Subject(s)
Locomotion/physiology , Animals , Brain/physiology , Mollusca/physiology , Neurons/physiologyABSTRACT
A tumor promoter phorbol 12-myristate 13-acetate (PMA) induces characteristic reversible changes in the cell shape in certain fibroblastic lines. This reaction to PMA may be regarded as a prototype of reorganizations involving formation of stable cytoplasmic processes. Two specific drugs, Taxol and Colcemid, were used to study the role of microtubules and vimentin-containing intermediate filaments (IF) in the development of PMA-induced reorganizations. A short (I h) exposure to PMA induced formation of processes in the control cells rather than in the Colcemid treated cells having depolymerized microtubules and the IF that collapsed around the nucleus. A longer (3-4 h) exposure to PMA of the colcemid-treated cells induced a partial reversal of the IF collapse; those parts of peripheral lamellae that contained IF were transformed into narrow noncontractile processes. It is suggested that the local interaction of the IF with the actin system is an essential step in the formation of processes from lamellae.
Subject(s)
Fibroblasts/drug effects , Intermediate Filaments/drug effects , Tetradecanoylphorbol Acetate/pharmacology , Actins/drug effects , Actins/ultrastructure , Alkaloids/pharmacology , Animals , Cell Line, Transformed , Cells, Cultured/drug effects , Cells, Cultured/ultrastructure , Demecolcine/pharmacology , Drug Interactions , Fibroblasts/ultrastructure , Fluorescent Antibody Technique , Intermediate Filaments/ultrastructure , Mice , Microtubules/drug effects , Microtubules/ultrastructure , PaclitaxelABSTRACT
Motility of neuroblastoma cells in the culture of cell line C-1300, clone N-18-A was investigated microcinematographically. In the course of morphological differentiation of the cells, after cytochalasin B treatment (1.8 mkg/ml for 24 hours), in some differentiated cells a special type of movement of the cytoplasmic mass together with the nucleus along elongated pseudopodia was detected. Such a type of movement has never been described. Sometimes, a shift in the nucleus position resulted in the complete change or reversion of cell polarity. The phenomenon of cell nucleus displacement relative to the cell configuration or reversion of the cell polarity can possibly play an important functional role for neural cells.
Subject(s)
Cell Nucleus/ultrastructure , Cell Transformation, Neoplastic/ultrastructure , Cytoplasm/ultrastructure , Neuroblastoma/ultrastructure , Pseudopodia/ultrastructure , Animals , Cell Line , Cell Movement/drug effects , Cell Nucleus/drug effects , Cell Transformation, Neoplastic/drug effects , Cytochalasin B/pharmacology , Cytoplasm/drug effects , Mice , Pseudopodia/drug effects , Tumor Cells, CulturedABSTRACT
A new type of reorganization of cytoskeleton induced by 12-o-tetradecanoyl-phorbol-13-acetate motility: division of the cell into an actin-rich active part and stable processes with numerous microtubules. Such a phenomenon was observed under a short-term influence of TPA on different lines of cultured fibroblasts: NRK, Balb/C 3T3, C-103, C-84, CAK-7. The effect of TPA was reversible and suppressed by cytochalasin B and colcemid. TPA is supposed to induce changes in the interaction between actin cortex and microtubule system.
Subject(s)
Cytoskeleton/drug effects , Fibroblasts/drug effects , Tetradecanoylphorbol Acetate/pharmacology , Actin Cytoskeleton/drug effects , Actin Cytoskeleton/ultrastructure , Animals , Cell Line , Cells, Cultured , Cytochalasin B/pharmacology , Cytoskeleton/ultrastructure , Demecolcine/pharmacology , Fibroblasts/ultrastructure , Intermediate Filaments/drug effects , Intermediate Filaments/ultrastructure , Mice , Microtubules/drug effects , Microtubules/ultrastructure , Rats , Tetradecanoylphorbol Acetate/antagonists & inhibitors , Time FactorsABSTRACT
Dissociated neurons from the brain of pteropodial mollusc were cultivated in a 25% Leibovitz medium containing 2% of calf serum. Neurite outgrowth was observed in 1-30% of the neurons. It was maximum during the first 3 days. Neurite length reached 300 microns. Membrane potential of neurons was 40-60 mV; they generated single spikes or bursts of impulses. Intercellular connections were tested on the 3-4th days in 70 pairs of neurons with neurites overlapped. Electrical connections between the cells were observed in 20% of the pairs tested, and in 6% of pairs stimulation of one of the neurons evoked an inhibitory postsynaptic potential in the other.
Subject(s)
Ganglia/cytology , Neuronal Plasticity , Animals , Cell Communication , Cells, Cultured , Membrane Potentials , Mollusca , Species Specificity , Synapses/physiology , Synaptic TransmissionABSTRACT
A model for coordinated execution of multijoint goal-directed limb movements is suggested from the following principles. (1) Central control signals for a single limb joint are individually formed, proceeding from its ability to bring the limb nearer to the target and leaving control signals directed simultaneously to other joint out of account. The joints thereby behave as a set of Tsetlin's abstract automata [11], each functioning independently and guided by a common, collective effect. (2) Neither levels of muscle activation, nor force and kinematic variables are directly specified by the command signals. They only modify the system's parameters that affect equilibrium joint positions, and thus make the limb to move to the goal. A concrete model based on the above principles is described and its behavior is compared with actual goal-directed movements in man and spinal frogs. Various control strategies for multiarticular movements in living organisms are discussed.
Subject(s)
Extremities/physiology , Joints/physiology , Movement , Animals , Anura , Biomechanical Phenomena , Humans , Models, BiologicalABSTRACT
The isolated pedal ganglia of the pteropodial mollusc Clione limacina generate the locomotor activity. In 30% of the pedal ganglion preparations, the locomotor rhythm was not regular, i. e. the locomotor generator worked in "bursts". These "locomotor bursts" were caused by spontaneous activations of command neurons located in the pedal ganglia. Single neurons were extracted from such preparations with an intracellular microelectrode and then their somas were put into the initial place between the ganglion cells. 25% of the isolated neurons (9 out of 35) renewed the "locomotor bursts"-related changes in the activity after the insertion into the ganglion. Neurons, originally excited during "bursts", continued to be excited after isolation, while inhibited neurons continued to be inhibited. It follows, therefore, that the command neurons can act on the target cells in the absence of morphological synapses.
Subject(s)
Ganglia/physiology , Locomotion , Mollusca/physiology , Action Potentials , Animals , Aplysia , Ganglia/cytology , In Vitro Techniques , Motor Neurons/physiology , Periodicity , Synapses/physiology , Synaptic TransmissionABSTRACT
In pedal ganglia of mollusc Clione limacina the growth of axons was studied in motoneurons and interneurons after transections of the wing nerve or of the pedal comissure. Neurons were stained by Lucifer Yellow. In motoneurons, neurites grown both from the transected end of the axon and from the neuron soma spread to all nerve trunks of ipsi- and contralateral ganglia. After nerve transection in the whole mollusc, wing movements restored 10 days later. In interneurons, neurites branched within the pedal ganglion or spread into cerebral ganglia but they did not extend out peripheral nerve trunks. Thus, the patterns of neurite sprouting in moto- and interneurons are different.
Subject(s)
Ganglia/physiology , Mollusca/physiology , Nerve Regeneration , Animals , Interneurons/physiology , Motor Neurons/physiology , MovementSubject(s)
Immunoglobulin Heavy Chains/immunology , Immunoglobulin Light Chains/immunology , Absorption , Animals , Binding, Competitive , Dose-Response Relationship, Immunologic , Drug Interactions , Hydrogen-Ion Concentration , Immunosorbent Techniques , In Vitro Techniques , Mice , Myeloma Proteins/immunology , Rats , Solutions , Time FactorsABSTRACT
The study of the morphological, clinical and functional manifestations of compensated chronic glomerulonephritis (CGN) in 317 patients revealed the advantage of the morphoclinical variants as compared to the morphological types for the evaluation of the gravity and prognosis of the disease. The morphoclinical variant means the combination of the morphological and clinical types. It was found that the morphoclinical variants of CGN determine the probability of the tubulointerstitial component, which deteriorates the prognosis of the disease more precisely than its morphological types. Renal dysfunction is more closely connected with the morphoclinal variant of CGN than with the morphological type. The data obtained are in favour of developing a morphoclinical classification of CGN on the basis of the morphoclinical variants of the disease.
Subject(s)
Glomerulonephritis/pathology , Kidney Glomerulus/pathology , Adolescent , Adult , Chronic Disease , Female , Glomerular Mesangium/pathology , Glomerulonephritis/classification , Glomerulonephritis/physiopathology , Glomerulosclerosis, Focal Segmental/pathology , Humans , Kidney/physiopathology , Male , Middle Aged , Nephrosis, Lipoid/pathology , PrognosisABSTRACT
The action of cytochalasin B (CB) on the differentiation of cultured neuroblastoma cells has been studied. CB treatment (1.8 micrograms/ml for 3 days) blocked cytokinesis, leading to the multinucleation of neuroblastoma cells. The replacement of medium with CB by standard medium without CB led to the improvement of cell spreading on the substrate and to the appearance of 43.7 +/- 4.1% of morphologically differentiated cells. 4.7 +/- 0.6% of differentiated cells formed in CB-untreated control cultures. Thus, incubation with CB followed by the agent removal from the medium induced the differentiation of neuroblastoma cells. A possible role of multinucleation in this process is discussed.
Subject(s)
Cytochalasin B/pharmacology , Neuroblastoma/pathology , Animals , Cell Differentiation/drug effects , Cells, Cultured , Mice , Neoplasms, Experimental/pathologyABSTRACT
Correlation of electrocardiographic and coronarographic findings in patients with severe chronic coronary heart disease and massive coronary arterial lesions has demonstrated a tendency to increasing proportion of clinically normal electrocardiograms as more arteries are drawn into the pathologic process. Relationships between ECG voltage and different variants of coronary arterial damage are reviewed: the involvement of the right and part (at least one branch) of the left coronary arteries corresponds to low-voltage ECG. The association between left-ventricular aneurysm and the number of affected coronary arteries is examined.
Subject(s)
Arteriosclerosis/complications , Coronary Angiography , Coronary Disease/complications , Adult , Arteriosclerosis/diagnostic imaging , Arteriosclerosis/physiopathology , Chronic Disease , Coronary Disease/physiopathology , Electrocardiography , Female , Humans , Male , Middle AgedABSTRACT
The authors suggest that the males under 60 with myocardial infarction who have no chronic circulatory insufficiency in their case history should be divided into the groups of high and low risk of the development of ventricular fibrillation, thromboembolic complications and acute cardiac aneurysm. The group of risk is determined on the basis of 5 clinical characteristics: the character of myocardial infarction, the stage of arterial hypertension, evaluation of the general state, heart failure and the heart rate.
Subject(s)
Arrhythmias, Cardiac/diagnosis , Myocardial Infarction/complications , Arrhythmias, Cardiac/epidemiology , Hospitalization , Humans , Male , Middle Aged , Moscow , Myocardial Infarction/diagnosis , Prognosis , Risk , Thromboembolism/diagnosis , Thromboembolism/epidemiology , Time FactorsABSTRACT
In order to prognoze recurrent bleedings during the nearest time after admission to the hospital the authors have analyzed the most frequently used objective data on patients with gastro-duodenal hemorrhages (the activity and intensity of bleeding, size and character of the ulcer, duration and severity of blood loss). A rule for prognozing recurrent bleedings is proposed.
Subject(s)
Peptic Ulcer Hemorrhage/etiology , Peptic Ulcer/complications , Hemostatic Techniques , Humans , Peptic Ulcer/surgery , Prognosis , Recurrence , Retrospective StudiesABSTRACT
A new method is proposed for data selection with respect to solving medical diagnosis problems. It reduces the scope of information, leaving for further processing only the facts the physician actually needs for problem-solving. The protocols of "diagnostic games" reflect the physician's mental process and can be used in the development of a physician model.