in plasma with a relative standard deviation of less than 15%.
Animals↗
Purification of rat liver plasma membranes by wheat-germ-agglutinin affinity partitioning.
Rat liver plasma membranes were separated from other cellular membranes by affinity partitioning in an aqueous polymer two-phase system by using the lectin wheat-germ agglutinin covalently bound to dextran as the affinity ligand. In borate buffer the bulk of membranes partitioned in the poly(ethylene glycol)-rich top phase, whereas plasma membranes were pulled selectively into the dextran-rich bottom phase in the presence of ligand. The purity and yield of plasma membranes prepared by lectin affinity partitioning and by conventional sucrose-density-gradient centrifugation was similar, as judged from marker-enzyme activities. The affinity procedure, not dependent on lengthy centrifugations, is fast and gentle and will be advantageous when studying labile components.
Animals↗
Central conduction and autonomic nervous function in HMSN I.
CNS conduction and autonomic nervous function were investigated in 15 patients with HMSN I. Central motor conduction time (CMCT) was estimated with magnetic brain stimulation and electrical nerve root stimulation. Somatosensory evoked potential (SEP) and visual evoked potential (VEP) were used for assessment of central sensory and visual conduction. Autonomic effector organ functions were assessed with the R-R variation test for parasympathetic function, and the sympathetic skin response test (SSR) for skin sympathetic sudomotor activity. Five of the patients had prolonged CMCT. Central sensory conduction was normal in 3, and slightly prolonged in 1 of the patients, but could not be estimated in 11 due to lack of response from the cervical recording. VEP was abnormal in 2 patients. R-R variations during normal breathing were low in 8 of 15 patients, and low also during deep breathing in 1 of 15. The SSR test was pathological in 5 of 15 patients. Thus, impaired central conduction and/or autonomic dysfunction was not an uncommon finding in patients with HMSN I.
Adult↗
Improvement in diabetic neuropathy 4 years after successful pancreatic and renal transplantation.
We have studied the fate of diabetic neuropathy and autonomic function in 13 patients with long standing Type 1 (insulin-dependent) diabetes mellitus following combined pancreas and kidney transplantation. Fifteen diabetic patients with a kidney graft only served as controls. After initial improvement of the neuropathy in both groups, probably caused by the elimination of uraemia, a continuous improvement during the 48 months study was seen in the euglycaemic pancreas graft recipients only. Autonomic (parasympathetic) function improved only slightly and to a similar extent in both groups.
Action Potentials↗
Human surfactant protein D: SP-D contains a C-type lectin carbohydrate recognition domain.
Lung surfactant protein D (SP-D) shows calcium-dependent binding to specific saccharides, and is similar in domain structure to certain members of the calcium-dependent (C-type) lectin family. Using a degenerate oligomeric probe corresponding to a conserved peptide sequence derived from the amino-terminus of the putative carbohydrate binding domain of rat and bovine SP-D, we screened a human lung cDNA library and isolated a 1.4-kb cDNA for the human protein. The relationship of the cDNA to SP-D was established by several techniques including amino-terminal microsequencing of SP-D-derived peptides, and immunoprecipitation of translation products of transcribed mRNA with monospecific antibodies to SP-D. In addition, antibodies to a synthetic peptide derived from a predicted unique epitope within the carbohydrate recognition domain of SP-D specifically reacted with SP-D. DNA sequencing demonstrated a noncollagenous carboxy-terminal domain that is highly homologous with the carboxy-terminal globular domain of previously described C-type lectins. This domain contains all of the so-called "invariant residues," including four conserved cysteine residues, and shows high homology with the mannose-binding subfamily of C-type lectins. Sequencing also demonstrated an amino-terminal collagenous domain that contains an uninterrupted sequence of 59 Gly-X-Y triplets and that also contains the only identified consensus for asparagine-linked oligosaccharides. The studies demonstrate that SP-D is a member of the C-type lectin family, and confirm predicted structural similarities to conglutinin, SP-D, and the serum mannose binding proteins.
Amino Acid Sequence↗
Autoradiography with saturation experiments of 11C-Ro 15-1788 binding to human brain sections.
In vitro autoradiography of a 11C-labelled ligand, Ro 15-1788, was used in saturation experiments in order to quantify benzodiazepine receptor binding in whole human brain hemisphere cryo-sections. A special incubation chamber was developed with the aim of performing standardized quantitative studies with short-lived positron emitting isotopes. 11C-labelled ligand binding was studied in temporal cortex, cerebellum, white manner and pons incubated in vitro. White manner, lacking benzodiazepine receptor binding, was used as an estimated of nonspecific binding, for calculation of Saturability of binding was demonstrated in the neocortical and cerebellar regions. Radioactivity counting of incubated adjacent tissue sections was done as a control. Computerized densitometry of the autoradiograms gave similar results as the tissue counting. A comparison with in vivo saturation experiments using the same 11C-labelled ligand and positron emission tomography in healthy human subjects also gave binding characteristics of the same magnitude. The 11C-autoradiograms showed a good spatial resolution (about 180 microns). 11C-autoradiography with suitable radioligands should be a valuable technique of screening the distribution and characteristics of neuroreceptors in the human brain. This quantitative method will provide the PET investigator with preliminary binding data, and may thus supply valuable information concerning positioning in PET and concerning significant regions of interest.
Autoradiography↗
Purification of liver membranes highly enriched in phosphatidylinositol kinase.
Membranes highly enriched in phosphatidylinositol (PtdIns) kinase were purified from rat liver by sucrose density gradient centrifugation of a plasma membrane-depleted microsomal fraction. PtdIns kinase-containing membranes had a lower density than membranes containing Golgi and plasma membrane markers, both in sucrose and Nycodenz gradients, without being completely resolved from these other membranes. They also had a lower density than an endosomal marker. Furthermore, lectin affinity partitioning showed that PtdIns kinase did not reside in plasma membranes. PtdIns kinase in different membrane fractions was of type II and had similar kinetic properties. We suggest that the isolated membranes are the major site for phosphatidylinositol 4-phosphate formation in the liver cell, and that these membranes are part of the exocytic pathway. Thus, PtdIns kinase might be a convenient marker for the exocytic process.
1-Phosphatidylinositol 4-Kinase↗
Effect of pancreas transplantation on glucose counterregulation in insulin-dependent diabetic patients prone to severe hypoglycaemia.
Pancreatic transplantation was performed in three patients with insulin-dependent diabetes mellitus in whom recurrent and severe episodes of hypoglycaemia had been found to be due to defective glucose counterregulation. Thus in these patients the spontaneous blood glucose recovery after insulin-induced hypoglycaemia (0.1 U kg-1 h-1 i.v. insulin until blood glucose levels fell below 2.8 mmol l-1) was delayed, and the responses of glucagon, epinephrine and growth hormone (GH) were absent or diminished. After pancreas transplantation the patients exhibited essentially normal blood glucose control. When the insulin infusion test was repeated 3 months after the transplantation, the blood glucose level recovered rapidly after insulin withdrawal. The glucagon response was restored, and the responses of epinephrine and GH were improved. Plasma C-peptide was suppressed by approximately 50%, which is less than is observed in normal subjects. It is concluded that glucose counterregulation improves after pancreas transplantation. This appears to be mainly due to an improvement in the hypoglycaemia-induced glucagon response, but an amelioration of sympatho-adrenal and hypothalamic-pituitary regulatory mechanisms may also be involved. The apparent failure to suppress completely the insulin release from the denervated pancreas transplant indicates that inhibition of beta-cell secretion during insulin-induced hypoglycaemia may be partly under neural control.
Adult↗
A comparison of clinical and evoked potential (VEP and median nerve SEP) evolution in patients with MS and potentially related conditions.
A clinical and electrophysiological (VEP and median nerve SEP) follow-up was performed in 27 subjects selected among 200 consecutive patients previously examined by multimodality evoked potentials because of MS or potentially related conditions. The mean interval between the examinations was 20 months. There was a concordance between the clinical and electrophysiological evolution for the majority of examined pathways. However, alterations were more frequent for evoked potentials than for clinical symptomatology: six VEPs and 16 SEPs were changed compared to the initial recordings whereas clinical alterations occurred in one eye and 11 arms. Definitely contradictory evolutions were observed in only two arms (in one of the MS patients). Significant deteriorations between examinations occurred for two VEPs and two SEPs, although the recordings remained within normal limits. We conclude that evoked potential recordings are valuable for monitoring and that serial recordings may increase the number of abnormal findings.
Adult↗
A follow-up study of children with neonatal herpes simplex virus infections with particular regard to late nervous disturbances.
Forty-five children with neonatal herpes simplex virus (HSV) infection, representing all known cases in the diagnostic records of four virological laboratories within a 15-year period, were followed up. Twelve children had died. Sixteen of the 33 survivors were healthy. Thirteen children had severe disabilities: all of them showed severe mental retardation; moreover, 11 were tetraplegic, one was hemiplegic with hydrocephalus and one had a pronounced behavioural abnormality. Four children had slight to moderate disabilities: one child was mildly mentally retarded and three, although mentally normal, had hemiplegia and delayed speech development, one of them having a learning disorder as well. Of these 17 neurologically impaired children 16 had ophthalmological abnormalities. EEG recordings were made in 29 patients in the neonatal period. They were markedly abnormal in 24 patients, 14 of whom had localized periodic complexes. An abnormal EEG was a bad prognostic sign. The neurological outcome was better in the HSV-1-infected children (10 cases) than in the HSV-2-infected ones (35 cases). Progressive or recurrent encephalitis was strongly suspected in two preterm children.
Child↗
Primary translation products of pulmonary surfactant protein D.
Surfactant protein D (SP-D) is a collagenous, surfactant-associated, carbohydrate-binding protein that is synthesized by alveolar type II epithelial cells. To further characterize SP-D, we isolated RNA from adult rat lungs and rat type II cells and translated mRNAs in vitro. [35S]methionine-labeled translation products were precipitated with antibodies to rat SP-D, resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and visualized by fluorography. Immune precipitates of translation reactions for rat lung or rat type II cells demonstrated a single collagenous polypeptide (39.3 kDa) that was smaller than surfactant-associated SP-D (43 kDa, reduced) but larger than the mature secreted form of rat SP-A. This component was not identified in translation reactions of rat liver, gut, brain, mammary gland, or rat L2 cell RNA. There was a fivefold enrichment of SP-D mRNA in freshly isolated type II cells relative to lung; however, the levels of translatable SP-D mRNA decreased rapidly during the first 24 h of cell culture. The SP-D translation product migrated faster than the major cellular form of SP-D but approximately 1 kDa slower than cellular SP-D synthesized in the presence of 2,2'-dipyridyl plus tunicamycin. Translation in the presence of canine pancreatic microsomes gave a single glycosylated, endoglycosidase F-sensitive form (40.6 kDa) and demonstrated cleavage of a small signal peptide. These results indicate that SP-D is a secretory product of differentiated type II epithelial cells and that SP-D is secreted in a mature form that does not undergo further proteolytic processing in vivo.
Animals↗
Developmental expression of pulmonary surfactant protein D (SP-D).
Surfactant protein D (SP-D) is a collagenous, surfactant-associated, carbohydrate-binding protein that is synthesized by pulmonary epithelial cells. In the present studies, we examined the expression of SP-D and SP-D mRNA during late fetal (day 17, 19, 21) and early postnatal (day 5) rat lung development using immunochemical, cell-free translation, and Northern hybridization assays. SP-D mRNA and immunoreactive SP-D protein were first detected in guanidine extracts of whole rat lung at 21 days of gestation and reached even higher concentrations during the postnatal period. Likewise, immunoperoxidase studies of rat lung using affinity-purified antibodies to SP-D showed no staining at day 17 or 19, but demonstrated strong cytoplasmic staining of cuboidal epithelial cells lining immature airspaces at day 21 and strong cytoplasmic staining of type II and nonciliated bronchiolar cells in adult lung. SP-D also appeared in amniotic fluid by day 21 and was partially purified by affinity chromatography on maltosyl-agarose under conditions used for the isolation of rat lung SP-D. These studies indicate that the production of SP-D is increased shortly prior to birth, and that the increases in total lung SP-D and SP-D mRNA are temporally correlated with SP-D secretion and the appearance of SP-D in amniotic fluid.
Amino Acid Sequence↗
Quantitative analysis of laryngeal EMG in normal subjects.
A method for quantitative analysis of the electromyographic interference pattern called "turns/amplitude analysis" was carried out with recordings from the cricothyroid and thyroarytenoid muscles of 12 normal subjects, 6 males and 6 females. The purpose was to investigate how the two muscles vary contraction force in relation to variations in pitch and voice intensity. Sustained phonations with systematic variation of pitch and intensity were analysed. The contraction force, in terms of turns and amplitude, increased with increasing pitch in both the cricothyroid and thyroarytenoid. More variability in contraction activity as a function of intensity was noted in the cricothyroid than in the thyroarytenoid. The increase in turns and amplitude in the thyroarytenoid with increasing pitch was highly significant, while little effect was seen of intensity variation. No great differences between males and females were noted.
Adult↗