Histometric study of root resorption on human premolars following experimental replantation

Abstract – A histometric method was applied for evaluation of root resorption in 57 experimentally replanted teeth and 22 controls. Representative axiobuccolingual sections were selected for measurement of resorptions at a magnification of × 40. The frequency of root resorption in the control teeth was low. In replanted teeth marked resorptive activity elicited by the trauma appeared after 2 wk. The extent of active resorptions increased until the third postoperative week. On an average 14% of the root periphery was affected at this stage. After the sixth postoperative week progressive cement deposition took place in the resorption lacunae. Incidental ankylosis of the periodontal membrane also occurred from this observation time but there was no increase among the long-term groups.     

Microradiographic and polarized light study of red deer root dentin with special reference to occurrence of giant tubules

Abstract – Radiolucent bands following the course of the dentinal tubules were observed in sections of undemineralized roots of permanent red deer incisors. Some of these bands, previously unreported in mammalian root dentin, contained giant tubules similar to those described earlier by the author in the coronal dentin of this animal. The root giant tubules initiated with funnelshaped orifices at the border of the pulpal cavity and, generally, terminated in the peripheral dentin, whereas a few penetrated into the cementum. Whether the giant tubules should be considered to be anomalous dentinal tubules or a different type of structure could not be determined. The distinction between root giant tubules and accessory canals being part of the apical ramification did not represent any problem.     

Yersuche über mikrochemische Reaktionen.

• 1 Die fällende Wirkung von Sulfosalizylsäure und Lanthannitrat auf Eiweiss, Nucleinsäure und Eiweiss-Nucleinsäuregemische bei verschiedenen Wasserstoffionenkonzentrationen wurde quantitativ untersucht. Es wurde gezeigt, dass, während Eiweiss von Sulfosalizylsäure, Nucleinsäure von Lanthannitrat (aber nicht umgekehrt) gefällt wurden, Eiweiss-Nucleinsäure-Gemische mit beiden Reagentien Fällungen gaben.
• 2 Mit gepufferten Lösungen von Sulfosalizylsäure und Lathannitrat konnte gezeigt werden, dass rote Blutkörperchen von Eidechsen in einem gewissen Funktionsstadium, das möglicherweise mit der Zellteilung zu tun hat, eiweissfreie oder sehr eiweissarme Zellkerne hatten, während die Zellkerne der eigentlichen Zellteilungsprozesse stark eiweisshaltig waren.

     

Column-like structures following the course of tubules in human dentin

Abstract – Sections, 60–180μm thick, of permanent teeth, intact or with minor fillings, were cut parallel or transversal to the course of the dentinal tubules. Some teeth were dermineralized, embedded in paraffin wax, cut in series, and stained with toluidine blue pH 5.6, hematoxylineosin, or PAS. Altogether, sections of 90 teeth were examined by ordinary and polarized light microscopy and contact microradiography. Alternating light and dark bands, usually 8–30μm wide, extended from the pulpal border along the course of the tubules, gradually increasing in width, fading in the mantle dentin. Cross-sectioned bands appeared as dark and light "discs". This was the background for the term "columns". In the dark columns, usually exhibiting crowding of tubules, the intertubular dentin was dark and radiolucent; in the light columns, light and radiopaque. Dark columns contained a high amount of GAGs, assumed to have exerted an inhibitory effect on their mineralization. The columns probably represent structural elements in the architecture of dentin, possibly offering resistance against mechanical stress. It was suggested that the columns might depict functional differences in the matrix secretion and mineralization capacities of odontoblasts.     

PNEUMOENCEPHALOGRAPHIC FINDINGS IN VARIOUS PRIMARY and SECONDARY MUSCULAR DISORDERS

Pneumoencephalography was carried out in 23 patients with various muscular disorders, i.e. spinal neurogenic atrophy, classified as Wohlfart-Kugelberg-Welander's and Charcot-Marie-Tooth's diseases, and muscular dystrophy. EEG-registrations and psychological testing were carried out. Pneumoencephalography revealed ventricular enlargement and cortical changes in 17 out of 23 cases. Changes were found in all three groups studied; cortical changes were, however, only found in the neurogenic atrophy groups. Cases where there clearly might be exogenous causes for ventricular dilatation were excluded. The changes found, therefore, supposedly form an integral part of the disease process. It should be emphasized that the precaution does not entirely exclude a traumatic etiology in some cases. EEG-registrations (pathological in three out of 20 cases) as well as psychological evaluation (pathological in six out of 14 cases) supported the assumption of organic brain changes. Pneumoencephalography, however, seemed to be the most sensitive parameter for unveiling brain involvement in these disorders.     

Structure of experimental in vitro and in vivo lesions around composite (Addent XV®) fillings

abstract — In the in vitro experiments of the present study Class V Addent XV® fillings were inserted on buccal surfaces of 32 permanent human teeth. Lesions were produced by placing acidified gelatin around the fillings. In the corresponding in vivo experiments, caries was produced around similar fillings in 17 permanent teeth. In both series, sections of the teeth with the fillings in situ were studied by polarized light microscopy and microradiography. All teeth showed "outer lesions", but the tendency to development of "cavity wall lesions" was negligible. A comparison with lesions produced previously in corresponding experiments with silver amalgam and silicate fillings has been done.     

Reduction of Blood Pressure by Treatment with Alphacalcidol

ABSTRACT Disturbances of calcium or vitamin D metabolism have been suggested to be of pathogenetic importance both for hypertension and impaired glucose tolerance, two disorders that are commonly associated. In the present study 65 men, aged 61–65 years, with impaired glucose tolerance were enrolled in a prospective, double-blind, placebo-controlled study over 12 weeks evaluating the effects of 0.75 μg alphacalcidol, a synthetic analog to the active metabolite of vitamin D. In the 26 patients with blood pressure ≥ 150/90 mmHg before treatment a significant reduction (p < 0.01) of both the systolic (SBP) and diastolic (DBP) blood pressure was found after therapy (from 171/95 to 150/88 mmHg). The effect was additive to concomitant antihypertensive treatment and was correlated (p = 0.03) to a reduction of serum levels of parathyroid hormone. Also in the whole group of patients given alphacalcidol blood pressure was moderately lowered from a mean of 152/87 ± 22/10 (SD) to 143/84 ± 17/8 mmHg. There were no relationships between the changes in body weight, blood glucose or insulin parameters and the changes in blood pressure during the trial. The findings are compatible with the concept that calcium metabolism influences blood pressure regulation and suggest that supplementation with a physiologic dose of active vitamin D could be beneficial for patients with high blood pressure.     

Evaluation of rat incisor mesenchymal cells in bleomycin injected animals fixed by immersion or perfusion

Bleomycin was administered to four groups of rats in a single intravenous injection of 25 mg/kg, 50 mg/kg, 75 mg/kg and 100 mg/kg, respectively. The animals were killed by perfusion or by decapitation followed by immersion fixation at 24 h and 5 days after injection. Sections were made of maxillary incisors and evaluated by light microscopy. Bleomycin produced a transitory arrest of dividing cells resulting in an apparent synchronization of the cell population. Necrotic cells were found within the basal pulp and the preodontoblasts at 1 day observation time. After 5 days a dentinal lesion was observed at the two highest dose levels and the necrotic areas were filled in by proliferating adjacent cells. A better quality of fixation, especially of cells surrounded by dentin, was observed in perfusion fixed animals but the fixation procedure did not influence the alterations found in experimental animals.