Carrier-borne epidemics with immigration. I — Immigration of both susceptibles and carriers

Much of the theory of epidemics (see Bailey, 1957) has been concerned with models for their behaviour in closed populations. In such models the epidemic ultimately dies out, and interest has been concentrated on, for example, the ultimate size of the epidemic and its duration in time. In practice a population is rarely completely closed, and for many diseases an endemic model rather than an epidemic model is appropriate. To create models for endemic diseases it is necessary to introduce both new persons susceptible to the disease into the population and new sources of infection. For the so-called general stochastic epidemic, Ridler-Rowe (1967) has obtained certain limiting properties of the population where immigration of both susceptibles and infectives into the population takes place, but much work remains to be done to obtain, for example, the general equilibrium behaviour of this model.

Interleukin-4 and interferon-γ orchestrate an epithelial polarization in the airways

Interferon-γ (IFN-γ) and interleukin-4 (IL-4) are key effector cytokines for the differentiation of T helper type 1 and 2 (Th1 and Th2) cells. Both cytokines induce fate-decisive transcription factors such as GATA3 and TBX21 that antagonize the polarized development of opposite phenotypes by direct regulation of each other's expression along with many other target genes. Although it is well established that mesenchymal cells directly respond to Th1 and Th2 cytokines, the nature of antagonistic differentiation programs in airway epithelial cells is only partially understood. In this study, primary normal human bronchial epithelial cells (NHBEs) were exposed to IL-4, IFN-γ, or both and genome-wide transcriptome analysis was performed. The study uncovers an antagonistic regulation pattern of IL-4 and IFN-γ in NHBEs, translating the Th1/Th2 antagonism directly in epithelial gene regulation. IL-4- and IFN-γ-induced transcription factor hubs form clusters, present in antagonistically and polarized gene regulation networks. Furthermore, the IL-4-dependent induction of IL-24 observed in rhinitis patients was downregulated by IFN-γ, and therefore IL-24 represents a potential biomarker of allergic inflammation and a Th2 polarized condition of the epithelium.

The Crystal and Molecular Structure of the 1:2 5,10-Dihydro-5,10-diethylphenazine-(E2P)-2,2′-(2,5-Cyclohexadiene-1,4- diylidene)bispropanedinitrile (TCNQ) Complex

C16H18N2·2 C12H4N4, C40H26N10, Mr = 646.7, crystallizes in space group P1̄ with a = 6.843(2), 6 = 7.845(3), c = 16.208(7) Å, α = 84.59(3), β = 81.63(3), γ = 75.75(3)°, V = 832.9 Å3 , Z = 1, dc = 1.29 Mgm-3 . Final weighted R = 0.107 based on 2894 reflections. The structure consists of stacks of TCNQ π-dimers with interplanar distances of 3.25(1) Å within a dimer and 3.54(1) A between dimers. The phenazine species do not form stacks and show no electronic interaction with adjacent E2P or TCNQ molecules.

The Structure of 5,10-Dihydro-5,10-diethylphenaziniumyl (E2P+)-2,2′-(2,5-cyclohexadiene-1,4-diylidene)-bispropanedinitrilate(TCNQ-) and its Difference to the Phenazine Doped Species E2P-P-(TCNQ)2 (P = Phenazine)

Phenazine free E2P-TCNQ, C28H22N6, Mr = 442.53 is monoclinic, P21/c, a = 10.875(3), b = 14.679(4), c = 14.526(2) Å, β = 90.90(2)°, V = 2321.9 Å3 , Z = 4, dc = 1.27 Mgm-3 , the compound doped with 50% phenazine, E2P-P-(TCNQ)2 C52H34N12, Mr = 826.93, is triclinic, P1̅, a = 7.739(3), b = 15.899(6), c = 17.037(7) Å, α = 83.44(3), β = 88.34(3), γ = 83.19(3)°, V = 2067.7 Å, Z = 2, dc= 1.33 Mgm-3. E2P-TCNQ was refined to R = 0.066 for 1880 reflections. It consists of planar TCNQ anions and bent E2P cations (dihedral angle 17.7° along the line N-N) arranged in regular mixed stacks along c. The structure of E2P-P-(TCNQ)2 could be solved principally, but did not refine well (R = 0.165 for 1206 reflections). Regular segregated stacks of the phenazine and the TCNQ moieties are formed, and along the cationic stack the E2P+ cations and the neutral phenazine molecules alternate.

Compound heterozygosity of two functional null mutations in the ALPL gene associated with deleterious neurological outcome in an infant with hypophosphatasia

Hypophosphatasia (HPP) is a heterogeneous rare, inherited disorder of bone and mineral metabolism caused by different mutations in the ALPL gene encoding the isoenzyme, tissue-nonspecific alkaline phosphatase (TNAP). Prognosis is very poor in severe perinatal forms with most patients dying from pulmonary complications of their skeletal disease. TNAP deficiency, however, may also result in neurological symptoms such as neonatal seizures. The exact biological role of TNAP in the human brain is still not known and the pathophysiology of neurological symptoms due to TNAP deficiency in HPP is not understood in detail. In this report, we describe the clinical features and functional studies of a patient with severe perinatal HPP which presented with rapidly progressive encephalopathy caused by new compound heterozygous mutations in the ALPL gene which result in a functional ALPL "knock out", demonstrated in vitro. In contrast, an in vitro simulation of the genetic status of his currently asymptomatic parents who are both heterozygous for one mutation, showed a residual in vitro AP activity of above 50%. Interestingly, in our patient, the fatal outcome was due to progressive encephalopathy which was refractory to antiepileptic therapy including pyridoxine, rather than hypomineralization and respiratory insufficiency often seen in HPP patients. The patient's cranial MRI showed progressive cystic degradation of the cortex and peripheral white matter with nearly complete destruction of the cerebrum. To our knowledge, this is the first MRI-based report of a deleterious neurological clinical outcome due to a progressive encephalopathy in an infant harboring a functional human ALPL "knock out". This clinical course of disease suggests that TNAP is involved in development and may be responsible for multiple functions of the human brain. According to our data, a certain amount of residual TNAP activity might be mandatory for normal CNS function in newborns and early childhood.

Incidence of type 1 diabetes in childhood before and after the reunification of Germany--an analysis of epidemiological data, 1960-2006

OBJECTIVE

To examine the impact of rapidly changing environmental factors on the incidence of type 1 diabetes mellitus (T1D).

METHOD

We compared the frequency of T1D in children before and after the reunification of Germany by means of the registries of the German Democratic Republic (GDR, 1960-1989) and of Baden-Wuerttemberg (BW, 1987-2006). The number of cases of diabetes onset in East Germany after the reunification was predicted by a mathematical model. The observed incidence rate in the Eastern part of Germany after the reunification was taken from the literature 1.

RESULTS

In Germany, the incidence rate of T1D in children aged 0-14 was 7.2/100 000/year (95%-CI 6.9-7.5, GDR, 1980-1987), and 10.4/100 000/year (95%-CI 9.5-11.4, BW, 1987-1994). For the whole observation period (1960-2006), the observed incidence rates y could be described by the square of a linear function [GDR: y=(1.86 + 0.040 * (year - 1960))²; r²=0.85; BW: y=(3.03 + 0.085 * (year - 1987))², r²=0.89]. The mean rise in incidence before the reunification was less than half the mean rise after the reunification (mean slope: BW 0.085, 95%-CI 0.080-0.090 vs. GDR 0.040, 95% CI 0.036-0.044). The observed incidence for East Germany after 1989 was higher than the prediction on the basis of the GDR -registry (GDR 12.3/100 000/year vs. Saxony 15.7/100 000/year, 95%-CI 14.2-17.3, n=412; 1999-2003).

CONCLUSION

We conclude that the basis for the disease progress is a genetic predisposition. Environmental factors may modify changes in incidence of type 1 diabetes but do not determine the overall risk.

Hypericin for visualization of high grade gliomas: first clinical experience

AIMS

We aimed to demonstrate that Hypericin, a component of St. Johns Wort, selectively visualizes malignant gliomas. Hypericin is known as one of the most powerful photosensitizers in nature with excellent fluorescent properties.

METHODS

In five patients with a recurrence of a malignant glioma a newly developed water soluble formulation of hypericin was given intravenously (0.1 mg/kg body weight) 6 h before the surgical procedure. Tumor resection was performed under white light and fluorescence mode. The intensity grade of the tissue fluorescence was categorisized by the surgeon in three grades, highly fluorescent, weakly fluorescent and not fluorescent. In these areas tissue samples were taken and investigated by two blinded independent neuropathologists. Tissue samples were histologically classified differentiating between tumor tissue, tumor necrosis, tissue with scattered tumor cells and normal brain tissue.

RESULTS

In all patients tumor tissue was clearly distinguishable by its typically red fluorescence color from normal brain tissue which was colored blue under a special fluorescent filter. Histological evaluation of the 110 tissue samples showed a specificity of 100% and sensitivity of 91% for one of the two neuropathologists, whereas specificity for second pathologist was 90% and sensitivity 94%. The i.v. application of Hypericin proofed to be safe in all cases and there were no side effects observed.

CONCLUSION

Hypericin in its water soluble form is a well tolerated drug. In addition to its high photosensitizing properties hypericin will open up interesting new therapeutic possibilities especially when used in combination with fluorescence detection and simultaneously photodynamic therapy.

Spatio-temporal deleted in colorectal cancer (DCC) and netrin-1 expression in human foetal brain development

AIMS

Deleted in colorectal cancer (DCC) and its ligand netrin-1 are known as axonal guidance factors, being involved in angiogenesis, migration and survival of precursor cells in the embryonic mammalian central nervous system (CNS). So far, little is known about the distribution of those molecules in human CNS development.

METHODS

We investigated 22 human foetal brain specimens (12th and 28th week of gestation) for DCC and netrin-1 expression by means of immunohistochemistry, immunofluorescence and confocal laser microscopy. Statistical analysis was performed by applying a semi-quantitative score, including staining intensity and frequency and correlation with foetal age.

RESULTS

DCC and netrin-1 were differentially expressed throughout the developing human foetal telencephalic and cerebellar cortical layers. Netrin-1 exhibited the highest levels in telencephalic germinal layers, whereas the strongest DCC immunoreactivity was seen in the developing cortical plate. Netrin-1 and DCC were predominantly present on cerebellar external granule layer cells. Distinct co-expression was seen in maturing foetal brainstem nuclei, cerebellar external granular layer and the choroid plexus. In contrast, endothelial cells showed strong netrin-1 expression with subsidiary DCC immunoreactivity. Pontine and telencephalic axonal fibre tracts also demonstrated strong netrin-1 expression.

CONCLUSIONS

We show that DCC and netrin-1 are ubiquitously expressed in the human foetal brain; however, both exhibit a distinct spatio-temporal expression pattern. Together with the data from animal experiments, our findings might indicate also an important role for DCC and netrin-1 in human foetal CNS development.

Professional risk for skin cancer development in male mountain guides--a cross-sectional study

OBJECTIVE

For reasons of their outdoor work, mountain guides (MG) are heavily exposed to ultraviolet radiation during their work.

METHODS

A standardized interview and examination were performed on 283 male MG (median 41 years) from Germany, Switzerland and Austria and 309 age-matched controls. The median occupation time as MG was 17 years; 39.9% were working full-time.

RESULTS

The incidence of skin cancer and precancerous lesions was obtained. Precancerous lesions as solar keratosis (SK) were significantly more frequent in MG (25.4% vs. 7.4%). There was no skin cancer [BCC, SSC, melanoma (MEL)] in the control subjects. Basal cell carcinoma (BCC) was diagnosed in 20 MG (7.1%) and SSC in four MG (1.4%). There were 10 highly suspicious melanocytic lesions; one MG had a histologically confirmed malignant MEL. Risk factors for SK in the multivariate analysis included occupation (P < 0.0001), age (P < 0.0001) and skin type (P = 0.0002). Within the MG group, age (P < 0.0001) and hair colour (P = 0.0058) were independent risk factors for SK. Severe lifetime sunburns (P = 0.0007) and skin type (P = 0.041) were the significant risk factors for BCC, within the MG group in addition to the number of guiding days (P = 0.010). The risk factor for skin cancer (BCC, SCC and MEL) was the number of heavy sunburns during lifetime (P = 0.0014).

CONCLUSION

The present study demonstrates an association between high occupational ultraviolet-exposure and an increased prevalence of precancerous skin lesions and skin cancer. MG may be considered as an example for other outdoor professionals. Skin cancer of outdoor workers is likely to be an occupational disease. Primary and secondary prevention should be enforced.

[Radical transurethral resection of the prostate. An alternative therapy for the treatment of prostate cancer]

The value of radical transurethral resection of prostate cancer (TURPC) as an alternative therapy was investigated in this prospective study. From January 1995 to July 2008, 533 patients with a median age of 67 years (range 40-89 years) and with clinically localized prostate cancer were resected by the corresponding author with curative intention. The tumor stages were as follows: pT1 8%; pT2 61%; pT3 31%; G1 2%; G2 80%; G3 18%. TURPC requires continuous low-pressure irrigation with the irrigator liquid level at 10 cm water above the pubic region. It also requires a suprapubic trocar, a resectoscope with a 28F sheath, an autoregulated electrosurgical unit, and video monitoring. The prostate is resected completely with peripheral capsule and seminal vesicles. The specimen is retrieved in fractions for correct histopathological staging. If indicated, laparoscopic staging lymphadenectomy is performed. A secondary session for control of positive margins follows after 8 weeks. The transfusion rate was 1.5%, revision for hemorrhage 2.4%, lung embolism 0.2%, bladder neck incision 14%, grade 2 incontinence 0.6% out of 314, and impotence 30% out of 136. The prostate-specific antigen (PSA) nadir was < or =0.2 ng/ml in 95% of 444 cases. PSA recurrence at 5 years was 6% for pT1, 18% for pT2, and 31% for pT3. Postoperative survival at 10 years was 96% for pT1, 91% for pT2, and 85% for pT3 patients. Prostate cancer can be resected transurethrally with reasonable oncological results. The outcome with respect to survival and PSA recurrence is comparable with the results of other published procedures. Low-pressure irrigation with a suprapubic trocar is mandatory for safe performance.

Evaluation of Red Blood Cell Deformability and Uterine Blood Flow in Pregnant Women with Preeclampsia or IUGR and Reduced Uterine Blood Flow Following the Intravenous Application of Magnesium

OBJECTIVE

Red blood cells (RBC) deformability is one of the factors determining microcirculation. In preeclampsia (PE) and some cases of intrauterine growth restriction (IUGR), RBC deformability and, consequently, microcirculation appear to be impaired. Magnesium sulfate is administered to reduce the risk of seizures in PE. The aim of our study was to detect the effect of 24-hour intravenous (IV) magnesium on RBC deformability and on uterine artery blood flow in pregnant patients with preeclampsia or IUGR and pathologic uterine blood flow.

METHODS

Magnesium IV (1 g/h) was administered to 25 pregnant women with reduced uterine blood flow for a period of at least 24 hours. The RBC deformability was measured by uterine artery Doppler. Measurements were taken before the start of magnesium therapy and 24 h later. Magnesium plasma levels were measured at the same time.

RESULTS

High plasma levels of magnesium improve RBC deformability from E = 0.109 (SD +/- 0.023) to E = 0.115 (SD +/- 0.021) after 24 h IV magnesium (p = 0.043). There is no correlation of E to the plasma magnesium level either before or after 24 h magnesium treatment. Blood volume flow in the uterine arteries increased significantly from 5.09 mL/s (SD +/- 3.03) to 10.02 mL/s (SD +/- 5.86) after 24 h magnesium (p = 0.0002). The differences in the resistance index do not significantly differ from 0 (p = 0.46).

CONCLUSION

A high IV dosage of magnesium over a period of 24 hours dilates the uterine arteries of pregnant women with PE and/or IUGR, reduces uterine blood flow and improves the deformability of RBC. Both parameters enhance the oxygen supply to the fetus, a clinical parameter in these pregnancies. Thus magnesium might not only be effective as phrophylaxis against seizures but also in cases of IUGR with a reduced uterine blood flow. The clinically observed beneficial effect of magnesium in PE could be due to the improved blood supply for the fetus.

HLA-associated multipeptide vaccination in biochemically relapsed prostate cancer patients

5134

Background: We conduct a phase I/II monocenter clinical trial using multi peptide vaccination in patients with hormone naive, biochemically relapsed prostate cancer. The synthetic peptides applied are MHC-class I (HLA-A2) and -class II binders for activating CD4+ and CD8+ T- effector cells in vivo. Study endpoints are side effects as well as PSA- and T-cell response. Methods: Patients (pts) with rising PSA after primary curative surgical treatment without metastatic imageable lesions receive 14 peptides emulsified in Montanide ISA51 subcutaneously, combined with one of four T-cell stimulatory adjuvants versus no adjuvant for 18 months (mo) or until progression. PSA doubling time (DT) and clinical performance are monitored. T-cell activity and specifity are assessed with Elispot assay, tetramer staining and intracellular cytokine stainings. Results: 25 out of 35 pts have terminated the study treatment so far. During the vaccination period, geometric mean PSA DT increased from 7.8 mo (range 1.5 - 44.8 mo, 25 pts) to 11.8 months (range 2.2 - 571.3 mo, 24pts) whereas 1 pt showed a decreasing PSA value. Overall 8/25 pts (32%) had a mean rise of PSA DT of 81.6 mo and four of them did not receive any further treatment and were evaluable for follow-up (FU) after peptide vaccination (FU median 16 mo, range 5–33). These four pts raised their mean geometric PSA DT from 8.2 mo prior study treatment to 51.9 mo at treatment end and 52.5 mo at end of FU. PSA progressed unchanged in 10 patients (40%) or increased intermittently only in 4 pts. Two pts had PSA decline or DT increase during FU but not during the treatment period. Four patients (16%) exhibited an allergic reaction CTCAE II°. All pts reacted to at least one of the tumor antigen-derived HLA-class I epitopes after the fourth vaccine injection and up to six peptides were recognized simultaneously by CD8+ T cells in some individuals. Conclusions: Multi peptide vaccination stabilized or slowed down PSA progress in 11 of 25 cases. Stimulation of specific T-cell response is observed. Rise of PSA DT delaying standard treatment up to 33 mo and thus, delaying disease specific mortality is feasible.

No significant financial relationships to disclose.

Erythropoietin receptor is expressed in meningiomas and lower levels are associated with tumour recurrence

AIMS

The Epo-EpoR pathway plays a role in tumour growth, metastasis and treatment resistance and is a potential target in oncological treatment. As the EpoR status in human meningiomas is unknown, our aim was to characterize EpoR expression in these tumours.

METHODS

We examined 131 meningioma samples of all WHO grades from 116 patients by immunohistochemistry for EpoR. Among these, 25 meningiomas showed brain invasion and 29 patients had a further tumour recurrence. A group of 20 patients without tumour recurrence served as controls. In 12 cases we were able to compare both the primary and the following recurrent tumours. The presence of EpoR in meningiomas was confirmed by RT-PCR and Western blot.

RESULTS

EpoR was expressed in all meningiomas. Statistical analysis revealed that the mean expression levels of EpoR were significantly lower in primary tumours with known recurrence compared with a recurrence-free control group. Additional matched pair analysis in individual cases showed no significant differences between primary and recurrent tumours. No significant correlation between EpoR expression and WHO grade, age, sex or brain invasion was detected. Using specific primer pairs for RT-PCR, we were able to detect all three known isoforms of EpoR: the full-length isoform EpoR-F, the truncated isoform EpoR-T and the soluble isoform EpoR-S.

CONCLUSIONS

Our results demonstrate the expression of EpoR in meningiomas. Lower EpoR mean levels might be a useful marker for a higher recurrence risk, but further studies are needed to clarify the influence of EpoR on recurrences and the role of the different isoforms.

Immune depression syndrome following human spinal cord injury (SCI): a pilot study

Experimental spinal cord injury (SCI) has been identified to trigger a systemic, neurogenic immune depression syndrome. Here, we have analyzed fluctuations of immune cell populations following human SCI by FACS analysis. In humans, a rapid and drastic decrease of CD14+ monocytes (<50% of control level), CD3+ T-lymphocytes (<20%, P<0.0001) and CD19+ B-lymphocytes (<30%, P=0.0009) and MHC class II (HLA-DR)+ cells (<30%, P<0.0001) is evident within 24 h after spinal cord injury reaching minimum levels within the first week. CD15+ granulocytes were the only leukocyte subpopulation not decreasing after SCI. A contributing, worsening effect of high dose methylprednisolone cannot be excluded with this pilot study. We demonstrate that spinal cord injury is associated with an early onset of immune suppression and secondary immune deficiency syndrome (SCI-IDS). Identification of patients suffering spinal cord injury as immune compromised is a clinically relevant, yet widely underappreciated finding.

[Transurethral resection in prostate cancer, a radical procedure. Experience with 1017 cases]

OBJECTIVES

From the beginning of TUR in 1931 the reseccionists thought of resecting prostate cancer. Execution however failed for deficient instruments and techniques. The first transurethral resection for prostate cancer: TURPC--was performed at our institution in 1957 by Hans J. Reuter. Low pressure irrigation enabled safe transurethral resection of the prostate including the capsule. Thus we started in 1985 a prospective study to verify TURPC as a radical procedure.

METHOD

TURPC requires continuous low pressure irrigation with irrigating reservoir fixed at the operating table. The liquid level within is to maintain less than 20 cm. water above the pubic region in lithotomy position. Continuous flow is maintained by suprapubic trocar and a resectoscope with 28Fr. sheath. An autoregulated electro-surgical unit is indispensable. It automatically adjusts the high-frequency current to suit the cut tissue's electrical resistance for precise cutting. Videomonitoring is mandatory. The prostate is resected completely with its capsule into periprostatic fat together with the seminal vesicles. The specimen is retrieved in fractions to guarantee correct histopathological staging. If indicated laparoscopic staging lymphadenectomy is performed. A secondary session for control of positive margins follows after 12 weeks.

RESULTS

From 1985-2004 1,017 patients with a mean age of 68.9 years and with clinically localized prostate cancer were resected by 5 surgeons with curative intention. The cancer stage distribution was in %: T1: 12, T2: 43, T3: 41, T4: 4.--G1: 8, G2: 72, G3: 20. Mortality 1 out of 1,017. Bladder neck incision 8.9%. Incontinence grade 3: none. Postoperative survival over 10 years was 82% in T1, 87% in T2, 81% in T3 and 34% in T4 patients. Biochemical recurrence as of the rise of three consecutive PSA-values was within 5 years 15% in T1, 19% in T2, 27% in T3.

CONCLUSIONS

Considering our results we conclude that prostate cancer can be resected transurethrally as radical as with open surgery. The outcome as to survival and PSA-recurrence is comparable, the incontinence rate is less then with open surgery. It is mandatory to have low pressure irrigation with suprapubic trocar, 28Fr. sheath and on autoregulated electrosurgical unit, video monitoring and a well experienced reseccionist.

Telomere length analysis in monocytes and lymphocytes from patients with systemic lupus erythematosus using multi-color flow-FISH

In order to analyse telomere length in subsets of human peripheral blood lymphocytes and monocytes, we modified a recently developed multicolor flow- fluorescent in situ hybridization (FISH) methodology that combines flow-FISH and antibody staining for cell surface antigens. We analysed telomere length of peripheral blood mononuclear cells in a group of 22 patients with systemic lupus erythematosus (SLE) and 20 age-matched healthy donors. We found that neither CD4+, CD8+, CD19+ cells nor CD14+ monocytes have significantly shorter telomeres compared with their healthy counterparts. On the basis of these findings, we then used monocyte telomere length as internal reference in order to control for intra-individual variability in telomere length. By using this approach, we could demonstrate significant telomere shortening in all three lymphocyte subsets (in all cases P < 0.05) compared with monocytes. However, these differences did not vary significantly between SLE patients and controls. In summary, telomere lengths in subpopulations of hematopoietic cells can be monitored in patients with SLE using multicolor flow-FISH. While confirming data by other groups on telomere length in lymphocyte subpopulations, our data argue against an increased proliferation rate of peripheral blood monocytes reflected by accelerated telomere shortening in patients with SLE.

The Residual Platelet Aggregation after Deployment of Intracoronary Stent (PREDICT) score

BACKGROUND

Recent studies suggest a high interindividual variability of response to clopidogrel associated with adverse cardiovascular outcome. Different clinical factors are considered to influence a persistent residual platelet aggregation (RPA) despite conventional antiplatelet therapy.

OBJECTIVES

To investigate clinical factors that affect RPA after 600-mg clopidogrel loading in a large unselected cohort of patients with symptomatic CAD.

METHODS

The study population included a consecutive cohort of 1,092 patients treated with coronary stenting for stable angina and acute coronary syndromes (ACS). Residual platelet activity was assessed by ADP (20 micromol L(-1))-induced platelet aggregation >or= 6 h after LD. Eleven clinical factors were included in the primary analysis.

RESULTS

In multivariate regression analysis increased RPA was significantly influenced by ACS, reduced LV-function, diabetes mellitus, renal failure (creatinine > 1.5 mg dL(-1)), and age > 65 years. In a factor-weighed model the risk for high RPA increased with higher score levels (OR for patients with a score of 1-3, 1.21, 95% CI 0.7-2.1; score 4-6, OR 2.0, 95% CI 1.17-3.5; P = 0.01; score 7-9, OR 3.3, 95% CI 1.8-6.0). During a 30-day follow-up the incidence of major adverse events was higher in patients with RPA in the upper tertile (4.8% vs. 2.5% in the 2nd and 1.5% in the 1st tertile; P < 0.05).

CONCLUSIONS

The PREDICT score provides a good tool to estimate residual platelet activity after clopidogrel LD by easily available patient details. Additionally, we demonstrate its association with short-term outcome. Thus, patients with a high score may benefit from intensified antiplatelet therapy by improved platelet inhibition and risk reduction for thromboischemic events.

[T-plate osteosynthesis--an obsolete osteosynthesis procedure for proximal humeral fractures? Middle-term clinical and radiological results]

AIM

The present clinical trial was performed to assess the clinical and radiological outcome after operative treatment of proximal humeral fractures using the T-plate.

METHODS

All patients who were treated with the T-plate were included into the study. Patient satisfaction,complications and radiological findings were assessed. The clinical results were evaluated using the Constant-Murley score, the UCLA score, and the DASH score. Between December 1996 and October 2003, 74 patients (with 76 fractures)were treated with the T-plate. Surgically treated complications were 2 hematomas and 3 failures of the osteosynthesis under functional physiotherapy. In 19 patients the implants were removed because of persisting complaints.

RESULTS

After an average follow-up period of 67 months 52 patients (54 fractures) were examined. According to the Neer classification there were 34 2-part, 15 3-part and 5 4-part fractures.80% of the patients were satisfied with the result. According to the evaluated scores, 74 to 89% of the patients had an excellent to satisfactory outcome.

CONCLUSION

The T-plate enables the stable fixation of complex proximal humeral fractures and permits even in the elderly patient an early functional treatment. Anatomical reconstruction and stable fixation followed by early rehabilitation are most important to achieve a good functional outcome in the patient.

Reactive astrocytes and activated microglial cells express EAAT1, but not EAAT2, reflecting a neuroprotective potential following ischaemia

AIMS

Glutamate receptor antagonists have failed clinical stroke trials and it has been proposed that the action of N-methyl D-aspartate receptors is necessary for neuronal survival. Thus, excitatory amino acid transporters (EAATs) might be a promising therapeutic target. The aim of this study was to investigate glial expression of EAATs following ischaemia.

METHODS AND RESULTS

Expression of EAAT1 (GLAST) and EAAT2 (Glt-1) in 24 cases of ischaemia was examined by immunohistochemistry. Cortical expression of both EAATs in the lesion decreased within 24 h (P < 0.01, each). Whereas EAAT1+ white matter cells increased 18-fold (P < 0.05) within 24 h in the lesion and remained elevated for months in adjacent (469-fold, P < 0.01) and remote areas (20-fold, P < 0.05), EAAT2+ white matter cells were equivalent in ischaemia and controls. In the first week after stroke mainly activated (ramified and amoeboid) microglia expressed EAAT1, whereas monocytic cells in perivascular spaces and foamy macrophages lacked EAAT1. After more than 1 week, predominantly reactive astrocytes expressed EAAT1.

CONCLUSIONS

Microglial EAAT1 expression is restricted to the early/intermediate stage of activation and blood-derived (perivascular) monocytes do not contribute to EAAT1+ cells following ischaemia. Whether a pharmacological increase in glial EAAT expression may compensate for loss of cortical EAAT expression and reduce neuronal damage following stroke requires investigation by further functional studies.

De novo erythropoietin receptor (EPO-R) expression in human neoplastic glial cells decreases with grade of malignancy but is favourably associated with patient survival

The erythropoietin receptor (EPO-R) is mainly known as a regulator of erythropoiesis. However, recent studies revealed that the EPO-R is not exclusively expressed in haematopoietic tissues but also in various cancer cell types and normal tissue such as the central nervous system (CNS). EPO-R is up-regulated under hypoxia and is able to counteract the deleterious effects of hypoxia on tumour growth, metastasis and treatment resistance. Therefore, the EPO-EPO-R signalling pathway is considered as a possible target for tumour treatment. Here, we investigated brain tumour samples obtained from patients between 1993 and 2003 to study EPO-R expression in vivo. Tissue samples included 194 gliomas of different WHO grades, additionally 25 infiltration zone samples and 31 relapses of WHO grade IV glioblastomas as well as 23 normal CNS tissue specimens to address the in vivo situation. Immunohistochemistry of the tissue microarray samples revealed significantly higher levels of EPO-R expression in neoplastic glial cells compared with glial cells derived from normal brain. EPO-R expression showed a highly significant decrease from low- to high-grade gliomas. Age-stratified Kaplan-Meier analysis revealed longer survival for patients exhibiting high EPO-R status in high-grade gliomas. Our results show a grade-dependent EPO-R down-regulation and might contribute to the understanding of high-grade glioma resistance to radio- and chemotherapy as both were shown to be improved by a well functioning EPO-EPO-R pathway in previous studies. Further studies are needed to investigate to what extent the decreased mortality in age-stratified patient groups with high EPO-R levels reflects a direct beneficial role of EPO-R expression.

[Quality of life in patients with oropharyngeal carcinoma. Gender influences the subjective evaluation]

BACKGROUND

The purpose of this study was to evaluate the impact of patient characteristics and surgical interventions on quality of life (QoL) after primary surgery and postoperative irradiation in patients with oropharyngeal carcinoma.

PATIENTS AND METHODS

Between January 1997 and February 2002, 169 patients with carcinoma of the oropharynx were treated with curative intent. In September 2002, a total of 88 disease-free survivors were identified and included in this study. A retrospective chart review was performed and patient responses to the SF-36 Health Survey, EORTC QLQ-C30 and EORTC QLQ-H&N35 questionnaires were evaluated. The questionnaires were completed by 34 patients (39% response rate).

RESULTS

All patients were treated with primary surgery followed by postoperative irradiation. The median follow-up was 2.3 years (range 0.5-4.9 years). Using Bonferroni-Holm adjustment for alpha, gender was found to be an important factor in QoL. Females scored significantly worse than males in all three questionnaires. We could not identify other factors influencing QoL.

CONCLUSION

The impact of gender on QoL must be considered as very significant.

Expression of EAAT1 reflects a possible neuroprotective function of reactive astrocytes and activated microglia following human traumatic brain injury

Glutamate-mediated excitotoxicity is known to cause secondary brain damage following stroke and traumatic brain injury (TBI). However, clinical trials using NMDA antagonists failed. Thus, glial excitatory amino acid transporters (EAATs) might be a promising target for therapeutic intervention.

METHODS AND RESULTS

We examined expression of EAAT1 (GLAST) and EAAT2 (Glt-1) in 36 TBI cases by immunohistochemistry. Cortical expression of both EAATs decreased rapidly and widespread throughout the brain (in lesional, adjacent and remote areas) following TBI. In the white matter numbers of EAAT1+ parenchymal cells increased 39-fold within 24h (p<0.001) and remained markedly elevated till later stages in the lesion (90-fold, p<0.01) and in peri-lesional regions (86-fold, p<0.01). In contrast, EAAT2+ parenchymal cells and EAAT1+ or EAAT2+ perivascular cells did not increase significantly. Within the first days following TBI mainly activated microglia and thereafter mainly reactive astrocytes expressed EAAT1. Perivascular monocytes and foamy macrophages lacked EAAT1 immunoreactivity. We conclude that following TBI i) loss of cortical EAATs contributes to secondary brain damage, ii) glial EAAT1 expression reflects a potential neuroprotective function of microglia and astrocytes, iii) microglial EAAT1 expression is restricted to an early stage of activation, iv) blood-derived monocytes do not express EAAT1 and v) pharmacological modification of glial EAAT expression might further limit neuronal damage.

Diagnostic accuracy ofin vitropanoramic radiographs depending on the exposure

OBJECTIVES

The aim was to evaluate the effect of dose reduction on diagnostic accuracy in panoramic radiographs with increased tube potential and reduced milliampere settings.

METHODS

Panoramic radiographs of 12 dried human skulls prepared with lesions in the bone, teeth and peri-implant bone in ascending size were taken. Medium and regular film--screen combinations and a storage phosphor system were used for imaging. All systems were exposed at a low and a high tube potential level. To compare the dose at different tube potential settings, dose length product was measured at the secondary collimator. Five observers assessed the presence (response: 1) or absence (response: 0) of lesions. Sensitivity, specificity and diagnostic accuracy were evaluated and 36 000 ratings were made in all. All settings were repeated once. Intrarater agreement was expressed by Cohen's kappa coefficient.

RESULTS

There was no significant difference in diagnostic accuracy between a medium and a regular film--screen combination at a low tube potential level (70 kV; 0.935 and 0.930) and the medium film--screen system at a high tube potential level (85 kV; 0.926). Compared with this group, the regular film-screen combinations at high tube potential level (85 kV, 0.906) and all digital radiographs were significantly different (0.886 and 0.866), irrespective of the tube potential level. The digital panoramic radiograph was only comparable with the best film--screen combinations with an exposure for a medium film-screen system and at a low tube potential level. Sensitivity was 89.9% and specificity 93.7%. The kappa coefficient for intrarater agreement was high (0.81).

CONCLUSIONS

The medium intensifying screen can be used at high tube potential settings instead of low tube potential settings, or the regular intensifying screen can be used at low tube potential settings with the same diagnostic value. A dose reduction of about 40% is possible. The storage phosphor plates should be exposed at least like a regular film-screen system and at a low tube potential level.

Influence of tube potential setting and dose on the visibility of lesions in intraoral radiography

OBJECTIVES

The objectives were to determine the diagnostic accuracy of different image receptors when first, the tube potential setting was increased from 60 kV to 90 kV and second, when the milliampere setting was reduced at unchanged tube potential for storage phosphor plates.

METHODS

Intraoral radiographs (films of speed class F, storage phosphor plates) were taken of 12 dried human skulls prepared with lesions in both teeth and peri-implant bone, in ascending size. Five observers assessed the presence (response=1) or absence (response=0) of lesions. The digital intraoral radiograph was exposed at 60 kV and 90 kV with half and a quarter of the film exposure. Some of the radiographs were assessed a second time. In total, 6000 assessments were made. Intrarater agreement was expressed by Cohen's kappa coefficient.

RESULTS

The digital combinations showed the lowest diagnostic accuracy in all combinations, but the results demonstrated an equivalence of all combinations of films and storage phosphor plates. The differences in diagnostic accuracy were low (94-96.5%). The kappa coefficient for intrarater agreement was high (0.85).

CONCLUSIONS

Regarding peri-implant and decayed lesions, intraoral films and storage phosphor plates demonstrated equal quality in this in vitro study regardless of exposure at 60 kV or 90 kV.

[Tissue engineering of peripheral nerves]

BACKGROUND

In spite of considerable progress in microsurgical techniques, the treatment of long distance defects in peripheral nerves remains challenging for the surgeon. Autologous nerve grafting has been the only applicable procedure to overcome such defects in the past. Due to the known disadvantages of this procedure (neuroma formation and sensory deficits at the donor-site, limited availability of donor-material, etc.) and impaired regenerative results, different tubulisation techniques are discussed more frequently as alternatives to the autologous nerve grafts.

AIM OF THE STUDY

In this work, the authors summarise their experiences and results with different synthetically developed materials, cellular and acellular tubes and venous conduits for the reconstruction of peripheral nerve defects.

MATERIAL AND METHODS

To analyse peripheral nerve regeneration, we utilised a median nerve model in rats. In these studies nerve gaps up to 40 mm were induced. Guiding tubes of various materials (trimethylene carbonate-epsilon-caprolactone, polyethylene, veins, and collagen) were employed. Furthermore, we introduced Schwann cells as cellular elements into some of the trimethylene carbonate-epsilon-caprolactone tubes. The longest postoperative observation period was nine months.

RESULTS

The results demonstrated that only in the case of cellular filled tubes (syngenic Schwann cells) did regeneration occur across the 20 mm gap. This regeneration was comparable to that induced after autologous grafting. Across a 40 mm gap the autologous graft demonstrated the best results.

Possibilities of dose reduction in lateral cephalometric radiographs and its effects on clinical diagnostics

OBJECTIVES

The aim of the present study was to determine (1) the absorbed and the exit radiation doses for cephalometric exposures on a phantom head with various exposure settings and image receivers, and (2) the diagnostic image quality for various modalities assessed on cephalometric radiographs of patients.

METHODS

The dose measurements for lateral cephalometric radiographs were performed with a semiconductor detector, and also with thermoluminescent detectors and an Alderson phantom. Both the integral and the effective doses were determined. Two radiographs of each patient (n=119) were taken at two different times, one at a low tube potential setting, 75+/-5 kV, and one with a decreased dose. Film-screen systems with speed class 400 and one storage phosphor plate were used. Five observers assessed the radiographs for the visualization of six cephalometric reference points on a three-point scale with -1, 0 and 1. Twenty-seven image pairs were rescored to determine inter- and intrarater reliability. The statistical analysis was done using analysis of variance and Tukey's HSD (honestly significant difference) post hoc test.

RESULTS

Increasing the tube potential setting led to an average dose reduction to 83% (integral dose) or to 87% (effective dose). Instead of taking the radiograph at a low tube potential setting (75 kV), a dose reduction of about 15% was feasible at a high tube potential setting (90 kV). A significant difference in reference point visibility existed between film radiographs at low tube potential settings (mean score 0.984) and at high tube potential settings (90 kV, mean score 0.958). For the storage phosphor plates, there was no significant difference to the film-screen combinations at low tube potential and halved milliampere seconds settings. In the second assessment, there was a high degree of agreement (96.6%) compared with the first assessment (unadjusted for random agreement).

CONCLUSIONS

As there is only minimal dose reduction at increased tube potential settings, for a dose reduction, it seems to be more useful to use storage phosphor plates at unchanged tube potential and halved milliampere seconds settings compared with the film-screen combination.

Comparative neuro tissue engineering using different nerve guide implants

At the moment autologous nerve grafting remains the only reasonable technique for reconstruction of peripheral nerve defects. Unfortunately, this technique has a lot of complications and disadvantages. These problems are related to the autologous nerve that is harvested for this procedure. Donor site morbidity with loss of sensitivity, painful neuroma formation and of course the restricted availability of autologous nerves stimulates the idea for alternative techniques on that field. In this paper we describe our experience with different graft materials for reconstruction of a 2 cm nerve gap in a median nerve model in rats. After implantation of various materials (biological/synthetic) the main experiments were conducted with a synthetic, biodegradable nerve conduit seeded with autologous Schwann cells. With this material we were able to reconstruct successfully a 2 cm gap in the rat median nerve. Regeneration with this material was found to be equally to an autologous nerve graft.

Differential microglial regulation in the human spinal cord under normal and pathological conditions

As the primary intrinsic immune effector cells of the central nervous system, microglia are involved in virtually all pathological processes of the brain and spinal cord including inflammatory, neurodegenerative, traumatic, neoplastic and vascular diseases. Despite this important role, there is a lack of data concerning microglial distribution and protein expression in the human spinal cord. In this study, we immunohistochemically investigated 10 normal human spinal cords to establish reference data and compared these results with 15 pathological human spinal cords deriving from distinct pathologies. Each spinal cord was evaluated at eight different levels for three white and two grey matter areas for both constitutive (MHC-II, CD68, IL-16, AIF-1, LCA, CD4) and reactive (MRP-8, MRP-14) microglial antigens. Whereas previous studies revealed significant regional differences in microglial distribution and protein expression in human brain, normal spinal cord displayed a uniform expression pattern, reaching levels of up to 17% MHC-II positive cells of the total cell population. This datum formed the basis for the further evaluation of microglia expression levels in pathological spinal cords, where levels of up to 45% positive cells were observed. Our results represent important reference values for future neuropathological diagnostic and therapeutical approaches in spinal cord pathologies.

The effect of dose reduction on the detection of anatomical structures on panoramic radiographs

OBJECTIVES

The aim was to evaluate the effect of dose reduction on diagnostic accuracy using different screen-film combinations and digital techniques for panoramic radiography.

METHODS

Five observers assessed 201 pairs of panoramic radiographs (a total of 402 panoramic radiographs) taken with the Orthophos Plus (Sirona, Bensheim, Germany), for visualization of 11 anatomical structures on each side, using a 3-point scale -1, 0 and 1. Two radiographs of each patient were taken at two different times (conventional setting and setting with decreased dose, done by increasing tube potential settings or halving tube current). To compare the dose at different tube potential settings dose-length product was measured at the secondary collimator. Films with medium and regular intensifying screens (high and low tube potential settings) and storage phosphor plates (low tube potential setting, tube current setting equivalent to regular intensifying screen and halved) were compared. The five observers made 27 610 assessments. Intrarater agreement was expressed by Cohen's kappa coefficient.

RESULTS

The results demonstrated an equivalence of regular screens (low tube potential setting) and medium screens (high and low tube potential settings). A significant difference existed between medium screens (low tube potential setting, mean score 0.92) and the group of regular film-screen combinations at high tube potential settings (mean score 0.89) and between all film-screen combinations and the digital system irrespective of exposure (mean score below 0.82). There were no significant differences between medium and regular screens (mean score 0.88 to 0.92) for assessment of the periodontal ligament space, but there was a significant difference compared with the digital system (mean score below 0.76). The kappa coefficient for intrarater agreement was moderate (0.55).

CONCLUSIONS

New regular intensifying screens can replace medium screens at low tube potential settings. Digital panoramic radiographs should be taken at low tube potential levels with an exposure equivalent at least to a regular intensifying screen.

Acute musculoskeletal infection: comparison of different methods for intraoperative bacterial identification

PURPOSE OF THE STUDY

Various techniques are used for detection of pathogens in musculoskeletal infection. These methods differ with respect to reliability and ease of handling. A prospective study was performed to evaluate the efficacy of three intraoperative techniques.

MATERIAL AND METHODS

In 20 cases (18 patients) with clinically confirmed acute musculoskeletal infections, intraoperative collected swab samples, tissue samples and fluid samples injected into standard blood culture vials were used for microbiological diagnosis. Identification of bacteria, time necessary for detection and ease of handling during surgery was evaluated.

RESULTS

In 19 cases bacterial growth was demonstrated using either intraoperative swabs or blood culture technique (95% sensitivity), whereas 18 tissue biopsies were positive (90% sensitivity. 27 bacterial species were isolated. In 18 instances for the swab technique, 14 instances for the tissue biopsy and 4 operations for the blood culture vials, ease of handling was rated as excellent.

DISCUSSION

The study demonstrated differences between the three tested methods with respect to ease of handling. With respect to the number of detected organisms and time for their detection there are no significant differences. These last findings are in contrast to of the results of other authors. The reason for this could be that during operative dissection an accurate and specific collection of specimens from the acute deep infected soft tissues and bones independent from the type of surgical procedure is possible. Therefore, even with the swab method a high amount of microorganisms can be recovered. Especially for intraarticular infections, fluid samples injected into standard blood vials is a practical method for the surgeon. In acute musculoskeletal infections other than joint infections, there is less benefit for the blood culture vials.

CONCLUSION

Intraoperative swab technique yields valid results comparable to other techniques and is an accurate technique for detection of pathogens from acute musculoskeletal infections. Key words: implant, infections, bacteriological techniques, comparative study.