[More extensive psychotherapy education is needed].
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Clinical Competence↗
Biomedical subjects
R Persson
Publications and source records attributed to R Persson.
Accumulation of Golgi-processed secretory proteins in an organelle of high density upon reduction of ATP concentration in rat hepatocytes.
We have previously shown that when rat hepatocytes are incubated with 4 mM azide, which reduces the intracellular ATP concentration to about 30% of its normal level, secretory proteins are reversibly arrested within the cell. Analysis of haptoglobin after 150 min of azide incubation shows that its carbohydrates have been processed by Golgi enzymes (Persson, R., Ahlström, E., and Fries, E. (1988) J. Cell Biol. 107, 2503-2510). Here, we have further characterized the site of arrest. Subcellular fractionation by density gradient centrifugation showed that albumin and haptoglobin fractionated like a marker for the endoplasmic reticulum. Localization of albumin by immunoelectron microscopy showed, however, that it occurred in flattened cisternae and that the endoplasmic reticulum was devoid of the protein. A possible explanation for these results is that the azide treatment blocks transport through the Golgi complex, leading to an accumulation of secretory proteins in a pre- or early Golgi compartment of high density. This compartment could contain sufficient amounts of Golgi enzymes to carry out the observed carbohydrate processing upon prolonged incubation or possibly acquire them as an effect of the azide treatment.
Adenosine Triphosphate↗
Coexpression of the membrane glycoproteins G1 and G2 of Hantaan virus is required for targeting to the Golgi complex.
To study the intracellular transport and targeting to the Golgi complex of the membrane glycoproteins G1 and G2 of Hantaan virus, we have expressed them together and separately using recombinant vaccinia viruses. When expressed from the same recombinant vaccinia virus, G1 and G2 were localized to the Golgi complex as analyzed by both immunofluorescence and subcellular fractionation. However, when the glycoproteins were expressed from separate recombinant viruses, both proteins remained in the endoplasmic reticulum. Using several monoclonal antibodies, it was found that G1 expressed alone did not acquire its correct conformation. Finally, if cells were coinfected with G1- and G2-expressing recombinant viruses, the proteins were again targeted to the Golgi complex. The N-linked glycans remained in all cases largely endoglycosidase-H sensitive. With none of the recombinant viruses were expression of the glycoproteins observed on the cell surface. Neither did chasing in the presence of cycloheximide result in the surface expression of G1 or G2. Our results indicate that for transport out of the endoplasmic reticulum and proper targeting to the Golgi complex, the two glycoproteins have to be coexpressed. The most likely interpretation is that G1 and G2 have to interact with each other in the endoplasmic reticulum in order to become transport competent.
Cell Compartmentation↗
Association of the nonstructural protein NSs of Uukuniemi virus with the 40S ribosomal subunit.
The small RNA segment (S segment) of Uukuniemi (UUK) virus encodes two proteins, the nucleocapsid protein (N) and a nonstructural protein (NSs), by an ambisense strategy. The function of NSs has not been elucidated for any of the bunyaviruses expressing this protein. We have now expressed the N and NSs proteins in Sf9 insect cells by using the baculovirus expression system. High yields of both proteins were obtained. A monospecific antibody was raised against gel-purified NSs and used to study the synthesis and localization of the protein in UUK virus-infected BHK21 cells. While the N protein was detected as early as 4 h postinfection (p.i.), NSs was identified only after 8 h p.i. Both proteins were still synthesized at high levels at 24 h p.i. The half-life of NSs was about 1.5 h, while that of the N protein was several hours. Sucrose gradient fractionation of [35S]methionine-labeled detergent-solubilized extracts of infected BHK21 cells indicated that NSs was firmly associated with the 40S ribosomal subunit. This association took place shortly after translation and was partially resistant to 1 M NaCl. NSs expressed by using the T7 vaccinia virus expression system, as well as in vitro-translated NSs, was also associated with the 40S subunit. In contrast, in vitro-translated N protein was found on top of the gradient. Immunolocalization of NSs, in UUK virus-infected cells, by using an affinity-purified antibody showed a granular cytoplasmic staining. A very similar pattern was seen for cells expressing NSs from a cDNA copy by using a vaccinia virus expression system. No staining was observed in the nuclei in either case. Furthermore, NSs was found neither in virions nor in nucleocapsids isolated from infected cells. In vivo labeling with 32Pi indicated that NSs is not phosphorylated. The possible function of NSs is discussed in light of these results.
Animals↗
Periodontal status of teeth adjacent to nongrafted unilateral alveolar clefts.
The purpose of this study was to compare the periodontal condition of teeth adjacent to the cleft with contralateral teeth in adult subjects with a nongrafted unilateral alveolar cleft. Periodontal parameters were evaluated in 18 subjects who had at least one tooth immediately adjacent to the cleft. For each tooth investigated, plaque index, gingival index, and probing depth were recorded and each tooth was assigned a mobility score. Width of attached gingiva and extent of recession was measured. Bone level was assessed using standardized magnified radiographs and a computerized digitizing system. The overall findings of this study support those of other studies and indicate that in individuals with a nongrafted alveolar cleft, teeth adjacent to the defect show signs of gingivitis but not of periodontal disease. The anatomic defect, eruption pattern, orthodontic tooth movements, and the presence of restorations appear to contribute to the reduced bone level on the central incisor adjacent to the cleft and to the presence of gingivitis.
Adult↗
Differences in salivary flow rates in elderly subjects using xerostomatic medications.
Stimulated whole salivary flow rate (SWSFR) was measured in a group of elderly subjects who were examined for the use of xerostomia-inducing medications. SWSFR was significantly reduced in elderly subjects using one of these medications when compared with control subjects (0.94 vs 1.52 ml/min). Increasing use of up to four different xerostomia-inducing medications did not result in additional significant reduction of stimulated salivary flow rate. Psychotropic and diuretic agents were the most commonly used xerostomatic medications, and these were almost equally potent in reducing mean flow rate (0.79 vs 0.84 ml/min). The use of potentially xerostomatic medications did not affect decayed, missing, or filled surface scores or unstimulated whole saliva pH values. A weak, statistically significant, positive correlation (r = 0.39, p less than 0.01) was found between subject age and salivary flow rate in this population of elderly subjects, and this suggests that SWSRF is influenced more by factors such as medication than by aging.
Age Factors↗
Formation and intracellular transport of a heterodimeric viral spike protein complex.
We have analyzed the heterodimerization and intracellular transport from the ER to the Golgi complex (GC) of two membrane glycoproteins of a bunyavirus (Uukuniemi virus) that matures by a budding process in the GC. The glycoproteins G1 and G2, which form the viral spikes, are cotranslationally cleaved in the ER from a 110,000-D precursor. Newly synthesized G1 was transported to the GC and incorporated into virus particles about 30-45 min faster than newly synthesized G2. Analysis of the kinetics of intrachain disulfide bond formation showed that G1 acquired its mature form within 10 min, while completion of disulfide bond formation of G2 required a considerably longer time (up to 60 min). During the maturation process, G2 was transiently associated with the IgG heavy chain binding protein for a longer time than G1. Protein disulfide isomerase also coprecipitated with antibodies against G1 and G2. In virus particles, G1 and G2 were present exclusively as heterodimers. Immunoprecipitation with monoclonal antibodies showed that heterodimerization occurred rapidly, probably in the ER, between newly made G1 and mature, dimerization competent G2. Taken together, our results show that these two viral glycoproteins have different maturation kinetics in the ER. We conclude that the apparent different kinetics of ER to GC transport of G1 and G2 is due to the different rates by which these proteins fold and become competent to enter into heterodimeric complexes prior to exit from the ER.
Animals↗
The role of periodontal probing depth in clinical decision-making.
This retrospective study examines the role of periodontal probing depth in clinical decision-making. The expected values of no treatment and surgical and non-surgical therapies were obtained by combining the probability of each treatment outcome and utility values denoting the preference for each outcome. The expected value for non-surgical therapy was higher for sextants exhibiting a positive response to initial therapy than sextants which did not respond to initial therapy (0.735 versus 0.706). This trend was not observed for sextants treated surgically. Surgical therapy was effective over all levels of disease severity and was the preferred form of therapy with respect to reduction of probing depth except for sextants exhibiting 4 to 5 mm pockets. In this latter situation, the expected value at 3 years for non-surgical and surgical therapy was 0.795 and 0.792, respectively. Neither form of therapy could consistently achieve periodontal probing depths equal to or less than 3 mm throughout a given sextant. This study facilitates the selection of an optimal therapeutic strategy with respect to periodontal probing depth.
Adult↗
Measurement of interleukin-1 alpha and -1 beta in gingival crevicular fluid: implications for the pathogenesis of periodontal disease.
Samples of gingival crevicular fluid (GCF) were harvested from sites manifesting features characteristic of active disease including inflammation, periodontal attachment loss, and radiographic signs of alveolar bone destruction in untreated patients with advanced periodontitis. The presence and concentrations of interleukin-1 alpha (IL-1 alpha) and interleukin-1 beta (IL-1 beta) were measured using ELISAs specific for these cytokine molecules. IL-1 alpha and/or IL-1 beta were identified in the GCF of 15 of 15 patients having untreated periodontitis. Ninety percent (71 of 79) of the sites tested contained measureable amounts of IL-1, with IL-1 beta as the more frequently occurring form. IL-1 alpha levels ranged from 0.23 nM to 13.9 nM in the GCFs. IL-1 beta levels were between 0.04 nM and 5.28 nM. Marked reductions of total IL-1 levels were observed following effective treatment. Both forms of IL-1 messenger RNA (mRNA) were detected in 17 of 17 gingival tissue samples from 6 patients. These results demonstrate that IL-1 is produced and released locally in periodontal disease at concentrations sufficient to mediate tissue inflammation and bone resorption. IL-1 may serve as a marker of periodontal tissue destruction.
Adult↗
A longitudinal evaluation of periodontal therapy using the CPITN index.
A retrospective 3-year longitudinal evaluation of periodontal therapy using the CPITN index was performed. Each sextant in 123 patients exhibiting moderate to advanced adult periodontitis was given a score that recorded the condition of the worst affected site in that sextant. Whereas very few sextants had an initial CPITN Code 0, the prevalence of sextants with an initial CPITN Code 4 was quite high. Posterior sextants with CPITN Code 4 were more likely treated with surgery than sextants with CPITN Code 3. Although surgery appeared to be more effective than non-surgical therapy in reducing the CPITN Codes for posterior sextants at 1 year, there were no differences between the 2 forms of therapy at the 3-year examination. Anterior sextants were treated with a non-surgical approach regardless of CPITN Code at either initial examination or reevaluation. The outcome of therapy in this study using the CPITN index is comparable to other studies utilizing mean pocket depth and attachment level. Although the CPITN index does not prescribe specific therapeutic interventions, this index provides a useful tool to monitor patients in the treatment of periodontitis.
Adult↗
[Compulsory psychiatric commitment--a delicate task].
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Commitment of Persons with Psychiatric Disorders↗
[Compulsory psychiatric care--converted and non-converted patient attitudes].
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Attitude to Health↗
Differential arrest of secretory protein transport in cultured rat hepatocytes by azide treatment.
The effect of reduced cellular ATP content on intracellular transport of two secretory proteins, albumin and haptoglobin, in isolated rat hepatocytes was studied. The cells were labeled with [35S]methionine and the cellular ATP content was then rapidly reduced to different stable levels by incubation with azide at different concentrations (2.0-10 mM). The amount of the radioactively labeled secretory proteins in the cells and in the medium after 150 min of incubation was determined by immunoprecipitation followed by gel electrophoresis, fluorography, and densitometry. At progressively lower ATP levels, down to 50% of normal, the protein secretion was unaffected, whereas at even lower levels an increasing portion of the proteins remained in the cells; at 30 and 10% of normal ATP level, 25 and 75% of albumin, respectively, was arrested intracellularly. Analysis of the carbohydrate structure of intracellularly arrested haptoglobin showed that in cells with an ATP level of approximately 30% of normal, the majority of haptoglobin molecules (55%) were fully or partially resistant to endoglycosidase H. This result indicates that exit from the medial and/or the trans part of the Golgi complex (GC) was inhibited under these conditions. It also shows that the protein had accumulated in the GC, since under normal conditions the fraction of the intracellular haptoglobin that is endoglycosidase H resistant is approximately 10%. By similar criteria it was found that at ATP levels below 10% of normal transport of haptoglobin from the endoplasmic reticulum to the medial GC (and possibly also to the cis GC) as well as from the trans GC to the medium were blocked.
Adenosine Triphosphate↗
Labelling of proteins with [35S]methionine in monolayer cultures of rat hepatocytes.
Optimal conditions for the labelling of proteins with [35S]methionine in monolayers of rat hepatocytes have been established. The ability to incorporate the radioactive amino acid was constant for at least 26 h and independent of whether the medium was buffered with CO2/HCO3 or with 4-(2-hydroxyethyl)-1-piper-azineethanesulphonic acid (Hepes). Preincubation in methionine-free medium for up to 30 min yielded increasing, and from 60 to 180 min decreasing, rates of incorporation. An apparent Km value of 0.06 mM was obtained for the incorporation reaction in cells preincubated for 40 min.
Animals↗
Differential permeabilization of membranes by saponin treatment of isolated rat hepatocytes. Release of secretory proteins.
Monolayer cultures of rat hepatocytes were treated with increasing concentrations of saponin (prepared from Gypsophila plants) for 30 min at 6 degrees C. Differential permeabilization of the intracellular membranes could be demonstrated: at 0.040 mg of saponin/ml the plasma membrane was permeabilized, as assessed by the release of 50% of the total cellular amount of lactate dehydrogenase, and at 0.20 mg/ml the endoplasmic reticulum was permeabilized, as measured by the release of 50% of pulse-35S-labelled albumin. The Golgi complex was permeabilized at an intermediate saponin concentration, as indicated by the release of homogeneously 35S-labelled albumin; about half the intracellular albumin is located in this organelle. At 1.0 up to 5.0 mg of saponin/ml 90-95% of the radioactively labelled albumin was released. Even at 5.0 mg/ml less than 10% of the membrane of the endoplasmic reticulum was solubilized, as judged by the degree of release of a membrane-bound enzyme specific for this organelle. These results demonstrate the usefulness of saponin as a tool for investigating the interior of different intracellular compartments.
Albumins↗
Virus-receptor interaction in the adenovirus system: characterization of the positive cooperative binding of virions on HeLa cells.
The established positive cooperativity of adenovirus 2 binding to HeLa cells revealed a strong temperature dependence. The degree of cooperativity, quantified by means of Hill coefficients, progressively increased from 10 degrees C to reach a maximum level, which was maintained between 20 and 37 degrees C. On the other hand, negative cooperativity of virion attachment was apparent at 3.0 degrees C and on glutaraldehyde-stabilized cells. The corresponding monovalent ligand of the system, the fiber antigen, demonstrated only weak-positive cooperativity of the binding at 37.0 degrees C, which was absent at 3.0 degrees C. Dithiothreitol and dansylcadaverine, reagents inhibiting clustering of ligand-receptor complexes in the plasma membrane, markedly reduced the degree of positive cooperative binding at 37.0 degrees C. Evidently, the positive cooperative binding of adenovirus to HeLa cells at 37.0 degrees C is a consequence of both the multivalency of virus attachment proteins, i.e., fibers, on the virion and of the capacity of the receptor sites to migrate in the plane of the plasma membrane, forming local aggregates of virus-receptor site complexes.
Adenoviruses, Human↗
On the relation between peripheral atherosclerosis and serum lipoproteins.
The occurrence and degree of peripheral atherosclerosis in 30 male patients with symptoms of intermittent claudication were studied by arteriography. The changes observed in the angiograms were codified. In all patients the concentrations of triglycerides and cholesterol were determined in whole serum and in the three major lipoprotein classes--very low density, low density and high density lipoproteins. These data were compared with those of a control material and were also correlated to the codified angiographic findings in each individual patient. Positive significant correlation was not found between the arteriographic changes and the serum concentrations of lipids and lipoproteins, which might be explained by an advanced stage of the disease where such relationships might not appear.
Adult↗
An unusual complication of selective renal angiography.
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Adult↗