Linkage between growth retardation and pituitary cell morphology in a dystrophin-deficient pig model of Duchenne muscular dystrophy.

OBJECTIVE: Human patients with Duchenne muscular dystrophy (DMD) commonly exhibit a short stature, but the pathogenesis of this growth retardation is not completely understood. Due to the suspected involvement of the growth hormone/insulin-like growth factor 1 (GH/IGF1) system, controversial therapeutic approaches have been developed, including both GH- administration, as well as GH-inhibition. In the present study, we examined relevant histomorphological and ultrastructural features of adenohypophyseal GH-producing somatotroph cells in a porcine DMD model. METHODS: The numbers and volumes of immunohistochemically labelled somatotroph cells were determined in consecutive semi-thin sections of plastic resin embedded adenohypophyseal tissue samples using unbiased state-of-the-art quantitative stereological analysis methods. RESULTS: DMD pigs displayed a significant growth retardation, accounting for a 55% reduction of body weight, accompanied by a significant 50% reduction of the number of somatotroph cells, as compared to controls. However, the mean volumes of somatotroph cells and the volume of GH-granules per cell were not altered. Western blot analyses of the adenohypophyseal protein samples showed no differences in the relative adenohypophyseal GH-abundance between DMD pigs and controls. CONCLUSION: The findings of this study do not provide evidence for involvement of somatotroph cells in the pathogenesis of growth retardation of DMD pigs. These results are in contrast with previous findings in other dystrophin-deficient animal models, such as the golden retriever model of Duchenne muscular dystrophy, where increased mean somatotroph cell volumes and elevated volumes of intracellular GH-granules were reported and associated with DMD-related growth retardation. Possible reasons for the differences of somatotroph morphology observed in different DMD models are discussed.

Erosion Prevention Potential of an Over-the-Counter Stabilized SnF2 Dentifrice Compared to 5000 ppm F Prescription-Strength Products.

OBJECTIVE: To determine the relative ability of various F-containing products to protect enamel against the initiation and progression of tooth surface loss due to erosive acid challenges. METHODS: Cores of enamel were prepared from extracted human teeth, soaked in pooled human saliva (pellicle formation), and then treated in a 1:3 slurry (product:saliva) of either OTC level (1100 ppm F) or prescription level (5000 ppm F) products, followed by a standardized erosion cycling procedure (five days of cycling) that included 10-minute challenges with an erosive dietary acid (1% citric acid at pH 2.3) applied 60 minutes after each dentifrice treatment (repeated four times per day). Enamel surface loss was measured using transverse microradiography. Two studies were conducted. Study 1 included: A) 1100 ppm F as NaF; B) 1100 ppm F as stabilized SnF; C) 5000 ppm F as NaF; and D) 5000 ppm F as NaF + acidulated phosphate. Study 2 included: 1) 1100 ppm F as stabilized SnF; 2) 5000 ppm F as NaF + tricalcium phosphate; and 3) 1100 ppm F as NaF. RESULTS: Study 1: Treatment B (1100 ppm F as SnF), where specimens lost only 8.0 µm of the enamel surface, was significantly more effective than Treatments A, C, and D at protecting enamel against the initiation and progression of erosive acid damage (p < 0.05). Specimens treated with product A exhibited 22.8 (1.25) µm (mean ± sem) of enamel loss; 20.0 (0.71) µm of enamel loss with treatment C and 24.0 (1.4) µm of enamel loss with Treatment D. Study 2 also demonstrated significantly greater erosion protection with the stabilized SnF2 dentifrice (p < 0.05), with only 5.8 (1.93) µm of tooth surface loss, while groups 2 and 3 lost 19.8 (0.75) µm and 18.0 (2.16) µm, respectively. CONCLUSION: Results from both studies demonstrated the OTC dentifrice formulated with stabilized SnF2 provides significantly greater protection against erosive acid attack compared to some of the most popular prescription level (5000 ppm F) fluoride treatments available.

[TSH-reference range of adults: results from the population-based study KORA F4]. / TSH-Referenzbereich bei süddeutschen Erwachsenen: Ergebnisse aus der bevölkerungsbasierten KORA F4-Studie.

INTRODUCTION: There is no valid nationwide reference value for Thyroid-stimulating hormone (TSH) for German adults because of different iodine supply and different laboratory equipment, however, reference values for single regions of Germany have been defined. The aim of this study was to find a reference value for South Germany and to compare this with results of other population-based studies. METHODS: 3080 individuals from the KORA-F4 study (Cooperative Health Research in the Region of Augsburg) at the age range of 32 to 81 years were examined regarding their thyroid characteristics (anamnesis, sonography and clinical chemistry). After excluding individuals with known as well as unknown thyroid disorders revealed by the KORA study, there were 710 thyroid-healthy individuals left to evaluate TSH-, fT3- and fT4-reference ranges. RESULTS: For thyroid-healthy men and women we evaluated a TSH-reference range of 0.52-3.60 mIU/l on Siemens Vista Analysers with a median of 1.49 mIU/l. We could not find any statistically significant influence of age or sex. Median iodine excretion in urine was 118.6 µg/g creatinine in our healthy population which is above the recommended target value of 100 µg/g. DISCUSSION: The TSH-reference value of the South German population is higher than the one assessed in the Northeast-German SHIP-study 10 years ago. For the definition of a TSH-reference value, population-based and apparatus-specific examinations are necessary.

Renal carcinoma relapse presenting as a peripheral nerve sheath tumor: A case report and brief review of the literature.

We report a rare case of renal carcinoma metastasis involving a lumbar nerve root. Metastases to nerve roots are rare occurrences, and to our knowledge, only six cases have been reported so far in the literature. The patient in this report presented with weakness in the right lower limb and intractable pain irradiating along the L5 dermatome. MRI findings revealed a right-sided L5 nerve root mass, suggestive of a schwannoma, involving the spinal ganglion and its extraforaminal region. Complete macroscopic resection of this mass was performed, and histopathologic analysis confirmed the lesion to be a metastasis of a renal clear cell carcinoma. Local radiotherapy was given and tyrosine kinase inhibitors administered. At 5 months, the patient was pain-free and his right limb weakness had completely resolved. A tumoral recurrence could be observed on the control MRI 5 months after surgery. This report presents the first case of a patient with a renal clear cell carcinoma metastasis to a L5 nerve root, as well as a brief review of previous cases of metastases to peripheral nerve roots.

WE-G-BRA-05: Simulated Troubleshooting Session for Medical Physics Resident Rotations.

PURPOSE: Troubleshooting is a difficult to train, but critical skill for a clinical medical physicist. It is unlikely that residents will have opportunities to troubleshoot many real clinical scenarios during a typical 3 month rotation. The ability to analyze and correct abnormal clinical situations is imperative to providing safe radiation therapy care. We have developed a novel strategy to train medical physics residents to gain such important clinical physics skill. METHODS: Simulated troubleshooting sessions were designed for each rotation, featuring problematic clinical scenarios. The resident was required to troubleshoot each scenario in a given time frame. Using a brachytherapy rotation as an example, the transfer tubes connecting the afterloader to the Tandem and Ovoids (T&O) applicators were purposely inserted incorrectly. The resident was asked to deliver a dummy T&O plan in a reasonable time frame including troubleshooting all problems that may occur. Many simulated troubleshooting situations were presented to the resident. Two residents went through a 3 month brachytherapy rotation, one with and the other without the simulated troubleshooting session. All other rotation activities were the same. At the end of the rotation, an oral exam was given to test how well the residents understood the brachytherapy clinical practice. RESULTS: Both residents were able to pass the exam. However, the resident that received the troubleshooting session performed better'‴a superior understanding of the reasons behind the clinical practice and better troubleshooting skills were demonstrated. CONCLUSIONS: To train residents to better handle the clinical situations, it is important to include a simulated troubleshooting session into clinical rotations. Simulated troubleshooting sessions are excellent and necessary supplements to the clinical rotations for the residents to gain practical clinical skills.

SU-E-T-635: Effect of Planning Parameters on Tomotherapy Dosimetric Quality and Treatment Efficiency.

PURPOSE: To investigate how the setting of optimization parameters, fractional dose and tuning structure in tomotherapy treatment planning affects plan dosimetric quality and treatment efficiency. METHODS: A digital phantom to simulate head and neck radiotherapy was constructed for this study. Tumor was 10cm long C-shaped with two surrounding parallel normal structures (P-NS) and one serial normal structure (S-NS). Dose prescription was 54 Gy in total. Fourteen treatment plans were generated with varied parameters in five categories: a) jaw size (1 to 5cm), b) pitch (0.215 to 0.43), c) modulation factor (1.5 to 4), d) dose per fraction (100 to 600cGy) and e) whether to use tuning structure. Plans were compared with multiple dosimetric endpoints including target minimum/maximum/mean dose, V100%, conformity, heterogeneity, S-NS maximum dose, P-NS and body mean dose, and treatment times. The reference plan was defined for the plan with conventional parameters: jaw 2.5cm, pitch 0.287, modulation factor 3.0, 200cGy per fraction and use of a 2cm ring structure in optimization. RESULTS: Compared with 2.5cm jaw reference plan, 1cm jaw plan decreased the mean body dose 10.7% while 5 cm jaw plan increased the dose 17.9%. Smaller pitch (p=0.215) made the plan more conform than reference plan, and bigger pitch (p=0.43) had opposite effect. A small modulation factor (M=1.5) failed to spare critical structures. A medium modulation factor (M=2) resulted in similar plan to the reference but with 29% less treatment time. A low fractional dose (100 cGy) planned with similar parameter as reference had much inferior target coverage (V100%=85.6% vs V100%=96.4). Lastly, the use of tuning structure improved the conformity of target. CONCLUSIONS: Selection of optimization parameters in tomotherapy treatment planning affects target coverage, critical structure sparing, body dose, and treatment time. Target coverage is compromised if fractional dose is low to the range of 100 cGy.

The use of automatic speech recognition showing the influence of nasality on speech intelligibility.

Altered nasality influences speech intelligibility. Automatic speech recognition (ASR) has proved suitable for quantifying speech intelligibility in patients with different degrees of nasal emissions. We investigated the influence of hyponasality on the results of speech recognition before and after nasal surgery using ASR. Speech recordings, nasal peak inspiratory flow and self-perception measurements were carried out in 20 German-speaking patients (8 women, 12 men; aged 38 ± 22 years) who underwent surgery for various nasal and sinus pathologies. The degree of speech intelligibility was quantified as the percentage of correctly recognized words of a standardized word chain by ASR (word recognition rate; WR). WR was measured 1 day before (t1), 1 day after with nasal packings (t2), and 3 months after (t3) surgery; nasal peak flow on t1 and t3. WR was calculated with program for the automatic evaluation of all kinds of speech disorders (PEAKS). WR as a parameter of speech intelligibility was significantly decreased immediately after surgery (t1 vs. t2 p < 0.01) but increased 3 months after surgery (t2 vs. t3 p < 0.01). WR showed no association with age or gender. There was no significant difference between WR at t1 and t3, despite a post-operative increase in nasal peak inspiratory flow measurements. The results show that ASR is capable of quantifying the influence of hyponasality on speech; nasal obstruction leads to significantly reduced WR and nasal peak flow cannot replace evaluation of nasality.

[Pretherapeutic and posttherapeutic laryngeal imaging]. / Prä- und posttherapeutische Larynxbildgebung.

Cross-sectional imaging with CT, MRI and more recently PET CT plays an indispensable complementary role to endoscopy in the pretherapeutic diagnostic and staging of laryngeal neoplasms and in the evaluation of the operated or irradiated larynx. Adequate interpretation of the CT, PET CT and MR images requires a thorough knowledge of the patterns of submucosal spread and familiarity with the diagnostic signs of neoplastic invasion as seen with each modality. In addition, one should be aware of the implications of imaging for staging and treatment. Both CT and MR imaging are highly sensitive for the detection of neoplastic invasion of the preepiglottic and paraglottic spaces, subglottic region and cartilage. The high negative predictive value of both CT and MRI allows a relatively reliable exclusion of neoplasm cartilage invasion. The specificity of both CT and MRI is, however, moderately high and both methods may, therefore, overestimate the extent of tumor spread. However, recent investigations have shown that the specificity of MRI may be significantly improved by using new diagnostic criteria which allow differentiation of tumor from peritumoral inflammation in many instances. Both cross-sectional imaging methods also significantly improve the pretherapeutic staging accuracy of laryngeal tumors if used in addition to clinical examination and endoscopic biopsy. In the presence of a submucosal mass, CT and MRI play a key role for the diagnosis, as they may characterize the lesion, reliably depict its submucosal extent and guide the endoscopist to perform deep biopsies which allow the definitive histological diagnosis. Cross-sectional imaging also plays a key role in the evaluation of laryngoceles, recurrent laryngeal nerve paralysis and fractures.

Pilocytic astrocytoma in the elderly.

Pilocytic astrocytoma (WHO Grade 1) is a low-grade glioma with a favorable prognosis most commonly diagnosed in patients aged below 20. It is the most common glioma in children, and cases discovered in elderly patients are rare. We report the highly unusual case of an 85-year-old man whose neurological signs included Parkinsonism, and in whom post mortem examination revealed a pilocytic astrocytoma of the brainstem. We also discuss the clinical, neuroradiological and neuropathological differential diagnosis.

Interference with nuclear factor kappa B and c-Jun NH2-terminal kinase signaling by TRAF6C small interfering RNA inhibits myeloma cell proliferation and enhances apoptosis.

The tumor necrosis factor receptor (TNFR)-associated factor (TRAF) family of six adaptor proteins (TRAF1-6) links the TNFR superfamily to the nuclear factor kappa B (NF-kappaB) and activator protein-1 (AP-1) transcriptional activators. Unlike other TRAFs, TRAF6 is also involved in Toll-like/interleukin (IL)-1 receptor (TIR) signal transduction. Thus, inhibition of TRAF6 function could interrupt both CD40 (TNFR family) and IL-1 growth signals, pathways critical to myeloma proliferation. To block TRAF6-mediated IL-1 signaling, we constructed small interfering RNA (siRNA) against TRAF6. We found that siRNA targeting the TRAF6 C-terminal (siTRAF6C) receptor interaction domain specifically reduced only TRAF6 protein expression, without affecting TRAF2 or 5 levels, and substantially interfered with IL-1-induced NF-kappaB and c-Jun/AP-1 activation. Inhibition by siTRAF6C was concentration-dependent. SiTRAF6C also significantly reduced myeloma proliferation and enhanced apoptosis in a similar dose-dependent fashion in vitro. More importantly, marked siTRAF6C growth inhibition was detected in vivo when these cells were implanted into the bone marrow of irradiated normal mice. In contrast, introduction of siRNA derived from the TRAF6 Zn-finger domain or an irrelevant siRNA construct failed to alter cell growth or cell death. These studies suggest that TRAF6 may be a new molecular target to block cell signal transduction important for the survival and proliferation of multiple myeloma cells.

Expression and localization of VEGF-C and VEGFR-3 in glioblastomas and haemangioblastomas.

Primary human brain tumours account for approximately 2% of all cancers. High levels of expression of vascular endothelial growth factor-A (VEGF-A), a potent angiogenic factor, are linked to poor prognosis. In contrast, the potential role in human brain tumour biology of newer VEGF family members, VEGF-C and VEGF-D, both of which are lymphangiogenic factors, is poorly understood. In the present study, the expression of all VEGFs (VEGF-A, -B, -C, and -D) and their receptors (VEGFR-1, -2, and -3) has been assessed in 39 primary human brain tumours. The well-established findings were confirmed with VEGF-A. Surprisingly, however, VEGF-C and VEGF-D, as well as VEGFR-3, were expressed in some tumour types such as haemangioblastomas and glioblastomas, despite their lack of lymphatic vessels. VEGF-C and VEGFR-3 transcripts were localized to the tumour palisade around necrotic areas in glioblastomas and were evenly distributed throughout haemangioblastomas. VEGF-C protein was localized by immunohistochemistry to the palisade layer in glioblastomas. More than 50% of VEGF-C-positive cells also expressed the intermediate-stage inflammatory macrophage marker CD163; however, a significant proportion of VEGF-C-positive cells were CD163-negative. These data demonstrate the presence of molecules, primarily described as regulators of lymphangiogenesis, in normal human brain and brain tumours that are devoid of lymphatics. Their localization in macrophages points to a role in tumour-associated inflammation.

Neuronal expression of the drug efflux transporter P-glycoprotein in the rat hippocampus after limbic seizures.

In the brain, the efflux transporter P-glycoprotein (Pgp) is predominantly located on the luminal membrane of endothelial cells lining brain microvessels and forming the blood-brain barrier. Many lipophilic drugs, including antiepileptic drugs, are potential substrates for Pgp. Overexpression of Pgp in endothelial cells of the blood-brain barrier has been determined in patients with drug resistant forms of epilepsy such as temporal lobe epilepsy and rodent models of temporal lobe epilepsy and suggested to lead to reduced penetration of antiepileptic drugs into the brain. Expression of Pgp after seizures has also been described in astrocytes, whereas it is not clear whether neurons can express Pgp. In the present study, Pgp expression was studied by immunohistochemistry in rats 24 h after a status epilepticus induced by either pilocarpine or kainate, widely used models of temporal lobe epilepsy. Unexpectedly, in addition to endothelial Pgp staining, intense Pgp staining was found in neurons in the CA3c/CA4 sectors and hilus of the hippocampus formation, but not in other brain regions examined. The neuronal Pgp staining was confirmed by two different Pgp antibodies. Double immunolabeling and confocal microscopy showed that Pgp was colocalized with the neuronal marker neuronal nuclear antigen, but not with the glial marker glial fibrillary acidic protein. No neuronal Pgp staining was seen in control rats. The expression of Pgp in neurons after limbic seizures was substantiated by determining Pgp encoding genes (mdr1a, mdr1b) in neurons by real time quantitative RT-PCR. Increased Pgp expression in hippocampal neurons is likely to affect the action of drugs with intraneuronal targets and, in view of recent evidence from other cell types, could be associated with prevention of apoptosis which is involved in neuronal damage developing after seizures such as produced by pilocarpine.

[Biochemical stress monitoring during cataract surgery; phenylephrine 10% shows no changes in serum-catecholamines in comparison with phenylephrine 5%]. / Biochemisches Stressmonitoring in der Kataraktchirurgie: Phenylephrin 10% zeigt im Vergleich mit Phenylephrin 5% keine Veränderung der Serum-Katecholamin-Werte.

BACKGROUND: There is a controversy about the concentration of topical phenylephrine recommended for diagnostic or therapeutic mydriasis. Phenylephrine 10% leads to a faster and more pronounced mydriasis but cardio-vascular side-effects like hypertension and arrhythmia have been reported. A maximal pupillary dilatation is a prerequisite for successful cataract surgery. The aim of this study was to evaluate the risk-benefit ratio of phenylephrine 10% in comparison to 5% in the daily practice of the cataract-surgery unit in our clinic by clinical assessment and monitoring of biochemical stress parameters. PATIENTS AND METHODS: 30 informed and consenting patients were randomly allocated to 2 groups of equal size. After a single application of 2 drops of phenylephrine 5% in group 1 and 10% in group 2 respectively and 1 drops of cyclopentolate 1% with neutral pupil (time 0), an ECG was recorded and blood pressure, pulse, oxygen-saturation and pupil size were measured. Simultaneously a blood-sample was taken and the serum-catecholamines adrenaline and noradrenaline were determined by HPLC (High Pressure Liquid Chromatography). These measurements were repeated after 5, 10 and 30 minutes. RESULTS: The mean pupil area after 30 minutes in group 1 was 31.97 (+/- 0.43) mm2 compared to 45.72 (+/- 0.39) mm2 in group 2. Our data showed no other significant variation between the groups: neither clinical monitoring nor catecholamine measurements showed concentration-dependent patterns in blood pressure development or serum levels. No systemic cardiovascular effects were observed. CONCLUSION: These results demonstrate that a controlled application of phenylephrine 10%--under observation of contraindications--yields no increased risk for the occurrence of cardio-vascular side-effects in comparison with phenylephrine 5%. Therefore, we recommend the use of phenylephrine 10% in the described dosage as routine medication for cataract surgery.

Efficacy and drug interactions of the new HMG-CoA reductase inhibitors cerivastatin and atorvastatin in CsA-treated renal transplant recipients.

BACKGROUND: Hyperlipidaemia is an important risk factor for cardiovascular disease in renal transplant recipients. The aim of this study was to test the efficacy and possible drug-drug interactions of the new HMG-CoA reductase inhibitors (statins) atorvastatin and cerivastatin in cyclosporin A (CsA)-treated renal transplant patients. Subjects and methods. Thirty patients with stable graft function and LDL cholesterol of 130 mg/dl were randomly assigned to active treatment groups (10 mg atorvastatin or 0.2 mg cerivastatin), or a control group. CsA blood trough levels were controlled on a weekly basis and adapted if they changed more than 25% from baseline values (100-150 ng/ml). Lipid levels and routine laboratory parameters before and after a treatment period of 3 months were compared. RESULTS: In the group treated with cerivastatin no significant changes in CsA blood trough levels occurred (CsA 116+/-21 ng/ml vs 110+/-20 ng/ml). In contrast, in the group treated with atorvastatin, four of 10 patients had a rise in CsA blood trough levels of more than 25% within 7-14 days of starting therapy. In the remaining patients no significant changes in CsA drug levels occurred. After therapy with atorvastatin or cerivastatin, total cholesterol, LDL cholesterol, and triglycerides were significantly lower compared with baseline conditions. No changes of CsA or lipoprotein levels were present in the control group. CONCLUSION: In our study population both statins were very effective in lowering elevated LDL cholesterol levels. Cerivastatin did not influence CsA blood trough levels, whereas atorvastatin increased CsA levels in four of 10 patients. Further research in a larger study is necessary in order to confirm these results and to investigate the possible reasons for this drug interaction.

Protective effects of riluzole on dopamine neurons: involvement of oxidative stress and cellular energy metabolism.

Riluzole is neuroprotective in patients with amyotrophic lateral sclerosis and may also protect dopamine (DA) neurons in Parkinson's disease. We examined the neuroprotective potential of riluzole on DA neurons using primary rat mesencephalic cultures and human dopaminergic neuroblastoma SH-SY5Y cells. Riluzole (up to 10 microM:) alone affected neither the survival of DA neurons in primary cultures nor the growth of SH-SY5Y cells after up to 72 h. Riluzole (1-10 microM:) dose-dependently reduced DA cell loss caused by exposure to MPP(+) in both types of cultures. These protective effects were accompanied by a dose-dependent decrease of intracellular ATP depletion caused by MPP(+) (30-300 microM:) in SH-SY5Y cells without affecting intracellular net NADH content, suggesting a reduction of cellular ATP consumption rather than normalization of mitochondrial ATP production. Riluzole (1-10 microM:) also attenuated oxidative injury in both cell types induced by exposure to L-DOPA and 6-hydroxydopamine, respectively. Consistent with its antioxidative effects, riluzole reduced lipid peroxidation induced by Fe(3+) and L-DOPA in primary mesencephalic cultures. Riluzole (10 microM) did not alter high-affinity uptake of either DA or MPP(+). However, in the same cell systems, riluzole induced neuronal and glial cell death with concentrations higher than those needed for maximal protective effects (> or =100 microM:). These data demonstrate that riluzole has protective effects on DA neurons in vitro against neuronal injuries induced by (a) impairment of cellular energy metabolism and/or (b) oxidative stress. These results provide further impetus to explore the neuroprotective potential of riluzole in Parkinson's disease.