A peptide resembling COOH-terminal tetrapeptide amide of gastrin from a new gastrointestinal endocrine cell type.
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Amino Acid Sequence↗
Biomedical subjects
L Larsson
Publications and source records attributed to L Larsson.
Control of the pars intermedia of the lizard, Anolis carolinensis. IV. Transection of the pituitary stalk. Effects on colour change and histology.
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Adaptation, Physiological↗
Serum calcium ion activity. Some aspects on methodological differences and intraindividual variation.
Sera were analyzed for calcium ion activity on the Orion 99-20 and SS-20 systems. Samples from 84 healthy subjects were analyzed on both systems and, because of a change of electrode composition, 74 of them were reanalyzed after this change. Additional 89 were analyzed on only SS-20. The distribution of serum calcium ion activity was close to Gaussian. The difference between the 99-20 and SS-20 readings was 0.048+/-0.017 mmol/liter (range -0.01 to 0.08) before the electrode change and -0.085+/-0.027 mmol/liter (range -0.14 to 0.02) after. The reference ranges were 1.02--1.23 mmol/liter for 99-20 and 0.93--1.20 mmol/liter for SS-20 before the electrode change. The following characteristics may contribute to differences in the readings: higher temperature, higher flow rate, new calcium and reference electrodes, new liquid junction construction and a new pumping procedure. For 74 subjects the determination of serum calcium ion activity (99-20 system) was performed with a five year interval and the difference between the first and second measurements was -0.0046+/-0.0168 mmol/liter (mean +/-SD), ranging from -0.04 to 0.03 mmol/liter. This corresponded to an intraindividual variation of 1.5%. The corresponding variations for serum total calcium and corrected calcium were 4.8% and 3.3% respectively.
Adolescent↗
Gas chromatographic characterization of porcine and human strains belonging to the Mycobacterium avium-intracellulare complex.
Trifluoroacetylated whole-cell methanolysates of 23 strains designated as belonging to the Mycobacterium avium-intracellulare complex by biochemical, growth chromogenicity and chicken pathogenicity tests, were analysed by gas chromatography. Twenty of the strains were isolated from pigs and the remainder from human beings. Serological typing showed that 13 of the porcine strains, but none of the human strains, belonged to M. avium. The remaining strains, except one which showed autoagglutination, did not react with antisera to M. avium (serotypes 1-3), thus suggesting that they belonged to M. intracellulare. Five different, highly reproducible chromatographic patterns, the main peaks of which were considered as representing bacterial carbohydrates and fatty acids, could be distinguished by visual examination and by cluster analysis. The chromatographic results could not be correlated with those obtained from serotyping of the strains studied. Mycobacteria recovered from different organs of one and the same pig gave virtually identical chromatograms. The strains isolated from three human beings had a chromatographic pattern which was identical with one of those produced by the porcine strains. The present investigation indicates that the gas chromatographic analytic technique used differentiates bacteria within the M. avium-intracellulare complex, without assigning the organisms to species.
Animals↗
Correlation between fluid reabsorption and proximal tubule ultrastructure during development of the rat kidney.
Parallel functional and ultrastructural studies were performed in maturing rats in order to elucidate factors determining the development of proximal tubular fluid reabsorption. Three groups of hydropenic animals, which were 22 to 24, 28 to 32 and 40 to 45 days old, were studied. Nephron function was evaluated at the single nephron level by micropuncture technique. The ultrastructure of the developing proximal tubules was analysed by morphometric techniques following fixation of single nephrons. Kidney weight, proximal convoluted tubule length and diameter increased during postnatal development. SNGFR increased from 2.98 to 8.57 and to 20.5 nl/min in respective group of rats whereas proximal tubular fluid reabsorption Jv (a) increased from 0.15 to 0.22 and 0.34 micron3.micron-2.s-1. Parallel to the functional development the relative area of lateral and basal cell membrane increased, resulting in a constant relationship between net fluid reabsorption and the lateral and basal cell membrane area during the fourth postnatal week and then only a slight increase in this relation during the further development. The results suggest that net fluid transport during hydropenia is determined by the amount of available lateral and basal cell membranes where the transporting enzyme for sodium is located.
Age Factors↗
Skeletal muscle metabolism, morphology and function in sedentary smokers and nonsmokers.
Smokers and nonsmokers of a homogeneous population of sedentary men have been compared with respect to skeletal muscle (vastus lateralis) morphological, metabolic and functional characteristics. The percentage type I fibres was lower and that of type IIB fibres higher in the smokers. Fibre areas were almost equal in the two groups. Muscle oxidative capacity was lowered in the smokers, as judged from decreased mitochondrial enzyme activities and a lowered fibrillar space mitochondrial volume fraction. Isometric and dynamic strengths were lower in the smokers, except at the highest velocity of movement studied. Dynamic strengths expressed in relation to isometric strength were similar at all velocities except the highest, where the smokers were relatively stronger. Muscular endurance, measured in short-term isometric and dynamic tests, was not different. It is suggested that the lowered muscle oxidative capacity and strength in the smokers may be partly a consequence of the different fibre type distribution. A possibly lower physical activity level, and tobacco smoke constituents (e.g. carbon monoxide) may also be instrumental. It is not clear whether the different fibre type distribution in the smokers is an effect of smoking per se, or if background factors are responsible.
Adult↗
Muscle strength and speed of movement in relation to age and muscle morphology.
Maximum values for isometric strength, dynamic strength, and speed of movement (MEV) in the quadriceps muscle were measured in 114 male subjects who were between 11 and 70 yr. Biopsy samples were taken from the quadriceps muscle in 51 of the subjects (22-65 yr. old). Isometric and dynamic strength increased up to the third decade, remained almost constant to the fifth decade, and then decreased with increasing age. However, no measurable external atrophy of the quadriceps muscle, explaining the decline in strength, could be seen in old age. Histochemical changes in the muscle tissue such as decreased proportion of type II fibers and a selective atrophy of type II fibers, were seen with increasing age. The strength decline in old age was also observed to correlate significantly with the type II fiber area. Multiple regression analyses indicated, however, that mechanisms other than the type II fiber atrophy might be responsible for the decline in strength performance during aging. The implications of these findings are discussed.
Adolescent↗
Demonstration of tuberculostearic acid in sputum from patients with pulmonary tuberculosis by selected ion monitoring.
Selected ion monitoring was used to detect tuberculostearic acid (10-methyloctadecanoic acid) in sputum from patients with pulmonary tuberculosis. The specimens were autoclaved, lyophilized, extracted, and methanolysed before being subjected to thin-layer chromatography and injected into the gas chromatograph/mass spectrometer. Tuberculostearic acid could be detected in five of six tuberculous sputum specimens containing acid-fast rods detectable by light microscopy of Ziehl-Neelsen stained smears. After the sputum specimens had been cultured for five days on Löwenstein-Jensen medium, when still no colonies could be observed visually, the presence of tuberculostearic acid was demonstrated in all six cases of tuberculosis. In corresponding analyses of sputum from eight patients with non-tuberculous pneumonia, tuberculostearic acid was not found. This fatty acid, the presence of which was also demonstrated in cultures of various mycobacterial and nocardial species, is characteristic of organisms of the order Actinomycetales. The demonstration of tuberculostearic acid in sputum specimens may constitute a rapid and sensitive way of diagnosing pulmonary tuberculosis.
Chromatography, Gas↗
Effect of fasting and lactovegetarian diet on rheumatoid arthritis.
16 patients with classical rheumatoid arthritis (RA) selected at random underwent fasting for 7--10 days, followed by a 9-week period on a lactovegetarian diet. 10 RA patients acted as controls, taking normal diet. Pain, stiffness, medication, and clinical and biochemical findings were recorded before fasting, on the first day after the conclusion of the fasting period, and at the end of the lactovegetarian period. After fasting, 5 of 15 patients showed objective signs of improvement, compared with only one of the controls. The fasting patients showed reduced pain, stiffness, consumption of analgetics, several clinical variables, and serum concentration of orosomucoid. At the conclusion of the lactovegetarian diet period only one Diet patient showed objective improvement. No differences were found between the Diet patients and the controls concerning symptoms, drug consumption, or clinical and biochemical variables. We conclude that fasting may produce subjective and objective improvements in RA, though of short duration, but the findings of this investigation do not indicate that lactovegetarian diet has any beneficial effects.
Adult↗
Calcium infusion in suspected hyperparathyroidism: changes in parathyroid hormone concentration related to histopathological findings.
Changes in parathormone, total and free calcium concentrations in serum were studied in 27 patients with suspected hyperparathyroidism (25 with normocalcemia judged from CaT). Six patients were classified as normals. In 21 patients neck explorations was performed. Patients with definite pathology in the parathyroid glands had higher parathormone, total and free calcium levels than patients with borderline pathology or normal glands. The mean parathormone concentration fell significantly during calcium infusion in patients with histologically normal parathyroid glands. In patients with definitely pathological glands the parathormone concentration remained unchanged during the calcium infusion.
Adenoma↗
Biochemical and morphological findings in patients with increased serum ionized calcium.
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Adenoma↗
Peroperative estimation of the size of the thyroid remnant.
A new method for estimation of the size of the remaining tissue after thyroid resection is described. The method has been tested on cadavers and during lobectomy in a series of patients. It is shown that intraoperative quantification of the thyroid remnant can be performed mostly with +/- 0.5 g for an individual thyroid lobe with a coefficient of variation of +/- 7.6%. In patients with toxic nodular goiter and calcifications, however, the error might be larger due to the varying homogeneity of the thyroid tissue. In 73 patients with negative antibody titers operated on for hyperthyroidism it was shown that the size of the thyroid remnant was negatively correlated to the delta TSH, determined 6 weeks after the operation.
Cadaver↗
[Grouping patients with kidney calculi disease].
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Humans↗
Control of the pars intermedia of the lizard, Anolis carolinensis. I. Ultrastructure of the intact neural lobe.
The ultrastructure of the neural lobe of the lizard, Anolis carolinensis, was studied after fixation in a threefold aldehyde solution. The neural lobe appeared as narrow vertical diverticula separated from one another and from the pars intermedia by a continuous vascular septum. No nerves passed through this septum. The ependymal, fibrous and external layers were readily recognized. Peptidergic fibres were the main component of the fibrous layer. The peptidergic endings were in intimate contact with the ependymal cells, suggesting that the ependyma mediates the release of neural lobe peptides. The external layer contained ependymal end-feet and numerous aminergic terminals, ending directly on the perivascular basal lamina and/or on the ependymal end-feet. The functional aspects are discussed in terms of intermediate lobe control. The findings suggest that aminergic substances take part in the control of the intermedia, but do not exclude the involvement of peptide hormones.
Animals↗
Analysis of amines and other bacterial products by head-space gas chromatography.
A gas chromatographic (GC) head-space technique is presented, which is suitable for the analysis of volatile products in bacterial broth cultures. This is exemplified by studies on Clostridium septicum, Klebsiella pneumoniae and Proteus mirabilis. The media were acidified or made alkaline and after heating, samples of the gas phase above the media were directly injected into the gas chromatograph. A gas chromatograph equipped with dual columns and flame ionization detectors was used, employing Porapak Q and Chromosorb 103 as stationary phases. Analysis of acidified media, using Porapak Q, gave chromatograms representing acidic and neutral volatile products, while when analysing samples made alkaline, using Chromosorb 103, alkaline and neutral compounds could be detected. Interest was particularly concentrated on the analysis of bacterial amines. P. mirabilis was found to produce isobutylamine and isopentylamine, which were identified by mass spectrometry and GC retention times C. septicum produced ethylamine. The GC head-space technique described constitutes a means for rapid identification of microorganisms. It is adaptable for use on a routine basis in the clinical microbiological laboratory.
Acids↗
Histochemical and biochemical changes in human skeletal muscle with age in sedentary males, age 22--65 years.
Biopsies for histochemical and biochemical analyses were taken from the vastus lateralis muscle of 55 untrained, healthy male subjects from 22 to 65 years of age. Fibre type distribution changed towards a decrease in the percentage of type II fibres, both in type IIA and type IIB fibres, whereas type IIB/IIA fibre ratio and type IIC percentage did not change with increasing age. It was found that the type IIB/IIA fibre ratio was inversely related to type I fibres, i.e. subjects rich in type I fibres had a relatively smaller proportion of type IIB fibres. Fibre area determinations revealed a selective decrease in type II fibre area. Consequently, the type II/I fibre area ratio and relative type II fibre area decreased. No changes in the specific activities of Mg2+ stimulated ATPase and myokinase were observed, while the activity of lactate dehydrogenase (LDH) was higher in the youngest groups than in the oldest. LDH isozyme pattern shifted towards a decrease in percentage distribution of the muscle specific isozymes and a corresponding decrease in muscle specific activity while the activity of the heart specific isozymes did not change.
Adenosine Triphosphatases↗
Isometric and dynamic endurance as a function of age and skeletal muscle characteristics.
The aim of the study was to investigate the influence of age on endurance of human skeletal muscle. An attempt was made to correlate muscular performance at various ages with some morphological and enzymatic characteristics of the muscle. Fifty healthy men, 22-65 years of age, with low daily physical activity (clerks) volunteered for the study. Isometric and dynamic endurance were determined under standardized conditions and measured in relation to maximum strength, thereby correcting for individual as well as age differences in maximum strength. Biopsies taken from the quadriceps muscle were used for muscle fibre classification, fibre area determinations, and measurements of some enzyme activities (Mg2+ stimulated ATPase, myokinase (MK), lactate dehydrogenase (LDH),LDH isozymes). Maximum isometric and dynamic strength decreased in the older groups while no significant change was seen in isometric or dynamic endurance. Significant correlations were observed between endurance and fibre type distribution, fibre areas, and LDH isozyme activities.
Adenosine Triphosphatases↗
Skeletal muscle metabolism and ultrastructure in relation to age in sedentary men.
In order to find out if there are age-related changes in human skeletal muscle metabolism or ultrastructure, biopsy material from 56 sedentary men aged 22-65 years was studied by means of enzyme activity determinations, histochemistry and quantitative electron microscopy. For comparison, a younger (16-18 years) and an older (66-76 years) group were included. These subjects were relatively more active. There was an increase in percentage of slow twitch fibres with age. Mitochondrial volume fraction decreased with age, primarily due to diminished mean mitochondrial volume. In spite of this, no overall decrease in the activities of five enzymes, representative of the major pathways in energy metabolism, was observed. Thus, increased amounts of enzymes per unit mitochondrial volume are implicated. Lipofuscin was more frequently found in the older groups. Correlations were present between fibre type distribution and oxidative enzymes, as well as between different enzymes. It was concluded, that the decrease in maximal oxygen uptake and muscular strength in aging humans probably may not be explained in terms of a deteriorating skeletal muscle energy metabolism.
Adolescent↗