Direct experimental verification of neutron acceleration by the material optical potential of solid 2H2

We have measured the acceleration of neutrons by the material optical potential of solid 2H2. Using a gravitational spectrometer, we find a minimal kinetic energy Ec = (99+/-7) neV of neutrons from a superthermal ultracold neutron (UCN) source with solid 2H2 as an UCN converter. The result is in excellent agreement with theoretical predictions, Ec = 106 neV.

Occupational risks for adenocarcinoma of the nasal cavity and paranasal sinuses in the German wood industry

OBJECTIVES

To examine the risk of wood dust and chemical exposures for adenocarcinoma of the nasal cavity and paranasal sinuses (ADCN) among German wood workers.

METHODS

An industry-based case-control study with 86 male ADCN cases and 204 controls was conducted in the German wood-working industries. Cumulative and average wood-dust exposure was quantified with a job-exposure matrix based on wood-dust measurements at recent and historical workplaces. Probabilities of exposure to wood preservatives, stains, varnishes, and formaldehyde were semi-quantitatively rated. Odds ratios and 95% confidence intervals were calculated with logistic regression analysis conditional on age and adjusted for smoking and other factors. For estimating the risks of either wood dust or chemical additives, the authors additionally adjusted for the corresponding co-exposure.

RESULTS

ADCN occurred relatively more frequently among wood workers that had ever worked as cabinet makers or joiners (OR 2.96, 95% CI 1.46 to 6.01) than as saw millers (OR 0.15, 95% CI 0.03 to 0.68). Average exposure to inhalable wood dust >/=5 mg/m(3) was associated with a high risk (OR 48.47, 95% CI 13.30 to 176.63) compared to levels below 3.5 mg/m(3). Assuming 40 years of exposure under these concentrations, the corresponding OR was 4.20 (95% CI 1.69 to 10.43). Exposure between 3.5 and 5 mg/m(3) was also found to pose a risk (OR 10.54, 95% CI 3.34 to 33.27). Exposure to pigment stains before 1970 was associated with an increased risk (OR 3.03; 95% CI 1.11 to 8.26). No significant associations were estimated for wood preservatives, varnishes, and formaldehyde.

CONCLUSIONS

The authors found an elevated ADCN risk for exposure to inhalable wood dust above 3.5 mg/m(3). The rareness of the disease does not allow the exclusion of risk below that concentration. For pigment stains, there is evidence for an association of historical exposure with the development of ADCN in German wood workers.

Acute hantavirus infection or renal transplant rejection

Hantaviruses belong to the so-called emerging pathogens that are transmitted to humans by infected rodents and their excreta. In Central Europe, hantavirus infections usually occur in a mild to moderate form of hemorrhagic fever with renal syndrome. In contrast to the mostly benign or even asymptomatic course of hantavirus infections in previously healthy individuals, the acute hantavirus infection in kidney transplant recipients represents an exceptional situation regarding diagnosis and therapy. We describe the case of a 44-year-old kidney transplant recipient with acute renal transplant failure associated with acute hantavirus infection.

Multidirektionale winkelstabile Versorgung der instabilen distalen Radiusfraktur

PURPOSE/BACKGROUND

Open reduction and internal fixation with plates is a valid treatment of displaced extra- and intra-articular distal radius fractures. This report presents our experience treating unstable distal radius fractures by using a multidirectional palmar fixed-angle plate system (Aptus(R) Radius 2.5 by Medartis). The subchondral support of the articular surface by fixed angle screws prevents secondary dislocation allowing early mobilisation.

PATIENTS AND METHOD

61 patients with distal radius fractures were treated during 6/2003 and 10/2004 using this palmar fixed-angle plate fixation without bonegraft. Postoperative X-rays showed anatomical reduction in all cases. 55 patients could be evaluated postoperatively. The follow-up examination included the patient's history, physical and radiographic examination as well as the DASH questionnaire and the Krimmer's modified Cooney wrist score.

RESULTS

The average follow-up time was 9.6 +/- 5.2 months. The mean age of the examined patients was 53.9 +/- 17.8 years. The fractures were classified according to AO. There were eleven A3, four B2 and five B3 fractures, ten C1, 16 C2 and nine C3 fractures. All fractures united without complications. Just two cases showed a loss of length. At follow-up the average palmar angulation was 8 degrees , ulnar inclination 21 degrees and ulnar variance + 0.2 mm. Wrist motion averaged a decrease for extension and flexion of 12 %, for ulnar and radial deviation of 9 % and for pronation and supination only of 2 % in comparison to the uninjured side. Grip strength reached an average of 85 % of the contralateral side. Patients regained good function as represented in a mean DASH score of 14 points and a Krimmer score of 82 points.

CONCLUSIONS

The treatment of unstable distal radius fractures with this plate fixation provided stable internal fixation and allowed early function. Due to multidirectional angle fixation and two lines of cortical screws it is possible to achieve an optimal restoration. The fixation of the central articular surface is guaranteed by the distal line, the dorsal subchondral support by the proximal line.

Sobemoviruses possess a common CfMV-like genomic organization

Based on structural differences in the ORF2 region, the sobemoviruses have been subdivided into southern cowpea mosaic virus (SCPMV)-like and cocksfoot mottle virus (CfMV)-like types of genome organization. However, nearly identical amino acid sequences are encoded by these subgroups in different reading frames of ORF2, suggesting that insertion or deletion of appropriate nucleotides could restore similar genomic organizations for these viruses. We resequenced the regions of inconsistency for isolates of four SCPMV-like viruses: lucerne transient streak virus, ryegrass mottle virus, southern bean mosaic virus, and SCPMV. A comparison of nucleic acid composition of these sequences with previously published ones revealed crucial differences that established a common CfMV-like genomic organization for these sobemoviruses.

Nephrin loss in experimental diabetic nephropathy is prevented by deletion of protein kinase C alpha signaling in-vivo

Albuminuria in diabetic nephropathy is due to endothelial dysfunction, a loss of negative charges in the basement membrane, and changes a of the slit-membrane diaphragm composition. We have recently shown that protein kinase C alpha (PKCalpha)-deficient mice are protected against the development of albuminuria under diabetic conditions. We here tested the hypothesis that PKCalpha mediates the hyperglycemia-induced downregulation of the slit-diaphragm protein nephrin. After 8 weeks of streptozotocin (STZ)-induced hyperglycemia the expression of glomerular nephrin was significantly reduced. In contrast, other slit-diaphragm proteins such as podocin and CD2AP were unaltered in diabetic state. In PKCalpha-/- mice, hyperglycemia-induced downregulation of nephrin was prevented. Podocin and CD2AP remained unchanged. In addition, the nephrin messenger RNA expression was also reduced in hyperglycemic wild-type mice but remained unaltered in PKCalpha-/- mice. We postulate that the underlying mechanism of the hyperglycemia-induced regulation of various proteins of the glomerular filtration barrier is a PKCalpha-dependent regulation of the Wilms' Tumor Suppressor (WT1) which previously has been shown to act as a direct transcription factor on the nephrin promoter. Our data suggest that PKCalpha activation may be an important intracellular signaling pathway in the regulation of nephrin expression and glomerular albumin permeability in the diabetic state.

Interaction of verapamil with lipid membranes and P-glycoprotein: connecting thermodynamics and membrane structure with functional activity

Verapamil and amlodipine are calcium ion influx inhibitors of wide clinical use. They are partially charged at neutral pH and exhibit amphiphilic properties. The noncharged species can easily cross the lipid membrane. We have measured with solid-state NMR the structural changes induced by verapamil upon incorporation into phospholipid bilayers and have compared them with earlier data on amlodipine and nimodipine. Verapamil and amlodipine produce a rotation of the phosphocholine headgroup away from the membrane surface and a disordering of the fatty acid chains. We have determined the thermodynamics of verapamil partitioning into neutral and negatively charged membranes with isothermal titration calorimetry. Verapamil undergoes a pK-shift of DeltapK(a) = 1.2 units in neutral lipid membranes and the percentage of the noncharged species increases from 5% to 45%. Verapamil partitioning is increased for negatively charged membranes and the binding isotherms are strongly affected by the salt concentration. The electrostatic screening can be explained with the Gouy-Chapman theory. Using a functional phosphate assay we have measured the affinity of verapamil, amlodipine, and nimodipine for P-glycoprotein, and have calculated the free energy of drug binding from the aqueous phase to the active center of P-glycoprotein in the lipid phase. By combining the latter results with the lipid partitioning data it was possible, for the first time, to determine the true affinity of the three drugs for the P-glycoprotein active center if the reaction takes place exclusively in the lipid matrix.

Differential expression of p73 isoforms in relation to drug resistance in childhood T-lineage acute lymphoblastic leukaemia

The T-lineage phenotype of childhood acute lymphoblastic leukaemia (ALL) is associated with an increased relapse-risk and in vitro resistance to drugs as compared to a precursor B phenotype. Antiapoptotic isoforms of p73 that lack part of the transactivation (TA) domain (DeltaTA-p73, i.e. p73Deltaex2, p73Deltaex3, p73Deltaex2/3 and DeltaN-p73) may cause resistance to anticancer agents through inhibition of p53 and/or proapoptotic p73 family members (TA-p73). We demonstrate in our study that the expression of total p73 mRNA was higher in childhood T-ALL compared to controls (P=0.004). In T-ALL, the relative contribution of antiapoptotic DeltaTA-p73 (88%) was larger than of proapoptotic TA-p73 (12%). Leukaemic cells of T-ALL patients expressing higher levels of antiapoptotic p73 were more resistant to the DNA-damaging drug daunorubicin compared to cells of patients with low or negative expression or these isoforms (P(trend)=0.045). Interestingly, p73Deltaex2 was the most abundantly expressed antiapoptotic isoform in daunorubicin-resistant patient cells (44% of total p73). No association was found between high expression of proapoptotic TA-p73 or antiapoptotic DeltaTA-p73 and relapse-risk. Our results suggest that childhood T-ALL is associated with a high expression of DeltaTA-p73. These isoforms may play a role in cellular resistance to DNA-damaging drugs in children at initial diagnosis of T-ALL.

Relation between genetic variants of the ataxia telangiectasia-mutated (ATM) gene, drug resistance, clinical outcome and predisposition to childhood T-lineage acute lymphoblastic leukaemia

The T-lineage phenotype in children with acute lymphoblastic leukaemia (ALL) is associated with in vitro drug resistance and a higher relapse-risk compared to a precursor B phenotype. Our study was aimed to investigate whether mutations in the ATM gene occur in childhood T-lineage acute lymphoblastic leukaemia (T-ALL) that are linked to drug resistance and clinical outcome. In all, 20 different single nucleotide substitutions were found in 16 exons of ATM in 62/103 (60%) T-ALL children and 51/99 (52%, P = 0.21) controls. Besides the well-known polymorphism D1853N, five other alterations (S707P, F858L, P1054R, L1472W, Y1475C) in the coding part of ATM were found. These five coding alterations seem to occur more frequently in T-ALL (13%) than controls (5%, P = 0.06), but did not associate with altered expression levels of ATM or in vitro resistance to daunorubicin. However, T-ALL patients carrying these five coding alterations presented with a higher white blood cell count at diagnosis (P = 0.05) and show an increased relapse-risk (5-year probability of disease-free survival (pDFS) = 48%) compared to patients with other alterations or wild-type ATM (5-year pDFS = 76%, P = 0.05). The association between five coding ATM alterations in T-ALL, their germline presence, white blood cell count and unfavourable outcome may point to a role for ATM in the development of T-ALL in these children.

[Mid-term results after proximal row carpectomy and review of the literature]

PURPOSE

The aim of this study is to evaluate the results after proximal row carpectomy and to compare them with results in the literature.

METHOD

Between 1994 and 2001, 37 patients underwent proximal row carpectomy. 30 patients were available for follow-up. In all cases the proximal row carpectomy was performed through a dorsal approach. Clinical parameters were evaluated by using the conventional wrist score (Krimmer score) as well as the DASH-score.

RESULTS

Follow-up examination shows a range of motion (ROM) for wrist extension and flexion of 46 % of the contralateral side. ROM for ulnar and radial deviation is 42 % of the other side, ROM for pronation and supination is equal to the other side. Mean grip strength is determined to be 58 % of the contralateral side. 90 % of the patients are satisfied with the result of the operation. The Krimmer score amounts to 58 and the DASH score to 39 points.

CONCLUSION

We consider proximal row carpectomy to be a good therapeutic option for lunate necrosis stage IIIB or IV or carpal collapse stage II (SNAC or SLAC wrist) with a concomitant lesion of extrinsic ligaments with ulnar translocation. Another indication is the acute, non-reconstructable or the chronic perilunar luxation with arthrosis.

Ethylene glycol intoxication and xylitol infusion--metabolic steps of oxalate-induced acute renal failure

Acute renal failure is a major complication in patients with increased oxalate serum concentration. To describe the metabolic mechanisms of oxalate-induced glomerular and tubular damage, we report a case of ethylene glycol intoxication as well as a case of xylitol infusion in a patient with previously unknown primary hyperoxaluria type 1. Both patients presented with acute renal failure associated with histologically proven renal oxalate accumulation. This excessive oxalate overloading resulted from elimination and metabolization of ethylene glycol or xylitol. Thus, key enzymes in the elimination pathway of these substances represent targets for pharmacological treatment. Simultaneous hemodialysis is often necessary to reduce oxalate serum concentration. Whereas renal function of the ethylene glycol-poisoned patient recovered, the second patient who received xylitol infusion required chronic hemodialysis due to the unmasked hyperoxaluria type 1. Our cases demonstrate that patients with excessive endogenous oxalate generation are at high risk to develop acute renal failure. Therefore, to prevent end-stage renal failure in these patients, important clinical factors should be considered as indicators for the underlying cause: history of alcohol abuse and severe high anion gap acidosis for ethylene glycol intoxication or history of long-lasting parenteral nutrition for xylitol-associated acute renal failure.

Acute liver failure: a message found under the skin

Acute liver failure is a rare syndrome with rapid progression and high mortality. It is characterised by the onset of coma and coagulopathy usually within six weeks but can occur up to six months after the onset of illness. Viral hepatitis, idiosyncratic drug induced liver injury, and acetaminophen ingestion are common causes. This report describes the case of a 35 year old man who presented with acute liver failure shortly after binge drinking. Repeated history taking disclosed a gluteal disulfiram implant that the patient had received to treat his alcohol dependence. The patient recovered with maximum supportive care after surgical removal but without liver transplantation. This case illustrates that only meticulous history taking will disclose the sometimes bewildering causes of acute liver failure.

Effect of Different Operative Techniques for Myocardial Revascularisation on Hemodynamics and Myocardial Perfusion in a Porcine Model

BACKGROUND

During surgical coronary revascularisation hemodynamics and myocardial contractility can be affected. This in vivo study aimed to determine the effects of different operative techniques on hemodynamics and regional myocardial perfusion.

METHODS

In 24 pigs IMA to LAD bypass was constructed using ECC (n = 8) and cardioplegic arrest, OPCAB techniques (n = 8), or the Impella elect 100 support device (n = 8). 8 animals received a sham operation. Mean arterial pressure (MAP), cardiac output (CO), and left ventricular pressure (LVP, LVdp/dt) were recorded. Regional myocardial perfusion (RMP) of both ventricles was assessed by fluorescent microspheres.

RESULTS

MAP significantly decreased during revascularisation in all groups ( p < 0.05), staying below preoperative values thereafter ( p < 0.05). After ECC norepinephrine was administered to maintain MAP. CO and LVdp/dt were impaired more distinctly during OPCAB than with Impella ( p < 0.05) during subsequent recovery. RMP showed global reactive hyperemia during early reperfusion after ECC, remained unchanged in OPCAB, and showed low flow during and after Impella pump run ( p < 0.05).

CONCLUSIONS

ECC led to hemodynamic impairment with post-ischemic reactive hyperemia. OPCAB created hemodynamic depression but left RMP unchanged. Hemodynamic depression can be reduced by the Impella pump, however regional myocardial blood flow is decreased.