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Biomedical subjects

A Hagman

Publications and source records attributed to A Hagman.

At least 19 recordsLinked to original sources

Rapid reversed-phase high-performance liquid chromatography method for quantitation, at high pH, of the recombinant apolipoprotein A-IMilano in Escherichia coli fermentation broth.

An automated reversed-phase high-performance liquid chromatography method for quantitative determination of recombinant apolipoprotein A-IMilano (r-Apo A-IM) in E. coli fermentation broth has been developed and evaluated. The use of a unique matrix (Poros IIR/H) makes it possible to achieve rapid separation and good resolution at high pH. The r-Apo A-IM-containing fraction is well separated from other proteins allowing a reliable quantification. The automation and high sample throughput of this method makes it very useful for routine determination of r-Apo A-IM in fermentation broth and in eluates from the various purfication steps. With suitable modifications and adaptions this method is likely to be useful for similar rapid analytical determination of recombinant proteins in complex solutions.

Apolipoprotein A-I

A multisensor array for visualizing continuous state transitions in biopharmaceutical processes using principal component analysis.

An array of sensors with varying sensitivities, a so-called multisensor array, has been used for monitoring the growth and production states of biopharmaceutical processes. The sensor array produced continuous and characteristic response patterns from the processes due to the differences of the sensors. By analysing these patterns with the multivariate method principal component analysis, the state as well as the change of state of the bioprocesses could be visualized. The sensors used in the array were well-known semiconductor and optical gas sensors and the array was connected in an on-line set-up to the bioreactor's headspace effluent. The sensor array was applied to the monitoring of two recombinant bioprocesses, the production of human growth hormone in Escherichia coli and human factor VIII in Chinese ovary hamster cells. The sensor array could clearly visualize the characteristic transitions during the main growth or production phases of these two bioprocesses.

Animals

The nuclear-encoded PsbW protein subunit of photosystem II undergoes light-induced proteolysis.

The repair of photoinhibitory damage to photosystem II involves the rapid degradation and turnover of the D1 reaction center subunit. Additional protein subunits which show a limited degradation at high light intensities are the complementary reaction center subunit, D2, and the two chlorophyll a binding proteins, CP 47 and CP 43. In this work, we provide the first evidence for light-induced degradation of a nuclear-encoded subunit of photosystem II, the recently discovered PsbW protein. This 6.1 kDa protein is predicted to have a single membrane span and was found to be closely associated with the photosystem II reaction center. The degradation of the PsbW protein was demonstrated by photoinhibitory experiments, both in vitro, using thylakoid membranes and photosystem II core particles, and in vivo using leaf discs. The PsbW protein showed almost the same rate and extent of degradation as the D1 protein, and its degradation was more pronounced compared to the D2 and CP 43 proteins. The degradation of the PsbW protein was shown to share many mechanistic similarities with the more well characterized D1 protein degradation, such as oxygen dependence, sensitivity to serine protease inhibitors, and high light triggering while the actual degradation could readily occur in total darkness. The degradation of the PsbW protein was impaired by protein phosphorylation, although this protein was not itself phosphorylated. This impairment was correlated to the phosphorylation of the D1 protein which has been shown to block its degradation during photoinhibitory conditions. It is concluded that the PsbW protein is not degraded as a direct consequence of primary photodamage but due to a general destabilization of the photosystem II complex under conditions were the D1 protein becomes degraded in the absence of a sufficient repair system. The results are discussed in terms of a requirement for coordination between degradation and protein synthesis/integration during the repair process of photodamaged photosystem II reaction centers.

Cell Nucleus

A model for quality assessment in primary health care using the tracer condition technique with insulin treated diabetes as one of the tracers.

OBJECTIVE: To find a method for quality assessment in primary health care and to apply this method on a defined disease. DESIGN: General practitioners and hospital doctors worked out a programme for evaluating the quality of outpatient care of patients with insulin treated diabetes as one of five tracers. An expert committee comprising experienced general practitioners and hospital doctors compared two health centres with one outpatient medical department. Data were collected during a defined period combined with a one-year retrospective view, official statistics on medical care, and a questionnaire completed by the patients. SETTING: Two primary health care centres and one outpatient medical department in southwestern Sweden. PATIENTS: 243 insulin treated diabetic patients attending the hospital and 87 insulin treated patients attending the health centres. MAIN RESULTS: There were no difficulties for the expert panel to agree on which indicators were to be studied. The expert panel concluded that there was no difference between the quality of the two levels of care studied. CONCLUSIONS: Medical audit was a useful method for evaluating medical quality. Co-operation between hospital doctors and general practitioners was of great value for evaluation of the quality of primary health care.

Adult

Oxidation of human insulin-like growth factor I in formulation studies, II. Effects of oxygen, visible light, and phosphate on methionine oxidation in aqueous solution and evaluation of possible mechanisms.

PURPOSE: The oxidation of methionine in human Insulin-like Growth Factor I (hIGF-I) in aqueous solution was studied with respect to oxygen, visible light and sodium phosphate. METHODS: Aqueous solutions of hIGF-I were prepared with different amounts of phosphate and dissolved oxygen. The solutions were stored either in darkness or exposed to artificial visible light. The oxidized hIGF-I was quantified by RP-HPLC. A two level full factorial experimental design, with two levels of each of the three factors studied, was used. RESULTS: Oxidation was found to be positively correlated with light oxygen content and, interestingly, phosphate. The increasing effect of phosphate on the oxidation appears not to originate from metal contaminants. The influence of both oxygen and phosphate increased with time. The pH dependence of oxidation indicated the formation of a phosphorylated sulfonium ion as an oxidation intermediate. A significant interaction effect between phosphate and visible light suggested participation of radicals. CONCLUSIONS: Factorial experiments provide a valuable tool when studying complex mechanisms with interacting factors. The oxidation of methionine in hIGF-I is significantly affected by light but also by the presence of phosphate buffer.

Chemistry, Pharmaceutical

Medical audit used for estimation of optimum level of outpatient care.

OBJECTIVE: To create a model for determining the optimum level of outpatient medical care and to determine this level. DESIGN: Expert committees were established comprising one or two hospital physicians and two general practitioners who checked medical records for all outpatient visits to doctors made by a defined population during a defined period of time. The determination of optimum level was made blindly by each member of the expert committee. SETTING AND PARTICIPANTS: The study comprised all visits to physicians during 10 weeks, in total more than 4,000, made by the people in a Swedish community, of which 2,084 were randomized. RESULTS: Total agreement between the members of the committee was initially reached for 84% of the visits and, after a common discussion between the committee members, for 99%. A general practitioner was considered to be the optimum level of care for 76% of the patients in the total series, in the upper ages (above 80) for about 85%. CONCLUSION: This method seemed suitable for determining the optimum level of care in a population and may be of value when planning for an optimum health care service. Based on the results from our study it seems reasonable to assume that general practitioners whose training corresponds to that of Swedish ones are competent to treat about 75% of all consultations.

Adolescent

Referral notes used as a tool for evaluating the co-operation between general practitioners and hospital physicians.

OBJECTIVE: To study what proportion of clinical visits to a general practitioner working at a Swedish health centre leads to a referral to a specialist, the adequacy of the reason for the referral, the quality of the referral notes, and the quality of the answers by the specialists to whom the patients had been referred. DESIGN: A referee committee representing the different medical specialists and the general practitioners studied all referral notes dealing with internal medicine, surgery, orthopaedics, and otorhinolaryngology during a defined period from two health centres as to adequacy of the reason for referral, the quality of the referral notes, and the quality of the answers to the referrals. SETTING AND PARTICIPANTS: Altogether 188 consecutive referral notes and 171 answers to these referrals from two Swedish health centres were evaluated. RESULTS: Of the visits to a general practitioner, 7-8% resulted in a referral to a hospital specialist, and 90% of these were answered by letter. The referee committee agreed that the vast majority of the reason for referral were adequate, and that the referral notes as well as the answers to these with few exceptions were adequately formulated. CONCLUSIONS: The referrals from primary health care to different medical specialists worked adequately, but it was concluded that it may be further improved. When evaluating the co-operation between two medical systems, it is important that the evaluation as well is made in co-operation by representatives from the two systems.

Family Practice

On the molecular mechanism of light-induced D1 protein degradation in photosystem II core particles.

The mechanism of D1 protein degradation was investigated during photoinhibitory illumination of isolated photosystem II core preparations. The studies revealed that a proteolytic activity resides within the photosystem II core complex. A relationship between the inhibition of D1 protein degradation and the binding of the highly specific serine protease inhibitor diisopropyl fluorophosphate to isolated complexes of photosystem II was observed, evidence that this protease is of the serine type. Using radiolabeled inhibitor, it was shown that the binding site, representing the active serine of the catalytic site, is located on a 43-kDa polypeptide, probably the chlorophyll a protein CP43. The protease is apparently active in darkness, with the initiation of breakdown being dependent on high light-induced substrate activation. The proteolysis, which has an optimum at pH 7.5, gives rise to primary degradation fragments of 23 and 16 kDa. In addition, D1 protein fragments of 14, 13, and 10 kDa were identified. Experiments with phosphate-labeled D1 protein and sequence-specific antisera showed that the 23- and 16-kDa fragments originate from the N- and C-termini, respectively, suggesting a primary cleavage of the D1 protein at the outer thylakoid surface in the region between transmembrane helices D and E.

Chlorophyll

Efficacy of enprofylline in acute airway obstruction.

The efficacy and safety of different regimens of intravenously administered enprofylline, an anti-asthma xanthine, were evaluated in a randomized open study, including 155 patients with acute exacerbation of obstructive lung disease. The regimen 2.5 mg/kg i.v. over 10 min was canceled after seven patients had been included, due to two cases of hypotensive/vasovagal reactions. The regimens 2.0 mg/kg/20 min and 2.5 mg/kg/20 min were significantly more effective with regard to bronchodilation than 2.0 mg/kg/10 min (PEF increase +35%, +30% and +17% respectively). Nausea and headache were the most common side effects (16-33% and 23-33% of the patients respectively on different regimens) with the lowest frequency on 2.0 mg/kg/20 min. Four additional hypotensive reactions occurred; one on each 2.0 mg/kg regimen and two on 2.5 mg/kg/20 min. The regimen 2.0 mg/kg20 min was found to be the most favourable with regard to efficacy and side effects. Enprofylline i.v. was found to be an effective bronchodilating treatment of acute airway obstruction but the frequency of side effects has to be considered.

Acute Disease

Analgesic treatment in acute myocardial infarction. A double-blind comparison of ketobemidone + the spasmolytic A29 (Ketogan) and morphine.

The analgesic effect of ketobemidone hydrochloride + the spasmolytic component A29 (Ketogan) and morphine hydrochloride was compared double-blindly in patients with suspect acute myocardial infarction. The test drugs were administered i.v. in an initial dose of 0.5 ml (2.5 mg Ketogan, 5 mg morphine) followed, if necessary, by additional injections of 0.25 ml. Altogether, 309 patients participated in the trial. The total consumption of the test drugs showed that 5 mg Ketogan was equipotent with 10 mg of morphine. Treatment with Ketogan resulted in a significantly higher proportion of patients who were completely free of pain 15 and 30 min after the initial injection: 16% and 15% more, respectively, compared to morphine. Within 2 hours after the initial injection, approximately 15% of the patients in both treatment groups had reported nausea and about 7% had vomited (patients who vomited or were nauseated before treatment were not included in this analysis). The frequency of other side-effects was low, with no differences between the two treatment groups. Morphine caused a greater reduction of the systolic blood pressure than Ketogan. The effect of both drugs on pulse rate and respiration was the same.

Adult

Identification and quantification of arsenocholine and acetylarsenocholine in trace amounts in biological material by use of pyrolysis gas chromatography/mass spectrometry.

An analytical method, based on a selective extraction and pyrolysis gas chromatography/mass spectrometry assay of arsenocholine and acetylarsenocholine in aquatic organisms, is described. Characteristic fragmentation patterns were obtained from pyrolytically demethylated compounds. The molecules were rearranged in unique pathways which differed from those of corresponding nitrogen analogues. Qualitative determination of arsenocholine and acetylarsenocholine was achieved by gas chromatographic as well as mass spectrometric analysis of the thermal degradation products (trimethylarsine, dimethylvinylarsine and the demethylated arsenocholine or acetylarsenocholine). Arsenocholine and acetylarsenocholine in fish from industrially polluted water were isolated and identified. Massfragmentographic quantification of the arsenic compounds in fish was carried out by use of deuterium labelled analogues of arsenocholine and acetylarsenocholine as internal standards. The method showed a high sensitivity.

Animals

Potassium sparing by amiloride during thiazide therapy in hypertension.

Several studies have shown that 5 mg amiloride can counteract the hypokalemic effect of 50 mg hydrochlorothiazide (HCTZ). In a double-blind study of 30 subjects with mild to moderate primary hypertension, we determined whether this effect could be obtained with half the dose of amiloride (2.5 mg) in combination with 25 mg HCTZ. The effect of twice the dosage was evaluated in subjects with unsatisfactory blood pressure (BP) on the lower dose. Both 25 mg HCTZ/amiloride 2.5 mg and 25 mg HCTZ alone lowered BP. In subjects with untreated diastolic BP between 110 and 115 mm Hg, these doses were inadequate; twice the dose resulted in a greater reduction in BP. Irrespective of dosage, a potassium-sparing effect resulted from the combination of HCTZ and amiloride, with a reduction in serum potassium levels from HCTZ alone as well.

Adult

Syncope caused by lithium treatment. Report on two cases and a prospective investigation of the prevalence of lithium-induced sinus node dysfunction.

Lithium salts have been widely used for several years in the treatment of manic-depressive psychosis. Various side-effects of lithium salts have been described. The present case report present two patients in whom sinus node dysfunction leading to syncope was caused by lithium. One of the cases showed signs of depressed sinus node function even when not on lithium, but no symptoms arose until lithium treatment was commenced. The second case showed no signs of depressed sinus node function when lithium was withdrawn. To study the prevalence of sinus node dysfunction in patients on lithium therapy, 97 consecutive patients on lithium were examined. The examination included case history, ECG and carotid massage. In two patients lithium could not be ruled out as being responsible for sinus node depression and in one patient the same was true for the atrioventricular node. None of these patients had any symptoms. It is concluded that lithium treatment may result in sinus node dysfunction. This side-effect is, however, not common. Lithium treatment can obviously be instituted in all patients without a history suggesting sinus node dysfunction. Patients with a history of dizziness and/or syncope should not be given lithium until thorough cardiological examination has been carried out. Likewise, a cardiological examination should be performed if patients on lithium develop symptoms of this type.

Aged

Origin of the translocated segment of the 14q+ marker in non-Burkitt lymphomas.

The cytogenetic findings by G-banding in two histiocytic lymphomas are described. Both tumors had a stemline with a 14q+ marker. The origin of the extra segment on No. 14 was determined, and it was different in the two cases. These observations, and those from non-Burkitt lymphomas with 14q+ markers reported in the literature, indicate an inconsistent pattern for the origin of the extra material on No. 14. The only feature in common for all cases is instability of the distal region of the long arm of No. 14, and liability of this region to be involved in structural rearrangements, particularly translocations.

Biopsy