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Biomedical subjects

K Axelsson

Publications and source records attributed to K Axelsson.

At least 55 records · Page 3Linked to original sources
PubMed1990

Influence of intravenous local anaesthetics upon quadriceps muscle function.

This study was undertaken to assess the effects of intravenous administration of mepivacaine and etidocaine on muscle function. Seven male volunteers were given mepivacaine (5 mg/kg) and etidocaine (50 mg) intravenously, on separate occasions. A reference group of 11 male volunteers received 0.9% saline solution intravenously. Muscle function was tested by measurements of isometric muscle force of knee extension and by quantitative electromyographic (EMG) recordings from the quadriceps muscle during knee extension at different degrees of isometric muscle force. At the end of the mepivacaine and etidocaine infusions, the mean venous plasma concentrations of the two anaesthetic agents were 2.9 and 1.2 micrograms/ml, respectively. The muscle strength remained unchanged during infusion of the two local anaesthetics. Mepivacaine had a minor effect on the mean rectified EMG amplitudes at the end of the infusion at maximal voluntary muscle contraction, but no such effect was observed at submaximal knee extension force. However, at the plasma concentrations mentioned above, the clinical influence of intravenous infusion of the local anaesthetics on muscle function was negligible.

Adult↗
PubMed1990

Separation and identification of growth hormone variants with high performance liquid chromatography techniques.

Liquid chromatography techniques were used to separate and identify human growth hormone (hGH) variants. N-terminal modified forms, such as des-Phe (2-191) and methionyl-hGH (met-1-191), were separated from recombinant human growth hormone (rhGH (1-191] by hydrophobic interaction chromatography (HIC). A proteolytically cleaved ('clip') form of rhGH which has a break in the polypeptide chain between Thr(142) and Tyr(143), also proved to be separable from rhGH by HIC. In addition, a mutated form of rhGH with only two amino acid substitutions, Glu(65) to Val(65) and Glu(66) to Lys(66), on a random coil domain of the molecule, was separated from rhGH by HIC, indicating that these substitutions altered the hydrophobicity of the molecule. Treatment of rhGH with hydrogen peroxide led to sulphoxide formation in two methionine residues Met(14) and Met(125); it was not possible to oxidize Met(170). The oxidized forms of rhGH were readily separated from rhGH(1-191) by reversed-phase chromatography. Analyses of rhGH batches showed very low levels (less than 0.3%) of oxidized rhGH, indicating that rhGH is highly resistant to oxidative reactions. Deamidations were induced in rhGH by heat treatment. The primary deamidation site was found to be Asn(149). Monodesamido rhGH and didesamido rhGH were efficiently separated from rhGH(1-191) by anion-exchange chromatography.

Chromatography, High Pressure Liquid↗
PubMed1989

Isolation and characterization of a glycosylated form of human insulin-like growth factor I produced in Saccharomyces cerevisiae.

Expression and secretion of human insulin-like growth factor-I (IGF-I) in Saccharomyces cerevisiae was achieved by linking an actin (ACT) promoter to an MF alpha 1 prepro leader peptide/IGF-I gene fusion. Purified human IGF-I from yeast culture media was found to contain, in addition to the native form, also a glycosylated variant. Structural studies showed that both IGF-I forms were processed identically, resulting in 70-amino-acid long polypeptides, with intact N-terminal and C-terminal residues of glycine and alanine, respectively. The glycosylation site was determined to threonine-29 (Thr29), by 1H NMR spectroscopy and protein sequence analysis of an isolated tryptic peptide(22-36). No other glycosylation sites were found. Only mannose was detected in the sugar analysis, with an estimated content of 4.5% w/w corresponding to 2 mannose residues per molecule of IGF-I. The carbohydrate structure, determined by 1H and 13C NMR spectroscopy, was found to be alpha-D-Manp(1----2)alpha-D-Manp(1----3)Thr corresponding to an O-linked glycoprotein structure. No other post-translational modifications could be identified in the glycosylated IGF-I form. Furthermore, this form was highly active, comparable to native IGF-I, exhibiting a specific activity of 20,500 units/mg, as determined by a radio-receptor assay.

Actins↗
PubMed1989

Aberrant eating behavior in elderly parkinsonian patients with and without dementia: analysis of video-recorded meals.

Aberrant eating behavior among 14 elderly, non-demented and 10 demented patients with Parkinson's disease was studied by means of video-recordings. The findings revealed problems in handling food on the plate, transporting food into the mouth, manipulating food in the mouth, and swallowing. Interpretations were performed based on impairments of autonomic processes, perception, cognition, emotion, and motor performance that occur in the disease.

Aged↗
PubMed1989

Motor blockade and EMG recordings in epidural anaesthesia. A comparison between mepivacaine 2%, bupivacaine 0.5% and etidocaine 1.5%.

In a double-blind study young volunteers randomly received 20 ml of mepivacaine 2%, bupivacaine 0.5% or etidocaine 1.5% epidurally, all solutions with adrenaline. The mean cephalad spread of pin-prick analgesia was equal (T10) in the groups, but the duration was longest for bupivacaine and etidocaine. The motor blockade of the rectus abdominis muscles was assessed quantitatively by rectified integrated electromyographic recordings (RIEMG) and as number of turns in EMG recordings [changes in the direction (rise/fall) of the EMG; TURNS] from three different segmental levels, T7, T9 and T11. The motor blockade of the quadriceps muscles was estimated by EMG recordings simultaneously with muscle force measurements at maximal isometric knee extension. Motor blockade was also evaluated by the Bromage scale. There was good correlation (correlation coefficient 0.91) between RIEMG values and muscle force in knee extension during epidural anaesthesia. TURNS showed a non-linear relationship to isometric force during epidural anaesthesia and added no further information. At the lower parts of the abdomen (T11), etidocaine gave more profound and longer motor blockade than mepivacaine. For quadriceps muscle function, motor blockade was almost complete with all three local anaesthetics; the duration of maximum motor blockade was short (45-60 min) for mepivacaine, but about 5 h with etidocaine. At the time when the Bromage scale indicated complete regression of motor blockade, the muscle force of knee extension was only 30% and the quadriceps RIEMG 35% of control values and 1-3 h remained until the time of mobilization.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetanilides↗
PubMed1989

Motor and sensory blockade after epidural injection of mepivacaine, bupivacaine, and etidocaine--a double-blind study.

In a double-blind study of epidural anesthesia, 30 young volunteers were given either 2% mepivacaine (400 mg), 0.5% bupivacaine (100 mg), or 1.5% etidocaine (300 mg), all solutions containing epinephrine (1:200,000). The spread of analgesia was equal in the groups, whereas the longest duration was noted in the etidocaine and bupivacaine groups. With use of a method for determining muscle force, motor blockade during anesthesia was recorded quantitatively for hip flexion, knee extension, and plantar flexion of the big toe. Onset of motor blockade was significantly more rapid with etidocaine than with bupivacaine and mepivacaine. All subjects given etidocaine developed complete motor blockade, but with the other local anesthetics 5%-33% of the initial muscle force remained. The least motor blockade was found in the L5-S2 segment (plantar flexion of the big toe). The duration of maximal motor blockade varied between 60 min (mepivacaine) and 360 min (etidocaine). With each of the three local anesthetics, motor function returned simultaneously in the three muscle groups tested. Complete restoration of muscle function occurred significantly later for etidocaine (600 min) than for bupivacaine (360 min) and mepivacaine (180 min). With etidocaine, the motor blockade outlasted the sensory blockade by 150 min. The Bromage scale corresponded to the motor blockade only during the first half of the regression phase. Not until 1-3 h after attainment of Bromage grade 0 was the muscle force of all movements restored (90% of control values).

Acetanilides↗
PubMed1989

Eating problems and nutritional status during hospital stay of patients with severe stroke.

Eating problems and nutritional status were studied in a consecutive series of patients who had had strokes. From this cohort, 32 subjects (mean age 73 years) with a hospital stay of 21 days or more are described. Eating problems were identified by direct participant observations of the patients' eating behavior, interviews on admission, inspections of the mouth, and discussions with the patients. Nutritional status was assessed by weight, triceps skinfold thickness (TSF), arm muscular circumference (AMC), plasma albumin, serum transferrin, and plasma prealbumin on admission and then weekly. Eating problems were identified in 27 patients. In a general linear hypothesis program, poor nutritional status 3 weeks after admission was found to be associated with (in decreasing order) low self-care performance, poor nutritional status on admission, male sex, intravenous energy-containing fluids, advanced age, paresis of the right arm, and eating problems. Factors other than eating problems seem to be important for undernutrition in patients with strokes during hospital stay.

Cerebrovascular Disorders↗
PubMed1988

Nutritional status in patients with acute stroke.

By measuring three anthropometric variables (relative weight, triceps skinfold thickness and arm muscle circumference) and three circulating proteins (albumin, transferrin and prealbumin), nutritional status was assessed in 100 consecutive patients with acute stroke. On admission to hospital, two or more indicators showed subnormal values for 16%; this was associated with the female sex, high age and a history of atrial fibrillation. At discharge, 22% had two or more subnormal indicators. Poor nutritional status during the hospital stay appeared to be related to infections, the male sex, the intake of cardiovascular drugs and high age. Fewer of the patients with two or more subnormal nutritional indicators were able to return home than of the patients with none or one subnormal nutritional indicator. We conclude that undernutrition is not uncommon at the onset of stroke and that certain risk groups for the development of undernutrition during hospital stay can be identified.

Acute Disease↗
PubMed1988

Venous blood concentration of lidocaine after nasopharyngeal application of 2% lidocaine gel.

In 34 subjects undergoing topical anaesthesia with lidocaine gel (2% xylocaine gel), the concentrations of lidocaine base were measured in repeated venous blood samples. Twenty-three patients (Group I) were given 20 ml of 2% lidocaine gel (400 mg of lidocaine) and six subjects (Group II) 40 ml of 2% lidocaine gel (800 mg of lidocaine) nasopharyngeally, the gel reaching the pharynx being swallowed. Five minutes after administration of the gel, a gastric tube was introduced via the nasal cavity. In six patients (Group III), the bladder was catheterised in addition to insertion of a gastric tube. Before the catheter was introduced, these patients were given lidocaine gel nasopharyngeally (400 mg) and endourethrally (400 mg). After the introduction of the gastric tube, all subjects (except four volunteers in Group II) were given general anaesthesia. Before intubation, the patients in Group III also received lidocaine spray laryngotracheally (50 mg; 10% xylocaine spray). The initial absorption of lidocaine was rapid, although the blood concentrations were low. The mean peak concentrations (Cmax) of lidocaine in the three groups were 0.57, 1.39 and 0.73 micrograms/ml, respectively. The blood concentration in Group II was significantly higher than those in Groups I and III. The mean length of time between the nasopharyngeal application of lidocaine gel and the time when Cmax was reached (tpeak) was the same in all three groups (60-70 min).(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗
PubMed1988

Evaluation of motor blockade by isometric force measurement and electromyographic recording during epidural anaesthesia--a methodological study.

Methods for assessing motor blockade by means of isometric force measurements and surface electromyographic (EMG) recordings in the lower extremities and abdominal wall were evaluated in 30 volunteers. The coefficients of variation were 10% for force measurements and 14% and 20% for average rectified EMG (RIEMG) recordings over the quadriceps muscle and abdominal muscles, respectively, and 8% overall for TURNS (the number of changes in the sign of the direction of the EMG signal). Seven of the 30 volunteers received epidural anaesthesia with 20 ml of mepivacaine 2% with adrenaline. The mean maximal cephalad analgesic level was T9. At that abdominal segment, RIEMG showed a reduction of 50% and TURNS of 20%. Isometric force and RIEMG recorded simultaneously in the quadriceps muscles during epidural anaesthesia displayed a linear relationship with a correlation coefficient of 0.91. TURNS was insensitive to force variations above 60% of maximum voluntary contraction. During the regression phase, 90% of both the initial force and RIEMG value was noted 180 min after the epidural injection. It is concluded that recording of RIEMG is a good method for quantitative assessment of motor blockade during epidural anaesthesia.

Abdominal Muscles↗
PubMed1988

In vivo production of thromboxane and prostacyclin in patients following total hip arthroplasty.

The in vivo production of thromboxane and prostacyclin was studied by measurements of their major urinary metabolites in eight patients undergoing total hip arthroplasty. Specific methods based on gas chromatography-mass spectrometry were used to measure the urinary excretion of 2,3-dinor-TxB2 and 2,3-dinor-6-keto-PGF1 alpha. The excretion of these metabolites increased about 10-fold during the intra and immediate postoperative period and 4 days after surgery was still higher than during the preoperative period. The increased thromboxane formation reflects probable activation of platelets whereas the increased prostacyclin could be part of a vascular defense against induced thrombotic activity. These findings may have pathophysiological implications.

6-Ketoprostaglandin F1 alpha↗
PubMed1987

Stress-behavior interactions in hamster tumor growth.

The aim of this study was to investigate the effects of a mechanical stressor and individual behavior differences (separately and in combination) on tumor development in the female Syrian hamster. Studies by other investigators have documented the tumor-enhancing effects of such mechanical stressors as rotational stress. Previous studies by our group found that both size of tumor and time to tumor detection were significantly related to a dimension we call "activation." Eighty 100-day old female Syrian hamsters were placed in circular plexiglas environments in groups of 10. Nineteen days after introduction to the cages, a stress condition was imposed on half the animals (four cages). This consisted of shaking each cage of animals three times a week for three 10-minute intervals. Each group's behavior was videotaped in multiple samples to document pre- and poststress behaviors. Twelve days after the stress condition was initiated, each animal was injected subcutaneously midback with one melanoma tumor fraction. Animals were palpated every three days to determine time to detection of tumor. The videotaped behavior samples were coded for behaviors associated with "activation," inactivity, and interaction. Factor analysis resulted in basically the same first factor of activation found in our previous studies. Hamsters in the nonstressed groups had a significantly longer time to tumor development than those in the stressed groups (22.5 days vs. 12.6 days, p less than 0.005). While no prestress behaviors were associated significantly with time to tumor detection, the poststress activation factor was significantly correlated with longer time to tumor development in the stressed group (r = .61, p less than 0.0001). These results suggest that while the stress condition is more powerful than prestress individual behaviors in affecting the outcome variable, stress appears to interact with the individual behaviors related to "activation" to mitigate the negative effects of stress on tumor growth.

Animals↗
PubMed1986

Morning care of patients with Alzheimer-type dementia. A theoretical model based on direct observations.

Five hospitalized patients in different stages of Alzheimer-type dementia were monitored by unstructured, direct observations during morning care. Orem's model of nursing as a compensation for the patient's lack of self-care capabilities was used as a frame of reference for an analysis of the behaviours of patients and nurses during morning care. A 12-step classification system was developed to be used as a guide to understand and determine abilities essential for performance of morning care for demented patients. The quantitative assessment showed that none of the patients was able to manage morning care independently, but there was a wide variation in their highest level of performance.

Activities of Daily Living↗