Effect of diet on muscle glycogen and blood glucose utilization during a short-term exercise in man

7 subjects were studied at rest and during a 6 min submaximal exercise (65% of VO2 max) on two occasions, the first preceded by a fat rich diet and the second by a carbohydrate rich diet. Oxygen uptake and respiratory exchange ratio (R) were measured at rest and heart rate both at rest and during exercise. Arterial-femoral venous differences for oxygen, glucose, lactate and beta-hydroxybutyrate and arterial concentrations of free fatty acids were measured at rest and during exercise. Changes in muscle glycogen (in 6 subjects) and lactate concentration were determined by biopsies from m. quadriceps femoris taken before and immediately after exercise. Muscle glycogen decreased less during exercise after the fat than after the carbohydrate diet in 5 of the 6 subjects, whereas blood glucose extraction by the exercising legs did not change with diet. Muscle lactate accumulation and release were smaller after the fat diet. In conclusion, the muscle glycogen utilization during a short-term exercise appeared to be lower after the fat than after the carbohydrate diet, but not the concomitant blood glucose extraction. These differences between diets were similar to those observed after a more prolonged work at the same load.

Viruses of mycoplasmas and spiroplasmas

Acholeplasmas, mycoplasmas and spiroplasmas of the class Mollicutes have been shown to carry DNA viruses. Morphologically they occur as rods, polyhedrons with short or long tails and as enveloped spheres. These latter resemble enveloped nonlytic animal viruses and are now placed in the new family of bacterial viruses the Plasmaviridae. Viruses of mycoplasmas and spiroplasmas present a suitable experimental model for studies of the virus-cell interactions.

Effect of diet on the utilization of blood-borne and intramuscular substrates during exercise in man

20 subjects were studied at rest and during a 25 min submaximal exercise (65% of VO2 max) on two occasions, the first preceded by a fat rich diet and the second by a carbohydrate rich diet. Oxygen uptake, respiratory exchange ratio (R) and arterial-femoral venous differences for glucose, lactate, beta-hydroxybutyrate and FFA (based on the fractional extraction of 3H-palmitate) were measured at rest and during exercise. Changes in intramuscular glycogen, triglyceride and lactate concentrations were determined in muscle biopsies taken before and immediately after exercise form m. quadriceps femoris. R was lower after the fat than after the carbohydrate diet and simultaneously the FFA extraction by the exercising leg was higher. The muscle triglycerides did not changes significantly during exercise after either diet. The glucose extraction was insignificantly greater after the fat diet. The glycogen reduction was numerically smaller after the fat diet, but the difference was uncertain and difficult to evaluate due to a large variation after the carbohydrate diet. However, muscle lactate accumulation and release by the exercising leg was smaller after the fat diet, indicating a slower rate of muscle glycogenolysis. It is concluded that a fat rich diet increases the relative contribution of fat to the oxidative metabolism, that this increase, to a great extent, is covered by plasma FFA and that the concomitant decrease in carbohydrate utilization concerns muscle glycogen rather than blood glucose.

Serological characterisation of Ureaplasma urealyticum strains by enzyme-linked immunosorbent assay (ELISA)

A modification of enzyme-linked immunosorbent assay (ELISA) was developed for the serological characterisation and identification of strains of Ureaplasma urealyticum. The eight recognised human serotypes of U urealyticum and antisera produced against them were used as reference for the evaluation and standardisation of the method. The serological profile illustrating reactions of antigen with homologous and heterologous antisera was specific and reproducible for each serotype. The homologous reaction was always very prominent but some cross-reactivity was seen, most clearly between serotypes 2 and 5. The method was found to be suitable for serological typing of clinical isolates of U urealyticum because of rapid and simple technical procedure, good reproducibility of the results and economical consumption of antisera and other reagents.

Isolation and preliminary characterisation of mycoplasmavirus 20-P

A mycoplasmavirus, MV 20-P, was isolated from the fastidious, slow-growing human mycoplasma 20-P, previously identified by the growth inhibition test as Mycoplasma hominis type 2. Its broth culture was ultracentrifuged into 35% saccharose, the pellet was resuspensed in buffer, and the suspension was dropped onto laws of the virus indicator Acholeplasma laidlawii BCL-13. The virus was washed off the plaque areas by buffer. MV 20-P appeared in electron microscopy as spherical, enveloped particles about 80 nm in diameter. It was sensitive to lipid solvents. These preliminary results indicate that MV 20-P is a MVL2 type mycoplasmavirus and possibly the first of human origin.

Diet induced changes in sympatho-adrenal activity during submaximal exercise in relation to substrate utilization in man

In order to study how the diet may influence sympatho-adrenal activity during exercise, 7 subjects were examined at rest and during submaximal exercise (25 min at 65% of VO2 max) on two occasions. The first occasion was preceded by 5 days on a carbohydrate poor diet (5% carbohydrate, 72% fat and 23% protein) and the second one by 5 days on a carbohydrate rich diet (78% carbohydrate, 8% fat and 14% protein) with the same energy content. Oxygen uptake, respiratory exchange ratio (R), heart rate and arterial plasma concentrations of adrenaline, noradrenaline, dopamine, insulin, glucose, lactate, free fatty acids (FFA), glycerol and beta-hydroxybutyrate were measured at rest and during exercise. Oxygen uptake and heart rate during exercise were higher and R was lower after the carbohydrate poor than after the carbohydrate rich diet. During exercise the arterial plasma concentrations of FFA, glycerol and beta-hydroxybutyrate were higher after the carbohydrate poor than after the carbohydrate rich diet whereas concentrations of insulin and lactate were lower. At rest arterial plasma noradrenaline and adrenaline levels were similar on the two diets (0.70 +/- 0.31 nM noradrenaline and 0.35 +/- 0.32 nM adrenaline one the carbohydrate rich diet, mean values +/- SD). Exercise induced increases in noradrenaline were more pronounced after the carbohydrate poor than after the carbohydrate rich diet (12.42 +/- 3.41 vs. 7.45 +/- 2.68 at 25 min of exercise, p less than 0.001). A similar, although more variable accentuation of exercise induced increases in adrenaline was found. It is concluded that, when compared to a carbohydrate rich diet, a carbohydrate poor diet increases the relative contribution of fat to oxidative metabolism and increases the sympatho-adrenal response to exercise. Stimulation of lipolysis by sympatho-adrenal mechanisms might be of importance for the substrate availability when carbohydrate intake in low.

On the significance of the respiratory exchange ratio after different diets during exercise in man

Total respiratory exchange ratio (R) was compared to the respiratory exchange ratio over the legs (RQL) during exercise after different diets, to evaluate if R (which represents a mean for the whole body) can be used to estimate the relative proportions of fat and carbohydrate oxidation in exercising muscle. One important prerequisite for this is a steady state acid base balance, 7 subjects were studied at rest and during the later part of a 25 min exercise (65% of Vo2 max) on two occasions, the first preceded by a fat rich diet and the second by a carbohydrate rich diet. Oxygen uptake, R and arterial-femoral venous differences for [O2], [CO2], PCO2 and pH and arterial concentrations for lactate and beta-hydroxybutyrate were measured. Respiratory exchange ratio over the exercising legs (RQL) and ventilation/oxygen uptake were calculated. Arterial pH, PCO2, lactate and beta-hydroxybutyrate as well as specific ventilation attained steady levels during the later part of exercise after both diets. Although arterial lactate and beta-hydroxybutyrate differed between the diets, the arterial pH and specific ventilation were the same. Both R and RQL were higher after the carbohydrate than after the fat diet and there was no systematic difference between R and RQL. Therefore, it seems likely that R estimates the proportion of fat and carbohydrate oxidation in skeletal muscle during submaximal exercise after extreme diets.

Acid soluble and insoluble glycogen in human skeletal muscle

Quantitative biochemical analysis of glycogen was performed with and without perchloric acid pretreatment on biopsy specimens of varying glycogen content, obtained at rest and immediately after exercise after different diets. If analysis was carried out after perchloric acid pretreatment, as is commonly done, lower values were obtained than without such pretreatment. This could be explained by the existence of glycogen in forms of greater and lesser solubility. Evidence for this was obtained by quantitative analysis of glycogen in the perchloric acid extract. The acid soluble form in the extract constituted a greater fraction of total glycogen at supra-normal than at low concentrations. This might also explain why supra-normal levels of glycogen cannot be detected by histochemical methods. The existence of soluble and insoluble glycogen may also be of physiological importance, e.g. by interacting differently with enzymes of glycogen metabolism.

Time course of muscle metabolic changes during tourniquet ischemia in man

Muscle biopsies form the vastus lateralis muscle of the thigh were obtained from 11 patients before and at 15-min intervals following tourniquet application and 15 min after tourniquet release. The total circulatory occlusion time varied from 60 to 120 min. The concentrations of lactate, creatine phosphate and adenosine triphosphate were determined, and the muscle temperature was recorded. During the ischemic period, the lactate concentration increased from 1.9 mmol x kg-1 wet wt to 14.9 mmol x kg-1 wet wt after 90 min of ischemia. During the last 30 min of ischemia, no further increase in lactate concentration was observed. The creatine phosphate concentration decreased from 20.4 to 5.2 mmol x kg-1 wt wt after 120 min of ischemia. The temperature fell rapidly during the first 15 min from 35.9 degrees to 33.5 degrees and was then constant until 95 min when a further small decrease was observed. The adenosine triphosphate concentration did not change significantly during the ischemic period.

Fiber type area and metabolic potential of the thigh muscle in man after knee surgery and immobilization

The muscle atrophy of the quadriceps muscle was investigated in patients after knee operations and immobilization in a long leg plaster cast. Muscle biopsies were taken before operation and after 5 weeks immobilization. The activity of oxidative (SDH) and glycolytic (PFK) enzymes was determined. The fiber area of the different fiber types were measured and enzyme activities in single characterized fibers were analyzed. A selective type 1 atrophy was found with a reduced cross-cut area of the type 1 fiber, and a reduced oxidative enzyme activity occurred in the slow-twitch type 1 fibers. The effect of the muscle tension in the immobilized leg and the inhibiting role of the postoperative pain is discussed.

Examination of men with nongonococcal urethritis and their sexual partners for Chlamydia trachomatis and Ureaplasma urealyticum

Chlamydia trachomatis was recovered from 39 (52%) of 75 men who had nongonococcal urethritis and from 28 (37%) of their sexual partners. Of the partners of men with Chlamydia-positive nongonococcal urethritis, 64% excreted Chlamydia, compared with 8% of the partners of men with Chlamydia-negative nongonococcal urethritis. In contrast, an apparently sexual mode of transmission was not observed with Ureaplasma urealyticum. Rates of recovery of U. urealyticum from men with nongonococcal urethritis whose cultures were Chlamydia-positive and those whose cultures were Chlamydia-negative were the same. Significant seroconversion was detected bythe single-antigen immunofluorescence test in about 50% of patients who had Chlamydia-postive cultures.

Cross-sectional area of the thigh muscle in man measured by computed tomography

Nine subjects with different training background were studied by means of muscle biopsy from musculus vastus lateralis. The cross-cut area of the different muscle fibre types was measured. By the use of a soft tissue X-ray technique, computed tomography, a cross-sectional picture of the thigh was produced at the same level as the biopsy was taken. The total cross-cut area of the vastus lateralis muscle was measured from this picture. This technique to measure a cross-cut muscle area from an X-ray picture was evaluated and found to be accurate and reproducible. The mean fibre area was highly correlated (r = 0.91; P less than 0.001) to the cross-cut area of the vastus lateralis muscle. The total number of fibres in the vastus lateralis muscle was estimated. It was concluded that the cross-sectional area of the thigh muscle can be accurately determined by means of computed tomography. The larger cross-sectional area of the vastus lateralis muscle in well trained subjects was primarily explained by a larger cross-sectional area of the fibre, while the total number of fibres in the vastus lateralis muscle seemed to be fairly equal among the subjects.

Electron probe X-ray microanalysis of human muscle biopsies

The elemental composition of human muscle fibres have been determined by electron probe microanalysis. In order to distinguish between different types of fibres, two approaches were used. In one approach individual fibres were isolated, portions of them used for a typing by histochemical methods and the main part used for X-ray microanalysis. In the other approach the muscle biopsy was serial-sectioned, some sections used for a histochemical typing and the others (16 micrometer thick cryosections) used for X-ray microanalysis in th eelectron microscopy. The comparison of the ratios between P, S and K in Study No. 1 and 2 indicates different concentrations of sulphur in the subsarcolemmal zone and in the interior of the fibre. Both routes give information on all elements (except the ten lightest ones) contained in the fibres or in sections of them, provided the concentration is high enough. In order to obtain quantitative data, expressed as mmol/kgw, the spectra of the specimens were compared to those of standards of known composition and the data subjected to a so called ZAF-correction (corrections for the atomic number effect, absorption of X-rays in the specimen and secondary fluorescence). Quantitative data concerning phosphorus, sulphur, chlorine and potassium were obtained in Study No. 2. A significantly higher sulphur concentration was found in type IIA muscle fibres as compared to those of type I.

Studies in sarcoidosis: intradermal Mycoplasma test

Mycoplasma strain 215-M, closely related to Mycoplasma orale type 1, was grown in human macrophage monolayers in vitro. Sonicated homogenates of macrophages diluted in saline solution were used for intradermal skin tests in 19 patients with sarcoidosis and in 25 patients with a variety of other diseases. Positive skin-test reactions to this newly developed Mycoplasma test material were observed significantly more often in the patients with sarcoidosis than in the other patients.

Fiber types and metabolic potentials of skeletal muscles in sedentary man and endurance runners

This description of some of the present knowledge on skeletal muscle fibers, their metabolic potentials, and their interplay with the degree of physical activity has revealed that skeletal muscle of man has a very large capacity for adaptation. Moreover, this adaptability appears to be of utmost importance for the metabolic response as well as for performance. Although all this is true, it should not distract us from the fact that we are lacking the most important information. The questions that need to be answered are: What triggers the changes to take place? Which are the regulatory mechanisms?

Muscle adaptation to extreme endurance training in man

To evaluate the effect of extreme endurance training on muscle fibre composition and activities of oxidative enzymes in different fibre types biopsies were taken from vastus lateralis, gastrocnemius and deltoideus of elite orienteers. Comparisons were made between the (trained) leg muscles and the (relatively untrained) arm muscles, and with leg muscles of 16--18 years old boys. The orienteers had the same percentage type I fibres and vastus lateralis and gastrocnemius as in deltoideus, but higher percentage type I fibres in vastus lateralis compared with the controls. The similarity between trained and untrained muscle in the orienteers suggests that training had not caused the high percentage type I fibres which rather might be the result of selection of individuals with the best prerequisites for high oxidative capacity. However, the distribution of type II subgroups in the leg muscles of the orienteers differed from both their own deltoideus and leg muscles of the controls, the relationship IIA/IIB being altered in favour of the more oxidative IIA. The leg muscles of the orienteers also showed an increased occurrence of the normally IIC fibre. These latter findings point at the possibility of a training induced alteration in the subgroup pattern. Unlike in the controls there was no significant difference in succinate dehydrogenase activity, measured in single fibres, between type I and II fibres in gastrocnemius of the orienteers. Thus, type II fibres have the ability metabolically to adapt to high oxidative demands. This might to some extent be mediated by a conversion from IIB to IIA form.

Isolation of a mycoplasma from three patients with lepromatous leprosy

Using a modified cell-free culture medium and modern microscopic equipment, a mycoplasma was isolated from scrapings of skin lesions of three patients with lepromatous leprosy. Three specimens were taken from the first patients. All five isolates were arginine-positive and their antibiotic sensitivity was identical with only one slight exception.

The nature of the training response; peripheral and central adaptations of one-legged exercise

13 male subjects were studied and placed in 3 groups. Each group exercised one leg with sprint (S), or endurance (E) training and the other leg oppositely or not at all (NT). Oxygen uptake (Vo2), heart rate and blood lactate were measured for each leg separately and for both legs together during submaximal and maximal bicycle work before and after 4 weeks of training with 4-5 sessions per week. Muscle samples were obtained from the quadriceps muscle and assayed for succinate dehydrogenase (SDH) activity, and stained for myofibrillar ATPase. In addition, eight of the subjects performed after the training two-legged exercise at 70% Vo2 max for one hour. The measurements included muscle glycogen and lactate concentrations of the two legs as well as the blood flow and the a-v difference for O2, glucose and lactate.

Metabolic characteristics of fibre types in human skeletal muscle

Muscle biopsy samples were obtained from healthy subjects in order to evaluate quantitative differences in single fibres of substrate (glycogen and triglyceride) and ion concentrations (Na+ and K+) as well as enzyme activity levels (succinate-dehydrogenase, SDH; phosphofructokinase, PFK; 3-hydroxyacyl-CoA-dehydrogenase, HAD; myosin ATPase) between human skeletal muscle fibre types. After freeze drying of the muscle specimen fragments of single fibres were dissected out and stained for myofibrillar-ATPase with preincubations at pH's of 10.3, 4.6, 4.35. Type I ("red") and II A,B, and C ("white") fibres could then be identified. Glycogen content was the same in different fibres, whereas triglyceride content was highest in Type I fibres (2-3 X Type II). No significant differences were observed for Na+ and K+ between fibre types. The activity for the enzymes studied were quite different in the fibre types (SDH and HAD, Type I is approximately 1.5 X Type II; PFK Type I is approximately 0.5 X Type II, Myosin ATPase Type I is approxiamtely 0.4 X Type II). The subgroups of Type II fibres were distinguished by differences in both SDH and PFK activities (SDH, Type II C is greater than A is greater than B; PFK, Type II B is greater than A is approximately C). It is concluded that contractile and metabolic characteristics of human skeletal fibres are very similar to many other species. One difference, however, appears to be than no Type II fibres have an oxidative potential higher than Type I fibres.

Fine structure of single fibres of human skeletal muscle

Individual muscle fibres were separated from freeze-dried needle biopsies and classed as type I or type II fibres according to their myofibrillar ATP-ase. Portions of the same fibres were processed for electron microscopy and their fine structure examined. Type I fibres were found to have thicker Z-bands and more mitochondria and lipid droplets than the type II fibres.

Recent progress in mycoplasma research

Today, 12 years after the identification of Eaton agent as a mycoplasma, much new information on this infection has accumulated. Better methods have become available, which will be helpful in determining whether other mycoplasmas might be human pathogens, e.g., some ureaplasmas in nongonococcal urethritis. Experimental mycoplasma infections in birds and animals have revealed common features with immune complex diseases in man. They may serve, therefore, as useful models for human mycoplasma disease. However, the most important finding in recent mycoplasma research has been the isolation of mycoplasma viruses. Viruses belonging to three different groups have been discovered. It will be interesting to study whether the virus determines the pathogenicity of mycoplasmas or not.

Studies on the pathogenicity for rat of a mycoplasma isolated from rheumatoid arthritis

The pathogenicity for rat of M. arthritidis strain Jasmin and strain 20-P from rheumatoid synovial tissue were studied. Only strain Jasmin produced signs of illness in four of the 12 rats infected. A mycoplasma was isolated from three tissue specimens. Ten of the 48 rats investigated showed mycoplasma antibodies. Five rats showed minor inflammatory changes in the distal joints of the limbs. The failure to induce arthritic symptoms in rats inoculated with strain 20-P from rheumatoid arthritis may be due to its 10-year long storage outside the animal host.

Mycoplasma antibodies in rheumatoid arthritis

Sera of 100 patients under examination at the Outpatient Department of the Rheumatism Foundation Hospital were studied by the indirect hemagglutination technique, using both mycoplasma reference strains, and isolates from RA and SLE as antigens. The series consisted of five groups: I, definite RA (49 patients); II, probable RA (11); III, possible RA or nonspecific inflammatory arthritis (34); IV, osteoarthrosis (2); V, Reiter's disease (4). Mycoplasma antibodies in titres of 16 or higher were encountered in groups I-IV in 26, 8, 19, and one case respectively. Twenty-one out of 106 blood donors had antibodies against an isolate from RA and/or M. arthritidis strain PG 6. The titres found were 16 or 32, except in two cases, 128. In the definite RA group, 21 out of 26 patients possessing mycoplasma antibodies, showed titres of 16 or higher against isolates from RA and/or SLE, 12 against M. arthritidis strain PG 6 and/or Campo, 8 against M. fermentans, and 6 against a T-strain from NGU. Antibodies against M. arthritidis strain Campo were found more often than against strain PG 6. The longer the duration of the arthritic symptoms was, the more frequent seemed also to be the occurrence of mycoplasma antibodies.

Ultrastructure of a mycoplasma recovered from the bone marrow in systemic lupus erythematosus

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Isolation of a mycoplasma from sarcoid tissue

Using a modified cell-free culture medium, a mycoplasma was isolated from sarcoid lymph nodes in two cases and from sarcoid skin lesions in four out of seven cases of chronic sarcoidosis. Growth inhibition tests showed that the isolates were related to Mycoplasma orale type 1. By the indirect haemagglutination method, 244 cases of definite or probable sarcoidosis, 160 patients with other diseases, and 355 blood donors were tested for antibodies against an isolated mycoplasma (strain 215-M). Titres [unk] 16 were found in 14% of the patients with sarcoidosis and in 8% of the patients with other diseases but only in 0.6% of the blood donors. The proportion of patients with high antibody titres among those with sarcoidosis and erythema nodosum was smaller (8%) than among those with other forms of sarcoidosis (17%). The role of the mycoplasmas isolated from sarcoid tissues remains obscure, but it is possible that these organisms are only an expression of altered immunity in sarcoidosis.

Scanning-beam electron microscopy of mycoplasma isolated from rheumatoid arthritis

Scanning-beam electron microscopic studies on an isolate from definite rheumatoid arthritis are presented.

An 8-year study on mycoplasma in rheumatoid arthritis

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Search for mycoplasma in rheumatoid arthritis

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Studies on T-strain mycoplasmas in nongonococcal urethritis

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Isolation of fastidious mycoplasma from human sources

A method for the isolation of fastidious mycoplasma from human sources is described.

Hospital staphylococci in helsinki

Abstract A total of 812 nasal swabs taken from the staff at 3 Helsinki city hospitals were examined. The carrier rate was 26%. Coagulase-positive staphylococci resistant to methicillin occurred in one hospital in 3%. They were multiple resistant. Strains belonging to phage group III dominated, accounting for 35%. Staphylococci of types 83A and 53/83A totalled 9% and those of type 6557 7%.