Search PubMed⌕ Search

Biomedical subjects

I Jonas

Publications and source records attributed to I Jonas.

At least 19 recordsLinked to original sources
PubMed1995

[Muscle relaxation by transcutaneous electric nerve stimulation (TENS) in bruxism. An electromyographic study].

In recent years transcutaneous electrical neuromuscular stimulation (TENS) has become increasingly more common in the treatment of functional diseases of the masticatory muscles and currently the practitioner can choose among a variety of stimulators. In an electromyographic study of 17 adults suffering from nocturnal bruxism and of a control group consisting of 18 adults without any functional disturbances of the masticatory muscles, the effect of this kind of neuromuscular stimulation on the temporal and masseter muscle was examined. The myoelectric signals were registered before and after TENS treatment in 3 different positions of the mandible. Each person was treated 3 times with both the Myo-Monitor (Myo-Tronics, Seattle) and the TNS SM2 MF stimulator (schwa-medico, Giessen). The different effects of continuous low frequency and intermittent high frequency muscular stimulation were studied simultaneously. Muscular activity was determined by computer aided integration of the electromyographically measured raw signals. A fourier analysis of the power spectrum yielded information on the frequency behavior of the studied muscles resulting from the TENS treatment. A statistical analysis of the results led to the following significant conclusions: 1. TENS treatment decreased the values of the registered integrated signals on all test persons, however, the treatment increased the median frequency and the mean power frequency (MPF). Since this effect is contrary to muscle fatigue, these electromyographic results can be interpreted as providing objective proof of a relaxation in the treated muscles. 2. The electromyographic changes after TENS treatment were similar when using either the Myo-Monitor or the TNS SM2 MF stimulator. In addition, the 2 different types of stimulation (high or low frequency) showed the same effects. 3. Compared to the persons in the control group, there was no significant increased muscular activity in patients with nocturnal bruxism. Following TENS treatment both groups showed the same alterations in the electromyograms. The results of the study provide further evidence that TENS treatment is an adequate supportive procedure in the treatment of nocturnal bruxism.

Adult↗
PubMed1993

[The effect of static magnetic fields on prostaglandin synthesis in L-929 and 3T3 mouse fibroblasts. An in-vitro study].

The aim of this study was to examine the influence of static, inhomogeneous magnetic fields on prostaglandin synthesis in L-929 and 3T3 mouse fibroblasts. Two pairs of magnets, one CoSm and the other NdFeB, were attached 10 mm apart under the culture chamber. One pair was in the attracting position and the other in the repelling position. The maximum magnetic induction measured was 85 respectively 120 mT and the incubation time was 72 hours. Control groups consisted of untreated cells and cells under the influence of demagnetized magnets. The following measurements were taken: prostaglandin synthesis (PGE2), protein content (GP), and the number (Z) of cells (only L-929 mouse fibroblasts). The data were analyzed statistically using the Tukey test and the significance niveau was set at alpha = 0.05. The results using this method demonstrated that the measurable effects of in vitro treatment of mouse fibroblasts with static magnetic fields of varying induction did not significantly differ from the control groups. The sensitivity of our method was verified beforehand with a recombinant, human TNF alpha stimulated reference group.

3T3 Cells↗
PubMed1992

Collagen stabilization induced by natural humic substances.

Humic substances are polyphenolic compounds. They have antiviral as well as desmutagenic effects and react with biopolymers such as collagen; thereby they have no toxic side effects by oral administration. In vitro incubation with humic substances raises the breaking point of the tail tendon of the rat by about 75%. The chemical resistance of the collagen fibres in tail tendon collagen is also increased by in vitro incubation with humic substances, at least insofar as the ultrastructurally and biophysically measurable destruction of the collagen fibres by 4 M guanidinium chloride is inhibited. As humic substances increase the mechanical and chemical resistance of collagen fibres and promote their "maturity", it seems likely that this effect of humic substances depends upon their interaction with the hydrogen bonding and covalent bonding of the collagen fibres. Such a conclusion is confirmed by the results of X-ray diffraction analysis.

Animals↗
PubMed1991

[Integrated and frequency spectra of the electromyograms in patients with temporomandibular symptoms].

With the aid of bipolar surface electrodes, the electromyographic activity of the anterior temporal and the superficial masseter muscles were recorded bilaterally and evaluated by counting the integrated potentials and mean power frequency using Fourier's analysis. A comparison between 17 patients with myofacial pain dysfunction (average age 21.3 years) and a group of 20 controls (average age 20.5 years) revealed a significantly greater activity in patients with pain syndrome, while no significant inter-group difference in mean power frequency was seen. The differences in the level of activity between the right and left sides in the control group were significantly smaller than in patients with pain dysfunction. An investigation of measures aimed at reducing the right/left asymmetry in a further 14 patients with pain dysfunction revealed the practice of "maximum occlusion with feedback" to be the most effective measure.

Adolescent↗
PubMed1989

[Frequency spectrum and integral value of electromyographic recordings of the masseter and temporal muscles in correlation with muscle length].

In 15 children and 15 adults the influence of muscle length on the EMG-recordings of the anterior temporal and superficial masseter muscles was investigated. Myoelectric activity was measured by surface electromyography during maximal clenching in habitual occlusion. The quantitative EMG analysis was performed by means of a computer program which allowed calculation of a) the integrated value and b) the mean frequency of the power spectrum (MPF) from the raw signal after Fourier transformation. Muscle length was determined with the aid of lateral cephalometric films. Using a correlation analysis this investigation revealed the following results: Under standardized functional conditions short muscles work with a higher activity and a higher MPF than long muscles. In children as well as in adults muscle activity and MPF show close negative correlations with the parameter "muscle length". These relations are directly proportional.

Adult↗
PubMed1988

[Caries occurrence and periodontal condition in 100 dental students in their clinical semester. A clinical study].

The purpose of this study was to examine the prevalence of caries and periodontal condition of 100 randomly selected clinical dental students (73 males, 27 females) in the age range of 22-37 years (means = 26.1 +/- 3.3 years). The statistical analysis revealed the following results: DMF-T Index (Klein & Palmer 1940) = 12.61 +/- 5.41 Plaque Index (Silness & Löe 1964) = 0.37 +/- 0.23 Gingiva Index (Löe & Silness 1963) = 0.39 +/- 0.20 Periodontal pocket depth = 1.65 +/- 0.27 mm. In relation to the results of other studies, clinical dental students had a decreased DMF-T Index and were in a better state of oral health and restaurations as compared to other groups of the same age. Female students had significantly less carious teeth, plaque and gingival disease than the male students. Increasing age had a highly significant correlation to DMF-T Index. Gingiva Index and pocket depth, whereas Plaque Index was correlated to a lesser degree. Plaque was confirmed as the essential factor of gingival disease.

Adult↗