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Biomedical subjects

G Nilsson

Publications and source records attributed to G Nilsson.

358 records · Page 20Linked to original sources
PubMedDate not supplied

Feedback on prescribing rate combined with problem-oriented pharmacotherapy education as a model to improve prescribing behaviour among general practitioners.

OBJECTIVE: To develop a working model with which prescribing behaviour among general practitioners might be influenced. DESIGN: Intervention based on feedback on prescribing rates and problem-oriented educational outreach visits, using educational material and local opinion leaders. Randomised study with three parallel intervention groups of general practitioners, which also served as controls for each other. The pharmacotherapeutic fields chosen were hypertension, peptic ulcer/dyspepsia and depression. Prescription data were retrieved from the electronic patient records for periods of 1 year before and after the intervention. SETTING: Six health care centres and three continuing medical education groups in Stockholm. SUBJECTS: Forty general practitioners. MAIN OUTCOME MEASURES: Drug prescribing rates and patterns before and after the intervention. RESULTS: In the hypertension field, desired trends in fractional prescribing (favouring diuretics and beta blocking agents) were recorded, with a significant (P < 0.05) effect on prescriptions for agents acting on the renin-angiotensin system, despite a pre-existing prescribing behaviour already much in line with the goals. In the peptic ulcer/dyspepsia field, desired trends were recorded for both types of therapies addressed. The fractional prescribing rates for proton-pump inhibitors decreased from 61.0% to 52.6% in the intervention arm and increased from 68.1% to 76.0% in the control arm (not significant due to low power). The depression group focused on better general attention to the disease and only minor changes were registered. CONCLUSION: Feedback of individual prescribing rates, combined with problem-oriented educational outreach visits, is a promising model for the improvement of prescribing behaviour. Data from the electronic patient record were feasible for feedback on prescribing rates.

Education, Medical, Continuing↗
PubMedDate not supplied

Growth-rate dependent regulation of mRNA stability in Escherichia coli.

The rate of production of bacterial gene products is known to vary with the rate of cell growth, the concentrations of many cellular proteins are altered during times of decreased growth rate. In addition, proteins whose in vivo levels show no significant alterations with changes in cell doubling time must be synthesized at rates that vary in direct proportion to the growth rate of the cell. In certain instances, growth-rate dependent gene regulation has been shown to occur at the transcriptional or translational level. Another potentially important element in the regulation of gene expression is the stability of messenger RNA. We report here the effect of bacterial growth rate on the half lives of four different monocistronic Escherichia coli mRNA species. The stabilities of two of these species, the transcripts of the ompA and cat genes, exhibited a marked dependence on cell growth rate, whereas the half lives of the transcripts of the lpp and bla genes are constant over a broad range of cell doubling times. Our results indicate that E. coli can alter the rate of synthesis of certain proteins by modulating mRNA stability in response to changes in the rate of cell growth.

Bacterial Outer Membrane Proteins↗
PubMedDate not supplied

Application of a high performance liquid chromatography method for screening of aldehyde dehydrogenase isozyme deficiency in hair roots from different ethnic groups.

A sensitive high performance liquid chromatography method has been used to measure aldehyde dehydrogenase (ALDH) activity in hair roots from Caucasian and Japanese subjects. Kinetic studies confirmed previous isoelectric focusing results that hair roots from Caucasians have two forms of ALDH, one low Km form and another high Km form, while hair roots from Japanese individuals who show a flushing reaction after ethanol intake lack, or have low activity of, the low Km form. By taking the ratio of the activities measured at a low (3 microM) and a high (75 microM) concentration of the substrate (3,4-dihydroxyphenylacetaldehyde), a suitable index for ALDH deficiency was obtained. The ratio varied between 1.6 and 3.5 for Caucasians and between 7 and 23 for Japanese flushers, and it was 2.5 for a Japanese nonflusher. The current method allows a more quantitative and qualitative assessment of the ALDH isozyme pattern in hair roots than that obtained with the isoelectric focusing technique.

3,4-Dihydroxyphenylacetic Acid↗
PubMedDate not supplied

Influence of ketamine and pentobarbital on microvascular perfusion in normal skin and skin flaps.

The influence of two anesthetics, ketamine and sodium pentobarbital, on the microvascular perfusion of normal skin and skin flaps was evaluated by the use of a laser Doppler perfusion imager which allows the rapid scanning of tissue perfusion. Arterial skin flaps with a distal random random portion were created on the ears of hairless mice (n = 20), and perfusion was measured in the proximal, central, and distal parts of the flap. No differences in microvascular perfusion throughout the whole experiment were found between the ketamine and the pentobarbital group. In normal skin microvascular perfusion decreased to 83-73% of baseline values after induction of anesthesia. After flap creation, the perfusion was further reduced in the distal and central parts of the flap to 48-43% of baseline values, whereas no significant change was found in the proximal part. Six hours after flap creation, with the animal awake, perfusion had increased again in all parts of the flap, remaining at a constant level during the rest of the experiment. Anesthesia had less effects on microvascular perfusion in skin flaps as observed 1 day after flap creation. Perfusion of the central and distal parts of the flap decreased by 10-16%, whereas, in contrast to normal skin, the proximal part remained unaffected. Our study shows that baseline measurements are required in skin flap models when the microvascular perfusion in skin flaps is analyzed under general anesthesia.

Animals↗
PubMedDate not supplied

Reverse transcriptase polymerase chain reaction on fine needle aspirates for rapid detection of translocations in synovial sarcoma.

OBJECTIVE: To evaluate the utilization of fine needle aspiration (FNA) biopsy to obtain material for reverse-transcriptase polymerase chain reaction (RT-PCR) in the detection of the t(X;18)(p11.2;q11.2) translocation in synovial sarcomas. STUDY DESIGN: We applied RT-PCR to detection of synovial sarcoma fusion gene transcripts on fine needle aspirates. Five clinical samples were first analyzed: one was a tumor previously diagnosed as malignant hemangiopericytoma, one was a poorly defined tumor, and three were suspected synovial sarcomas. FNA material was transferred directly to the RT-PCR reaction tube without RNA extraction. RESULTS: The t(X;18) translocation could be detected on the limited amount of material that FNA provides. In each of the cases studied the representivity of the tumor samples was confirmed microscopically. CONCLUSION: Our protocol permits analysis directly on representative samples without extraction of RNA. The results imply that RT-PCR offers reliable detection of sarcoma fusion gene transcripts on fine needle aspirates. The procedure, apart from being applicable to outpatients, is rapid and sensitive.

Adolescent↗
PubMedDate not supplied

Clinical and biochemical effects of spironolactone administered once daily in primary hypertension. Multicenter Sweden study.

In a prospective, double-blind, intraindividual, cross-over, placebo-controlled multicenter study, clinical and biochemical effects of once daily postprandial dose regimens of 50, 100, and 200 mg spironolactone were investigated in 45 outpatients with primary hypertension, WHO (World Health Organization) Stage I-II. Each of the three active therapy periods, which were randomly allocated to patients, were of 2 months' duration, with intervening placebo periods, Clinical and biochemical parameters, including furosemide-stimulated plasma renin activity (PRA), were recorded at regular intervals. All three spironolactone doses resulted in statistically significant blood pressure (BP) reductions independent of initial pretreatment levels and yielded satisfactory BP control in more than half of the patients. The 200 mg daily dose of spironolactone was found to be more effective than 50 but not 100 mg. When, correlating blood pressure response (delta MAP) to PRA, the profiling for positive spironolactone responders was characterized by high age and low PRA, irrespective of sex. Spironolactone therapy resulted in decreased serum sodium and magnesium values; potassium, creatinine, urate, and triglyceride levels were increased. However, all treatment values were within normal ranges. Side effects were infrequent and mainly of endocrine nature.

Administration, Oral↗
PubMedDate not supplied

Contemporary issues in mast cell biology.

Mast cells are the principal initial effector cells in the modulation of allergic inflammation. They are now known to arise from CD34+ pluripotential stem cells, circulate through the blood as CD34+, Fc epsilon RI-, Kit+ committed but undifferentiated cells, and migrate into tissues where they mature in the presence of Kit-ligand (stem cell factor) and other locally produced cytokines. Mast cells undergo programmed cell death (apoptosis) when stem cell factor is not available. Mast cells adhere to specific connective tissue components such as fibronectin and laminin. This interaction localizes mast cells to specific sites while altering their biologic responsiveness. Mast cells, when activated through Fc epsilon RI, release and generate a wide variety of cytokines including IL-4 and IL-5. This information provides new insights on how allergic reactions may be modified by developing strategies to effect mast cell viability, survival and localization; and the production of inflammatory mediators.

Animals↗
PubMedDate not supplied

Long-term results after stapedectomy.

296 cases of stapedectomy accomplished by vein grafting plus polyethylene tubing with a primary (one-year) result of a greater than 10 dB improvement in Air Conduction (AC) threshold in speech frequencies have been tested with pure tone audiometry 1-12 years postoperatively. The AC threshold of the operated ear increased by about 1 dB per year for both low and high frequencies. In the high frequency range this increment can be ascribed to normal aging; in the low range the reason is probably progressive conductive loss. There is no evidence to support the assumption that the operation impairs the sensorineural function of the operated ear. The AC threshold of the unoperated ear also increased--by more than that of the operated ear, for both low and high frequencies. In the low range this was ascribed to progressive stapes fixation; in the high range to stapes fixation plus normal aging. The progression for the non-operated ear is relatively slow, about 2 dB per year.

Adult↗
PubMedDate not supplied

The connection between terms used in medical records and coding system: a study on Swedish primary health care data.

Implementation of problem lists and their relation to standardized coding systems have been approached and analysed in different ways. Most evaluations concern quantitative aspects such as content coverage in a specific domain. In order to reveal the qualitative aspects of diagnostic coding, medical record texts from primary health care encounters were compared with terms from a coding system that was used for describing them statistically. The records were coded by six general practitioners, and in some cases, an applied diagnostic term was found within the text, while other record text-coding system relationships were categorized as synonyms, alternative terms, and interpretations. Thus, the categories roughly corresponded to a measure of semantic distance between the terms in the record text and the rubrics of the coding system, and there was a correlation between semantic distance and inter-rater agreement. The subcategories of this scheme corresponded fairly well to recently published desiderata for clinical terminology servers, including functionality such as word normalization and spelling correction. However, not all problems could have been automatically coded by means of lexical methods, which can be partly explained by the fact that diagnostic coding also relies on clinical knowledge. In addition, proper automation relies on context representation within the records.

Abstracting and Indexing↗
PubMedDate not supplied

Evaluation of a new X-ray fluorescent analysis technique for the creation of a Nordic hair database: elemental distributions within the root and the virgin segment of hair fibers.

A new, non-destructive X-ray fluorescence technique for quantitative estimation of elemental content in biological tissues has been developed. Technical and instrumental characteristics of the ITRAX X-ray spectrometer have been evaluated in relation to the properties of biological samples, i.e., human hair fibers. Thus, attenuation variations of the fluorescent X-rays in the hair bulk mass were demonstrated by analysis of sulfur, calcium, and zinc in a virgin part near the root of one hair fiber with elliptical cross section. By rotation of the hair fiber and successive analyses made of the same part of the hair fiber, the results showed that concentrations of elements varied as functions of the diameter of the analyzed hair volume. Other sources of errors are also discussed. The ITRAX instrument allows for precise, fast, non-destructive, simultaneous, quantitative recording of the detected elements and trace elements down to levels of 1 ppm (microg/g). It was used for assessment of normal values of physiologically important elements present in hair in a cohort of normal, healthy Swedish, Caucasian individuals. The database constructed from data retrieved from a conceivably homogeneous ethnic set of individuals represents, to our knowledge, the first of its kind.

Evaluation Studies as Topic↗
PubMedDate not supplied

Characteristics of the autonomic response in the visually evoked reflex in humans.

This study aimed (a) to investigate the effect of the visuogenic reflex on the skin microcirculation of the hand and foot, and (b) to compare it to that evoked by thermal stimuli. Fifteen volunteers took part in this study. The laser Doppler technique was used for measuring blood flow (BF). The results showed that a flash of light with a duration of 300 ms caused a significant decrease in BF (mean 38.4 +/- 14.8%) in 10 out of 15 subjects in the hand but not in the foot. The latency was 5.05 +/- 0.7 s and the duration 7.2 +/- 1.8 s. The reaction did not show a significant change when a longer stimulus of 14 s was applied. Repetitive stimuli evoked habituation (p < 0.01). There is significant difference (p < 0.01) between autonomic responses to visuogenic and to calorically evoked reflexes.

Adolescent↗