Loaded Microplasma-sprayed CaP-coated Implants in vivo

Microplasma spray equipment to deposit calcium phosphate ceramic (CaP) coatings has been developed. Fifty-six titanium implants were inserted into the mandibles of 7 adult beagle dogs. The implants were either acid-etched (NC), conventionally plasma-sprayed (PS), micro-plasma-sprayed (MPS), or micro-plasma-sprayed (aMPS) only at the apical part. After 6 weeks, implants in one half of the mandible were subjected to load. Fifty-two weeks thereafter, the animals were killed. Regardless of load, bone healing was comparable for all surfaces tested. It was concluded that loading of MPS CaP-coated implants evokes a favorable bone response, and that the bone response does not differ from that of PS CaP-coated implants. However, functional loading of PS as well as MPS CaP-coated implants might be associated with increased crestal bone maintenance as compared with non-coated implants.

Point-of-care testing in hospitals and primary care

BACKGROUND

Many medical laboratory tests can now be done near the patient (point-of-care testing, POCT), ranging from basic blood glucose measurement to complex coagulation testing. Switching from conventional laboratory testing to POCT shortens the time to decision-making about further testing or treatment, as delays are no longer caused by specimen transport and preparation, and the test results are rapidly available at the point of care. Better medical outcomes and lower costs may ensue.

METHOD

Selective literature review.

RESULTS

The available methods and equipment enable persons not specially trained in laboratory medicine to perform high-quality laboratory testing at the point of care, under certain conditions. Before POCT is introduced in a hospital or outpatient practice, a cost-benefit analysis should be performed, because the introduction is costly and requires a certain amount of organizational work especially for quality management. The potential medical and economic benefits should be assessed individually in each case.

CONCLUSION

POCT for certain applications is a useful complement to conventional laboratory testing. The future utilization of POCT will depend not only on technical advances, but also on developments in costs and reimbursement.

[POCT in coagulation. Quality assurance]

In the last years several point of care testing (POCT) systems used for coagulation parameters have been developed and became daily routine. As for other POCT applications (e. g. blood gas analysis) there is a need for user education and continuous improvement of quality assurance. For some POCT coagulation systems a comprehensive quality management has not been established yet. According to the feasibility and availability of control material and system self control each POCT coagulation method described in this article has a varying concept of quality management. Besides a high quality standard in manufacturing systems, devices and reagents the education of the user and the automatic self control of the instrument as well as the application of electronic and/ or liquid control samples contribute to the total quality assurance. Even if a "like versus like" control material is not available a comprehensive quality management should be implemented in daily routine concerning pre-analytic as well as technical and post-analytic criteria. Anyway to do nothing as the available control material seems to be not suitable is a bad decision.

Point-of-care testing in microbiology: the advantages and disadvantages of immunochromatographic test strips

BACKGROUND

Point-of-care testing (POCT) for the demonstration of pathogens was introduced several years ago. The present study describes the current technical status of POCT, giving some examples, and summarizes the specific advantages and disadvantages of the POCT approach in microbiology.

METHODS

Selective review of the literature found in medical databases under consideration of current German and international guidelines.

RESULTS/CONCLUSIONS

The test systems available today are technically mature and offer good to very good performance. For HIV, malaria, group A streptococci, and legionellae, POCT testing, when indicated, is on a par with conventional procedures. The information yielded by rapid tests for pneumococci and for influenza tends to be supplementary in nature. The rapid test for group B streptococci is unsuitable for routine use because its sensitivity is still too low compared with bacterial culture. POCT can be successful only if the tests are performed correctly by trained personnel, quality management procedures are followed, and the severity of illness and the epidemiological circumstances are taken into account when interpreting the results.

Familial elevated factor VIII in children with symptomatic venous thrombosis and post-thrombotic syndrome: results of a multicenter study

OBJECTIVE

To evaluate the role of factor (F) VIII in children with non-cancer related venous thrombosis (DVT), post-thrombotic syndrome (PTS) or recurrent DVT.

METHODS AND RESULTS

FVIII levels were measured in White patients and age- and gender-matched healthy controls. Heritability of factor VIII was estimated in 99 pedigrees by the variance component method implemented in SOLAR. The group of 103 patients showed higher median values of FVIII than 206 controls [FVIII:Ag, 115 versus 96 IU/dL, P<0.0001; FVIII:C, 119 versus 106 IU/dL, P=0.0009], and had a significantly increased odds ratio (OR) for fibrinogen-adjusted elevated FVIII levels [FVIII >90th percentile versus values below the cut-off: FVIII:Ag, OR 4.3, 95% confidence interval (CI) 1.5 to 12.1; FVIII:C, OR 5.5, CI 2.03 to 15.06]. PTS occurred in 19 of 59 children and persisted in 5 individuals. Recurrent DVT was seen in 8 patients. The heritable(h2)/household(c2) components were calculated for FVIII:Ag levels (h2, 0.48+/-0.15, P=0.0008; c2, 0.21), and FVIII:C (h2, 0.61+/-0.15, P<0.0001; c2, 0.41). When incorporating h2 and c2 in the estimate, the phenotypic variance for FVIII:Ag levels is predominantly explained by h2, whereas c2 stayed significant in the model for FVIII:C (P=0.00002).

CONCLUSIONS

Elevated FVIII levels increase the DVT-risk in children.

Functional and cognitive consequences of silent stroke discovered using brain magnetic resonance imaging in an elderly population

OBJECTIVES

To evaluate the prevalence of silent stroke and its associated consequences on physical, cognitive, and emotional functioning in an elderly population.

DESIGN

Population-based cross-sectional survey.

SETTING

The Memory and Morbidity in Augsburg Elderly project in the Augsburg region of southern Germany.

PARTICIPANTS

Two hundred sixty-seven community-dwelling persons aged 65 to 83.

MEASUREMENTS

The presence of silent stroke was determined using magnetic resonance imaging brain scan and a single question asking for physician-diagnosed stroke in each participant. The health effect of silent stroke was assessed using rating scales for self-perceived health status (36-item short-form health survey), activities of daily living (ADLs) and instrumental ADLs, cognitive function, and depression (Center for Epidemiologic Studies Depression scale).

RESULTS

Just fewer than 13% (12.7%) of participants were affected by silent stroke. Silent stroke was associated with a history of hypertension, heart surgery, and elevated C-reactive protein. Individuals with silent stroke showed impairments on the Mini-Mental State Examination test and in the cognitive domains of memory, procedural speed, and motor performance.

CONCLUSION

The presence of silent stroke has a considerable effect on cognitive performance in those affected. Determining the presence of silent stroke using brain imaging may contribute to identifying individuals at risk for developing gradual neurological deficits.

Interferences in coagulation tests – evaluation of the 570-nm method on the Dade Behring BCS analyser

The Dade Behring BCS is a coagulation analyser with optical reaction detection (standard 405nm). The present study was conducted to evaluate measurement at 570nm for analyses in interfering plasma samples. Prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen and D-dimer in normal (n=50), lipaemic (n=60), icteric (n=113), and haemolytic (n=58) samples were measured at 405 and 570nm. As they are unaffected by the optical properties of the sample, the mechanical STAcompact analyser (Roche Diagnostics) and an ELISA technique were defined as the “comparison” methods. The percentage of valid PT results using the 570-nm method varied from 54% (lipaemic samples) to 97% (haemolytic samples). Valid aPTT measurements were found in 67% (lipaemic samples) up to 93% (icteric samples) of samples. Fibrinogen measurement revealed valid results in 58% (lipaemic samples) to 100% (haemolytic samples) of samples. The number of valid D-dimer results varied from 28% (lipaemic material) up to 100% (haemolytic material). Significant inter-method differences were found: aPTT in lipaemic (BCS 405 vs. 570nm) and icteric samples (STAcompact vs. BCS 405 and 570nm); fibrinogen in lipaemic (BCS 405 vs. 570nm), icteric (BCS 405 vs. 570nm; STAcompact vs. BCS 570nm) and haemolytic samples (STAcompact vs. BCS 405 and 570nm). Differences between the BCS 570-nm and the STAcompact methods were in most cases low and less pronounced than between the BCS 570- and 405-nm methods, making the BCS 570-nm method an alternative to measurement at 405nm. Limitations have to be taken into account regarding lipaemic plasma.

Protease Inhibitors in Spontaneous Cervical Artery Dissections

Background and Purpose— Observations in patients with arterial aneurysms, fibromuscular dysplasia, and spontaneous cervical artery dissection (sCAD) indicate that protease inhibitor deficiency might boost the enzymatic destruction of arterial tissue and increase the risk of these arterial wall diseases. Here we present the first large investigation of the protease inhibitor hypothesis in patients with sCAD.

Methods— Eighty patients with sCAD were compared with 80 age- and sex-matched healthy individuals. α 1 -antitrypsin (α 1 -AT) and α 2 -macroglobulin (α 2 -MG) levels, and α 1 -AT genotypes were assessed and compared between groups.

Results— α 1 -AT and α 2 -MG levels as well as α 1 -AT genotypes did not differ significantly between patients and controls. The frequency of Z alleles in the patient group was higher than in the control group and than in other cohorts from Europe; however, the difference remained nonsignificant. All patients with Z alleles had internal carotid artery dissections.

Conclusions— Overall, this data does not support the hypothesis that protease inhibitor levels or α 1 -AT genotypes play an important role in the etiology of sCAD. The present data does not exclude that the Pi-Z allele might have an influence on subgroups of sCAD, such as internal carotid artery dissections.

Plasma homocysteine, MTHFR C677T, CBS 844ins68bp, and MTHFD1 G1958A polymorphisms in spontaneous cervical artery dissections

Mild hyperhomocysteinemia is a probable risk factor for atherosclerotic diseases and stroke. Recently, associations of elevated plasma homocysteine concentrations in the acute phase and of MTHFR 677 TT genotype with spontaneous cervical artery dissections (sCAD) have been reported. The purpose of this study was to test this hypothesis in the currently largest sample of patients with sCAD, taking into account known factors influencing plasma homocysteine levels. Ninety-five patients with past sCAD were compared with 95 age- and sex-matched healthy individuals. Homocysteine, vitamin B6, B12, folate, and polymorphisms of methylenetetrahydrofolate reductase (MTHFR C677T), cystathionine beta-synthase (CBS 844ins68bp) and methylenetetrahydrofolate dehydrogenase/methenyltetrahydrofolate cyclohydrolase/formyltetrahydrofolate synthetase (MTHFD1 G1958A) were assessed and any associations were analysed using multivariate statistics. The occurrence of sCAD was associated with elevated homocysteine levels with an odds ratio of 1.327 per 20 % percentile. Homocysteine levels were influenced by gender, smoking status, occurrence of hypertension, vitamin B12 and folate levels, and by the MTHFR TT genotype. MTHFR, CBS 844ins68bp, and MTHFD1 G1958A genotype were not independently associated with the occurrence of sCAD. These data suggest that elevated homocysteine is associated with the occurrence of sCAD. The MTHFR C677T polymorphism is associated with the homocysteine level.

Platelet GPIaC807T polymorphism is associated with negative outcome of sudden hearing loss

To determine the relevance of inherited prothrombotic risk factors in sudden hearing loss, we investigated 85 patients with sudden hearing loss of >/= 60 dB for the presence of inherited prothrombotic risk factors. The FV G1691A, FII G20210A, GPIa C807T, GPIIIa PIA1/A2, PAI-1 4G/5G, t-PA Alu repeat ID, MTHFR C677T and CBS 844ins68 genotypes were investigated. Allele frequencies found in patients were compared to those of 85 healthy control subjects of the same ethnic background using Chi-squared and odds-ratio analysis. The frequency of the GPIa807T allele was significantly elevated in patients compared to controls. In addition, allele frequency and genotype distribution of GPIa was significantly elevated in the patient group without recovery after 3 months of sudden hearing loss onset. Allele frequencies of all other prothrombotic risk factors investigated here did not differ from those of the control subjects. The single-nucleotide polymorphism of GPIa C807T seems to play a role as a prognostic factor in recovery from sudden hearing loss.

Cerebral venous thrombosis in children: a multifactorial origin

BACKGROUND

The present study was performed to assess the association of prothrombotic risk factors and underlying conditions (infections, vascular trauma, immobilization, malignancies, autoimmune diseases, renal diseases, metabolic disorders, obesity, birth asphyxia, cardiac malformations, and use of prothrombotic drugs) with cerebral venous thrombosis (CVT) in children.

METHODS AND RESULTS

From 1995 to 2002, 149 pediatric patients aged newborn to <18 years (median 6 years) with CVT were consecutively enrolled. In patients and in 149 age- and gender-matched children with similar underlying clinical conditions but without CVT, the factor V G1691A mutation, the factor II G20210A variant, lipoprotein(a) [Lp(a)], protein C, protein S, antithrombin, and antiphospholipid antibodies, as well as associated clinical conditions, were investigated. Eighty-four (56.4%) of the patients had at least 1 prothrombotic risk factor compared with 31 control children (20.8%; P<0.0001). In addition, 105 (70.5%) of 149 patients with CVT presented with an underlying predisposing condition. On univariate analysis, factor V, protein C, protein S, and elevated Lp(a) were found to be significantly associated with CVT. However, in multivariate analysis, only the combination of a prothrombotic risk factor with an underlying condition (OR 3.9, 95% CI 1.8 to 8.6), increased Lp(a) (OR 4.1, 95% CI 2.0 to 8.7), and protein C deficiency (OR 11.1, 95% CI 1.2 to 104.4) had independent associations with CVT in the children investigated.

CONCLUSIONS

CVT in children is a multifactorial disease that, in the majority of cases, results from a combination of prothrombotic risk factors and/or underlying clinical condition.

Immunohistochemical evaluation of matrix molecules associated with wound healing following treatment with an enamel matrix protein derivative in humans

Application of enamel matrix protein derivative (EMD) onto a debrided and conditioned root surface has been shown to promote periodontal regeneration in animals and humans. However, until now there is virtually no information from humans describing the expression of different matrix molecules in the newly formed periodontal tissues following treatment with EMD. This study investigated immunohistochemically in humans the expression of matrix molecules associated with periodontal tissues reformed after treatment with EMD. Eight patients with intrabony defects were treated with EMD. Six months after surgery teeth together with some of their surrounding soft and hard tissues were removed, fixed in buffered formalin, decalcified in EDTA, and embedded in paraffin. Serial sections of 6 micro m were cut in mesiodistal direction. Sections were evaluated immunohistochemically by means of polyclonal antibodies against osteopontin, collagen I and collagen III. The original (non-treated) parts of the periodontium served as controls. In all specimens the healing resulted to a varying extent in formation of cementum, periodontal ligament and alveolar bone. In all specimens the expression of the investigated matrix molecules was stronger at the reformed than at the original sites. Osteopontin expression was most intense at the border near the newly formed cementum and bone. In the regenerated periodontal ligament, collagen I and III were localized throughout the entire periodontal ligament connective tissue. Within the newly formed PDL connective tissue the immunohistochemical staining appeared stronger for collagen III than for collagen I. The present findings suggest that (a) treatment of human intrabony defects with EMD creates an environment favourable for periodontal regeneration and, (b) in humans the healing and/or remodelling process of the reformed tissues may be followed immunohistochemically for a period of 6 months.

Thromboembolic events in children with acute lymphoblastic leukemia (BFM protocols): prednisone versus dexamethasone administration

Alterations in hemostasis leading to symptomatic thromboembolism have been observed in patients with acute lymphoblastic leukemia (ALL) receiving Escherichia coli asparaginase (CASP) combined with steroids. Moreover, hereditary prothrombotic risk factors are associated with an increased risk for venous thromboembolism in pediatric ALL patients treated according to the BFM 90/95 protocols (including CASP combined with prednisone during induction therapy). To assess whether the thromboembolic risk associated with established prothrombotic risk factors is modified by treatment modalities (prednisone or dexamethasone), the present analysis was performed. Three hundred thirty-six consecutively recruited leukemic children treated according to different BFM protocols (PRED group, n = 280, 60 mg/m(2) prednisone; DEXA group, n = 56, 10 mg/m(2) dexamethasone during induction therapy) were studied. Study end point was the onset of symptomatic vascular accidents during induction therapy. Cumulative thromboembolism-free survival was significantly reduced in children in the PRED group (thrombosis frequency, 10.4%) compared with children in the DEXA group (thrombosis frequency, 1.8%; P =.028). Although no significant difference was found in the overall prevalence of prothrombotic risk factors, 46.5% of patients in the PRED group who experienced thromboembolic events were carriers of a prothrombotic risk factor, whereas no carrier in the DEXA group had a thromboembolism. At the time of maximum CASP activity, fibrinogen and activities of antithrombin, plasminogen, and protein S were significantly reduced in the PRED group. No significant correlation could be found between CASP activity and levels of coagulation factors. In conclusion, the use of dexamethasone instead of prednisone, administered with CASP, significantly reduced the onset of venous thromboembolism.