Showing papers by "University of Bergen published in 1970"

Periodontal conditions in patients treated with dental bridges.

Abstract: The investigation was undertaken to evaluate the effect on the periodontal conditions of fixed unilateral bridges which had been in the mouth 1 to 3 years. Seventy-three bridges in 73 patients (50 women, 23 men) were examined. One group of 35 individuals had been instructed in methods for improving their oral hygiene, whereas another group (38 individuals) had not. In all, 146 abutment teeth were examined. An equal number of homologus teeth in the same patients served as controls. The gingival state and oral hygiene were recorded according to index systems proposed by Loe and Silness (1963) and Silness and Loe (1964). Pocket depth measurements were made as explained by Glavind and Loe (1967). The location of the crown margins of the bridge retainers was recorded according to a Margin Index System proposed by the author. The distribution of soft deposits and the location of gingivitis were similar around the abutment teeth and the homologous teeth. The average pocket depth of the abutment teeth was not deeper than that of the controls. In areas with crown margins below the gingival crest, more severe gingivitis was registered than in the control areas. The periodontal conditions were better in the individuals who had been instructed to practice oral hygiene measures as compared to the non-instructed individuals. Possible reasons why soft deposits remain undetected on clinical examination of subgingival restorations are discussed. It is suggested that the gingival inflammation around the abutment teeth and the homologous teeth is caused by the usual bacterial mechanisms.

Congenital hypoplastic thrombocytopenia and cerebral malformations in two brothers.

Abstract: At least two syndromes comprising disturbed blood cell production and congenital abnormalities have been reported. In 1927 Fanconi (7) described three brothers, 5-7 years of age, who developed chronic pancytopenia which proved fatal whitin a year of onset. Patients with Fanconi syndrome often have multiple congenital anomalies, abnormal pigmentation of the skin, stunted growth, strabismus, exaggerated reflexes and microcephaly. Aplasia of the radius is only reported in a few cases (3, 11). Isolated congenital hypoplastic thrombocytopenia associated with one or more anomalies has been reported in at least 35 cases (4, 5 , 8, 12, 15, 18) since Greenwald & Sherman in 1929 reported the first case (9). Cases with known intrauterine viral infections have been excluded. Aplasia of the radii seems to occur in about 2 / 3 of the cases. In fact, an attempt has been made to separate a special syndrome consisting of “aplasia of the radii, amegakaryocytic thrombocytopenia and leukemoid reaction” from the other cases of congenital hypoplastic thrombocytopenia (1, 6, 15). The most frequent other abnormalities are: other skeletal defects, cardiac and urogenital anomalies. Only one case of persistent congenital hypoplastic thrombocytopenia associated with microcephaly has been found in the literature (5 ) .

The biology of six species of Anomura (Crustacea, Decapoda) from Raunefjorden, western Norway

Abstract: Populations of six sympatric species, Galathea intermedia, Pisidia longicornis, Pagurus bernhardus, P. cuanensis, P. prideauxi, and Anapagurus chiroacanthus from two shallow sounds, were investigated during 18 months. Four types of bottom were distinguished. G. intermedia and P. longicornis were positively correlated with the amount of coarse substrate mainly consisting of empty shells; A. chiroancanthus showed a negative correlation. The pattern of distribution was studied by using the coefficient of dispersion. G. intermedia and P. longicornis were contagiously distributed; the other species occurred in too low numbers for the result~ to be valid. G. intermedia lived c. 1 year, and the larvae settled from Aug. to Nov. 0.002% were infected by Lernaeodiscus galatheae. P. longicornis reached an age of c. 2 years (some probably 3) and reproduced the first. The larvae settled mostly in Aug. and Sept. P. bernhardus, older than c. 1 year, probably migrated to deeper water. 2.1% were infected by Peltog...

Periodic lattice images of hydroxyapatite crystals in human bone and dental hard tissues.

Abstract: In the electron microscope, a repeating pattern of minute striations has been observed within hydroxapatite crystals. This fringe pattern can be explained as projections of planes of atoms or molecules on the image plane with a periodicity equal to the spacing between these planes in the crystal lattice. Previous studies have reported a pattern of 8.2 A repeat periods in hexagonal crystals of young rat enamel, representing the resolution of the 100 planes of the hydroxyapatite crystal lattice. In the present study, fringe patterns were demonstrated in crystals of human enamel, dentin, cementum, and bone tissue. When the incident electron beam was parallel to thec axis, the three sets of equivalent lattice planes parallel to this axis could be resolved simultaneously. Even those crystals which had an unusual external form showed a substructure that consisted of arrays of straight lines. Defects of the fringe pattern indicating dislocations or stacking faults in the crystal lattice were occasionally observed, in particular near the midline of the crystals. Thus, it appears possible to demonstrate visually not only variations in crystal size and shape but also the presence of lattice defects within individual apatite crystals. By high resolution electron microscopy it may prove possible to correlate the crystallinity of bone and tooth apatites to the fine structure of these tissues in normal and pathological conditions.

The morphology, occurrence, and distribution of dilated cisternae of the endoplasmic reticulum in tissues of plants of theCruciferae

Abstract: Morphology, occurrence, and distribution of dilated cisternae of the endoplasmic reticulum (ER) were studied by electron microscopy. The cisternae which contained an electron-dense matrix were intimately associated with the granular ER membranes appearing as tubular necks at the edges of the ER profiles. After budding off from the ER the cisternae still had ribosomes attached to the outside of the bounding membranes. The accumulations were variable in shape, being 0.4 to 1.5μ in width and 4 to 5μ in length.

Inner shell ionization by heavy, charged particles and associated energy loss of the projectile

Abstract: The process ofL- andM-shell ionization of atoms by heavy, charged particles is analysed in detail by a semiclassical, time-dependent perturbation method. The target electrons are described by non-relativistic hydrogenic wave functions. For the projectile is assumed a well-defined straight-line path. The Coulomb deflection and the screening is partially taken into account.

Cytochemical localization of myrosinase (β-thioglucosidase) in root tips ofSinapis alba

Abstract: A method for electron microscopic cytochemical localization of aβ-thioglucosidase (myrosinase) has been developed. Since sulphate is one of the products of the hydrolysis of sinigrin by myrosinase, it was felt that if the incubation was carried out in the presence of Pb++-ions an insoluble precipitate of electron-dense PbSO4 would be formed at the reaction sites. Following formaldehyde fixation a few different cell organelles in the extreme root tip ofSinapis alba showed reaction specificity for myrosinase but following glutaraldehyde fixation the enzymatic activity was inhibited. Biochemical tests of the isolated enzyme showed complete inhibition of the myrosinase by glutaraldehyde. Variations in the substrate concentration and incubation time indicated that the enzyme was confined to the dilated cisternae of the endoplasmic reticulum and in a limited extent to the mitochondria.

A comparison of the dentin-removing ability of five root canal instruments.

Abstract: — The dentin-removing ability of five root canal instruments was studied by enlarging 140 canals drilled in slices cut from young premolars. All canals were operated for two minutes using the instruments with a push and pull motion. The canal openings on both sides of each slice were photographed pre- and postoperatively according to a standardized routine. Thirty specimens were also photographed after the first minute of instrumentation. The areas of the canal openings were traced twice, and each tracing was measured twice by a compensating planimeter. The enlargement of each canal opening was then calculated, and the results were analyzed statistically. The results justified a grouping of the tested instruments according to their ability to remove dentin. The most efficient instruments were the Antaeose® nerve canal file type K 99 No. 2, length 26 mm and the standardized Kerr root canal file No. 15, style B, length 25 mm, both operated by hand. The second group consisted of the same Antaeos file driven by a Racer® contra-angled handpiece at 1500 rpm and the hand-powered Hedstrom® file No. 1, length 23 mm. The third group, exhibiting the lowest dentin removing ability, comprised the Micro-Mega® broach No. 3, length 21 mm, driven by the Giromatic® contraangled handpiece.

Attachment of plaque and calculus to tooth surfaces.

Abstract: The ultrastructural nature of the interface between dental hard tissue and soft and calcified deposits was studied in undecalcified and decalcified thin sections from 28 extracted human teeth. Uncalcified plaques contained clusters of densely packed microorganisms which adhered to cuticular structures or directly to the tooth surface. In calcified deposits, on the other hand, larger amounts of intercellular material generally separated the cells from each other and from the tooth surface. An intimate relationship existed in most instances between the intercellular matrix of calculus and the organic matrix of the dental hard tissue as well as between the mineral crystals of calculus and those of the underlying tooth surfaces. Mechanical locking of the deposits in cracks, resorptions, carious lesions, and other defects of the tooth surface was frequently observed. Moreover, calculus was closely adapted to the sub-microscopic irregularities which were present even on “smooth” tooth surfaces. At the ultra-structural level, the predominant mode of attachment appeared to be the adhesion of organic interbacterial substance to the tooth surface, in addition to intercrystalline forces of inorganic nature acting between crystals of calculus and underlying tooth substance. The relative importance of the latter factor presumably increases as the concrement matures.

An estradiol mitotic rate inhibiting effect in the müllerian epithelium in neonatal mice

Abstract: Beginning within 24 hours after birth, young mice were given daily subcutaneous injections of 5 μg estradiol-17β in olive oil. The mice were sacrificed at varying times; six hours before death, they were given a subcutaneous injection of colchicine. The mitotic rate was studied in the epithelium in the uterine horns, uterine cervix, and mullerian vagina. Eighteen hours after the first estradiol injection, the mitotic rate was increased in the uterine epithelium, but decreased in the cervical and mullerian vaginal epithelium compared with the controls. At a continued treatment with estradiol, the mitotic rate values decreased to a level somewhat below the control level in the uterine horns; in the uterine cervix and mullerian vagina the mitotic rate decreased to very low values, significantly lower than in the corresponding regions in the controls. The mechanisms behind this mitotic rate inhibition as well as its consequences are discussed.

Antibodies in humans to an isolated antigen from oral fusobacteria.

Abstract: Sera from 31 individuals (19 females, 12 males, 23–58 years) were tested for antibodies agglutinating tanned sheep erythrocytes sensitized with two different preparations of Precipitinogen 2 from Fusobacterium. At 1:8 dilution positive reactions were found in 23 sera (74%). There appeared to be no correlation between titre levels of hemagglutinating antibody and the severity of perio-dontal disease as measured by the Periodontal Index (Russell 1956). In 5 out of 8 rabbits given 160 mg human γ-globulin (Kabi) intravenously, intradermal injections 20–45 min later of 0.1 to 0.4 mg of Precipitinogen 2 produced Arthus-like reactions, reaching a maximum after 4–8 hours. Intradermal injections in 6 rabbits of the same quantities of Precipitinogen 2 without previous injection of γ-globulin gave inflammation, sometimes slowly progressive and reaching a maximum after approximately 20 hours. Intravenous injection of 250 μg of endotoxin from Fusobacterium 24 hours after local injection of Precipitinogen 2 produced no change in the appearance of the lesions.

The effect of polyvinyl alcohol and polyvinyl pyrrolidone on diffusion artifacts in lactate dehydrogenase histochemistry.

Abstract: The effect of polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP), alone and in combination, on diffusion artifacts in histochemical incubations has been investigated using LDH as model enzyme. By measuring the amount of formazan in the medium at the end of the incubation it has been shown that both substances, but especially PVA, are effective in limiting diffusion. The significance of this is discussed in general as well as in relation to other procedures used to reduce diffusion artifacts.

On the morphology of the head in four species of the Cucullanidae (Nematoda).

Abstract: The morphology of the head, mouth, and oesophagus in four species of the nematode family Cucullanidae Cobbold, 1864, has been studied in detail. The species examined are: Cucullanus cirratus Muller, 1777 and C. heterochrous Rudolphi, 1802 from the west coast of Norway, C. minutus Rudolphi, 1819 from Scotland, and Dacnitis truttae (Fabricius, 1794) from east Norway; the first three are from marine fish, the last from a freshwater fish. In the Cucullanus species, transverse cuticular structures projecting into the muscle mass from the pseudobuccal capsule are described, illustrated, and named. Such projections are absent in Dacnitis, but the pseudobuccal cuticular lining forms thickened plates separated by narrow grooves which form a characteristic pattern. The morphology of the pseudobuccal capsule and its associated cuticular structures may be used as taxonomic characters at the species level, possibly also at genus and higher levels. A new definition of Dacnitis is proposed. The functional signi...

Subcorneal pustular dermatosis. Pathogenetic aspects.

Abstract: SUMMARY.— Two patients with subcorneal pustular dermatosis are presented. No qualitative or quantitative changes of the serum proteins were revealed by immunoelectrophoresis and radial immunodiffusion. Microtome sections of frozen blister specimens were incubated with human red cells (O Rh-negative). The erythrocytes adhered to the stratum corneum composing the roof of the blister. This reaction was inhibited by conglutinin. The blister fluid selectively lacked antibodies to stratum corneum. These results suggest the formation of antigen/antibody/complement complexes in vivo. At least part of the tissue damage in subcorneal pustular dermatosis may be immunologically mediated.