Biomedical subjects

L Antoni

Publications and source records attributed to L Antoni.

7 recordsLinked to original sources

PubMed1987

Salivary immunoglobulins in healthy white and black adults compared with oesophageal cancer patients.

Saliva is a readily accessible mucosal secretion and salivary antibodies reflect the repertoire of gut-associated antigens; it therefore appears to be ideal for the study of gastro-intestinal disease. A study of salivary immunoglobulins in healthy white and black adults and patients with oesophageal cancer showed that salivary immunoglobulin A levels were higher (but not significantly) in whites than blacks. The levels, however, were similar in healthy blacks and oesophageal cancer patients. There is a wide variation in normal levels of salivary immunoglobulins. Also, immunoglobulins are readily influenced by physiological factors and so at present are unreliable indices of gastro-intestinal disease.

Adult↗

PubMed1986

Electrophysiological study of size and fibre distribution of motor units in the human masseter and temporal muscles.

Probably related to their unique function, human jaw muscles have a specialized muscle-fibre composition different from that of limb and trunk muscles. In jaw muscle from healthy young adults, there were large groups of densely-packed fibres of the same histochemical type, a finding which indicates re-innervation when seen in limb muscles. The number of muscle fibres per motor unit, the local distribution of muscle fibres within motor units and the neuromuscular transmission in human masseter and temporal muscles were examined by single-fibre EMG and macro EMG. One hundred and forty-seven low-threshold motor units in four healthy subjects were recorded. The first dorsal interosseus muscle of the hand was similarly measured. In the jaw and hand muscles the low-threshold motor units were slightly smaller, than in large arm and leg muscles. The temporal muscle differed from the masseter in having significantly-higher fibre density, which may be explained by the higher frequency of small type-II fibres in the temporal causing closer packing of the type-I, low-threshold motor units. The fibre concentration within motor units was similar to that of normal limb muscles without any sign of grouping of fibres from the same motor unit. Normal motor end-plate transmission was another argument against re-innervation.

Adult↗

PubMed1984

Flexibility in motor-unit firing pattern in the human temporal and masseter muscles related to type of activation and location.

Morphological studies have shown that each human jaw muscle and its sub-portions have a characteristic fibre-type pattern, suggesting special functional tasks. The firing pattern of 68 low-threshold motor units in different portions of the temporal and masseter muscles in 5 healthy subjects were determined by single-fibre EMG during voluntary isometric muscle contraction. The findings showed that each unit may have different activity patterns for different types of activation, which is not so for limb muscles. Thus, a given motor unit discharged with a different regularity in firing rate during retraction of the mandible than during clenching of the jaws in the intercuspal position, probably related to a changed central and peripheral influence on the motoneurone pool. No activity of single units was detected in the mandibular rest position. The results underline the complexity of the human stomatognathic system and the importance of combined morphological and physiological studies.

Adolescent↗

PubMed1983

Automated analysis of neuromuscular 'jitter'.

This paper describes an interactive program for real time analysis of the neuromuscular jitter. Two implementations, using different hardware for data acquisition, reflect the modular design and flexibility of the software. Details on the time windows are given as well as the available commands. The program features: (1) immediate feedback of acquired data; (2) optional manual editing of data; (3) simple, yet flexible commands; (4) several plot options of raw or analysed data; (5) database interface.

Action Potentials↗

PubMed1979

Jittermeter--a microcomputer-based system for single fibre electromyography.

In single fibre electromyography (SFEMG) an exact measurement and computation of a number of time parameters is required. This paper describes a low-cost microprocessor-based measurement system for SFEMG data acquisition, computation of the parameters and display, as an alternative to a general purpose-computer based system. Time measurement is performed at dual resolution: 0.1 microsecond and 0.1 msec. Erroneous data due to disturbing voltages are automatically eliminated. A variety of SFEMG applications is covered by 3 basic modes of data handling. The microprocessor unit is based on the 6800 family and contains 3K of program memory, input-output modules and 4K data memory. The instructions are entered through a keyboard and output is provided by an LED display, line-printer and X-Y storage display.

Action Potentials↗

PubMed1978

A minicomputer system for display and rate analysis in vectorcardiography.

A system has been constructed for recording vectorcardiographic signal with a FM taperecorder. Off-line AD-conversion and analysis of rates and magnitudes of partial vectors are made with a minicomputer. The reason for studying particularly initial vectorrates is that according to our hypothesis these contain valuable information for classification of certain cardiac arrythmias according to supraventricular or ventricular impulse focus. Preliminary results confirm the hypothesis. In vectorcardiography one difficulty is to give an easily comprehensible presentation of the vectorloop. In this study a method for '3-dimensional' display has been developed, using a graphic display processor and varying intensities of the beam. The system is to a high degree man-machine interactive.

Arrhythmias, Cardiac↗

PubMedDate not supplied

On-line analysis of neuromuscular bioelectric potentials.

A computer system is presented which provides for on-line data capture and analysis of evoked end-plate potentials and action potentials, and on-line data capture with off-line analysis of spontaneously occurring miniature end-plate potentials at the end-plate region of the neuromuscular junction. Sampling of evoked waveforms begins after an adjustable delay following the stimulus. Spontaneously occurring waveforms are captured by 'freezing' the contents of a circular buffer. The software provides MENU selectable support functions including storage and retrieval of data and calculated parameters, analog and digital display of waveforms, data calibration and gain modification, data editing, file management, and hardcopy output. Calculated parameters of the waveform are optionally placed in a data base file by the analysis programs. The data base may be used for editing, arithmetic operations, and subsetting of variables as well as statistical analysis and plotting of any selected variables.

Action Potentials↗