Periodontal conditions of adult regular dental care attendants

Abstract The purpose of the present study was to examine longitudinal alterations in the periodontal conditions of regular dental care attendants, 225 randomly selected patients (age 18–65 years) at 12 community dental clinics in the county of Värmland, Sweden, were subjected to a baseline clinical and radiographic examination in 1978 and to a re-examination in 1990. During the study period, all participants received preventive and therapeutic measures according to decisions made by the dentist on duty in the clinics. The examinations involved assessments of number of remaining teeth, plaque, gingivitis, probing pocket depth, loss of probing attachment and periodontal bone height. The results showed that during the 12 years of monitoring, an average of 0.4 teeth were lost, The % of tooth sites with gingivitis was lower in 1990 (4%) than in 1978 (15%), but no major changes were found for the mean probing pocket depth. The mean probing attachment loss during the 12 years amounted to 0.5 mm. The tooth site analysis revealed that buccal sites had experienced more loss of attachment than lingual and approximal surfaces. Whereas no differences were observed between age groups with respect to longitudinal loss of attachment at lingual and approximal tooth sites, the youngest age group demonstrated more pronounced loss at buccal surfaces than older subjects. The radiographic assessments of the alveolar bone height revealed a mean longitudinal loss amounting to 0.2–0.4 mm in the various age groups. The time-lag comparison revealed less tooth mortality, lower gingivitis scores, less probing attachment loss and less periodontal bone loss in 1990 than in 1978 for subjects of the age 30–53 years, whereas the data were similar for older subjects. The improvement was the result of less breakdown at lingual and approximal sites, whereas no difference was evident for buccal surfaces.     

Anti-Gal activity In diabetic patients transplanted with fetal porcine Islet cell clusters

Abstract: The natural anti-Gal antibody seems to create a major obstacle for discordant xenotransplantation in humans. It is produced in large amounts in humans (20–100 μg/ml serum), and interacts specifically with the carbohydrate structure Galα1–3Galβ1–4GlcNAc-R (termed, the a-galactosyl epitope). The a-galactosyl epitope is produced in large amounts on porcine cells, as on cells of other nonprimate mammals (1×10⁶ to 35×10⁶ epitopes per cell). The interaction of anti-Gal with α-galactosyl epitopes on the xenograft was found to mediate the immune destruction of discordant xenografts. In view of the intensive production of anti-Gal under physiologic conditions, it was of interest to determine whether the immune system in humans reacts against α-galactosyl epitopes on xenografts by increasing the activity (i.e., titer and affinity) of this antibody. For this purpose, anti-Gal titer and affinity were studied in sera of diabetic patients transplanted with fetal porcine islet cell clusters (ICC) by Groth and colleagues (Lancet 1994:344:1402). Titers of anti-Gal were determined by a hemagglutination assay with rabbit red blood cells and by ELISA with mouse laminin as a solid-phase antigen. Affinity of the antibody was estimated by equilibrium dialysis with the radiolabeled free haptenic form of the a-galactosyl epitope, i.e. [³H]Galα1–3Galβ1–4GlcNAc. All assays revealed a marked increase in anti-Gal activity within 5–8 weeks posttransplantation. The increase in anti-Gal titers ranged between eight-and sixty-four fold. A similar increase was observed in the affinity of anti-Gal, as assayed in equilibrium dialysis. Immunoglobulin concentration did not increase posttransplantation, suggesting that the observed increase in anti-Gal activity is the result of a specific immune response against α-galactosyl epitopes on the xenograft. The elevation in anti-Gal activity was observed in all three immunoglobulin classes and the highest activity was found within the IgG class. Furthermore, analysis of antibodies against porcine endothelial cells in ELISA has indicated that most of the increased activity against these cells in the serum of the transplanted patients, may be attributed to the elevation in activity of anti-Gal. These findings raise the possibility that anti-Gal, which is highly active in patients with xenotransplants, may contribute to chronic rejection of the xenograft by binding effectively to α-galactosyl epitopes on the xenograft cells and inducing inflammatory reactions against the graft.     

A comparison of strengths of five core and post-and-core systems.

OBJECTIVE: In this in vitro study, the strength of several core and post-and-core systems was compared. A second aim was to compare the strength of posts and cores on root-filled teeth with that of cores on vital teeth. The failure modes of the core and post-and-core systems were also studied. METHOD AND MATERIALS: For root-filled teeth, Composipost carbon fiber dowels and gold alloy posts and cores were tested. For vital teeth, glass-ionomer cement with threaded parapulpal retention pins, resin composite with threaded parapulpal retention pins, and gold alloy with parallel parapulpal pins were tested. Specimens were tested in a Zwick universal material-testing machine. RESULTS: A significant variation in strength was found among core systems of cast gold, resin composite, and glass-ionomer cement constructed on vital teeth. The strength of the systems constructed on root-filled teeth did not vary significantly. The mode of failure varied, depending on the core or post-and-core material. CONCLUSION: Composipost posts and cores and cast gold posts and cores were equivalent in strength and did not vary significantly from gold cores constructed on vital teeth. The low strength values obtained for glass-ionomer cement in combination with threaded retention pins makes this combination a poor choice for core buildup.     

Electroencephalographic findings and epilepsy in the slit ventricle syndrome of shunt-treated hydrocephalic children

Overdrainage of the cerebrospinal fluid (CSF) and collapse of the ventricles, slit ventricles (SLV), can cause clinical symptoms and result in the slit ventricle syndrome (SLVS). The EEG changes and the frequency and type of epilepsy in patients with SLV was analysed from a material of 113 shunt-treated hydrocephalic children. During the follow-up time (mean 8.9 years), 63 patients (56%) had developed SLV. The age at initial shunting was significantly lower (1.2 years) in patients who developed SLV than for those who did not (2.7 years). After initial shunting generalized spike and sharp wave activity (SWA) developed more frequently in patients who developed SLV (81%) than in those who did not (54%). Severe generalized SWA developed almost entirely in patients in the SLV group. This severe generalized SWA disappeared from the EEG in patients after treatment of the SLVS. Epileptic seizures appeared after initial shunting in 44% of patients in the SLV group but in only 6% of the non-SLV group. Treatment of the SLVS decreased the frequency of epilepsy to a level corresponding with the non-SLV group. Repeated EEG evaluation of shunt-treated hydrocephalic children is a valuable aid in follow-up. If EEG abnormality appears after initial shunting, especially SWA, shunt malfunction and overdrainage of the CSF should be suspected.     

Effect of radiologic contrast media and local anaesthetics on the blood-brain barrier and on the leptomeninges

The leptomeninges of cats were exposed to lidocaine, metrizamide and methiodal sodïum and compared with control brains exposed to Ringer's solution.
As a sign of blood-brain barrier damage, an increased extravasation of albumin into the cerebral cortex was recorded after exposure to methiodal sodium; lidocaine or metrizamide did not produce such damage.
Scanning electron microscopy revealed minor cellular reactions in the mesothelial cells of the leptomeninges after application of metrizamide, lidocaine and Ringer's solution. Methiodal sodium produced an extensive cellular damage of the leptomeningeal cells
The importance of testing the leptomeningeal reactions and the reactions of the blood-brain barrier to all liquid media used on the brain surface is emphasized.     

Gamma-vinyl-GABA: A single-blind trial in patients with epilepsy

The anti-epileptic effect of gamma-vinyl-GABA (GVG) was studied using a placebo-controlled, single-blind design in 15 patients with therapy-resistant epilepsy, the majority experiencing complex partial seizures. GVG was added to concomitant treatment, which was kept at constant serum levels. Following administration of 1 g, 2 g and 3 g per day, significant reductions in seizure frequency were observed. A poor correlation was found between GVG serum levels and clinical effect. Only mild and transient side-effects were observed.     

Transplacental movement of inorganic lead in early and late gestation in the mouse

203Pb(NO3)2 was administered i.v. to pregnant C57BL mice at different stages, from day 8 to day 18 of gestation. The whole animals or excised uteri were subjected to autoradiography or were autopsied for scintillation counting of excised organs. Lead appeared in embryonic and fetal tissues at all stages of gestation. Early (approx. day 8-11) lead was restricted mainly to the embryonic blood, suggesting that free lead was essentially not transferred to the embryo but may have been incorporated in the embryonic hemoglobin when the erythrocytes were formed in the yolk sac placenta (an extraembryonic membrane). From day 12 and later, an uptake was seen in the liver and the cartilaginous skeleton, and from day 14, a strong accumulation was found in calcified bone. This means that the overall fetal concentration increased successively with gestational age of the conceptus. The uptake in fetal liver may be related to the erythropoiesis taking place in the liver in later gestation. While an accumulation of lead was observed in proximal tubuli of the maternal kidney, no corresponding uptake occurred in the fetal kidney. Although lead is teratogenic, causing among others skeletal defects, no effect of inorganic lead in mM concentration was seen on a chondrogenic cell system in vitro. Due to the predominance of lead in hemoglobin, a mechanism of teratogensis based on inhibition of fetal hemoglobin synthesis or function is discussed.     

A physiological pharmacokinetic model for morphine disposition in the pregnant rat

A physiological model was used to examine the disposition of morphine in the pregnant rat. In the model was incorporated an expression of both a linear and a nonlinear binding term of morphine to the maternal muscular tissue. Furthermore, the experimental data suggested that a diffusion-limited transport of morphine occurred across the placenta. Morphine showed a relatively high partition into the maternal kidney and muscle tissues. The concentration of morphine in the foetus was about 1.5 times higher than that of the maternal plasma, whereas the foetal brain concentration was about 4 times higher than that of the maternal plasma. The influence on morphine disposition by changes in both the tissue binding of the maternal muscle and the placental plasma flow was explored by model simulations. Due to the diffusionlimited transport of morphine across the placenta, a change in the placental plasma flow would only have an effect on the concentration-time profile of morphine in the foetal tissues if the plasma flow approached and became less than the diffusion clearance across the placenta. An increase in the partition of morphine into the maternal muscle produced an increase in the terminal half-life in all tissues including the foetus.