L-carnitine protects DNA oxidative damage induced by phenylalanine and its keto acid derivatives in neural cells: a possible pathomechanism and adjuvant therapy for brain injury in phenylketonuria

Although phenylalanine (Phe) is known to be neurotoxic in phenylketonuria (PKU), its exact pathogenetic mechanisms of brain damage are still poorly known. Furthermore, much less is known about the role of the Phe derivatives phenylacetic (PAA), phenyllactic (PLA) and phenylpyruvic (PPA) acids that also accumulate in this this disorder on PKU neuropathology. Previous in vitro and in vivo studies have shown that Phe elicits oxidative stress in brain of rodents and that this deleterious process also occurs in peripheral tissues of phenylketonuric patients. In the present study, we investigated whether Phe and its derivatives PAA, PLA and PPA separately or in combination could induce reactive oxygen species (ROS) formation and provoke DNA damage in C6 glial cells. We also tested the role of L-carnitine (L-car), which has been recently considered an antioxidant agent and easily cross the blood brain barrier on the alterations of C6 redox status provoked by Phe and its metabolites. We first observed that cell viability was not changed by Phe and its metabolites. Furthermore, Phe, PAA, PLA and PPA, at concentrations found in plasma of PKU patients, provoked marked DNA damage in the glial cells separately and when combined. Of note, these effects were totally prevented (Phe, PAA and PPA) or attenuated (PLA) by L-car pre-treatment. In addition, a potent ROS formation also induced by Phe and PAA, whereas only moderate increases of ROS were caused by PPA and PLA. Pre-treatment with L-car also prevented Phe- and PAA-induced ROS generation, but not that provoked by PLA and PPA. Thus, our data show that Phe and its major metabolites accumulated in PKU provoke extensive DNA damage in glial cells probably by ROS formation and that L-car may potentially represent an adjuvant therapeutic agent in PKU treatment.

[Surgical treatment of a perforated cornea in a zebra]

Microsurgical procedures in zoo and wildlife animals are challenging because of the reduced perioperative sterility and postoperative care. This case report describes the positive result of the surgical treatment of a perforated corneal ulceration with prolapsed iris in an 18-year-old Grévy's zebra mare. The postoperative development and the results of the histomorphological examination 3.5 years after surgery are described.

In vitro model to study cocaine and its contaminants

Cocaine is one of the most popular illicit drug worldwide. Due its great addictive potential, which leads to euphoria and hyperactivity, it is considered a public health concern. At the central nervous system, the drug acts inhibiting catecholamine re-uptake. It is now known that in addition to the toxicity of the drug itself, the contaminants present in the street drug have raised concern about the harmful effects on health. Toxicological in vivo and in vitro studies have demonstrated the toxic effects of cocaine correlated with the generation of reactive oxygen species (ROS), which in turn lead to oxidative damage to the cells. Therefore the aim of this work was to propose an in vitro model that reunites the main parameters of toxicity of the cocaine already observed in the literature so far, and we tested this model using cocaine and seizure cocaine sample (SCS), kindly provided by Federal Police of Brazil. For that, we used a C6 glioblastoma cells and evaluated cell death, oxygen reactive species induction, oxidation of macromolecules as membrane lipids and DNA and loss of mitochondrial membrane potential after cocaine exposure. The results showed that cocaine can decrease cellular viability in a dose-dependent way in the C6 cell immortalized and astrocytes primary culture. Cocaine also induced cellular death by apoptosis. However, in the seizure cocaine sample (SCS), the predominant cell death was due to necrosis. Using dichlorofluorescein (DCF) assay, we confirmed ROS production after cocaine exposition. In agreement with these findings, occurred an increasing in MDA production, as well as increased superoxide dismutase (SOD) and catalase (CAT) activity. The induction of DNA damage was observed after cocaine. Our results demonstrate the occurrence of mitochondrial dysfunction by depolarization of mitochondrial membrane as a consequence of cocaine treatment. In summary, these results demonstrated that cocaine can induce reactive oxygen species formation, leading to oxidative stress. As a consequence of this unbalance, DNA damage, lipidic peroxidation and loss of mitochondrial membrane occurred, which could be an answer to cell death observed.

Diagnostic odyssey in severe neurodevelopmental disorders: toward clinical whole-exome sequencing as a first-line diagnostic test

The current standard of care for diagnosis of severe intellectual disability (ID) and epileptic encephalopathy (EE) results in a diagnostic yield of ∼50%. Affected individuals nonetheless undergo multiple clinical evaluations and low-yield laboratory tests often referred to as a 'diagnostic odyssey'. This study was aimed at assessing the utility of clinical whole-exome sequencing (WES) in individuals with undiagnosed and severe forms of ID and EE, and the feasibility of its implementation in routine practice by a small regional genetic center. We performed WES in a cohort of 43 unrelated individuals with undiagnosed ID and/or EE. All individuals had undergone multiple clinical evaluations and diagnostic tests over the years, with no definitive diagnosis. Sequencing data analysis and interpretation were carried out at the local molecular genetics laboratory. The diagnostic rate of WES reached 32.5% (14 out of 43 individuals). Genetic diagnosis had a direct impact on clinical management in four families, including a prenatal diagnostic test in one family. Our data emphasize the clinical utility and feasibility of WES in individuals with undiagnosed forms of ID and EE and highlight the necessity of close collaborations between ordering physicians, molecular geneticists, bioinformaticians and researchers for accurate data interpretation.

Shared rhytidectomy continued to lateral canthoplasty in a Mastiff with excessive facial folding and macroblepharon

A 3.5-year-old male Neapolitan Mastiff was presented with an obstructed visual axis because of excessive facial skin folds, brow droop, macroblepharon, upper eyelid entropion and lower ectropion-entropion. To address these major defects a technique was performed which combines rhytidectomy with shortening of the palpebral fissure and stabilization of the lateral canthus. Postoperatively the dog showed an unobstructed visual axis with comfortable and symmetrical eyes.

Cocaine induces DNA damage in distinct brain areas of female rats under different hormonal conditions

We evaluated levels of neuronal DNA damage after acute or repeated cocaine treatment in different brain areas of female rats after ovariectomy or sham surgery. Rats in the control and acute groups were given saline i.p., whereas in the repeated group were given 15 mg/kg, i.p., cocaine for 8 days. After a 10 day washout period, the control group was given saline i.p., whereas rats in the acute and repeated groups were given a challenge dose of 15 mg/kg, i.p., cocaine. After behavioural assessment, rats were killed and the cerebellum, hippocampus, hypothalamus, prefrontal cortex and striatum were dissected for the Comet assay. Acute cocaine exposure induced DNA damage in all brain areas. This effect persisted after repeated administration, except in the hypothalamus, where repeated treatment did not cause increased DNA damage. Sexual hormones exhibited a neuroprotective effect, decreasing cocaine-induced DNA damage in cycling rats in all brain areas.

All-fiber pulse shortening of passively Q-switched microchip laser pulses down to sub-200 fs

We present an all-fiber concept that generates ultrashort pulses using a passively Q-switched microchip seed laser. A proof-of-principle configuration combines nonlinear pulse compression applying a chirped fiber-Bragg-grating, dispersion-free pulse shortening by means of a fiber-integrated spectral filtering, and a final hollow-core-fiber compression to reach the sub-200-fs pulse-duration region. In a compact all-fiber pulse-shortening unit, initial 100 ps long microchip pulses at 1064 nm wavelength have been shortened to 174 fs and shifted to 1034 nm while preserving a high temporal quality.

[New AHA and ACC guidelines on the treatment of blood cholesterol to reduce atherosclerotic cardiovascular risk : Statement of the D•A•CH Society for Prevention of Cardiovascular Diseases, the Austrian Atherosclerosis Society and the Working Group on Lipids and Atherosclerosis (AGLA) of the Swiss Society for Cardiology]

Guidelines for the reduction of cholesterol to prevent atherosclerotic vascular events were recently released by the American Heart Association and the American College of Cardiology. The authors claim to refer entirely to evidence from randomized controlled trials, thereby confining their guidelines to statins as the primary therapeutic option. The guidelines derived from these trials do not specify treatment goals, but refer to the percentage of cholesterol reduction by statin medication with low, moderate, and high intensity. However, these targets are just as little tested in randomized trials as are the cholesterol goals derived from clinical experience. The same applies to the guidelines of the four patient groups which are defined by vascular risk. No major statin trial has included patients on the basis of their global risk; thus the allocation criteria are also arbitrarily chosen. These would actually lead to a significant increase in the number of patients to be treated with high or maximum dosages of statins. Also, adhering to dosage regulations instead of cholesterol goals contradicts the principles of individualized patient care. The option of the new risk score to calculate lifetime risk up to the age of 80 years in addition to the 10-year risk can be appreciated. Unfortunately it is not considered in the therapeutic recommendations provided, despite evidence from population and genetic studies showing that even a moderate lifetime reduction of low-density lipoprotein (LDL) cholesterol or non-HDL cholesterol has a much stronger effect than an aggressive treatment at an advanced age. In respect to secondary prevention, the new American guidelines broadly match the European guidelines. Thus, the involved societies from Germany, Austria and Switzerland recommend continuing according to established standards, such as the EAS/ESC guidelines.

Smoothed spectra for enhanced dispersion-free pulse duration reduction of passively Q-switched microchip lasers

We present an enhanced technique for dispersion-free pulse shortening, which exploits the interplay of different third-order nonlinear effects in a waveguide structure. When exceeding a certain value of the pulse energy coupled into the waveguide, the typical oscillations of self-phase modulation (SPM)-broadened spectra vanish during pulse propagation. Such smoothed spectra ensure a high pulse quality of the spectrally filtered and, therefore, temporally shortened pulses independently of the filtering position. A reduction of the pulse duration from 138 to 24 ps has been achieved while preserving a high temporal quality. To the best of our knowledge, the nonlinear smoothing of SPM-broadened spectra is used in the context of dispersion-free pulse duration reduction for the first time.

Frequency, severity and predictors of playing-related musculoskeletal pain in professional orchestral musicians in Germany

Playing-related musculoskeletal disorders (PRMD) in professional musicians are common. Existing literature demonstrates that up to 86 % of musicians are affected. The aim of the study was to evaluate the frequency of musculoskeletal pain in professional orchestral musicians with regard to their instrument affiliation. Of special interest were pain intensity and its association with predictors such as gender, instrument group, age or stage fright. Professional orchestra players completed a self-report questionnaire to assess playing-related musculoskeletal pain and its frequency and intensity in various body regions on a numeric rating scale (NRS). Relative frequencies and prevalence ratios for different instrument groups were estimated. Out of 720 approached musicians, 408 were included in the sample (response rate 57 %); overall, 89.5 % had been affected by current or past playing-related musculoskeletal pain, 62.7 % reported pain in the previous 3 months, and 8.6 % reported current pain. Pain distribution and frequency varied between instrument groups. For all instrument groups, the neck was the most common pain region. About 43 % of musicians presented more than five pain regions, in particular violin players. Approximately 40 % of musicians indicated frequent or permanent pain. Average pain intensities increased from NRS 3.8 up to a range of 5.9 and 7.4 for frequent and permanent pain, respectively. Female gender and stage fright were proven to be predictors for musculoskeletal pain. Professional orchestral musicians are greatly affected by PRMD, often experiencing frequent or permanent pain, high pain levels and pain in various body regions. As PRMD might contribute considerably to performance disability, sick leave and the possibility of premature termination of a musicians' career, this study highlights the necessity for tailored therapeutic and preventive strategies in performing arts medicine.

Symptoms of craniomandibular dysfunction in professional orchestra musicians

BACKGROUND

Up to 80% of professional musicians are affected by playing-related musculoskeletal disorders, but data regarding the frequency of craniomandibular dysfunction (CMD) in professional orchestra musicians is scarce.

AIMS

To evaluate the frequency of CMD and its relation to musculoskeletal pain in various body regions.

METHODS

A questionnaire-based survey approach assessing CMD symptoms and musculoskeletal pain in professional orchestra players was adopted. Relative prevalence rates and prevalence ratios for different instrument groups were estimated.

RESULTS

A total of 408 musicians completed the questionnaire (response rate 57%). Playing-related pain in the teeth or jaw was reported by 19-47% of musicians and TMJ pain by 15-34%, depending on the instrument group. Current pain in the face indicating a painful CMD was reported in 6-10% and related symptoms such as teeth grinding in 25-34%, jaw clenching in 33-42% and jaw locking in 11-18% of musicians. Females were 2.4 times (95% confidence intervals (CI) 1.49-3.84) more likely to report having had orofacial pain within the last month. Musicians reporting orofacial pain within the last month were 4.8 times (95% CI: 2.83-8.02) more likely to report pain in the neck and 2.5-3.8 times (P < 0.05) more likely to report pain in other body regions, including shoulders, right wrist, left fingers and the thoracic and lumbar spine.

CONCLUSIONS

Symptoms suggesting CMD were common in this study of professional orchestra musicians and were associated with pain in the neck, shoulder and hands. There is a need to enhance awareness of CMD to optimize early medical diagnosis and treatment.

Wavelength-tunable, sub-picosecond pulses from a passively Q-switched microchip laser system

We present a novel concept to generate sub-picosecond pulses from a passively Q-switched Nd:YVO4 microchip laser system with an adjustable wavelength shift up to a few tens of nanometers around the original emission wavelength of 1064 nm. This concept comprises two stages: one that carries out a nonlinear compression of fiber-amplified microchip pulses and a subsequent stage in which the compressed pulses are coupled into a further waveguide structure followed by a bandpass filter. In a proof-of-principle experiment, pedestal-free 0.62 ps long pulses have been demonstrated with a wavelength shift to 1045 nm.

Ist eine Höhenrekonstruktion mit vergleichsweise wenig Zement für die Radiofrequenz-Kyphoplastie über einen monopedikulären Zugang möglich?

Hintergrund: Perkutane Zementaugmentationssysteme haben sich in den letzten 10 Jahren als eine effektive Behandlungsmethode bei Kompressionsfrakturen durchgesetzt. Als Sonderform ist nun seit 2009 die Radiofrequenz-Kyphoplastie (RF) hinzugekommen, die durch applizierbare Energie die Viskosität des Zements erhöht. Ziel dieser Studie war es, herauszufinden, ob mit einer vergleichsweise geringen Zementmenge eine Wirbelkörpererhöhung für osteoporotische Wirbelkörperfrakturen bei der RF-Kyphoplastie zu erreichen ist. Material und Methode: Bei diesem minimalinvasiven Verfahren wurde das „StabiliT® Vertebral Augmentation System“ der Firma DFine verwendet. Im Rahmen einer retrospektiven Studie wurden von 2011 bis Januar 2012 insgesamt 35 Patienten mit 49 osteoporotischen Wirbelkörperfrakturen versorgt. Als Parameter wurden die Altersstruktur mit Geschlechtsverteilung sowie klinisch der Verlauf der Schmerzintensität anhand der visuellen Analogskala (VAS0–100) ausgewertet. Radiologisch wurde die Wirbelkörpererhöhung (Vorder-, Hinterkante, mittlere Wirbelkörperhöhe und Kyphosewinkel) erfasst und mit dem applizierten Zementvolumen verglichen. Ergebnisse: Alle Patienten hatten vor der Operation eine gescheiterte konservative Behandlung mit weiterhin bestehenden Schmerzen auf Höhe des frakturierten Wirbelkörpers. Bis zur operativen Versorgung vergingen durchschnittlich 3,0 ± 1,3 Wochen. Die durchschnittliche VAS reduzierte sich signifikant von 71 ± 9,2 präoperativ auf 35 ± 6,2 postoperativ (p < 0,001) und nach 3 Monaten weiter auf 30 ± 5,7 (p < 0,001). Mit einem durchschnittlichen Zementvolumen von 2,9 ± 0,7 ml (1,8–4,1) im Thoralbereich und einem durchschnittlichen Zementvolumen von 3,0 ± 0,7 ml (2,0–5,0) im Lumbalbereich wurde eine statistisch signifikante Wirbelkörperaufrichtung erreicht. Die Vorderkante und die mittlere Wirbelkörperhöhe wurden signifikant um 2,3 mm und 3,1 mm angehoben, der Kyphosewinkel reduzierte sich ebenfalls signifikant um 2,1° nach 3 Monaten. Bei 2 Wirbelkörpern (4,1 %) zeigte sich ein minimaler Zementaustritt in die angrenzende Bandscheibe ohne klinische Konsequenz. Bei 2 Patienten entwickelten sich Anschlussfrakturen im kranialen Segment, die erneut mit einer RF-Kyphoplastie behandelt wurden. Schlussfolgerung: Mit einem durchschnittlichen Zementvolumen von 3 ml konnte mit der RF-Kyphoplastie eine schnelle und kurzfristige Besserung der Schmerzsymptomatik erreicht werden. Zusätzlich konnte mit diesem geringen Zementvolumen eine signifikante Wirbelkörperaufrichtung erzeugt werden. Es zeigte sich keine Korrelation zwischen der Wirbelkörperaufrichtung und dem klinischen Ergebnis. Mit der ermittelten Zementleckagenrate von 4,1 % gehört die Radiofrequenz-Kyphoplastie zu den sicheren und effektiven minimalinvasiven perkutanen Zementaugmentationsverfahren. Unsere Daten bestätigen die in der Literatur angegebene höhere Sicherheit für die Kyphoplastie im Vergleich zur Vertebroplastie.

Playing-related musculoskeletal disorders in music students-associated musculoskeletal signs

BACKGROUND

Pain and overuse are common problems for musicians. Up to 80% of professional musicians suffer from playing-related musculoskeletal disorders (PRMD). The prevalence rate in music students is very high as well. Sufficient data on the underlying musculoskeletal dysfunctions however is scarce. Additionally, the self-assessment of health in musicians seems to differ compared to non-musicians, which might influence their attitudes concerning preventive strategies.

AIM

Evaluation of frequency of PRMD in music students, investigation of signs and symptoms in music students compared to non-music controls, comparison of self-reported health and well-being between the two groups.

DESIGN

Prospective, cross-sectional, case control, non-randomized.

SETTING

Other (University volunteers).

POPULATION

Music students in comparison to a non-music control group.

METHOD

Musculoskeletal examination and questionnaire of 36 volunteers of a music university and 19 volunteer students of an university of education were analyzed. The total number of musculoskeletal dysfunctions and differences between the student groups were examined. The personal pain and health self-rating were compared between music and non-music students.

RESULTS

Eighty one percent of musicians experienced PRMD. Musicians experienced 6.19 pain regions on average compared to 4.31 of non-musicians. Musicians experiencing PRMD reported significantly (P<0.05) more pain locations than musicians without. Music students presented with nearly the double amount (8.39 versus 4.37) of musculoskeletal dysfunctions per person compared to the non-music control group. Nevertheless, musicians significantly (P<0.05) rated their health more positively than the controls.

CONCLUSION

Musicians presented with more pain regions and a higher amount of musculoskeletal dysfunctions. Further studies evaluating the clinical relevance and their role in the development of PRMD are warranted.

CLINICAL REHABILITATION IMPACT

Screening of musicians for musculoskeletal dysfunction may identify those musicians at increased risk. Early treatment may prevent PRMD in musicians. Additional research is needed to confirm our hypothesis.

Dispersion-free pulse duration reduction of passively Q-switched microchip lasers

We present a dispersion-free method for the pulse duration reduction of passively Q-switched microchip laser (MCL) seed sources. This technique comprises two stages: one that carries out the self-phase modulation induced spectral broadening in a waveguide structure and a subsequent spectral filtering stage in order to shorten the pulses in time domain. The setup of a proof-of-principle experiment consists of a fiber-amplified passively Q-switched MCL, a passive single-mode fiber used as nonlinear element in which the spectrum is broadened, and a reflective volume-Bragg-grating acting as bandpass filter. A reduction of the pulse duration from 118 to 32 ps with high temporal quality has been achieved with this setup.