[Patient with heparin-induced thrombocytopenia type II and implanted left ventricular assist device]. / Patient mit heparininduzierter Thrombozytopenie Typ II und implantiertem linksventrikulärem Assistdevice.

The administration of heparin can lead to life-threatening heparin-induced thrombocytopenia (HIT) type II, which is caused by antibodies against heparin-platelet factor 4-complexes. The multimorbid patient presented here suffered from HIT II. Preoperative and postoperative prevention of thrombosis was successfully conducted with argatroban and the management of anticoagulation is presented. During therapy with argatroban, discrepancies in the partial thromboplastin time (PTT) and the international normalized ratio (INR) appeared sporadically. The clinical causes for these differences remain unclear.

Possible modes of allergen-specific sensitization and boosting in an atopic child.

Several studies document that allergen-specific IgE levels are boosted by allergen contact via the respiratory tract in allergic patients. Only few data are available on whether other routes of allergen contact have an influence on systemic IgE responses. We report the case of a boy who developed egg allergy after heavy consumption of eggs by the mother during pregnancy and breast feeding. In contrast to other children who outgrow egg allergy during the first years of life, the boy experienced further dramatic increases in hen egg-specific IgE antibodies after prolonged consumption of ostrich eggs containing cross-reactive allergens. IgE antibodies to most of the important respiratory allergens remained either low or not detectable. The dramatic increases in hen egg-specific IgE antibody levels after oral intake of allergens demonstrate that systemic IgE responses in allergic patients can be strongly boosted by allergen contact via routes other than the respiratory tract.

Human G protein beta3 subunit variant does not alter hypercarbic or hypoxic ventilatory response.

Hypercarbic respiratory drive is mainly determined by PCO(2) and pH with activity of the intracellular Na+/H+ exchanger (NHE) playing an important role in maintaining intracellular pH and respiratory drive. Because NHE activity varies with genetically different G-protein beta3 subunits (GNB3) (C/T polymorphism at nucleotide position 825) different genotypes might alter respiratory regulation. To test the hypothesis that short-term ventilatory responses vary with different GNB3 healthy volunteers with different genotypes (CC, TC, TT) were exposed to either hyperoxic hypercarbia (n=33) or to isocapnic hypoxia (n=31), respectively. There was no difference between CC, TC, and TT genotypes in hypercarbic and hypoxic respiratory drive when assessed as the ratio of minute ventilation over endexpiratory PCO(2) changes (DeltaV.E/DeltaPETCO(2)), maximal tolerable PETCO(2), and ratio of changes in ventilation over arterial haemoglobin desaturation (DeltaV.E/DeltaSO(2)), respectively. Thus, short-term hypercarbic and hypoxic ventilatory drive do not differ between individuals with genotypes encoding different GNB3. Whilst respiratory control may still be influenced by G-protein aberration, other mechanisms seem to have a more important role in controlling ventilation.

The temporomandibular opening index (TOI) in patients with closed lock and a control group with no temporomandibular disorders (TMD): an initial study.

Mandibular movement may be assessed by measuring maximum mouth opening. This is a linear measurement from the maxillary to the mandibular incisal edge and is affected by gender, age and ramus length. It cannot be used to classify patients. The temporomandibular opening index (TOI) appears to be independent of these variables and has been shown to differ for different categories of patients with temporomandibular disorders (TMD). This study examined the TOI in a group of 11 patients with closed lock and a control group of 11 individuals with no signs or symptoms of TMD. The group with closed lock had a significantly different TOI from that of the control group (P < 0.001) according to the Mann-Whitney U-test. This suggests that the TOI may have greater diagnostic value than linear mouth opening.

Myogenous temporomandibular disorder patients and the temporomandibular opening index.

Limited mandibular movement is one of the cardinal signs of temporomandibular disorders, and is usually assessed by measurement of mouth opening. Linear measurement of mouth opening does not discriminate between diagnostic groups and has been shown to be influenced by gender, age and ramus length. A new temporomandibular opening index, however, can differentiate between diagnostic groups and is not influenced by the above variables. When patients with a myogenous temporomandibular disorder were examined, the temporomandibular opening index distinguished two subgroups, the first with values about the lower quartile and the second with values about the upper quartile. A similar identification of two subgroups was seen in electromyographic studies of myogenous temporomandibular disorder patients.

Echo-planar magnetic resonance imaging (EPI) with high-resolution matrix in intra-axial brain tumors.

The aim of this study was to assess the potential of high-speed interleaved echo-planar imaging (EPI) to achieve diagnostic image quality comparable to T2-weighted imaging in patients with brain tumors. Seventeen patients with intra-axial, supratentorial tumors (10 untreated gliomas, 7 radiated gliomas) were investigated on a 1. 5-T scanner. The conventional scan (SE, TR/TE = 2200/80 ms, 18 slices) was acquired in 8 min, 4 s, and EPI (TR/TE = 3000/80 ms, 18 slices) was completed in 25 s. The films were compared in a blinded trail by three radiologists. On the general impression and anatomic display, both sequences were rated to be of similar quality. Artifacts were slightly more pronounced at the skull base and around surgical clips using EPI. Tumor delineation was nearly equivalent using EPI, compared with the T2-weighted sequence. Echo-planar imaging reached diagnostic quality in all patients. Interleaved high-resolution EPI yielded sufficient quality to depict intra-axial, supratentorial brain tumors. Since EPI can be obtained in a small fraction of the time needed for conventional spin echo, in addition to other indications it could be considered to study patients unable to cooperate.

[Cost savings by disinfection for prevention of surgical wound dehiscence after gastrectomy]. / Kostensenkung durch Dekontamination zur Prävention der Nahtinsuffizienz nach Gastrektomie.

The aim of this study was to examine the effect of decontamination as compared to placebo medication on post-gastrectomy treatment costs. The results of a prospective double-blind placebo-controlled multicenter trial indicate that perioperative i.v. prophylaxis with cefotaxim and topical decontamination with polymyxin B, tobramycin, vancomycin and amphotericin B from the day before surgery until the 7th postoperative day is most effective in the prevention of esophagojejunal anastomotic leakage following total gastrectomy. For the cost analysis, only patients who had been decontaminated according to the study protocol (n = 90) were compared to the non-decontaminated patients (n = 103). The esophagojejunal leakage rate was 10.6% in placebo patients (n = 103) and could be reduced significantly to 1.1% in decontaminated patients (n = 90, P = 0.0061; two-tailed Fisher's exact test). There was only one asymptomatic leakage detected on Gastrografin swallow. The pulmonary infection (P = 0.0173) and overall complication rates (p = 0.0238) were significantly reduced in the decontamination group as well. During the observation period, 9 (8.7%) patients in the placebo group and 3 (3.3%) in the decontaminated group died (P = n.s.). Patients were followed up for the initial 42 postoperative days and treatment costs were calculated for this time period only. The parameters compiled in the study pertaining to use of medical resources formed the basis for the determination of the postoperative treatment costs. These were the costs for decontaminating drugs, intravenous antibiotics, reoperations and non-surgical reinterventions as well as daily treatment costs of the general ward, the intensive care unit (ICU) and rehabilitation. The average costs per patient in the placebo group amounted to DM 20,000 while the costs for decontaminated patients were only DM 16,200, which was due to a significantly lower number of patients requiring treatment in the ICU (P = 0.0082), significantly fewer patients requiring i.v. antibiotics (P = 0.0232) and fewer patients with reoperations (P = 0.0909). The prophylaxis employing decontaminating drugs in the amount of DM 400 lowered post-gastrectomy treatment costs by DM 3800 or 19%. The prophylaxis can be recommended, because it lowers morbidity, mortality and the costs of total gastrectomy.

The prevention of anastomotic leakage after total gastrectomy with local decontamination. A prospective, randomized, double-blind, placebo-controlled multicenter trial.

OBJECTIVE: A prospective, randomized, double-blind, placebo controlled multicenter trial was undertaken in 205 patients treated with total gastrectomy for gastric malignancies to evaluate whether local antimicrobial measures reduce the incidence of esophagojejunal anastomotic leakage. SUMMARY BACKGROUND DATA: Anastomotic leakage of the esophagojejunostomy is always a septic complication of total gastrectomy for gastric malignancies, but it never has been attempted to prevent this complication with the administration of topical antimicrobial agents during the critical phase of anastomotic wound healing. METHODS: To evaluate the efficacy and safety of topical decontamination, the study was carried out as a prospective, randomized, double-blind and placebo-controlled clinical multicenter trial in patients with total gastrectomy for gastric cancer. Patients received either placebo or decontamination with polymyxin B (100 mg), tobramycin (80 mg), vancomycin (125 mg), and amphotericin B (500 mg) four times per day orally from the day before the operation until the seventh postoperative day. All patients received a perioperative intravenous prophylaxis with cefotaxime 2 x 2 g. Other interventions including the administration of antibiotics and fluids, were not affected by the study protocol. RESULTS: Of 260 patients who were randomized, total gastrectomy was not carried out in 55 patients. They dropped out of the study. Patients receiving an esophagojejunostomy were observed until day 42, when they were discharged from the clinic or died. An intention-to-treat analysis of the data was carried out. Among the 103 recipients of placebo, there were 11 (10.6%) with an anastomotic leakage of the esophagojejunostomy, and among the 102 recipients of decontamination, there were 3 (2.9%) with an anastomotic leakage of the esophagojejunostomy (p = 0.0492). Pulmonary infections were observed in 23 patients (22.3%) receiving placebo and in 9 patients (8.8%) who were decontaminated (p = 0.02). There were 11 deaths (10.6%) among the recipients of placebo and 5 deaths (4.9%) among the recipients of decontamination (p = 0.1). CONCLUSIONS: Decontamination with polymyxin, tobramycin, vancomycin, and amphotericin B during anastomotic wound healing is safe and effective in the prevention of esophagojejunal anastomotic leakage after total gastrectomy.

Shear bond strength of a composite resin to differently silicoated base metal alloys.

This study was undertaken to determine the shear bond strength of Charisma composite resin to both thermal and pyrogenic silicoated base metal alloys namely, Duracast MS, Rexillium V and Wironit extra-hard. The bonded specimens were subjected to three stress treatments prior to shear bond testing. The results indicated that both silicoating techniques significantly improved shear bond strengths to sandblasted alloys, whereas wet heat and thermocycling treatments reduced the bond strengths, except for pyrogenic silicoated Wironit. Thermocycling was more detrimental to thermal than to pyrogenic silicoated Rexillium nad Wironit specimens.

[Prevention of allergy]. / Allergieprävention.

The increase in prevalence and morbidity of allergic disease requires more employment of prevention strategies. The time of manifestation, severity and clinical course of atopic disease are primarily determined by genetic factors. TH1 and TH2 cell behaviour may in the future be used as predictors of atopy. A great number of environmental influences, like exposure to allergens and adjuvant trigger factors are modulating the clinical course. Sensible strategies of prevention in high-risk-families, as breastfeeding, hydrolysed hypoallergenic formula and maternal food avoidance during pregnancy or lactation are discussed.

Prostanoid receptors of the EP3 subtype mediate the inhibitory effect of prostaglandin E2 on noradrenaline release in the mouse brain cortex.

Mouse or rat brain cortex slices were preincubated with 3H-noradrenaline and superfused with physiological salt solution containing desipramine. We studied the effects of prostaglandin E2 (PGE2), prostaglandin D2 (PGD2) and related drugs on the electrically evoked (50 mA, 2 ms, 0.3 Hz) tritium overflow. PGE2 inhibited the electrically evoked tritium overflow from mouse brain cortex slices; the maximum effect of PGE2 (79%) was attenuated by the alpha 2-adrenoceptor agonist talipexole (to 52%) and enhanced by the alpha 2-adrenoceptor antagonist rauwolscine (to 92%). Rauwolscine was added to the superfusion medium in all subsequent experiments. The effect of PGE2 was readily reversible upon withdrawal from the medium and remained constant upon prolonged exposure of the tissue to the prostanoid. Studies with EP receptor agonists, mimicking the inhibitory effect of PGE2, showed the following potencies (pIC50); sulprostone (8.22); misoprostol (8.00); PGE2 (7.74); PGE1 (7.61); iloprost (5.86). The concentration-response curve of PGE2 was marginally shifted to the right by the EP1 receptor antagonist AH 6809 (6-isopropoxy-9-oxoxanthene-2- carboxylic acid; apparent pA2 3.97) and by the TP receptor antagonist vapiprost (4.50). AH 6809, by itself, did not affect the evoked overflow whereas vapiprost increased it. PGD2 inhibited the evoked overflow at high concentrations (pIC50 4.90); this effect was not altered by the DP receptor antagonist BW A868C (3-benzyl-5-(6-carboxyhexyl)-1-(2-cyclohexyl-2- hydroxyethylamino)hydantoin), which, by itself, did not affect the evoked overflow. Indometacin slightly increased the evoked overflow and tended to increase the inhibitory effect of PGE2. PGE2 inhibited the electrically evoked tritium overflow also in rat brain cortex slices.(ABSTRACT TRUNCATED AT 250 WORDS)

H3 receptor-mediated inhibition of noradrenaline release: an investigation into the involvement of Ca2+ and K+ ions, G protein and adenylate cyclase.

The present study was aimed at the identification of mechanisms following the activation of histamine H3 receptors. Mouse brain cortex slices preincubated with 3H-noradrenaline were superfused and the (H3 receptor-mediated) effect of histamine on the electrically evoked tritium overflow was studied under a variety of conditions. The extent of inhibition produced by histamine was inversely related to the frequency of stimulation used to evoke tritium overflow and to the Ca2+ concentration in the superfusion medium. An activator (levcromakalim) and blocker (glibenclamide) of ATP-dependent K+ channels did not affect the electrically evoked tritium overflow and its inhibition by histamine. A blocker of voltage-sensitive K+ channels, tetraethylammonium (TEA), increased the evoked overflow and attenuated the inhibitory effect of histamine. TEA also reduced the inhibitory effect of noradrenaline and prostaglandin E2 on the evoked overflow. When the facilitatory effect of TEA on the evoked overflow was compensated for by reducing the Ca2+ concentration in the superfusion medium, TEA did no longer attenuate the effect of histamine. Exposure of the slices to the SH group-alkylating agent N-ethylmaleimide increased the evoked overflow and attenuated the inhibitory effect of histamine; both effects were counteracted by the SH group-protecting agent dithiothreitol, which, by itself, did not affect the evoked overflow and its inhibition by histamine. Mouse brain cortex membranes were used to study the effect of the H3 receptor agonist R-(-)-alpha-methylhistamine on the basal cAMP accumulation and on the accumulation stimulated by forskolin or noradrenaline.(ABSTRACT TRUNCATED AT 250 WORDS)

Shear bond strength of a composite resin after delayed bonding to a polymerised dentine bonding system.

Polymerised adhesive may serve as a temporary sealant on prepared dentine surfaces and may be used as a precursor to the final bonding of a resin restoration. This procedure may, however, have an adverse effect on the strength of the final bond. This study was undertaken on 40 extracted human molar teeth to assess the effect of delayed bonding on the shear bond strength of a composite resin luted with a luting resin to abraded dentine treated with the Scotchbond Multi-Purpose (SMP) Bonding System (3M). No significant difference (p = 0.969) could be demonstrated between shear bond strengths achieved after immediate and delayed bonding to the polymerised Scotchbond Multi-Purpose adhesive.

The 5-HT3 receptor agonist 1-(m-chlorophenyl)-biguanide facilitates noradrenaline release by blockade of alpha 2-adrenoceptors in the mouse brain cortex.

We analyzed the facilitatory effect of the 5-HT3 receptor agonist 1-(m-chlorophenyl)-biguanide (mCPBG) on the electrically evoked noradrenaline release in superfused mouse brain tissue. In addition, we determined the affinities of mCPBG and two other 5-HT receptor ligands, namely 2-methyl-5-hydroxytryptamine (2-methyl-5-HT; also a 5-HT3 receptor agonist) and 5-carboxamidotryptamine (5-CT; a 5-HT1 receptor agonist) for alpha 2 binding sites. The latter two 5-HT receptor agonists were included because of the claimed involvement of alpha 2-adrenoceptors in their effects on noradrenaline release. In superfusion experiments on mouse brain cortex slices preincubated with 3H-noradrenaline, tritium overflow evoked by 2-min periods of electrical field stimulation (3 Hz) was facilitated by mCPBG and, in addition, by rauwolscine (alpha 2-adrenoceptor antagonist) and tetraethylammonium (K+ channel blocker) (which were examined for comparison). The effect of mCPBG was not affected by the 5-HT3 receptor antagonist tropisetron or by desipramine but was abolished by rauwolscine. In slices superfused with medium containing desipramine, the concentration-response curve of unlabelled noradrenaline for its inhibitory effect on the electrically (0.3 Hz) evoked overflow was shifted to the right by mCPBG and rauwolscine (apparent pA2 5.35 and 7.88, respectively). In another series of superfusion experiments, 4 electrical pulses, administered at 100 Hz, were used to evoke tritium overflow. Tritium overflow evoked by this stimulation procedure (under which an endogenous tone of noradrenaline does not develop) was not affected by mCPBG and rauwolscine but still increased by tetraethylammonium.(ABSTRACT TRUNCATED AT 250 WORDS)

Predictability of color matching and the possibilities for enhancement of ceramic laminate veneers.

This study investigated the predictability of color (Hue, Value, and Chroma) on three illustrated surfaces of ceramic veneers and the extent to which laminates may be shade-adapted by use of tints and opaquers on the fitting surface. Significant discrepancies were found in the final color match. The dentist should opt for a lighter, more translucent shade, which can be modified before final cementation.

The effect of placement technique on marginal adaptation of posterior resins.

Polymerization shrinkage of posterior resin restorations leads to margins that pull away from the tooth, or to cracks in the material itself. The purpose of this study was to determine the effect of three different placement techniques on the marginal adaptation (or in effect the amount of polymerization shrinkage) of posterior resin restorative materials. Three posterior resin materials, namely, Distalite, Heliomolar and P30 were included in this study. Each of these materials were placed by means of three different placement techniques (Bulk pack, Horizontal layering and Vertical layering) into class II cavities in extracted human molars. No dentine bonding agents were used. The samples were light cured, the teeth sectioned longitudinally and stored dry before examination in a Scanning Electron Microscope. Results showed polymerization shrinkage with all three techniques, with the poorest the bulk pack technique where large marginal discrepancies were visible. No significant differences were detected between the horizontal and vertical placement techniques, but the two microfilled resins Heliomolar and Distalite showed significantly poorer marginal adaptation than the small particle conventional resin, P30. All three materials had better adaptation on the occlusal margins than on the margins situated along the floor of the cavity or the gingival margins of the proximal box of the cavity. It can be concluded that the bulk pack technique should be avoided as this leads to large contraction gaps at most of the margins of the restoration.

Shear bond strength of silicoated bonded orthodontic attachments.

The shear bond strength of bonded orthodontic attachments, coated with a silicon oxide layer to enhance adhesion, was tested and compared to that of untreated attachments. Twenty buttons for direct bonding (test group) were "silicoated" and bonded to surgically removed, unerupted human third molars, using "Right-On" adhesive. The control group consisted of 20 similar teeth to which untreated buttons were bonded. Half of the specimens in each group were then thermocycled to stress the bonds. Shear strength was tested with the use of the Instron Universal testing machine. The mean shear bond strength of the silicoated attachments was found to be higher than that of the untreated attachments. This was a highly significant finding (p less than 0.005). The bond strength after thermocycling decreased in both the test and control groups, although this decrease was only significant at the level p less than 0.01. The results obtained from this study indicate that silicoating of orthodontic attachments prior to bonding significantly increases their shear bond strength to dental enamel.