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Biomedical subjects

K Köhler

Publications and source records attributed to K Köhler.

228 records · Page 13Linked to original sources
PubMedDate not supplied

Evidence for a highly nuclease resistant RNA fragment in prosomes.

Prosomes, small cytoplasmic particles of mouse erythroblasts were found to contain low molecular weight RNA molecules in the range of 80 nucleotides. Nuclease digestion of prosomes suggests that prosomal proteins cover and protect almost the whole length of their RNA(s). Our results demonstrate clearly that RNA is an intrinsic component of prosomes.

Animals↗
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A comparison of lymphatic tissues from cats with spontaneous feline infectious peritonitis (FIP), cats with FIP virus infection but no FIP, and cats with no infection.

Lymphatic tissues (spleen, mesenteric lymph nodes, thymus) from 24 cats with spontaneous feline infectious peritonitis (FIP) were examined by light microscopy and immunohistochemistry for cellularity, cellular composition, and degree of cellular turnover. Additionally, the formation of granulomatous lesions in lymphatic tissues in cats with FIP was examined. For comparison, tissues from 14 specific pathogen-free (SPF) cats and seven cats infected with FIP virus (FIPV; as the result of long-term exposure) but free from FIP were examined. In cats with FIP, the precardial mediastinum (including site of the thymus) and mesenteric lymph node parenchyma were often affected by granulomatous-necrotizing processes. In general, lymphoid tissues showed T- and B-cell depletion, often including massive to complete thymic involution or atrophy. In some cases, the number of apoptotic lymphocytes was increased in lymphoid follicles as well as in T-cell zones. The number of macrophages was increased in the splenic red pulp. In contrast, the FIPV-exposed cats without FIP generally showed a distinct lymphoid hyperplasia. The findings indicated that the major difference in lymphatic tissues between FIPV-infected cats with FIP and those without FIP was the development of lymphocyte depletion in the first group and lymphocyte proliferation in the second.

Animals↗
PubMedDate not supplied

Preoperative angiography of the superior mesenteric and portal vein with prostaglandin F2 alpha in portal hypertension.

In a comparative study, we showed that a gain in diagnostic reliability justifies the routine use of PGF in indirect superior mesenteric venograms of patients with portal hypertension. Three radiologists without knowledge of patients' data and treatment analyzed 30 angiograms with and 30 examinations without PGF. Complicating factors, such as presence of varices and dose of contrast medium (CM), were taken into account by a Mantel and Haenszel procedure. When PGF was used, intrahepatic portal branches could be outlined beyond their second ramification more frequently. The superior mesenteric and portal veins, but not the confluence, were visualized significantly more often using this agent, so that patency, constriction, partial thrombosis or occlusion could be reliably diagnosed. Independent of the use of PGF, visualization of the confluence was improved by high CM doses in combination with high flow rates.

Adolescent↗
PubMedDate not supplied

Isolation of messenger ribonucleoproteins from HeLa cells by affinity chromatography on poly (U) sepharose.

Polysomes of HeLa cells were adsorbed on Poly(U)-Sepharose columns. This adsorption is probably due to poly(A) sequences at 3' terminus of the messenger. Stepwise elution initially removed ribosomal subunits thereafter mRNA and a set of proteins. These proteins are identical with the main components of the polysomal messenger ribonucleoprotein particles described previously. Thus, this method allows their rapid and easy separation from ribosomal and other proteins.

Cell Fractionation↗
PubMedDate not supplied

The role of acidic proteins from cytoplasmic fractions of Krebs II ascites cells for efficient translation.

Acidic proteins with affinity to RNA from cytoplasmic fraction of Krebs II Ascites cells were isolated by means of affinity chromatography on RNA-Sepharose CN-Br-columns. Stepwise elution with 350 mM [K+] and 1000 mM [K+] removed two fractions of proteins both of which are required for the formation of 40S- or 80S-initiation complexes and for efficient translation.

Animals↗
PubMedDate not supplied

Prosomes are involved in the repression of viral mRNA.

Prosomes are small cytoplasmic RNP complexes. We present evidence that their RNA is a potential and selective inhibitor of viral mRNA translation while translation of normal cellular mRNA e.g. rabbit globin mRNA or HeLa cell mRNA is not affected.

Adenoviridae↗
PubMedDate not supplied

Absorbable implants for open shoulder stabilization: a clinical and serial radiographic evaluation.

PATIENTS AND METHODS: Eighteen consecutive patients who had recurrent, unidirectional, post-traumatic shoulder instability were included. All the patients underwent surgery with a standardized open Bankart technique involving absorbable suture anchors. CLINICAL RESULTS: No redislocations occurred during the study period of 31 months (range 25 to 38 months). The Rowe and Constant scores were 86 points (range 61 to 98 points) and 89 points (range 73 to 99 points), respectively. The strength measurements revealed 8.6 kg (range 3.8 to 15 kg) in 90 degrees abduction compared with 9.3 kg (range 2.2 to 16.5 kg) in the control shoulders (not significant). The external rotation in abduction was 65 degrees (range 20 degrees to 90 degrees) compared with 91 degrees (range 80 degrees to 105 degrees) in the control group (P < .001). RADIOGRAPHIC RESULTS: Signs of minor or moderate degeneration were found in 10 of 18 patients on the preoperative radiographs, in 15 of 18 at 7 months, and in 16 of 18 at 33 months (P < .05 before surgery vs 33 months). From the preoperative examination to the 7-month control, 7 of 18 patients had an increase in degenerative changes, and from the 7-month to the 33-month control, an increase was found in 8 of 18 (P = .008, before surgery vs 7 months; P = .005, 7 months vs 33 months). At the 7-month control, 8 of 18 patients had invisible or hardly visible drill holes, and 10 of 18 had visible or cystic drill holes at the site of implantation for the absorbable suture anchors. At the 33-month control, 10 of 18 patients had invisible or hardly visible drill holes, and 8 of 18 had visible or cystic drill holes (not significant, 7 months vs 33 months). CONCLUSION: The method resulted in stable shoulders in 17 of 18 patients. Degenerative changes were present on the radiographs in most of the patients and appeared to increase over time. Visible drill holes or drill holes with cystic changes were seen on the radiographs in a significant number of patients at the 7-month and the 33-month control and did not appear to heal during the follow-up period.

Absorbable Implants↗
PubMedDate not supplied

Recovery of extracellular human insulin-like growth factor-I and II as a fusion protein from Escherichia coli culture broth by aqueous two-phase extraction.

The primary purification of human insulin-like growth factor-I (IGF-I) and IGF-II, produced extracellularly in Escherichia coli as a fusion to two domains (ZZ) derived from staphylococcal protein A, has been studied. First, the partitioning of IgG-affinity purified ZZ-IGF-I and ZZ-IGF-II, respectively, to the top phase in poly(ethylene glycol)/potassium phosphate aqueous two-phase systems were investigated. Thereafter, the extraction of ZZ-IGF-I with a poly(ethylene glycol) 1500/potassium phosphate system was performed directly in the bioreactor after the cultivation. This resulted in a reduction of the cultivation volume more than 3-fold with a recovery of about 90% of target protein in a poly(ethylene glycol)-rich phase. The majority of the cells partitioned to the potassium phosphate-rich bottom phase, while a smaller fraction was collected at the interface, and/or as a densely packed cake on top of the interface. Contaminating proteins were also eliminated to some extent, which resulted in an almost 2-fold protein purification. Some obvious benefits offered by the aqueous two-phase system in the primary purification have been demonstrated: Firstly, the possibility to an early process volume reduction and thereby a concentration of the target protein. Secondly, a simultaneous protein purification was achieved. From this work it can be concluded that aqueous two-phase extraction should be considered as an attractive candidate for the primary steps during the design of new purification processes for extracellular proteins.

Cell Separation↗