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Biomedical subjects

U Nyman

Publications and source records attributed to U Nyman.

At least 73 records · Page 4Linked to original sources

Intranuclear localization of a new snRNP-related antigen.

The intranuclear distribution of a new antigen (F78) associated with U snRNPs (small nuclear RNA-protein complexes) was compared with that of the RNP and Sm protein antigens previously identified on individual snRNP particles. Human and rat cells were double stained with human autoantisera and mouse monoclonal antibodies. The binding of the human and mouse antibodies was detected with secondary antibodies conjugated with fluorescein and rhodamine, respectively. The resulting immunofluorescence patterns were compared by digital image analysis. The F78, RNP, and Sm antigens show speckled fluorescence patterns which overlap to a great extent. The F78 pattern, however, also contains two classes of structural elements not present in the RNP pattern. Furthermore, during mitosis expression of the F78 antigen is completely suppressed from early prophase to telophase, while the RNP and Sm antigens are found evenly distributed throughout the cytoplasm of the dividing cells.

Animals↗

Antigenic domains on the U1 small nuclear ribonucleoprotein-associated 70K polypeptide: a comparison of regions selectively recognized by human and mouse autoantibodies and by monoclonal antibodies.

Antigenic regions on the U1 small nuclear ribonucleoprotein (snRNP)-associated 70K polypeptide recognized by human and mouse autoantibodies or by monoclonal antibodies were identified and compared. Using a set of 70K fusion proteins as antigen in enzyme-linked immunosorbent assay and immunoblotting revealed that serum autoantibodies of human and of MRL/Mp mouse origin recognized a common region of the 70K polypeptide. Monoclonal anti-70K antibodies derived from a patient with mixed connective tissue disease, from an autoimmune MRL/Mp mouse, and from a BALB/c mouse immunized with purified U1 snRNP were all shown to bind to a part of the 70K polypeptide rich in charged residues and different from the region recognized by most human and MRL/Mp mouse serum autoantibodies.

Animals↗

Ribosome-inhibiting proteins from in vitro cultures of Phytolacca dodecandra.

Phytolacca dodecandra (L'Herit) grown in cell cultures was investigated for content of ribosome-inhibiting proteins, which was evaluated by measuring inhibition of protein synthesis in a cell-free rat liver extract. Calli initiated from leaf, cotyledon, radicle, and hypocotyl and suspension cells initiated from leaf and cotyledon exhibited protein synthesis-inhibiting activity. Ribosome-inhibiting proteins were purified at least 14 times from suspension cells of P. dodecandra. The purified protein fraction contained two proteins as seen by sodium dodecyl sulphate polyacrylamide gel electrophoresis. The relative molecular masses were 30,000 and 31,000 and they showed a pI greater than 9.3. These new RIP's were shown to be different from dodecandrin with respect to molecular mass.

Animals↗

Percutaneous nephrolithotomy through an intercostal approach.

During a 5-year period percutaneous nephrolithotripsy through an intercostal space was performed in 56 of 231 procedures. Minimal thoracic complications were seen in 3 of 53 patients with 11th intercostal space tracts into a lower, middle, or upper pole calyx. A working sheath and a pyelostomy drainage catheter were used in all these cases. Hydro- and pneumothorax requiring treatment occurred in 2 of 3 patients with a 10th intercostal space approach into an upper pole calyx combined with improper use of the working sheath and/or the pyelostomy catheter. Review of the literature also indicates that an intercostal approach appears safe when performed via the 11th intercostal space into a lower or middle pole calyx. Thoracic complications occurred when punctures were made towards an upper pole calyx or above the 11th rib. The complications may be limited by identifying the posterior inferior lung border by fluoroscopy during puncture, and performing it under general anesthesia with controlled breath-holding. The use of a working sheath to seal the pleural opening during the procedure and an efficient pyelostomy drainage catheter to allow free drainage of urine and to tamponade the tract postoperatively are also recommended.

Adult↗

[Management of visceral aneurysm].

In the article we discuss our experience in dealing with visceral aneurysms at Malmö General Hospital during the period, 1971-85. Of the total of 25 patients diagnosed, eight had ruptured aneurysms, six underwent elective surgery, and 11 underwent no surgical intervention. Of the aneurysms found, nine were of the splenic artery, five of the superior mesenteric artery and its branches, three of the pancreaticoduodenal artery, two of the celiac artery, and one of the gastroduodenal artery. There was no mortality either among patients undergoing surgery, or from complications among those treated conservatively without surgery.

Aged↗

Human autoantibodies against the 70-kd polypeptide of U1 small nuclear RNP are associated with HLA-DR4 among connective tissue disease patients.

Serum samples from patients with connective tissue disease (CTD) were characterized using a recently developed enzyme-linked immunosorbent assay for reactivity with individual specific polypeptides of U1 small nuclear ribonucleoproteins, including the U1-70-kd protein. The distribution of HLA antigens was compared in CTD patients with and in those without anti-U1-70-kd autoantibodies and in normal controls. The frequencies of HLA-DR4 and HLA-DRw53 were increased among the anti-U1-70-kd autoantibody positive CTD group compared with the frequencies in anti-U1-70-kd autoantibody negative systemic lupus erythematosus patients and compared with normal controls. We conclude that the presence of autoantibodies reactive with the anti-U1-70-kd protein antigen is associated with HLA-DR4 and HLA-DRw53.

Antibodies, Antinuclear↗

Primary double pigtail stenting as a treatment of upper urinary tract leaks.

During a 5-year period 21 consecutive patients with iatrogenic or traumatic upper urinary tract leaks (nonmalignant) underwent treatment 5 to 28 days later with an indwelling double pigtail stent via an antegrade or retrograde approach. Six patients underwent initial nephrostomy drainage for relief of obstruction causing decreased renal function and/or septicemia. Stent placement was successful in 20 patients and complete healing occurred within 2 to 7 weeks in all 20. At followup 2 to 32 months later (median 3 months) no stricture formation or deterioration of kidney function was noted. There were no major complications and 85% of the patients were able to leave the hospital without any form of external drainage within 1 week after stent placement.

Adult↗

Recombinant 70-kD protein used for determination of autoantigenic epitopes recognized by anti-RNP sera.

A panel of high- and low-titre anti-RNP-positive patient sera was tested for reactivity with human snRNP proteins. The U1 snRNP-specific 70-kD peptide was found to be the most prominent RNP antigen recognized by high-titre anti-RNP sera, mainly found in patients with mixed connective tissue disease (MCTD). The reactivity with the 70-kD protein was further analysed with recombinant fusion proteins containing different segments of the protein. One major and two minor antigenic regions were found. Most patient sera, both with high- and low-titre anti-RNP antibodies, only recognized the major region. The most aminoterminal region, showing partial sequence homology with a mouse retroviral p30 gag protein, contained an epitope that was recognized by one serum only.

Adult↗

Appearance and origin of snRNP antigens in chick erythrocyte nuclei reactivated in heterokaryons.

Fusion of terminally differentiated chick erythrocytes (CE) with transcriptionally active rat myoblasts results in heterokaryons in which the CE nuclei undergo reactivation of RNA synthesis and splicing. In order to analyze the transport and assembly of small nuclear ribonucleoprotein (snRNP) particles and larger molecular complexes engaged in RNA processing, we have examined CE nuclei in heterokaryons for the presence of four U snRNP-related nuclear antigens (Sm, 70,000 Mr, F78 and M3G-cap) and for one antigen (La), associated with RNA polymerase III transcripts. Inactive erythrocyte nuclei showed low levels of Sm and F78 antigens, but the other antigens were undetectable. Immediately after fusion, the fluorescence of the pre-existing chicken Sm antigen was detected in the CEn, and then the intensity of the signal increased rapidly during reactivation. The other antigens appeared more slowly, reaching full intensity at different time points after fusion. Blocking of chick transcription did not block the appearance of Sm, 70,000 Mr, cap and La antigens but did effectively inhibit the appearance of the F78 antigen. It has previously been demonstrated that the structure recognized by this monoclonal antibody is physically associated with functional splicing complexes. Blocking of translation in heterokaryons abolished uptake of snRNPs into the chicken nuclei. Taken together, the results indicate that rat snRNP complexes were imported into the chick nuclei after assembly in the cytoplasm. For all the studied antigens, except F78, this translocation was independent of chick RNA synthesis. The appearance of the F78 antigen was totally dependent on expression of chicken genes.

Animals↗

Preoperative localization in unilateral parathyroid surgery. A cost-benefit study on ultrasound, computed tomography and scintigraphy.

In 50 patients with primary hyperparathyroidism, investigation before initial neck exploration included ultrasonography, computed tomography and 99technetium-201thallium subtraction scintigraphy. The sensitivity for correct preoperative localization was 50%, 54% and 56%, respectively. There was marked inter-observer variation in assessment of ultrasonography and computed tomography, while scintigrams were evaluated by only one person. The scintigraphic sensitivity increased with size of the glands. In cases where correct preoperative localization permitted unilateral parathyroidectomy, the time for surgery and anesthesia was significantly reduced. A cost-benefit analysis, however, revealed that the financial saving from this time reduction was outweighed by the cost of the localization procedures. The authors conclude that investigations for definition of enlarged parathyroid glands are not indicated prior to unilateral parathyroidectomy.

Adult↗

Demonstration of an amino terminal La epitope recognized by human anti-La sera.

In order to study the antigenic properties of the La protein we have isolated a 1650 base pair (bp)-long human cDNA encoding an anti-La reactive protein. Restriction enzyme analysis and DNA sequencing was used to compare this clone with two published but inconsistent partial sequences. Our clone extends about 220 bp further towards the 5' end than the two clones previously studied and includes a putative initiation codon. When introduced into an expression vector, stable fusion proteins were made both from the initial clone and from two deletion clones. The recombinant proteins were tested by immunoblotting against a panel of anti-La sera. All reacted with the fusion protein produced by the 1650-bp clone. About half of the anti-La sera showed reactivity against the recombinant protein from the shortest deletion clone. This indicates the presence of an epitope in the amino terminal part of the La protein, encoded by sequences not present in previously published clones.

Amino Acid Sequence↗

Early diagnosis and classification in acute pancreatitis. A comparison of clinical outcome with findings at computed tomography and Ranson's prognostic signs.

The clinical outcome in 52 consecutive episodes of suspected acute pancreatitis was compared with Ranson's prognostic signs and findings on noncontrast and contrast-enhanced computed tomography (CT) scans performed within 24 h of patient admission. The predictive value of CT scan for diagnosis was 95% for positive results and 53% for negative results. In providing an accurate prognosis of a single attack, scoring of extrapancreatic signs was as good as that of Ranson's prognostic signs. CT with contrast medium revealed pancreatic ischaemia in 3 cases of 4 with clinically severe disease. The risk of developing severe pancreatitis was 23% in first attacks and 6% in relapses. Early CT scan is recommended in most patients with suspected pancreatitis to confirm diagnosis and to predict the severity of an attack.

Acute Disease↗

Pathobiochemistry and early CT findings in acute pancreatitis.

Extrapancreatic findings at computed tomography (CT), performed within 24 h in 42 consecutive episodes of acute pancreatitis, were classified according to a scoring system (EP score) and were correlated to Ranson's prognostic signs, to duration of hospital stay, biochemical changes in plasma and pancreatic ischaemia found at CT with contrast enhancement. Increasing EP score was found to be related to increasing number of positive Ranson's signs, longer hospital stay and pancreatic ischaemia. Plasma levels of immunoreactive cationic trypsin and amylase were not proportional to EP score. alpha 1-protease inhibitor, antichymotrypsin but not immunoreactive pancreatic secretory trypsin inhibitor increased proportionally to EP score. No changes related to EP score were seen in alpha 2-macroglobulin levels. Serum levels of trypsin-alpha 1-protease inhibitor complex were maximal after 3 days and most pronounced in cases with high EP scores. Plasma levels of factor X, alpha 2-antiplasmin and C1-esterase inhibitor were found to be inversely proportional to EP score.

Acute Disease↗

Thromboprophylaxis in hip arthroplasty. Dextran with graded compression or preoperative dextran compared in 150 patients.

Totally, 150 patients, subjected to total hip arthroplasty, were randomly allocated into three prophylactic groups with either conventional dextran alone or with additional graded compression stockings or with additional preoperative administration of dextran. The overall frequency of deep venous thrombosis (DVT), as studied by radioactive fibrinogen uptake test and ascending phlebography of the operated on thigh was in the conventional dextran group 46 percent, the additional stockinged group 30 percent, and in the additional preoperative dextran group 52 percent. In the stockinged group, there was a lower frequency of DVT in the nonoperated on leg as well as, on an average, about 350 mL less peroperative bleeding as compared with the other two groups. No adverse reaction occurred from dextran administration. Increased and prolonged postoperative administration of dextran decrease the number of femoral DVTs.

Aged↗

Intranuclear localization of snRNP antigens.

Anti-Sm antibodies recognize a group of small, nuclear RNA-protein complexes (snRNPs) containing U1, U2, U4, U5, and U6 snRNAs. Anti-RNP antibodies only react with U1 snRNA-containing complexes. The intranuclear distribution of snRNP particles was studied by double immunofluorescence staining of human fibroblasts. Mouse monoclonal anti-Sm antibodies and polyclonal patient sera reacting with different peptides in the snRNP complexes were used. The immunofluorescence patterns obtained with fluorescein isothiocyanate-conjugated anti-mouse Ig and tetramethylrhodamine isothiocyanate-conjugated anti-human Ig second antibodies were examined using computer analysis of digitized images. With this approach the similarity of different patterns could be visualized and estimated with mathematical methods. It was found that human anti-Sm serum as well as three different anti-RNP sera produced speckled patterns overlapping with the anti-Sm monoclonal pattern. Thus, Sm antigenic intranuclear domains also reacted with anti-RNP antibodies, suggesting a high degree of co-localization of the antigenic structures. A partial overlap was found between speckles detected by mouse anti-Sm antibodies and a human La-antiserum. No significant co-localization occurred between speckles detected by mouse anti-Sm antibodies and speckles detected by human antisera reacting with Scl-70 and centromeric antigens. As the U1 snRNP complex is believed to play a role in the splicing of RNA polymerase II transcripts, it appears that the speckles detected by Sm and RNP antibodies may be regions of hnRNA synthesis and mRNA processing. Although no function has been demonstrated for the U2, U4, U5, and U6 snRNPs, the co-localization with the U1 RNA complexes shown in this report indicate that they too participate in some aspect of mRNA processing. The results suggest that computer-assisted analysis of nuclear immunofluorescence patterns will be a useful tool in studies of the spatial and functional organization of the interphase nucleus.

Antibodies, Monoclonal↗