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Biomedical subjects

M Grim

Publications and source records attributed to M Grim.

At least 55 records · Page 3Linked to original sources
PubMed1989

A hierarchy of determining factors controls motoneuron innervation. Experimental studies on the development of the plantaris muscle (PL) in avian chimeras.

Quail leg buds were grafted in place of chick leg buds or chick wing buds and vice versa at stages 18 to 21 after colonization by muscle precursor cells had been completed. Motor endplate pattern in the plantaris muscle of the grafts was analyzed before hatching by means of esterase and acetylcholinesterase staining techniques. Muscle fibre types were made visual using the myosin ATPase reaction. Investigations are based on the species-specific endplate pattern of the plantaris muscle: multiply innervated fibres in the chick and focally innervated fibres in the quail. Muscle pieces isolated from the adjacent medial gastrocnemius muscle of the grafted legs were histologically examined to judge their species-specific composition. Horseradish peroxidase was injected into the plantaris muscles of both the grafted and the opposite leg as well as in the plantaris muscle of normal quail embryos, in order to be sure that the plantaris muscle of the grafts is innervated by appropriate motoneurons. This procedural design offers for the first time a possibility to test experimentally the influences of motoneurons on endplate pattern formation under conditions corresponding to those in normal ontogenesis. It is shown that such appropriate motoneurons of one species which project to the plantaris muscle of the other species dictate the endplate pattern. When the plantaris muscle is innervated by inappropriate motoneurons, the endplate pattern inherent in the muscle primordium itself becomes realized. A sequence of hierarchically acting factors is proposed to bring different results in line. According to this, the neuronally set programme has priority compared with that set in the muscle. This is true for the normal development and might generate the high neuro-muscular specificity. If under experimental conditions the neuronal programme and the peripheral programme differ, the axons and muscle fibres selectively interact with respect to their inherent characteristics and the muscle-specific programme becomes expressed. If there is a lack of a certain axon type, muscle fibres might become innervated by non-corresponding motoneurons which alter the muscle fibre type.

Animals↗
PubMed1989

Morphological research of the locomotor apparatus.

This paper presents the results of a study focussed on the locomotor apparatus and on the biological systems integrated in it. This study was carried out by a large group of workers in the Institute of Anatomy in Prague, with close and mutual interweaving of their contributed works. The review demonstrates the ontological advancement achieved in the fields of morphology and development of these locomotor structures. From descriptive studies it proceeds towards experimental works specially oriented to understand developmental mechanisms and the causality of their origin, within the context of the most recent advancements in developmental morphology. Even individual applications in clinical practice, which might arise, have been pointed out. The whole set of works having been referred to, from which only a fraction necessarily limited due to the length of this publication could be cited, also demonstrated here the possibilities of employing knowledge obtained about the locomotor apparatus of the limbs in further research concerning the more generalized aspects of the mechanisms of development and their regulations, down to their molecular biological level.

Adult↗
PubMed1989

Regeneration in mouse skeletal muscle injured by Trichinella larvae.

During the infection caused by Trichinella pseudospiralis serious damage to muscles is partly compensated with regeneration process. Short, thin fibrillae with central position of the nuclei--regenerating myotubes originate 20--40th day post infection in endomysial tubes remaining after damaged muscle fibres, left by migrating larva. On the 10th day post infection in the vicinity of moving larva activation of nuclei and increased origin of satellite cells under basal membrane occur. With development of the infection endothelia in the vicinity of altered fibrillae are increasing in number but there is small inflammatory and fibroproductive reaction only. During the infection caused by Trichinella spiralis and T. nativa, alteration of muscle fibres is accompanied by early inflammatory and fibroproductive reaction towards immediate surroundings of larvae. In a changed segment of muscle fibre with the larva--in pseudocyst there is altered basal lamina as well, built in increased glycocalyx and in the course of 20 days encased by connective tissue. Revascularisation and regeneration in a short damaged segment does not occur even during long-lasting infection because of separation by capsule.

Animals↗
PubMed1988

A test for muscle lesions and their regeneration following intramuscular drug application.

A standard infiltration of the rat tibialis anterior muscle with 0.1 ml of local anesthetics was used as a model to help choose criteria for testing the intramuscular toxicity of drugs. Anesthetics used were 0.2% carbisocaine, 1% and 2% Lidocaine, 0.5% Marcaine, 1% and 2% Mesocaine, 1% and 2% Procaine. Increases in the serum levels of creatine kinase were monitored for 24 hours, and the weight, as well as macro- and microscopic changes in the muscle for a period of 1 month. Exposure of the muscle to local anesthetics resulted in 2 types of lesions. One was characterized by selective muscle fiber damage in the injected area. The other type of lesion was a generalized one that involved a number of cell types. To assess the intramuscular toxicity of drugs we defined the type of lesion, its size, and the rate of subsequent muscle regeneration. We recommend the following criteria for the assay of myotoxicity of new drugs being developed as pharmaceutical agents: 1) serum creatine kinase level 1 hour after intramuscular injection of the drug; 2) microscopic findings at 3, 7, and 21 days; 3) the cross-sectional area of the lesion at 3 days; and 4) the weight of the muscle at 7 and 21 days.

Anesthetics, Local↗
PubMed1986

Enzymatic heterogeneity of the capillary bed of rat skeletal muscles.

This study of the capillaries in rat skeletal muscle involved the use of a histochemical method that allows one to distinguish between arterial and venous portions of capillaries. Under controlled staining conditions, the arterial portion of the capillary bed reacts positively for alkaline phosphatase (AP) activity, and the venous portion is positive for dipeptidyl peptidase IV (DPP IV) activity. A short transitional capillary segment is positive for the activity of both enzymes. Capillaries of the normal soleus muscle and the red and white portions of the sternomastoid muscle have been quantitatively analyzed. Quantitative data demonstrated differences in capillary dimensions among the muscles studied. Capillaries of the white part of the sternomastoid were the longest, and they had the shortest DPP IV-positive segment (8% of the total capillary length). Capillaries of the soleus muscle were the shortest, and they also had short DPP IV-positive segments (16%). In contrast, the DPP IV-positive segments of the red part of the sternomastoid occupied 60% of the total capillary length. Survey cross sections reveal a mosaic distribution of patches of capillaries stained for AP and DPP IV activity. This study reveals that within given bundles of muscle fibers, the capillaries that run parallel to the muscle fibers are aligned relative to one another in such a manner that their arterial and venous segments are in register.

Animals↗
PubMed1986

Enzymatic differentiation of arterial and venous segments of the capillary bed during the development of free muscle grafts in the rat.

The revascularization of freely grafted muscles in the rat was studied by histochemical reactions that on frozen sections stain the arterial part of the capillary bed blue (alkaline phosphatase [AP] reaction) and the venous part of the capillary bed red (dipeptidyl peptidase IV [DPP IV] reaction). In 112 rats the extensor digitorum longus or soleus muscles were freely grafted and removed at various times up to 93 days following the surgery. In cross section, the capillaries of a normal muscle show a mosaic pattern of staining for the activity of the two enzymes. After grafting, DPP IV activity of capillaries is lost throughout the entire graft within a day or two; but within ischemic muscle, weak and diffuse AP staining persists in capillary remnants for up to 6 days. In the very periphery of the graft AP staining is also preserved in partially damaged capillaries. By 4 days, new AP-positive capillaries can be identified at the periphery of the graft, and in succeeding days AP-positive capillaries are found progressively nearer the center of the graft. At 7 days, the capillary/muscle-fiber ratios are 66% of normal in the periphery of the graft and 44% in the intermediate zone. DPP IV-stained capillaries are not seen until 7 days after grafting. By 60 days, when the grafts have become stabilized, the mosaic pattern of capillary staining has become reestablished. In mature grafts, the number of capillaries per unit area was slightly higher than that in control muscles, but the capillary/muscle-fiber ratio was slightly lower, owing to the smaller than normal cross-sectional areas of the regenerated muscle fibers.

Animals↗
PubMed1985

Morphogenesis of the human gluteus maximus muscle arising from two muscle primordia.

In human embryos and fetuses a supernumerary muscle was found situated on the distal margin of the gluteus maximus muscle and supplied by the most distal main branch of the inferior gluteus nerve. According to its origin and insertion it is being named the coccygeofemoralis muscle. In embryos and fetuses of up to 40 mm in CR length the coccygeofemoralis muscle is separated by loose connective tissue from neighbouring fetal muscles. Later on, close contact between the coccygeofemoralis and the distal margin of the fetal gluteus maximus muscle develops, and during the prenatal period both fetal muscles gradually fuse. Postnatally, the coccygeofemoralis muscle is incorporated into the gluteus maximus muscle of which the pars sacroiliaca corresponds to the fetal gluteus maximus itself and the pars coccygea represents the fetal coccygeofemoralis muscle. With respect to the general process of muscle morphogenesis, the developmental pattern described for the gluteus maximus muscle demonstrates that adult muscles may be formed by a fusion of several fetal muscles.

Buttocks↗
PubMed1985

The feeding mechanism of intracellular muscle larvae, Trichinella nativa Britov et Boev, 1972 and T. pseudospiralis Garkavi, 1972.

We confirmed, with the electron microscope, that Trichinella larvae feed directly on the host tissue during their initial development. They suck, by means of a stylet acting as a piston, all components of the muscle cell which develops into a nurse cell, into their oral cavity. The stylet is controlled by a muscle retractor. At day 10 p.i., fragments of myofilaments and glycogen are present in the oesophagus of the larva of T. nativa, mitochondria occur in it at day 20 p.i. During the larval growth of T. pseudospiralis, remnants of a contractile material are present in the digestive system. The composition of the food ingested by the larva is in agreement with the development of changes in the muscle fibre. Initial changes in the fibre caused by the two Trichinella species are comparable, later changes are not. T. pseudospiralis influences the character of changes by its uninterrupted movement inside the fibre. From days 50-90 p.i. with T. pseudospiralis, a focally distributed sarcotubular system proliferates irregularly in different sites of the fibre. This is in contrast to a heavy proliferation of tubules inside a concentric membranous system around the larva of T. nativa becoming enclosed in a capsule. The larva which has ceased to feed on the host tissue at this time, feeds apparently on low-molecular substances of the membranous system transported from the surrounding vascular system which has increased in quantity in the endomysium. In the later course of the infection, the enzymatic activity of the AIP and the SDH increases in the vicinity of the larva of T. nativa, i.e., in the sarcoplasm inside the capsule.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Isoelectrically focused carboxyesterases as a biological marker in chimeras.

Species-specific multiple forms of carboxyesterases (CE) were determined in zymograms obtained by isoelectric focusing (IEF) using homogenized wing zeugopodal tissues of chick, quail and quail-chick chimeras. The validity of the CE pattern of chimeric tissues was verified by the nuclear marker technique. Analytical IEF of CE was found to be useful for investigation of the origin of tissues in chimeras.

Animals↗
PubMed1984

Histochemical differentiation of four species of the genus Trichinella from days 10-40 of their development in muscles of experimentally infected mice.

Differences in an infection of the muscle caused by larval T. pseudospiralis (from days 10-40 p.i.) and that caused by capsule-forming Trichinella larvae were disclosed with histochemical techniques. These were: An intense reaction of the modified sarcoplasm for neutral mucosubstances, and intense staining of spherical centres of re-differentiation in the sarcoplasm for tyrosine, activity of the acid phosphatase, a negative reaction for SS groups of proteins at the site of location of the parasite owing to the absence of a collagen-like substance deposited by capsule-forming Trichinella species. Alkaline phosphatase activity weak in a sarcoplasm infected with larval T. pseudospiralis, but intense in capsule-forming species suggesting a different, larval metabolism. The capsule of T. nativa which is produced later than that of T. spiralis and T.nelsoni, differs from these also histochemically in that it contains neutral polysaccharides on the surface of the outer capsule layer which stains for non-sulphonated, acid mucosubstances (hyaluronic acid). Inspection with the electron microscope disclosed a vacuolate substance containing glycoprotein, phospholipids, and displaying acid phosphatase activity. The substance was present in the vicinity of larvae of T. nativa occupying the space between the cuticle and the sarcoplasm. A slight, morphological difference between T. nelsoni and T. spiralis was observed in the more elongate shape of the capsule at days 30 and 40 p.o. Histochemical differences were in an oxidative reaction with aldehyde fuchsin (PAA AF, KMnO4 A F) showing an increased hypertrophy of the connective tissue surrounding muscle fibres infected with T. nelsoni.

Animals↗
PubMed1982

[Parvovirus enteritis and myocarditis in a confined colony of beagles. (The 1st detection of parvovirus infection in Czechoslovakia].

A description of the findings in a parvoviral epizooty, having occurred in a confined colony of 250 Beagle dogs in the autum and winter 1979-1980 and in 1981, is presented. 5 of the four month-old and older dogs perished in the course of an enteritic form of infection; 5 puppies, younger than 3 months, belonging to a group of 12 puppies derived from two infected litters, died in consequence of a parvoviral myocarditis. The simultaneous occurrence of myocarditis and enteritis was observed in a 9 day-old puppy. Among the seven remaining animals, two dogs were sacrificed at the ages of 18 and 23 months, respectively. Scars were found in the wall of the left ventricle of both of them. Parvoviral enteritis preceded the occurrence of parvoviral myocarditis. Characteristic intramuscular inclusions were demonstrated both in the enterocytes and in the myocardial cells. Electronmicroscopically particles of the size of the parvoviruses could be demonstrated in the nuclei of the myocardial cells, on one hand, and regressive changes of the nuclear components observed on the other hand.

Animals↗