Prokaryotic versus eukaryotic recombinant Lutheran blood group protein for antibody identification

BACKGROUND: At present, identification of antibodies against high-frequency antigens is limited to reference laboratories having panels of rare red blood cell (RBC) specimens in stock. Antibodies against Lu(b) are among the most frequent clinically relevant antibody specificities directed against high-frequency antigens. STUDY DESIGN AND METHODS: Soluble recombinant Lu(b) fusion proteins consisting of the first three N-terminal immunoglobulin superfamily domains and a V5-His tag were generated. Eukaryotic recombinant Lu(b) proteins were isolated from cell culture supernatant of stably transfected HEK293 cells with anti-V5 Sepharose. Prokaryotic Lu(b) fusion proteins were expressed in Escherichia coli, purified by Ni-NTA, and refolded by chromatographic procedures. Ten anti-Lu(b) serum samples, 6 anti-Lu(a) serum samples, 30 serum samples directed against other blood group antigens, 10 serum samples from patients with RBC autoantibodies, and 100 serum samples from randomly selected donors were used for antibody screening. RESULTS: Eukaryotic and prokaryotic recombinant Lu(b) proteins proved to be equally suited for identification of anti-Lu(b). Recombinant Lu(b) protein-based enzyme-linked immunosorbent assay correctly identified samples containing anti-Lu(b) sera, and the titers were at least two times higher than those measured by the gel agglutination-based indirect antiglobulin test. In hemagglutination inhibition assays, recombinant Lu(b) protein neutralized all anti-Lu(b), but none of the other alloantibodies decreased in reactivity. CONCLUSION: Antibody detection systems based on soluble eukaryotic or prokaryotic recombinant blood group proteins have the potential to replace current systems with rare RBCs for identification of alloantibodies against high- or low-frequency antigens. This innovation could bring routine laboratories one step closer to specialized antibody diagnostics.     

Estimation of the duration of ventricular fibrillation using ECG single feature analysis

The duration of untreated ventricular fibrillation (VF) is of paramount importance for CPR success. Moreover, therapeutic interventions taking into account the interval between cardiac arrest onset and initiation of CPR improve outcome. This study was performed to investigate whether VF feature analysis could be used to estimate the duration of VF in patients with out-of-hospital cardiac arrest. Demographic data recorded according to the Utstein guidelines and ECG recordings of 376 cardiac arrest patients from three European areas were analysed. Ten features in the time and frequency domain derived from different sub-bands of the initial VF ECG (n=127) were evaluated. The correlation between VF ECG features and cardiac arrest times was investigated using Pearson's correlation coefficient in a subset of 40 patients with reliably estimated downtimes and artefact-free initial VF tracings. No significant correlation (p<.05) between any of the VF ECG features and downtime could be found. The duration of cardiac arrest could not be estimated reliably from human VF ECG single feature analysis.     

In-vivo evaluation of convex array synthetic aperture imaging

This paper presents an in-vivo study of synthetic transmit aperture (STA) imaging in comparison with conventional imaging, evaluating whether STA imaging is feasible in-vivo and whether the image quality obtained is comparable with traditional scanned imaging in terms of penetration depth, spatial resolution, contrast resolution and artifacts. Acquisition was performed using our research scanner RASMUS and a 5.5 MHz convex array transducer. STA imaging was acquired using circular wave emulation by 33-element subapertures and a 20 micros linear FM signal as excitation pulse. For conventional imaging, a 64 element aperture was used in transmit and receive with a 1.5 cycle sinusoid excitation pulse. Conventional and STA images were acquired interleaved, ensuring that the exact same anatomical location was scanned. Image sequences were recorded in real time and processed off-line. Seven male volunteers were scanned abdominally and the resulting images were compared by three medical doctors using randomized blinded presentation. Penetration and image quality were scored and evaluated statistically. Results showed slightly but significantly (0.48 cm, p = 0.008) increased penetration using STA. Image quality was also highly significantly (p < 0.001) increased. Results show that in-vivo ultrasound imaging using STA is feasible for abdominal imaging without severe motion artifacts.     

Reversal of resistance in microorganisms by help of non-antibiotics

Intracellular efflux pumps have been largely the research focus in multidrug-resistant (MDR) Gram-positive and Gram-negative microorganisms and parasites including cancers. However, drug efflux mechanisms other than pumps per se have been observed, supported by the effects of isomeric, non-antibiotic depressant (DPR), phenothiazines and thixenes, and antidepressant (ADPR) phenylpiperidine neurotropic drugs, alone or in combination with classical antimicrobials on MDR Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Streptococcus pyogenes and Streptococcus pneumoniae. Of the non-antibiotics we investigated, the DPR l-thioridazine, trans-clopenthixol and isomers of phenylpiperidines NNC 20-4962 (isomer of femoxetine) and NNC 20-7052 (isomer of paroxetine) were potent antimicrobials with the least neurotropic activity, pointing to a possible general isomeric structure-activity relationship. These compounds may be regarded as new efflux inhibitors. Moreover, these isomers have considerably reduced, in some cases absent, neurotropism and reduced mammalian toxicity. This may alleviate concerns about adverse effects and therapeutic safety for infected patients in life-threatening situations where the non-antibiotic dosage would be in the lower, non-chronic dosage ranges generally prescribed for individuals with mild mental health problems. The results point to the prokaryotic and eukaryotic microorganisms' phospholipid/protein domain involvement of the cationic, amphiphilic, non-antibiotic DPR and ADPR, with the phospholipids being the initial sites attracting and concentrating the neurotropes to induce a form of suspended animation, followed by gross changes of cell wall and membrane structure, and thereby potentiating their destructive or immobilizing effects on various as yet only hinted at resistance and efflux mechanisms. Combination of appropriate isomeric non-antibiotic DPR and ADPR of low neurotropism and toxicity with conventional and classical antimicrobials promises early, new therapeutic strategies salutary against microbial resistance, resistance development, pathogenicity and virulence.     

The effect of activated protein C on plasma cytokine levels in a porcine model of acute endotoxemia

Objective To assess the anti-inflammatory effects of recombinant human activated protein C (rhAPC) in a porcine model of acute endotoxemia. Design and setting Animal randomized controlled study at the Laboratory of Clinical Institute, Aarhus University Hospital. Subjects Eighteen female landrace pigs (30 kg). Interventions By pairwise randomization, pigs were given either LPS or LPS and rhAPC. Both groups received a stepwise increasing LPS infusion for 30 min; whereafter the infusion continued at a lower rate (300 min LPS in both groups). The LPS+rhAPC group received rhAPC (100 μg/kg per hour) 15 min before the LPS infusion began and throughout the trial period. Results While rhAPC showed no modifying effects on peak plasma levels of pro- or anti-inflammatory cytokines (TNF-α, IL-6, IL-8, IL-10), TNF-α and IL-10 peaked significantly later in the rhAPC-treated animals. The profibrinolytic effects of rhAPC were confirmed by decreased plasminogen activator inhibitor 1 levels, while no differences were found in other coagulation markers, hemodynamic, metabolic, or leukocyte data between the two groups. Conclusions We found no significant effect of rhAPC on plasma levels of either pro- or anti-inflammatory cytokines in this porcine model of acute endotoxemia. However, TNF-α and IL-10 peaked significantly later in the rhAPC-treated animals.     

Iatrogenic injury to oral branches of the trigeminal nerve: records of 449 cases

The aims of this study were threefold: (1) to describe iatrogenic lesions to oral branches of the trigeminal nerve, signs and symptoms, and functional status, (2) to report on a simple neurosensory examination method, and (3) to discuss means of prevention of iatrogenic injury. The etiology and functional status of 449 injuries to oral branches collected over 18 years were retrospectively reviewed. A simple scheme of a clinical neurosensory examination was applied to enable a quantified rating of the perception. Injury to the lingual nerve (n = 261) is not only the most prevalent type of lesion, it also seems to be the most devastating type of lesion. Third molar surgery (n = 319) counts for the majority of injuries to the lingual, inferior alveolar, and buccal nerves. Lesions related to the injection of local analgesics was the second most frequent etiology (n = 78), and the lingual nerve was affected more frequently and severely than other oral branches of the trigeminal nerve. The female gender was overrepresented in incidence of injured nerves but no difference was found in the severity of affection between females and males. All grades of loss of neurosensory functions were found, and a range of neurogenic malfunctions was reported. Methodological obstacles in clinical neurosensory examination of trigeminal nerve injury and the magnitude of neurosensory impairment are discussed. Many nerve injuries are avoidable by critical reevaluation of indications, increased awareness of potential hazards, and modified surgical procedures.     

The lateral leeway in the habitual intercuspation: experimental studies and literature review

The habitual intercuspation is used ubiquitous for manufacturing small dental restorations. However, a little is known on its precision. The aim of the present study was therefore to investigate the unambiguity and accuracy of the habitual occlusion in mounted plaster casts from fully dentate persons. Eighty-one fully dentate volunteers, 36 women and 45 men aged 26.8 +/- 6.2 years (18-55 years), with minor fillings and no signs or symptoms of TMD took part in the experiments. Silicone impressions were taken, poured with stone plaster and the obtained casts mounted into Dentatus ARL(R)- articulators using an individual face bow transfer. Subsequently, the models were transferred to a custom-made measuring articulator where the lateral leeway and the accuracy of the hand-held habitual intercuspation were quantified in the condylar area. Measurements were repeated seven times with the upper cast pushed either to the maximum right or the maximum left intercuspation. The hand-held habitual intercuspation of upper and lower cast proved ambiguous in 57% of pairs of casts. The average lateral leeway of the habitual intercuspation in the condylar area was 0.10 +/- 0.05 mm (0-0.51 mm; median 0.07 mm) between the maximum right and left occlusal positions. The average accuracy of three repeated measurements was 0.22 +/- 0.09 mm (0.02-1.17 mm; median 0.16 mm). Natural occlusal surfaces in a full dentition do not guarantee an unambiguous habitual intercuspation of the plaster casts. The described leeway and technical limits might be possible causes for occlusal adjustments that are sometimes necessary when inserting restorations manufactured in habitual intercuspation.     

Subjective intensity of pain during ultrasonic supragingival calculus removal

OBJECTIVE: To assess subjective intensities of pain during supragingival calculus removal employing ultrasonic scaler tips of two different shapes. MATERIAL AND METHODS: Twenty patients were treated using a piezoelectric ultrasonic device (Sirosonic L) and two different scaler tips representing a conventional (Instrument No. 3) and a slim-line style (Perio Pro Line Instrument SI-11) in a split-mouth design. Pain was recorded during calculus removal at intervals of 0.5 s employing an inter-modal intensity comparison. Additionally, a visual analogue scale was used for evaluation directly after the treatment procedure. Treatment time was recorded to assess the efficiency of calculus removal. RESULTS: Pain assessment during treatment showed that the slim-line scaler tip (median pain score: 1.4 [U], maximum: 3.5 [U], minimum: 0 [U]) caused less pain than the conventional device (median pain score: 7.8 [U], maximum: 14.7 [U], minimum: 0 [U]) (p<0.05). These results could be confirmed by the visual analogue scale. Treatment with the slim-line tip took significantly longer than treatment with the conventional tip (p<0.05). CONCLUSIONS: Using slim-line-styled ultrasonic scaler tips for supragingival calculus removal, painful sensations can be reduced compared with conventional ultrasonic devices. Thus, it might be possible to increase the patient's compliance during dental treatment with oscillating instruments.