| 1. |
- Selber, K, et al.
(author)
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Large-scale separation and production of engineered proteins, designed for facilitated recovery in detergent-based aqueous two-phase extraction systems
- 2004
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In: Process Biochemistry. - 1873-3298. ; 39:7, s. 889-896
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Journal article (peer-reviewed)abstract
- The feasibility and scalability of extraction in detergent-based aqueous two-phase systems for the separation of proteins from culture broth is demonstrated. At the same time the large-scale production of a fusion protein and the influence of cultivation scale on the efficiency of separation were investigated. An amphiphilic fusion protein EGIcore-HFBI was chosen, consisting of the catalytic core of the cellulase endoglucanase I and the small protein hydrophobin I, expressed homologously in Trichoderma reesei. Using the technical nonionic detergent Agrimul NRE 1205 the separation was successfully scaled up to 1200 l. No differences in yield or in partition coefficient were observed at 10 ml and 1200 l scale. Changes in the fermentation temperature and scale, however, can influence the properties of the protein and thus alter partition coefficient and yield. The decreased separation efficiency appears to be correlated with changes in glycosylation at lower cultivation temperatures
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| 2. |
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| 3. |
- Becker, D., et al.
(author)
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Engineering of a glycosidase Family 7 cellobiohydrolase to more alkaline pH optimum : the pH behaviour of Trichoderma reesei CeI7A and its E223S/A224H/L225V/T226A/D262G mutant
- 2001
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In: Biochemical Journal. - 0264-6021 .- 1470-8728. ; 356, s. 19-30
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Journal article (peer-reviewed)abstract
- The crystal structures of Family 7 glycohydrolases suggest that a histidine residue near the acid/base catalyst could account for the higher pH optimum of the Humicola insolens endoglucanase Cel7B, than the corresponding Trichoderma reesei enzymes. Modelling studies indicated that introduction of histidine at the homologous position in T. reesei Cel7A (Ala(224)) required additional changes to accommodate the bulkier histidine side chain. X-ray crystallography of the catalytic domain of the E223S/A224H/L225V/T226A/D262G mutant reveals that major differences from the wild-type are confined to the mutations themselves, The introduced histidine residue is in plane with its counterpart in H. insolens Cel7B, but is 1.0 Angstrom (= 0.1 nm) closer to the acid/base Glu(217) residue, with a 3.1 Angstrom contact between N-2 and O'(1). The pH variation of k(cat)/K-m for 3,4-dinitrophenyl lactoside hydrolysis was accurately bell-shaped for both wildtype and mutant, with pK(1) shifting from 2.22+/-0.03 in the wild-type to 3.19+/-0.03 in the mutant, and pK(2) shifting from 5.99+/-0.02 to 6.78+/-0.02. With this poor substrate, the ionizations probably represent those of the free enzyme. The relative k(cat) for 2-chloro-4-nitrophenyl lactoside showed similar behaviour. The shift in the mutant pH optimum was associated with lower k(cat)/K-m values for both lactosides and cellobiosides, and a marginally lower stability. However, k(cat) values for cellobiosides are higher for the mutant. This we attribute to reduced nonproductive binding in the +1 and +2 subsites; inhibition by cellobiose is certainly relieved in the mutant. The weaker binding of cellobiose is due to the loss of two water-mediated hydrogen bonds.
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| 4. |
- Fagerstrom, Tim, et al.
(author)
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Complications and Clinical Outcome 18 Months After Bipolar and Monopolar Transurethral Resection of the Prostate
- 2011
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In: Journal of endourology. - : Mary Ann Liebert, Inc.. - 0892-7790 .- 1557-900X. ; 25:6, s. 1043-1049
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Journal article (peer-reviewed)abstract
- Purpose: To compare bipolar resection with the conventional monopolar transurethral resection of the prostate (TURP) with respect to peri- and postoperative complications and long-term outcome. Patients and Methods: Patients with consecutive benign prostatic hyperplasia needing surgery (n = 185) from the hospitals waiting list were randomized to TURP using either a bipolar or a monopolar system. Peri-and postoperative parameters were monitored, complications were registered, and timed micturition/International Prostate Symptom Score (TM/IPSS) forms were collected at 3 and 6 weeks and at 6 and 18 months. Results: Bipolar surgery was followed by a 16% to 20% higher percentage of the patients reporting ongoing improvement (fractional IPSS change greater than2) at 3 and 6 weeks after the surgery (p less than 0.05). There were fewer readmissions in the bipolar group than in the monopolar (5 vs. 13, p less than 0.05). No differences between the groups with respect to hospital stay and catheter duration was recorded. Bipolar and monopolar TURP resulted in marked and sustained improvements of IPSS, bother score, and TM. Conclusions: Bipolar TURP, using the transurethral resection in saline (TURis) system, resulted in significantly fewer postoperative readmissions, faster postoperative recovery, and equally long-lasting good results in TM/IPSS and bother score, as in monopolar TURP.
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| 5. |
- Fagerstrom, Tim, et al.
(author)
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Degree of Vaporization in Bipolar and Monopolar Resection
- 2012
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In: Journal of endourology. - : Mary Ann Liebert. - 0892-7790 .- 1557-900X. ; 26:11, s. 1473-1477
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Journal article (peer-reviewed)abstract
- Purpose: To compare the in vitro degree of vaporization in bipolar and monopolar resection. less thanbrgreater than less thanbrgreater thanMaterials and Methods: Using either a bipolar system or a monopolar system, samples of chicken muscle and lamb kidney were resected in an isolated basin and then desiccated in an incubator. The percentual degree of vaporization for each sample was obtained as a difference between the total fresh weight of the sample and the calculated fresh weights of the resected tissue and remains. less thanbrgreater than less thanbrgreater thanResults: Reference samples showed that the water content was 73% in muscle and 77% in kidney. More muscle (mean 52%) than kidney (32%; P andlt; 0.0001) tissue was vaporized. The fraction of vaporized tissue was significantly higher in the bipolar technique. In muscle, the differences between monopolar and bipolar were 17% (P andlt; 0.05) and 26% (P andlt; 0.001), respectively, depending on the type of irrigation used. For kidney, the differences were 27% (P andlt; 0.01) and 34% (P andlt; 0.01), respectively. Further exploration of the degree of vaporization when using the bipolar resection showed that the choice of loop (P andlt; 0.0001), fluid (P andlt; 0.03), and tissue (P andlt; 0.0001) were all independently associated with the degree of vaporization. less thanbrgreater than less thanbrgreater thanConclusions: This study indicated that vaporization removes 50% more tissue than the weight of the resected tissue during conventional tissue resection. Bipolar standard loop resection resulted in a significantly higher degree of vaporization in both muscle and kidney than did monopolar technique. Bipolar resection worked satisfactorily in Ringers acetate.
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| 6. |
- Hahn, Robert, et al.
(author)
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Isotonic saline in elderly men: an open-labelled controlled infusion study of electrolyte balance, urine flow and kidney function
- 2016
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In: Anaesthesia. - : WILEY-BLACKWELL. - 0003-2409 .- 1365-2044. ; 71:2, s. 155-162
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Journal article (peer-reviewed)abstract
- Isotonic saline is a widely-used infusion fluid, although the associated chloride load may cause metabolic acidosis and impair kidney function in young, healthy volunteers. We wished to examine whether these effects also occurred in the elderly, and conducted a crossover study in 13 men with a mean age of 73 years (range 66-84), who each received intravenous infusions of 1.5 l of Ringers acetate and of isotonic saline. Isotonic saline induced mild changes in plasma sodium (mean +1.5 mmol.l(-1)), plasma chloride (+3 mmol.l(-1)) and standard bicarbonate (-2 mmol.l(-1)). Three hours after starting the infusions, 68% of the Ringers acetate and 30% of the infused saline had been excreted (p < 0.01). The glomerular filtration rate increased in response to both fluids, but more after the Ringers acetate (p < 0.03). Pre-infusion fluid retention, as evidenced by high urinary osmolality (> 700 mOsmol.kg(-1)) and/or creatinine (> 7 mmol.l(-1)), was a strong factor governing the responses to both fluid loads.
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