Topical application of fluorides on teeth

Abstract Prevention of caries in exposed root surfaces constitutes an important clinical problem. It is thus important that clinicians involved with periodontology have an insight into fluoride prophylaxis. The understanding of the cariostatic mechanism of fluoride has improved during recent years. The aim of the present review is to give a short account of the present concept. Calcium fluoride appears to be the only product which is formed on enamel, dentin or cementum during brief topical treatments with fluoride or use of toothpaste containing fluoride. This calcium fluoride is stable in the oral environment: this is contrary to what was believed until recently. The calcium fluoride constitutes a pH-dependant reservoir of fluoride which releases fluoride when pH drops. The practical consequences of this concept is discussed.     

Synergistic actions of the vitamin D analogue MC 1288 and 15-deoxyspergualin in xenotransplantation

Abstract: The vitamin D analogue MC 1288 (20-epi-1α,25-dihydroxycholecalciferol) effectively postpones rejection of cardiac, intestinal, skin, and aortic allografts. MC 1288 binds to the vitamin D receptor and is thus assumed to exert its immunosuppressive effects via the same mechanisms as 1α,25-dihydroxycholecalciferol, the active form of vitamin D. 1α,25-Dihydroxycholecalciferol has been demonstrated to inhibit the production of various cytokines (interleukin-2, interferon-γ, granulocyte macrophage colony-stimulating factor, and interleukin-12) and to prevent B lymphocyte secretion of immunoglobulins. In the present study MC 1288 was evaluated for its ability to prevent rejection of mouse-to-rat cardiac xenografts, alone and in combination with 15-deoxyspergualin (DSG). Combined treatment with MC 1288 (given days -1 to 9) and DSG (given day -1 and onward) postponed rejection from day 3.0 (untreated recipients) until day 19.5. In rats treated with MC 1288 or DSG as monotherapy, rejection occurred after 3.0 and 7.5 days, respectively. Functioning grafts, obtained on day 9 from recipients treated with MC 1288 and DSG in combination, displayed an almost normal morphology without any obvious deposition of immunoglobulins in the vessels of the grafts and with just a few infiltrating cells. Thus, we have demonstrated synergistic actions of MC 1288 and DSG in delaying rejection of xenografts. Analysis of cellular infiltration, immunoglobulin deposition and graft survival times in the various treatment groups indicate a combined inhibitory effect of these two drugs on the level of macrophage effector function, direct or indirect via T lymphocytes, as well as on antibody production.     

CSF testosterone in 43 male suicide attempters.

Several studies have shown a relationship between high testosterone and violent aggressive behaviour. The general aim of this study was to gain knowledge of the importance of testosterone in suicide attempters. Testosterone in cerebrospinal fluid (CSF) was analysed in men with a recent suicide attempt, diagnostically subdivided into groups according to DSM-III-R axis I and II diagnosis and mode of suicidal behaviour. In general, our patients had lower CSF testosterone levels than aggressive violent patients in other studies. Patients with depression NOS or dysthymia showed higher CSF testosterone levels than the rest. Significant positive correlation between testosterone and irritability or a negative correlation with social desirability was found in diagnostic subgroup of patients, specifically axis II, cluster B personality disorders. The results suggest that suicide attempts may be mediated by different biological variables than aggression.     

Does the nature of the solvent affect the anti-inflammatory capacity of triclosan? An experimental study

Abstract The anti-inflammatory properties of triclosan have been revealed in several recent studies, including an effect on histamine-induced inflammation. In other studies, the nature of the solvent has been shown to be of importance for the plaque inhibiting as well as the antibacterial potential of triclosan. This study was aimed at examining whether the nature of the solvent also may influence the anti-inflammatory capacity of triclosan and further to study a possible dose/response relationship. The study was performed as 3 separate, double-blind experiments, comprising 10, 11 and 12 healthy females. In all 3 experiments, 5 sites on the lower part of the back of the volunteers were intradermally exposed to one drop of 1% histamine dihydrochloride for 15 min. The size of the resulting wheals was recorded before and after 40 min of triclosan treatment. In experiment I. 4 different concentrations of triclosan in 2-fold dilutions in absolute alcohol (0.125%-1%) were applied on the histamine-induced wheals. In experiments 2 and 3, 4 different solutions containing 0.5% triclosan and a saline solution as negative control were used. The solvents in experiment 2 were as follows: (1) absolute alcohol (positive control). (2) propylene glycol (PG), (3) polyethylene glycol (PEG). (4) olive oil, and in experiment 3: (1) absolute alcohol (positive control). (2) Tween 80. (3) sodium carbonate, (4) soy oil. The results showed a dose/ response effect of triclosan and further that the solvent may be of importance for its anti-inflammatory potential.     

Comparison of some salivary variables between vegetarians and omnivores

The aim of the study was to compare salivary variables in a group of vegetarians with a group of omnivores. Twenty-nine vegetarians, 19 women and 10 men, mean age 35 yr, and 28 omnivores, 20 women and 8 men, mean age 35 yr, were compared in terms of salivary secretion rate, pH, buffer capacity, mutans streptococci and lactobacilli. The vegetarians had a significantly higher secretion rate, but there were no other significant differences regarding the salivary variables. The difference in secretion rate may have been caused by some lifestyle factor(s) differing between vegetarians and omnivores which probably mainly include nutrient(s), texture and roughness of the food.     

Functional mri of human brain activation combining high spatial and temporal resolution by a cine flash technique

Functional mapping of human brain activation has been accomplished at high spatial and temporal resolution (voxel size 4.9 μl, temporal increment 100 ms). The approach was based on oxygenation-sensitive long-echo time FLASH MRI sequences synchronized to multiply repeated cycles of visual stimulation in a CINE acquisition mode. This high temporal resolution revealed that stimulus-related signal intensity changes in human visual cortex display an initial latency followed by increases extending over several seconds. Furthermore, the temporal characteristics of the complete CINE MRI signal time course depended on the absolute and relative durations of activation and control periods and, for example, caused an apparent absence of a poststimulation “undershoot” phenomenon. Complementing hyperoxygenation due to rapid hemodynamic adjustments, these results suggest signal intensity modulation by enhanced oxygen consumption and concomitant deoxygenation during prolonged and/or repetitive stimulation.     

The Stockholm breast cancer screening trial — 5-year results and stage at discovery

In screening programmes it is important to assess a preliminary effectiveness of the screening method as soon as possible in order to forecast survival figures. In March 1981 a controlled single-view mammographic screening trial for breast cancer was started in the south of Stockholm. The population invited for screening mammography consisted of 40,000 women aged 40–64 years, and 20,000 women served as a well-defined control group. The main aim of the trial was to determine whether repeated mammographic screening could reduce the mortality in the study population (SP) compared to the control population (CP).The cumulative number of advanced mammary carcinomas in the screening and the control populations from the first five years of screening have shown a tendency towards more favourable stages in the screened population aged 40–64 years. A breakdown by age suggests an effect in age group 50–59 years, but not yet in age groups 40–49 and 60–64 years.When comparing the rates of stage II+ cancer, an increased number is found in the study group. As the total rate of breast cancer is higher in SP than in CP, there ought to be a concealed group of stage II+ cancers in the CP which makes the comparison biased. A new approach has been designed, where an estimation of the hidden number of stage II+ cancers in CP is added to the clinically detected cases, and in this respect a comparison has shown a decrease in the cumulative number of advanced cancers in the SP in relation to the CP (p<0.05). According to this it could be important to add the estimated number of undetected, hidden cases in the control group in order to utilize the difference in detection rate in the screening- and control group respectively.     

The Genée-Wiedemann syndrome,an acrofacial dysostosis—further observation

We report on a consanguineous Brazilian couple whose 2 children had tibial aplasia-ectrodactyly. Femoral bifurcation was present in one of the affected children. The relationship of tibial aplasia-ectrodactyly to the Gollop-Wolfgang complex is discussed. Clinical and genetic aspects of the conditions involving tibial aplasia and femoral bifurcation are discussed.     

Immunolocalization of lamins and nuclear pore complex proteins by atomic force microscopy

The nuclear envelope functions as a selective barrier separating the nuclear from the cytosolic compartment. Nuclear pore complexes (NPCs) mediate nuclear import and export of macromolecules and, therefore, are potential regulators of gene expression. In this study we applied atomic force microscopy (AFM) to visualize the three dimensional (3D) structure of individual NPCs in the absence and presence of two different antibodies, one directed against a pore protein (gp62) and another directed against Xenopus lamin LIII, a component of the nuclear lamina, a filament meshwork localized on the nucleoplasmic side of the nuclear envelope (NE) adjacent to and interacting with NPCs. Using 12-nm gold-labelled secondary antibodies and transmission electron microscopy we could clearly localize the primary single anti-gp62 antibody on NPCs and the primary single anti-LIII antibody between NPCs. Using AFM, the secondary antibodies against anti-gp62 could be detected as particles 7 nm in height on the nucleoplasmic face of NPCs. The secondary antibodies against anti-LIII could be clearly identified between NPCs. The secondary antibodies, attached to a 12-nm colloidal gold particle and visualized on glass, revealed similar shapes and heights as found on NEs. According to the 3D images, the volume of a single gold particle conjugated with secondary antibodies was 10 203 nm³. This volume is equivalent to the volume of 38 IgG molecules associated with one individual gold particle. A similar volume of 11 987 nm³ was calculated from a model assuming that the 150-kDa IgG molecules perfectly cover the spherical gold particle. We conclude that AFM can be used for identifying antibodies or other macromolecules associated with biomembranes.