Gastrointestinal and in vitro release of copper, cadmium, indium, mercury and zinc from conventional and copper-rich amalgams

Abstract – Particles of a conventional lathe-cut, a spherical non-gamma 2 and a copper amalgam have been gastrointestinally administered to rats for the purpose of evaluation of the dissolution resistance. The animals were sacrificed after 20 hrs. The contents of copper, cadmium, indium, mercury and zinc in kidney, liver, lung or blood were measured using nuclear tracer techniques. From a copper amalgam an extreme release of copper was demonstrated. This study simulates the clinical condition of elemental release from swallowed amalgam particles after amalgam insertion or after removal of old amalgam fillings. Specimens of the same types of amalgams were also exposed to artificial saliva for a period of 10 days. The amounts of copper and mercury released were measured with flame and flameless atomic absorption spectrophotometry respectively. The levels of copper and mercury released from the copper amalgam were approximately 50 times those of the two other amalgam types studied.     

Muscle Function and Morphology in Myotonic Dystrophy

Abstract. Patients with myotonic dystrophy classified clinically into function groups were studied. Muscle strength for knee extension and flexion was, with few exceptions, moderately or markedly reduced with successively more severe clinical disability. The reduction in maximal walking speed showed a similar tendency. There was a large percentage of both type I and in relation to normal findings of type II C fibers in biopsies from most patients. The fiber area varied greatly even in the patients in the best function groups, some of whom had large type II fibers. The most common histopathological changes, found in all function groups, were fiber atrophy with small angular fibers, internal nuclei, splitting, fibrosis and moth-eaten fibers. A high percentage of type I fibers can already be seen in patients with practically no other morphological changes and without significant functional deterioration.     

Iron staining of the acquired enamel pellicle after exposure to tannic acid or chlorhexidine: preliminary report

Abstract – Extrinsic discoloration of teeth following a large consumption of tannin-containing beverages or a prolonged use of chlorhexidine mouthrinses is a well known observation. Tannins as well as chlorhexidine are denaturing agents. Based on preliminary studies revealing the presence of iron in chlorhexidine discolored pellicle material, the ability of iron to stain the integument after pretreatmentwith the two denaturants was studied in a human model. The denaturing effect of an acidic environment was also included. Enamel slabs fixedto acrylie appliances were carried in the oral cavity and alternately exposed to the test solutions in different sequences in vitro. Pretreatment with chlorhexidine or tannic acid led to marked discolorations upon iron application during 5-d tests, whereas the compounds individually had no such effect. A large content of the metal was found in the stained material. Stannous fluoride appeared to reduce the formation of the pigments, and strong oxidation completely bleached the established color. Possible mechanisms underlying the phenomena observed are discussed.     

Cinefluoroscopic study of long-term changes of bolus position and chewing cycle duration after fixed prosthetic treatment

Abstract— Some chewing parameters were studied in 12 patients with a complete maxillary denture and a 12-unit fixed mandibular denture anchored to the two canines. Registration by means of fluoroscopy were made before, 1 month after, and in four patients 13 yr after treatment. The mean velocity of the mandible during chewing increased after the prosthetic treatment and remained stable for meat during the observation period. At the first registration, before treatment, the bolus was most frequently located in the anterior region. After completion of the prosthetic rehabilitation, the bolus was mainly located to the lateral segments during chewing of the test foods, namely meat and bread. The recordings were almost identical 13 yr later. Despite a very reduced periodontal support, posterior cantilevered segments were satisfactorily used in comminution and the patients seemed to be unaware of the forces exerted on the remaining teeth.     

Comparison of effects of electromyographicbiofeedback and occlusal splint therapy on mandibular dysfunction

Abstract – In order to evaluate and compare the effects of biofeedback and occlusal splint therapy on mandibular dysfunction, 30 patients were randomly divided into two treatment groups. The patients were women aged 20–40 years without any obvious organic- reasons for their symptoms. There were no signiGcant differences between the two groups before the start of treatment in respect of signs and symptoms of mandifoiaiar dysfunction. One group used full coverage splints at night for 6 weeks. The other group received biofeedback training up to six times, 30 min per session. One month after completion of the therapy the patients were re-examined. Both groups showed a significant reduction in symptoms, both subjectively and clinically. No significant differences between the groups were found. The two treatments were thus equally effective in the short-term perspective in patients with signs and symptoms of mandibuiar dysfunction.     

Polysaccharide production by cell free transferases in saliva in relation to salivary microflora

Abstract – The supernatant of centrifuged whole saliva was incubated with radiolabeled sucrose to measure polysaccharide production by cell free transferases and to examine whether water-insoluble polysaccharides were produced. Amounts of polysaccharides were considered to reflect the level of cell free transferases in saliva. Plating samples on blood agar, MS and MSB plates gave salivary counts of total CFU, total streptococci, S. salivarius and S. mutans. The capability of the cell free portion of saliva to produce polymers was confirmed and it appeared that the cell free transferases were able to produce water-insoluble polysaccharides. Significant correlations were found between the total and the insoluble polysaccharides from ¹⁴C-G’-sucrose and total CFU, total streptococci, S. salivarius and S. mutans, respectively. Heavily S. mutans infected subjects seemed to produce particularly large amounts of water-insoluble polysaccharides from ¹⁴C-G’-sucrose. The apparently water-insoluble ¹⁴C-F’-polysaccharides correlated significantly to the number of S. salivarius. It was thus concluded that the constitution of the oral microflora and particularly the levels of S. mutans and S. salivarius were of importance for the level of cell free transferase activity.     

Transfer properties of the slowly adapting stretch receptor of the crayfish abdomen

The slowly adapting stretch receptor in the abdomen of freshwater crayfish (Astacus fluviatilis) was investigated to determine its properties under dynamic conditions. An in situ preparation was used; the necessary dissection did not involve the receptor organ or its immediate surroundings. Sinusoidal variations in the angle of flexion in the joint to which the receptor organ was connected, were generated by a feed-back controlled stretcher. Nerve spikes recorded from the axon of the receptor neurone and information about angle of flexion in the joint obtained by position transducers, were fed into a computer. Fourier transforms were performed on both input and output data to determine the amplitude of the 0. and I. harmonic together with the phase of the 1. harmonic. The receptor organ was investigated for linearity up to 1.5 degrees input amplitude, and proved to be surprisingly linear within this range. In addition, the transfer function of the receptor organ was determined by stimulating it with small-amplitude sinusoidals with different frequencies. With a steady flexion of 35–40° in the joint, the gain of the receptor organ increased 5–6 times when the modulation frequency of the input signal was increased from 0.1 to 5 cycles/s. A maximum in gain was constantly found at about 5 cycles/s, with a rapid fall towards 0 when the modulation frequency was increased further. A change in phase lead from positive (leading output) to negative with change in sign about 1 cycle/s was also found. These results resemble the results found by investigators of isolated preparations. A “hold” property is probably a part of the overall property of the receptor organ together with an element of Maxwell type. An element of the form h(s)=ksⁿ with n=0.45 is also a part of the transfer function of the receptor organ, although the physiological parallel to this element is uncertain.     

Metabolism of xylitol in dental plaque

Abstract – It has been reported previously that xylitol added to glucose used to challenge dental plaque in vivo caused a reduced acid formation. The aim of the present study was to approach the mechanism by which xylitol may affect glucose catabolism in plaque bacteria. Suspensions of freshly collected 4-day-old plaque bacteria were ineubated, one batch with labeled xylitol, one with labeled glucose, in vitro at 37°C. Samples of cells were taken out at time intervals, collected on paper discs and subjected to scintillation counting. It was observed that the plaque bacteria took up xylitol, the uptake increasing with incubation of more than 3–4 h, whereas the same cells took up glucose immediately. Cells which had taken up xylitol were extracted with boiling water, extracts concentrated and applied on thin-layer chromatography sheets. A radioactive component with mobility like xylitol-5-phosphate was isolated from the cell extracts, and also a component where labeled xylitol was associated with macromolecules. It is suggested that the accumulation of the metabolities within the cells inhibits glycolysis.     

One-year Sequential Follow-up of Venous Emptying Rate and Leg Temperature Profiles after Acute Deep Vein Thrombosis

Abstract. In order to study the natural course of venous flow and temperature reaction in the legs after symptomatic first episode of deep vein thrombosis (DVT), 65 patients (57 with proximal DVT) without further thromboembolic complications during the observation period were followed for 1 year by repeated plethysmography (PG) and thermography (TG). Regarding the non-invasive parameters substantial individual variations were observed during the observation period. After 1 year pathologic PG and TG were still demonstrated in 39% (I_μ (95%) = /0.43±0.05/) and 65% (I_μ (95%) = /1.18±0.11/), respectively, of the patients after proximal DVT. Only a minority of the patients were normalized permanently in both PG and TG during the first year. The high frequency of remaining venous obstruction and especially, persistent thermoactivity is notable and may be of clinical importance.     

Plaque inhibition by guanidino propyl piperazine (CKO 569A)

The plaque inhibiting effect of the antibacterial substance, guanidino propyl piperazine (CKO 569A) has been analyzed in a clinical study of 10 adults. Plaque formation was enhanced by three daily rinses with 15% sucrose. Normal hygiene was performed. The effects of a twice daily mouthwash of 30 s duration with 0.2, 0.1 and 0.05% CKO 569A, 0.05% chlorhexidine and a placebo on plaque formation were compared through a registration of plaque scores. Each solution was tested over a period of 5 days. As a result of this study it could be concluded that in humans CKO 569A is an effective inhibitor of plaque, and that lingual plaque scores appear to be a good indicator of plaque inhibiting activity.