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Biomedical subjects

S Kopp

Publications and source records attributed to S Kopp.

At least 109 records · Page 6Linked to original sources
PubMed1992

Hypothyroidism and autism spectrum disorders.

Five children (three boys and two girls) with autism or autistic-like conditions are described. Three of them had congenital hypothyroidism and two had mothers who had probably been hypothyroid in pregnancy. It is suggested that hypothyroid hormone deficiency in early development might cause central nervous system damage such that autistic symptoms are likely to ensue. An alternative explanation might be autoimmune factors linking hypothyroidism and autism.

Adolescent↗
PubMed1991

Radiologic changes in temporomandibular, hand, and foot joints of patients with rheumatoid arthritis.

Radiologic changes in the temporomandibular joint (TMJ) and in the joints of the hand and foot were recorded for 90 adult patients with rheumatoid arthritis. The severity of the changes was graded according to the Larsen classification of six grades (O to V), and mainly erosive changes were recorded. The assessment of the radiographs was performed with the aid of reference films. The radiologic changes in the TMJs corresponded to grade II (definite early abnormality) and paralleled those of most of the metacarpophalangeal and metatarsophalangeal joints. The most severe changes were localized to the wrists, with a median grade of III (moderate destructive abnormality). The severity of the changes was similar on the right and left sides of the TMJ. We conclude that TMJ involvement in patients with rheumatoid arthritis is severe and warrants a thorough initial clinical examination. Such a strategy will facilitate the diagnosis and treatment of TMJ changes in the early stages of the disease.

Adolescent↗
PubMed1991

Neuropeptides in temporomandibular joints with rheumatoid arthritis: a clinical study.

There is evidence that neuropeptides play a role in the development of arthritis. Synovial fluid from arthritic temporomandibular joints in patients with rheumatoid arthritis was therefore investigated for presence of the neuropeptides calcitonin gene-related peptide, substance P, neurokinin A and neuropeptide Y. All four peptides were found in the synovial fluid above plasma level, but calcitonin gene-related peptide showed the highest concentration and substance P the lowest.

Adult↗
PubMed1991

Magnetic resonance imaging of the masseter muscle of the rabbit.

Gross anatomy of the masseter muscle was studied in eight rabbits using a 2.34 tesla MRI-device. Anatomy was displayed and assessed consistent with previous dissectional findings. It is concluded that MRI, applied as described in the present study, is suitable for assessment of masseter morphology in experimental studies on the rabbit.

Animals↗
PubMed1991

Short-term effect of occlusal adjustment on craniomandibular disorders including headaches.

The aim of this study was to assess the short-term effect of occlusal adjustment on craniomandibular disorders. Fifty patients were randomly selected and divided into a treatment (T) and a control (C) group. The initial clinical examination and the follow-up were made by one observer and the occlusal adjustment by another. There were no significant differences between groups with regard to frequency of headaches, facial pain, pain on mandibular function, or duration of headaches and facial pain. Fifty-two percent of the patients in the treatment group and 20% of the patients in the control group reported reduced subjective symptoms overall at follow-up examination. The improvement was statistically significant within the T group and significantly greater than in the C group. There was no significant change within or between groups with regard to frequency of headaches, facial pain, or pain on mandibular movements. There was an almost significant difference between groups after treatment with regard to changes in the number of tender muscles. The results of this study indicate that occlusal adjustment provides a general subjective improvement of craniomandibular disorders.

Adolescent↗
PubMed1991

Intramuscular and skin surface temperatures of the resting human superficial masseter muscle.

The intramuscular and skin surface temperature of the central part of the superficial masseter muscle was measured with thermocouples in 25 individuals with none or mild signs of craniomandibular disorders. The intramuscular temperature averaged 35.7 degrees C, varying between 34.6 and 36.5 degrees C. The average difference between the right and left sides was 0.4 degrees C. The skin surface temperature averaged 33.2 degrees C, varying between 31.1 and 35.4 degrees C. The average difference between sides for this temperature was also 0.4 degrees C. The correlation between intramuscular and skin surface temperature was weak, and the average difference was 2.5 degrees C, with a range from 0.4 to 4.6 degrees C. The spatial variation in skin surface temperature 5 mm around the central measuring point was small. The reproducibility of both intramuscular and skin surface measurements, as assessed by the standard deviation for a single measurement, was acceptable.

Adult↗
PubMed1991

Long-term effect of intra-articular injections of a glucocorticosteroid into the TMJ: a clinical and radiographic 8-year follow-up.

The long-term (8 years) effect of intra-articular injections of glucocorticosteroid into the TMJ on subjective and clinical dysfunction in the stomatognathic system and on the radiographic appearance of the TMJ was investigated in 16 patients with signs of TMJ arthritis. The subjective symptoms as well as the clinical signs were significantly reduced at the follow-up examination. Erosions of the bony articular margins of the TMJ that could be observed radiographically before treatment were found to be remineralized at the follow-up and associated with bony remodeling (deviation in shape) of the joint. The results indicate that the long-term prognosis of intra-articular glucocorticosteroid injections for TMJ arthritis is good and that there are no radiographically demonstrable side effects of the treatment.

Adult↗
PubMed1991

Short-term effects of intra-articular sodium hyaluronate, glucocorticoid, and saline injections on rheumatoid arthritis of the temporomandibular joint.

The short-term effect (4 weeks) of intra-articular injections of sodium hyaluronate, glucocorticoid, and saline was studied in three groups comprising 41 patients with rheumatoid arthritis of the temporomandibular joint. Sodium hyaluronate and glucocorticoid treatments had a significant positive effect according to the patients' subjective evaluation. A comprehensive clinical dysfunction score was reduced significantly in all groups, while the number of tender muscle regions was significantly reduced and the maximum voluntary mouth opening significantly increased in the glucocorticoid and sodium hyaluronate groups only.

Adolescent↗
PubMed1990

The effects of an occlusal splint on the electromyographic activities of the temporal and masseter muscles during maximal clenching in patients with a habit of nocturnal bruxism and signs and symptoms of craniomandibular disorders.

The effects of a full arch maxillary plane occlusal splint on the level of electromyographic (EMG) activity in the anterior temporal and masseter muscles during maximal clenching were studied in 31 patients with a habit of nocturnal bruxism and signs and symptoms of craniomandibular disorders, before and after occlusal splint therapy. The results showed, before treatment, that the occlusal splint changed significantly (in 71% of patients) the level of EMG activity during maximal clenching. However, these changes were not consistent and differed between patients and even, in some patients, between muscles. After long-term occlusal splint therapy and improvement of the signs and symptoms of craniomandibular disorders, the number of patients who had an identical level of EMG activity during maximal clenching in the intercuspal position and on the occlusal splint tended to increase. Moreover, in these patients the level of symmetry of action in pairs of muscles during maximal clenching was strong, and the splint did not change this level of symmetry.

Adolescent↗
PubMed1989

Comparison of 133Xe clearance and laser Doppler flowmetry in assessment of blood flow changes in human masseter muscle induced by isometric contraction.

Changes induced by 30 s of isometric contraction at 10% and 50% of the maximum voluntary contraction were assessed in 10 healthy subjects; there was a median increase of 1.8 and 0.3 times in 133Xe clearance and 5.3 and 2.7 times in laser Doppler flowmetry. In the first minute after 10% maximum voluntary contraction, 133Xe clearance increased 12.1 times in relation to the initial resting level, and flowmetry values decreased to become 3.5 times higher than the basal flow; corresponding values after 50% maximum voluntary contraction were 24.3 times and 3.7 times. From the second minute after contraction, there was a rapid decrease in 133Xe clearance and a slow decrease in flowmetry values. Five minutes after biting at 10% maximum voluntary contraction, both methods showed a total net increase of about 15 times; after biting at 50% maximum voluntary contraction the corresponding values were 38 and 23 times. Thus laser Doppler flowmetry can be used to assess changes in blood flow in the masseter; it registers a greater increase in flow during isometric contraction than does 133Xe clearance. The significant difference between methods immediately after either chosen level of contraction disappears when the total net post-contraction hyperaemia is assessed over a period of 2 and 5 min, respectively.

Adult↗
PubMed1989

Rehydration of lyophilised cartilage grafts sterilized by different methods.

In in vitro experiments weight increase and rehydration speed of lyophilised cartilage grafts sterilized by different methods were determined. For periods of up to 72 h the increase in weight during rehydration was measured. The methods of sterilization used is only of little significance for such weight increase. Differences in rehydration speed clearly correlate with the initial weight of the lyophilised cartilage grafts. Smaller grafts are completely rehydrated after 5 to 6 h. This may explain the discrepancies in rehydration speed reported in the literature.

Absorption↗
PubMed1989

Assessment of occlusal interferences.

The variability in the assessment of occlusal variables was investigated in eight subjects by the repeated registrations of four observers. The following variables were investigated in three different ways: sliding between the RCP (retruded contact position) and the ICP (inter-cuspal contact position) in the sagittal, vertical and lateral plane. Interferences during lateral movements on the working and balancing sides as well as interferences causing deviation of the mandible during protrusive movements were recorded. The intra- and inter-observer error for the measurement of sagittal and vertical distance RCP-ICP was within acceptable limits. There was no significant difference between the three methods used. The intra- and inter-observer agreement between duplicate recordings of the lateral distance RCP-ICP was high and there were no differences between the different measurement modalities. The inter-observer agreement was lower than the intra-observer agreement concerning presence/absence of balancing side interferences, and positive inter-observer agreement was only found on lateral movement more than 3 mm from the RCP or the ICP. The observer error for the variable working side interferences should be acceptable for future research, while the observer error for measurement of lateral deviation of the mandible upon protrusion was somewhat larger.

Adult↗
PubMed1989

Methodology for a better evaluation of the relation between mechanical strength of solids and polymorphic form.

In order to evaluate the role played by polymorphism in the mechanical strength of solid dosage forms (e.g. compressed tablets) and minimize the influence of other factors (such as compaction force, porosity, particle size, and possibly crystal habit), a melted disc technology was developed. With this technique, tablet-shaped discs of zero porosity were prepared by melting powder and subsequent crystallization in the desired modifications. Taking phenobarbitone as a model drug, different methods were used to get discs of forms I, II and III and the amorphous form. Mechanical properties of the discs were assessed, primarily through their bending strength. The Vickers hardness number was also determined for some specimen discs and monocrystals. Results showed that the amorphous form and form III of phenobarbitone gave the toughest discs and would therefore the most suitable materials to manufacture coherent tablets. Moreover, the various preparation methods used resulted in discs of different internal structures. Both crystal size and crystal habit significantly affected the physical properties of the tested materials.

Chemistry, Pharmaceutical↗
PubMed1989

Reproducibility of estimation of blood flow in the human masseter muscle from measurements of 133Xe clearance.

The reproducibility of estimations of the masseter intramuscular blood flow (IMBF) was assessed bilaterally within and between clinical sessions. The 133Xe clearance in nine normal individuals was measured before, during, immediately after, and after endurance of isometric contraction at an attempted level of 50% of maximum voluntary clenching contraction. An overall low reproducibility of the estimations was found. This result was probably caused by uncertainties about the exact site of intramuscular 133Xe deposition, errors in assessment of the plots of clearance, and variabilities in the relative contraction levels sustained and, especially, in the overall muscle effort. In agreement with previous reports concerning other skeletal muscles, the 133Xe clearance method provided inconsistent estimates of absolute values of IMBF also in this clinical setting. Although there was a high intra-individual variation in the relative level of isometric contraction sustained, the endurance test induced distinct changes in IMBF, among which the estimate of post-endurance hyperemia was the most consistent for each individual. Therefore, measurements of 133Xe clearance seem to be useful to detect intra-individual changes in masseter IMBF resulting from isometric work.

Electromyography↗
PubMed1989

[Significance of the upper neck joints in the etiology of pain in the head and neck area].

The function of the atlantooccipital joints is intimately connected with the function of the spine in total and the temporomandibular joint in special. The present investigation gives report of the frequent combination of headache, facial pain and pain in the temporomandibular joint, which could be found in patients of an orthopedic practice. The role of the atlantooccipital joints is stressed in a special manner and explained with the function of the arthromuscular control loop.

Atlanto-Axial Joint↗