Mutations in Parkin are the most common cause of autosomal recessive Parkinson disease (PD). The mitochondrially localized E3 ubiquitin-protein ligase Parkin has been reported to be involved in ...respiratory chain function and mitochondrial dynamics. More recent publications also described a link between Parkin and mitophagy.
In this study, we investigated the impact of Parkin mutations on mitochondrial function and morphology in a human cellular model. Fibroblasts were obtained from three members of an Italian PD family with two mutations in Parkin (homozygous c.1072delT, homozygous delEx7, compound-heterozygous c.1072delT/delEx7), as well as from two relatives without mutations. Furthermore, three unrelated compound-heterozygous patients (delEx3-4/duplEx7-12, delEx4/c.924C>T and delEx1/c.924C>T) and three unrelated age-matched controls were included. Fibroblasts were cultured under basal or paraquat-induced oxidative stress conditions. ATP synthesis rates and cellular levels were detected luminometrically. Activities of complexes I-IV and citrate synthase were measured spectrophotometrically in mitochondrial preparations or cell lysates. The mitochondrial membrane potential was measured with 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine iodide. Oxidative stress levels were investigated with the OxyBlot technique. The mitochondrial network was investigated immunocytochemically and the degree of branching was determined with image processing methods. We observed a decrease in the production and overall concentration of ATP coinciding with increased mitochondrial mass in Parkin-mutant fibroblasts. After an oxidative insult, the membrane potential decreased in patient cells but not in controls. We further determined higher levels of oxidized proteins in the mutants both under basal and stress conditions. The degree of mitochondrial network branching was comparable in mutants and controls under basal conditions and decreased to a similar extent under paraquat-induced stress.
Our results indicate that Parkin mutations cause abnormal mitochondrial function and morphology in non-neuronal human cells.
Evidence exist that motor observation activates the same cortical motor areas that are involved in the performance of the observed actions. The so called "mirror neuron system" has been proposed to ...be responsible for this phenomenon. We employ this neural system and its capability to re-enact stored motor representations as a tool for rehabilitating motor control. In our new neurorehabilitative schema (videotherapy) we combine observation of daily actions with concomitant physical training of the observed actions focusing on the upper limbs. Following a pilot study in chronic patients in an ambulatory setting, we currently designed a new multicenter clinical study dedicated to patients in the sub-acute state after stroke using a home-based self-induced training. Within our protocol we assess 1) the capability of action observation to elicit rehabilitational effects in the motor system, and 2) the capacity of this schema to be performed by patients without assistance from a physiotherapist. The results of this study would be of high health and economical relevance.
A controlled, randomized, multicenter, paralleled, 6 month follow-up study will be conducted on three groups of patients: one group will be given the experimental treatment whereas the other two will participate in control treatments. All patients will undergo their usual rehabilitative treatment beside participation in the study. The experimental condition consists in the observation and immediate imitation of common daily hand and arm actions. The two parallel control groups are a placebo group and a group receiving usual rehabilitation without any trial-related treatment. Trial randomization is provided via external data management. The primary efficacy endpoint is the improvement of the experimental group in a standardized motor function test (Wolf Motor Function Test) relative to control groups. Further assessments refer to subjective and qualitative rehabilitational scores. This study has been reviewed and approved by the ethics committee of Aachen University.
This therapy provides an extension of therapeutic procedures for recovery after stroke and emphasizes the importance of action perception in neurorehabilitation The results of the study could become implemented into the wide physiotherapeutic practice, for example as an ad on and individualized therapy.
Radiation-induced xerostomia still represents a common side effect after radiotherapy for head-and-neck malignancies. The aim of the present study was to examine the radioprotective effect of ...lidocaine hydrochloride during fractionated radiation in an experimental animal model.
To evaluate the influence of different radiation doses on salivary gland function and the radioprotective effect of lidocaine, rabbits were irradiated with 15, 25, 30, and 35 Gy (equivalent doses in 2-Gy fractions equivalent to 24, 40, 48, and 56 Gy, respectively). Lidocaine hydrochloride (10 and 12 mg/kg) was administered before every radiation fraction in the treatment groups. Salivary gland function was assessed by flow sialometry and sialoscintigraphy, and the morphologic changes were evaluated using transmission electron microscopy.
Functional impairment was first observed after 35 Gy and pretreatment with lidocaine improved radiation tolerance of both parotid and submandibular glands. The use of 12 mg/kg lidocaine was superior and displayed significant radioprotection with regard to flow sialometry and sialoscintigraphy. The ultrastructure was largely preserved after pretreatment with both lidocaine doses.
Lidocaine represents an effective radioprotective agent and a promising approach for clinical application to avoid radiation-induced functional impairment of salivary glands.
We evaluated blood culture-proven sepsis episodes occurring in microclusters in very-low-birth-weight infants born in the German Neonatal Network (GNN) during 2009-2010.
Thirty-seven centers ...participated in GNN; 23 centers enrolled ≥50 VLBW infants in the study period. Data quality was approved by on-site monitoring. Microclusters of sepsis were defined as occurrence of at least two blood-culture proven sepsis events in different patients of one center within 3 months with the same bacterial species. For microcluster analysis, we selected sepsis episodes with typically cross-transmitted bacteria of high clinical significance including gram-negative rods and Enterococcus spp.
In our cohort, 12/2110 (0.6%) infants were documented with an early-onset sepsis and 235 late-onset sepsis episodes (≥72 h of age) occurred in 203/2110 (9.6%) VLBW infants. In 182/235 (77.4%) late-onset sepsis episodes gram-positive bacteria were documented, while coagulase negative staphylococci were found to be the most predominant pathogens (48.5%, 95%CI: 42.01-55.01). Candida spp. and gram-negative bacilli caused 10/235 (4.3%, 95%CI: 1.68% -6.83%) and 43/235 (18.5%) late-onset sepsis episodes, respectively. Eleven microclusters of blood-culture proven sepsis were detected in 7 hospitals involving a total 26 infants. 16/26 cluster patients suffered from Klebsiella spp. sepsis. The median time interval between the first patient's Klebsiella spp. sepsis and cluster cases was 14.1 days (interquartile range: 1-27 days). First patients in the cluster, their linked cases and sporadic sepsis events did not show significant differences in short term outcome parameters.
Microclusters of infection are an important phenomenon for late-onset sepsis. Most gram-negative cluster infections occur within 30 days after the first patient was diagnosed and Klebsiella spp. play a major role. It is essential to monitor epidemic microclusters of sepsis in surveillance networks to adapt clinical practice, inform policy and further improve quality of care.
Low-frequency (0.5–2.5 Hz) and individually defined high-frequency (7–11 or 8–12 Hz; 11–15 or 14–18 Hz) oscillatory components of the electroencephalogram (EEG) burst activity derived from ...thiopental-induced burst-suppression patterns (BSP) were investigated in seven sedated patients (17–26 years old) with severe head injury. The predominant high-frequency burst oscillations (>7 Hz) were detected for each patient by means of time-variant amplitude spectrum analysis. Thereafter, the instantaneous envelope (IE) and the instantaneous frequency (IF) were computed for these low- and high-frequency bands to quantify amplitude–frequency dependencies (envelope–envelope, envelope–frequency, and frequency–frequency correlations). Time-variant phase-locking, phase synchronization, and quadratic phase couplings are associated with the observed amplitude–frequency characteristics. Additionally, these time-variant analyses were carried out for modeled burst patterns. Coupled Duffing oscillators were adapted to each EEG burst and by means of these models data-based burst simulations were generated. Results are: (1) strong envelope–envelope correlations (IE courses) can be demonstrated; (2) it can be shown that a rise of the IE is associated with an increase of the IF (only for the frequency bands 0.5–2.5 and 7–11 or 8–12 Hz); (3) the rise characteristics of all individually averaged envelope–frequency courses (IE–IF) are strongly correlated; (4) for the 7–11 or 8–12 Hz oscillation these associations are weaker and the variation between the time courses of the patients is higher; (5) for both frequency ranges a quantitative amplitude–frequency dependency can be shown because higher IE peak maxima are accompanied by stronger IF changes; (6) the time range of significant phase-locking within the 7–11 or 8–12 Hz frequency bands and of the strongest quadratic phase couplings (between 0.5–2.5 and 7–11 or 8–12 Hz) is between 0 and 1,000 ms; (7) all phase coupling characteristics of the modeled bursts accord well with the corresponding characteristics of the measured EEG burst data. All amplitude–frequency dependencies and phase locking/coupling properties described here are known from and can be discussed using coupled Duffing oscillators which are characterized by autoresonance properties.
The FTO gene, located on chromosome 16q12.2, and the MAF gene, located on chromosome 16q22-23, were identified as genes harboring common variants with an impact on obesity predisposition. We studied ...the association of common variants with birth weight, gain of body weight, body mass index (BMI), Ponderal index and relevant neonatal outcomes in a large German cohort of infants with a birth weight below 1500 grams.
The single nucleotide polymorphisms rs9939609 (FTO gene) and rs1424233 (MAF gene) were genotyped using allelic discrimination assays in a prospective multicenter cohort study conducted in 15 neonatal intensive care units in Germany from September 2003 until January 2008. DNA samples were extracted from buccal swabs according to standard protocols.
1946 infants were successfully genotyped at FTO and 2149 infants at MAF. Allele frequencies were not significantly different from other European cohorts. The polymorphisms were in Hardy-Weinberg equilibrium. The polymorphisms did not show associations with birth weight, BMI and Ponderal Index at discharge, and weight gain, neither testing for a dominant, additive nor for a recessive model.
Since an association of the polymorphisms with weight gain has been demonstrated in multiple populations, the lack of association in a population of preterm infants with regular tube feeding after birth and highly controlled feeding volumes provides evidence for the hypothesis that these polymorphisms affect food intake behavior and hunger rather than metabolism and energy consumption.
Lymphadenectomy is performed to assess patient prognosis and to prevent metastasizing. Recently, it was questioned whether lymph node metastases were capable of metastasizing and therefore, if ...lymphadenectomy was still adequate. We evaluated whether the nodal status impacts on the occurrence of distant metastases by analyzing a highly selected cohort of colon cancer patients.
1,395 patients underwent surgery exclusively for colon cancer at the University of Lübeck between 01/1993 and 12/2008. The following exclusion criteria were applied: synchronous metastasis, R1-resection, prior/synchronous second carcinoma, age < 50 years, positive family history, inflammatory bowel disease, FAP, HNPCC, and follow-up < 5 years. The remaining 421 patients were divided into groups with (TM+, n = 75) or without (TM-, n = 346) the occurrence of metastasis throughout a 5-year follow-up.
Five-year survival rates for TM + and TM- were 21% and 73%, respectively (p < 0.0001). Survival rates differed significantly for N0 vs. N2, grading 2 vs. 3, UICC-I vs. -II and UICC-I vs. -III (p < 0.05). Regression analysis revealed higher age upon diagnosis, increasing N- and increasing T-category to significantly impact on recurrence free survival while increasing N-and T-category were significant parameters for the risk to develop metastases within 5-years after surgery (HR 1.97 and 1.78; p < 0.0001).
Besides a higher T-category, a positive N-stage independently implies a higher probability to develop distant metastases and correlates with poor survival. Our data thus show a prognostic relevance of lymphadenectomy which should therefore be retained until conclusive studies suggest the unimportance of lmyphadenectomy.
Background: The incidence of therapy-related acute leukaemia (TRAL) in mitoxantrone treatment in multiple sclerosis (MS) is controversially discussed.
Methods and results: In a retrospective ...meta-analysis from six centres, we observed six cases of acute myeloid leukaemia (AML) (incidence 0.41% for patients with mean follow up after end of treatment of 3.6 years, n = 1.156; incidence 0.25% for all patients, n = 2.261). Potential influencing factors such as myelotoxic or glucocorticosteroid pretreatment/cotreatment were present in all but one case of TRAL. Between 1990 and 2010, 11 cases of TRAL were reported to the Drug Commission of the German Medical Association (estimated risk of 0.09–0.13%).
Conclusions: Regional differences in reported TRAL incidence may point to confounding cofactors such as administration protocols and cotreatments.
Aims
The aim of this work is the development of a mechanistic physiologically‐based pharmacokinetic (PBPK) model using in vitro to in vivo extrapolation to conduct a drug‐drug interaction (DDI) ...assessment of treosulfan against two cytochrome p450 (CYP) isoenzymes and P‐glycoprotein (P‐gp) substrates.
Methods
A PBPK model for treosulfan was developed de novo based on literature and unpublished clinical data. The PBPK DDI analysis was conducted using the U.S. Food and Drug Administration (FDA) DDI index drugs (probe substrates) midazolam, omeprazole and digoxin for CYP3A4, CYP2C19 and P‐gp, respectively. Qualified and documented PBPK models of the probe substrates have been adopted from an open‐source online model database.
Results
The PBPK model for treosulfan, based on both in vitro and in vivo data, was able to predict the plasma concentration‐time profiles and exposure levels of treosulfan applied for a standard conditioning treatment. Medium and low potentials for DDI on CYP3A4 (maximum area under the concentration‐time curve ratio (AUCRmax = 2.23) and CYP2C19 (AUCRmax = 1.6) were predicted, respectively, using probe substrates midazolam and omeprazole. Treosulfan was not predicted to cause a DDI on P‐gp.
Conclusion
Medicinal products with a narrow therapeutic index (eg, digoxin) that are substrates for CYP3A4, CYP2C19 or P‐gp should not be given during treatment with treosulfan. However, considering the comprehensive treosulfan‐based conditioning treatment schedule and the respective pharmacokinetic properties of the concomitantly used drugs (eg, half‐life), the potential for interaction on all evaluated mechanisms would be low (AUCR < 1.25), if concomitantly administered drugs are dosed either 2 hours before or 8 hours after the 2‐hour intravenous infusion of treosulfan.
PDF
