The influence of season on glutamate and GABA levels in the healthy human brain investigated by magnetic resonance spectroscopy imaging

Seasonal changes in neurotransmitter systems have been demonstrated in imaging studies and are especially noticeable in diseased states such as seasonal affective disorder (SAD). These modulatory neurotransmitters, such as serotonin, are influencing glutamatergic and GABAergic neurotransmission. Furthermore, central components of the circadian pacemaker are regulated by GABA (the suprachiasmatic nucleus) or glutamate (e.g., the retinohypothalamic tract). Therefore, we explored seasonal differences in the GABAergic and glutamatergic system in 159 healthy individuals using magnetic resonance spectroscopy imaging with a GABA-edited 3D-MEGA-LASER sequence at 3T. We quantified GABA+/tCr, GABA+/Glx, and Glx/tCr ratios (GABA+, GABA+ macromolecules; Glx, glutamate + glutamine; tCr, total creatine) in five different subcortical brain regions. Differences between time periods throughout the year, seasonal patterns, and stationarity were tested using ANCOVA models, curve fitting approaches, and unit root and stationarity tests, respectively. Finally, Spearman correlation analyses between neurotransmitter ratios within each brain region and cumulated daylight and global radiation were performed. No seasonal or monthly differences, seasonal patterns, nor significant correlations could be shown in any region or ratio. Unit root and stationarity tests showed stable patterns of GABA+/tCr, GABA+/Glx, and Glx/tCr levels throughout the year, except for hippocampal Glx/tCr. Our results indicate that neurotransmitter levels of glutamate and GABA in healthy individuals are stable throughout the year. Hence, despite the important correction for age and gender in the analyses of MRS derived GABA and glutamate, a correction for seasonality in future studies does not seem necessary. Future investigations in SAD and other psychiatric patients will be of high interest.

Effects of sex hormones on brain GABA and glutamate levels in a cis- and transgender cohort

Sex hormones affect the GABAergic and glutamatergic neurotransmitter system as demonstrated in animal studies. However, human research has mostly been correlational in nature. Here, we aimed at substantiating causal interpretations of the interaction between sex hormones and neurotransmitter function by using magnetic resonance spectroscopy imaging (MRSI) to study the effect of gender-affirming hormone treatment (GHT) in transgender individuals. Fifteen trans men (TM) with a DSM-5 diagnosis of gender dysphoria, undergoing GHT, and 15 age-matched cisgender women (CW), receiving no therapy, underwent MRSI before and after at least 12 weeks. Additionally, sex differences in neurotransmitter levels were evaluated in an independent sample of 80 cisgender men and 79 cisgender women. Mean GABA+ (combination of GABA and macromolecules) and Glx (combination of glutamate and glutamine) ratios to total creatine (GABA+/tCr, Glx/tCr) were calculated in five predefined regions-of-interest (hippocampus, insula, pallidum, putamen and thalamus). Linear mixed models analysis revealed a significant measurement by gender identity effect (p_corr. = 0.048) for GABA+/tCr ratios in the hippocampus, with the TM cohort showing decreased GABA+/tCr levels after GHT compared to CW. Moreover, analysis of covariance showed a significant sex difference in insula GABA+/tCr ratios (p_corr. = 0.049), indicating elevated GABA levels in cisgender women compared to cisgender men. Our study demonstrates GHT treatment-induced GABA+/tCr reductions in the hippocampus, indicating hormone receptor activation on GABAergic cells and testosterone-induced neuroplastic processes within the hippocampus. Moreover, elevated GABA levels in the female compared to the male insula highlight the importance of including sex as factor in future MRS studies. DATA AVAILABILITY STATEMENT: Due to data protection laws processed data is available from the authors upon reasonable request. Please contact rupert.lanzenberger@meduniwien.ac.at with any questions or requests.

Coexpression of Gene Transcripts with Monoamine Oxidase A Quantified by Human In Vivo Positron Emission Tomography

The monoamine oxidase A (MAO-A) is integral to monoamine metabolism and is thus relevant to the pathophysiology of various neuropsychiatric disorders; however, associated gene-enzyme relations are not well understood. This study aimed to unveil genes coexpressed with MAO-A. Therefore, 18 179 mRNA expression maps (based on the Allen Human Brain Atlas) were correlated with the cerebral distribution volume (VT) of MAO-A assessed in 36 healthy subjects (mean age ± standard deviation: 32.9 ± 8.8 years, 18 female) using [11C]harmine positron emission tomography scans. Coexpression analysis was based on Spearman's ρ, over-representation tests on Fisher's exact test with false discovery rate (FDR) correction. The analysis revealed 35 genes in cortex (including B-cell translocation gene family, member 3, implicated in neuroinflammation) and 247 genes in subcortex (including kallikrein-related peptidase 10, implicated in Alzheimer's disease). Significantly over-represented Gene Ontology terms included "neuron development", "neuron differentiation", and "cell-cell signaling" as well as "axon" and "neuron projection". In vivo MAO-A enzyme distribution and MAOA expression did not correlate in cortical areas (ρ = 0.08) while correlation was found in subcortical areas (ρ = 0.52), suggesting influences of region-specific post-transcriptional and -translational modifications. The herein reported information could contribute to guide future genetic studies, deepen the understanding of associated pathomechanisms and assist in the pursuit of novel therapeutic targets.

Development of a modular ICF-based core set for the German substance use disorders treatment

PURPOSE

We aimed to develop a modular Core Set based on the International Classification of Functioning, Disability and Health (ICF) for describing functioning in patients with substance use disorders (SUDs). To match the structure of the German health service system, the Core Set was split into modules for different service segments.

METHODS

We followed a consensus process including several preparatory studies. To identify candidate ICF categories, we performed an ICF linking of guideline-recommended assessments, patient focus groups and patient and expert surveys. Categories were prioritized for different service segments and compiled into preliminary modules. The Core Set was tested in 13 treatment sites. Health professionals rated each category's relevance, and contents of the Modular ICF-based Core Set for SUDs (MCSS) were compared to patient-reported treatment goals. An advisory board decided on revisions to the MCSS.

RESULTS

The MCSS consists of a basic module (25 categories) and five additional modules for these treatment segments: counselling (8), qualified withdrawal (6), orientation (7), rehabilitation (32), and social integration services (10).

CONCLUSIONS

The MCSS provides a framework for harmonizing communication, documentation and interface management in German SUD health services. The basic module, consisting of 25 categories, can be employed as a Brief ICF Core Set.Implications for rehabilitationThe MCSS can serve as a standard for describing functioning in patients with SUDs in Germany, as well as harmonize communication and reporting of treatment relevant information.In clinical practice, the MCSS can be used for the structured assessment of psychosocial problems and participation restrictions, goal setting, and outcome evaluation.Although the MCSS was developed in Germany, its proximity to the themes frequently identified in the literature regarding SUDs internationally suggests that it may be of use in other countries as well.The basic module may be employed as a Brief ICF Core Set.

THU0284 PREVALENCE OF NEUROPSYCHIATRIC LUPUS IN PSYCHOSIS PATIENTS WITH A POSITIVE ANTINUCLEAR ANTIBODY

Background:

Psychosis is a rare manifestation of Neuropsychiatric Systemic Lupus Erythematosus (NPSLE). Patients with SLE may have Psychosis as part of their initial presentation of disease1. Current guidelines do not make a recommendation regarding the use of Antinuclear Antibody (ANA) in the assessment of patients with psychosis2. There is limited evidence assessing the utility of ANA testing in this setting.

Objectives:

Primary objective: Determine the prevalence of NPSLE in patients admitted to a mental health service with a diagnosis of a psychosis, who have had a positive antinuclear antibody test.

Secondary objectives: Determine the frequency and proportion of positive ANA testing in this patient group. Determine the pattern and titres of positive ANAs. Determine the subsequent investigation, referral and diagnosis of patients with positive ANAs.

Methods:

Retrospective chart review of patients admitted to a mental health service of two metropolitan tertiary referral centres, Prince of Wales Hospital (POWH) and Royal Prince Alfred Hospital (RPAH), with a diagnosis of psychosis who had been tested for ANA. Patients were identified using their electronically entered diagnosis based on the International Classification of Disease3codes. Assessment of patient data for SLE used the 2019 ACR/EULAR classification criteria4. Decisions regarding attribution of psychosis related events to SLE follows the criteria used by Bortoluzzi et al5.

Results:

Between 1stof January 2010 and 31stof March 2018 there were 5585 (POWH) and 4620 (RPAH) mental health admission with an ICD diagnosis of psychosis representing 2451 and 2315 individual patients. 449/2451 (18%) and 462/2315 (20%) patients were tested for ANA. 78/449 (17%) and 57/462 (12%) were positive. Discharge data was available for all patients and long-term follow up data was completed for 53/78 (81% - POWH) patients and 50/57 (88% - RPAH). The mean follow-up time 43 ± 23 months and 51 ± 29 months respectively.

At discharge there were four patients who met 2019 ACR/EULAR for SLE. Of these, two patients met criteria for NPSLE. One was diagnosed clinically and treated specifically for NPSLE with intravenous methylprednisolone and rituximab.

There were no additional diagnoses of SLE or NPSLE clinically or by criteria found in the available follow up data. Hence the overall prevalence of NPSLE in patients admitted with psychosis was 1.3%, 95%CI [0,6.9%] and 1.8%, 95%CI [0,9.4%] respectively.

Conclusion:

The prevalence of neuropsychiatric lupus in patients with psychosis and a positive ANA was 1/78 and 1/57 a two tertiary referral centres. This study expands significantly on the limited evidence available as to the expected outcomes of a positive ANA test in a patient with psychosis.

References:

[1]Pego-Reigosa JM, Isenberg DA. Psychosis due to systemic lupus erythematosus: characteristics and long-term outcome of this rare manifestation of the disease. Rheumatology (Oxford). 2008; 47:1498–502.

[2]National Institute for Health and Care Excellence. Psychosis and schizophrenia in adults: prevention and management. London: NICE; 2014. Clinical guideline CG178.

[3]World Health Organization. (2004). ICD-10: international statistical classification of diseases and related health problems: tenth revision, 2nd ed.

[4]Aringer M, et al. 2019 European League Against Rheumatism/American College of Rheumatology classification criteria for systemic lupus erythematosus. Arthritis Rheum. 2019; 71(9): 1400–1412.

[5]Bortoluzzi A, et al. Development and validation of a new algorithm for attribution of neuropsychiatric events in systemic lupus erythematosus. Rheumatology. 2015; 54: 891-898.

Acknowledgments:

Gordana Popovic, Statistical Consultant, Stats Central, Mark Wainwright Analytical Centre, University of New South Wales, Sydney, Australia.

Disclosure of Interests:

None declared

Effect of Bias on the Response of GaN Axial p-n Junction Single-Nanowire Photodetectors

We present a comprehensive study of the performance of GaN single-nanowire photodetectors containing an axial p-n junction. The electrical contact to the p region of the diode is made by including a p⁺/n⁺ tunnel junction as cap structure, which allows the use of the same metal scheme to contact both ends of the nanowire. Single-nanowire devices present the rectifying current-voltage characteristic of a p-n diode but their photovoltaic response to ultraviolet radiation scales sublinearly with the incident optical power. This behavior is attributed to the dominant role of surface states. Nevertheless, when the junction is reverse biased, the role of the surface becomes negligible in comparison to the drift of photogenerated carriers in the depletion region. Therefore, the responsivity increases by about 3 orders of magnitude and the photocurrent scales linearly with the excitation. These reverse-biased nanowires display decay times in the range of ∼10 μs, limited by the resistor-capacitor time constant of the setup. Their ultraviolet/visible contrast of several orders of magnitude is suitable for applications requiring high spectral selectivity. When the junction is forward biased, the device behaves as a GaN photoconductor with an increase of the responsivity at the price of a degradation of the time response. The presence of leakage current in some of the wires can be modeled as a shunt resistance which reacts to the radiation as a photoconductor and can dominate the response of the wire even under reverse bias.

Clinical factors predicting treatment resistant depression: affirmative results from the European multicenter study

OBJECTIVES

Clinical variables were investigated in the 'treatment resistant depression (TRD)- III' sample to replicate earlier findings by the European research consortium 'Group for the Study of Resistant Depression' (GSRD) and enable cross-sample prediction of treatment outcome in TRD.

EXPERIMENTAL PROCEDURES

TRD was defined by a Montgomery and Åsberg Depression Rating Scale (MADRS) score ≥22 after at least two antidepressive trials. Response was defined by a decline in MADRS score by ≥50% and below a threshold of 22. Logistic regression was applied to replicate predictors for TRD among 16 clinical variables in 916 patients. Elastic net regression was applied for prediction of treatment outcome.

RESULTS

Symptom severity (odds ratio (OR) = 3.31), psychotic symptoms (OR = 2.52), suicidal risk (OR = 1.74), generalized anxiety disorder (OR = 1.68), inpatient status (OR = 1.65), higher number of antidepressants administered previously (OR = 1.23), and lifetime depressive episodes (OR = 1.15) as well as longer duration of the current episode (OR = 1.022) increased the risk of TRD. Prediction of TRD reached an accuracy of 0.86 in the independent validation set, TRD-I.

CONCLUSION

Symptom severity, suicidal risk, higher number of lifetime depressive episodes, and comorbid anxiety disorder were replicated as the most prominent risk factors for TRD. Significant predictors in TRD-III enabled robust prediction of treatment outcome in TRD-I.

On the validity of several previously published perturbation formulas for the acoustoelastic effect on Rayleigh waves

This article revisits the evaluation by a perturbation theory of the modification of the Rayleigh wave velocity under a static loading varying with depth. Two derivations, that have been exposed in the past and presented as comparable, are questioned. A new derivation of the perturbation formula is given by adapting Auld's approach. Validation with exact calculations is provided. The examples cover depth-varying static stress as well as depth-varying third order elastic properties.

Monolithic Axial and Radial Metal-Semiconductor Nanowire Heterostructures

The electrical and optical properties of low-dimensional nanostructures depend critically on size and geometry and may differ distinctly from those of their bulk counterparts. In particular, ultrathin semiconducting layers as well as nanowires have already proven the feasibility to realize and study quantum size effects enabling novel ultrascaled devices. Further, plasmonic metal nanostructures attracted recently a lot of attention because of appealing near-field-mediated enhancement effects. Thus, combining metal and semiconducting constituents in quasi one-dimensional heterostructures will pave the way for ultrascaled systems and high-performance devices with exceptional electrical, optical, and plasmonic functionality. This Letter reports on the sophisticated fabrication and structural properties of axial and radial Al-Ge and Al-Si nanowire heterostructures, synthesized by a thermally induced exchange reaction of single-crystalline Ge-Si core-shell nanowires and Al pads. This enables a self-aligned metallic contact formation to Ge segments beyond lithographic limitations as well as ultrathin semiconducting layers wrapped around monocrystalline Al core nanowires. High-resolution transmission electron microscopy, energy dispersive X-ray spectroscopy, and μ-Raman measurements proved the composition and perfect crystallinity of these metal-semiconductor nanowire heterostructures. This exemplary selective replacement of Ge by Al represents a general approach for the elaboration of radial and axial metal-semiconductor heterostructures in various Ge-semiconductor heterostructures.

Intersubband absorption in GaN nanowire heterostructures at mid-infrared wavelengths

In this paper, we study intersubband characteristics of GaN/AlN and GaN/Al_0.4Ga_0.6N heterostructures in GaN nanowires structurally designed to absorb in the mid-infrared wavelength region. Increasing the GaN well width from 1.5 to 5.7 nm leads to a red shift of the intersubband absorption from 1.4 to 3.4 μm. The red shift in larger quantum wells is amplified by the fact that one of the GaN/AlN heterointerfaces (corresponding to the growth of GaN on AlN) is not sharp but rather a graded alloy extending around 1.5-2 nm. Using AlGaN instead of AlN for the same barrier dimensions, we observe the effects of reduced polarization, which blue shifts the band-to-band transitions and red shifts the intersubband transitions. In heavily doped GaN/AlGaN nanowires, a broad absorption band is observed in the 4.5-6.4 μm spectral region.

Association of Protein Distribution and Gene Expression Revealed by PET and Post-Mortem Quantification in the Serotonergic System of the Human Brain

Regional differences in posttranscriptional mechanisms may influence in vivo protein densities. The association of positron emission tomography (PET) imaging data from 112 healthy controls and gene expression values from the Allen Human Brain Atlas, based on post-mortem brains, was investigated for key serotonergic proteins. PET binding values and gene expression intensities were correlated for the main inhibitory (5-HT1A) and excitatory (5-HT2A) serotonin receptor, the serotonin transporter (SERT) as well as monoamine oxidase-A (MAO-A), using Spearman's correlation coefficients (rs) in a voxel-wise and region-wise analysis. Correlations indicated a strong linear relationship between gene and protein expression for both the 5-HT1A (voxel-wise rs = 0.71; region-wise rs = 0.93) and the 5-HT2A receptor (rs = 0.66; 0.75), but only a weak association for MAO-A (rs = 0.26; 0.66) and no clear correlation for SERT (rs = 0.17; 0.29). Additionally, region-wise correlations were performed using mRNA expression from the HBT, yielding comparable results (5-HT1Ars = 0.82; 5-HT2Ars = 0.88; MAO-A rs = 0.50; SERT rs = -0.01). The SERT and MAO-A appear to be regulated in a region-specific manner across the whole brain. In contrast, the serotonin-1A and -2A receptors are presumably targeted by common posttranscriptional processes similar in all brain areas suggesting the applicability of mRNA expression as surrogate parameter for density of these proteins.

In vitro biomechanical comparison of a newly designed interlocking nail system to a standard DCP

Objective: To describe a newly designed interlocking nail system (Targon® Vet System, TVS) tested in a model of diaphyseal femoral fractures in cats. Material and methods: Introduction of the TVS and presentation of the system components. Evaluation of application range and biomechanical testing of the TVS in cadaver bones under cyclic loading until fatigue failure occurred. The first two test groups compared the influence of implantation and immediate removal of the TVS locking bolts and six holes created by 2.0 mm cortical screws on the stability of feline femora. In the third group the two fixation systems were compared to each other with implants in place in an osteotomy gap model. The failure mode was statistically compared for each group (p < 0.05). Results: Femora after implantation and removal of the bolts of the TVS were significantly stiffer than after implantation and removal of the six 2.0 mm cortical screws. In the osteotomy gap model, femora with the TVS in place failed somewhat later, but not statistically significant, than the opposite femur of the same cat with the 2.0 8-hole DCP in place. Conclusion and clinical relevance: Using this testing method, stability of the TVS seems to be biomechanically comparable to conventional osteosynthesis plate systems. Therefore the TVS may be an encouraging alternative to conventional osteosynthesis systems in diaphyseal fractures, offering several advantages without the need for extensive specialized equipment.

Prevention of seasonal affective disorder in daily clinical practice: results of a survey in German-speaking countries

BACKGROUND

Seasonal affective disorder (SAD) is a seasonally recurrent type of major depression. This predictable aspect makes it promising for preventive treatment. However, evidence for the efficacy and harm of preventive treatment of SAD is scarce, as are recommendations from clinical practice guidelines. The aim of this study was to assess the current use of preventive treatment of SAD in clinical practice in German-speaking countries for the first time.

METHODS

We conducted a postal and web-based survey sent to the heads of all psychiatric institutions listed in the inventory "Deutsches Krankenhaus Adressbuch, 2015" that contains all psychiatric hospitals in Germany, Austria, and Switzerland.

RESULTS

One hundred institutions (out of 533 institutions, 19%), which treated in total more than 3100 SAD patients in the years 2014/2015, responded. Of those, 81 reported recommending preventive treatment to patients with a history of SAD. There was no consensus on the optimal starting point for preventive treatment. Most of the institutions that implemented prevention of SAD, recommended lifestyle changes (85%), antidepressants (84%), psychotherapy (73%), and light therapy (72%) to their patients. The situation was similar in northern and southern regions.

CONCLUSIONS

Most hospitals recommended the use of preventive treatment to SAD patients, although evidence on efficacy and harm is limited. A wide variety of interventions were recommended, although guidelines only include recommendations for acute treatment. To assist psychiatrists and patients in future decision making, controlled studies on preventive treatment for SAD that compare different interventions with one another are needed.

Default mode network deactivation during emotion processing predicts early antidepressant response

Several previous functional magnetic resonance imaging (fMRI) studies have demonstrated the predictive value of brain activity during emotion processing for antidepressant response, with a focus on clinical outcome after 6-8 weeks. However, longitudinal studies emphasize the paramount importance of early symptom improvement for the course of disease in major depressive disorder (MDD). We therefore aimed to assess whether neural activity during the emotion discrimination task (EDT) predicts early antidepressant effects, and how these predictive measures relate to more sustained response. Twenty-three MDD patients were investigated once with ultrahigh-field 7T fMRI and the EDT. Following fMRI, patients received Escitalopram in a flexible dose schema and were assessed with the Hamilton Depression Rating Scale (HAMD) before, and after 2 and 4 weeks of treatment. Deactivation of the precuneus and posterior cingulate cortex (PCC) during the EDT predicted change in HAMD scores after 2 weeks of treatment. Baseline EDT activity was not predictive of HAMD change after 4 weeks of treatment. The precuneus and PCC are integral components of the default mode network (DMN). We show that patients who exhibit stronger DMN suppression during emotion processing are more likely to show antidepressant response after 2 weeks. This is, to our knowledge, the first study to show that DMN activity predicts early antidepressant effects. However, DMN deactivation did not predict response at 4 weeks, suggesting that our finding is representative of early, likely treatment-related, yet unspecific symptom improvement. Regardless, early effects may be harnessed for optimization of treatment regimens and patient care.

Epidemiology and socioeconomic impact of seasonal affective disorder in Austria

BACKGROUND

Seasonal affective disorder (SAD) is a subtype of recurrent depressive or bipolar disorder that is characterized by regular onset and remission of affective episodes at the same time of the year. The aim of the present study was to provide epidemiological data and data on the socioeconomic impact of SAD in the general population of Austria.

METHODS

We conducted a computer-assisted telephone interview in 910 randomly selected subjects (577 females and 333 males) using the Seasonal Health Questionnaire (SHQ), the Seasonal Pattern Assessment Questionnaire (SPAQ), and the Sheehan Disability Scale (SDS). Telephone numbers were randomly drawn from all Austrian telephone books and transformed using the random last digits method. The last birthday method was employed to choose the target person for the interviews.

RESULTS

Out of our subjects, 2.5% fulfilled criteria for the seasonal pattern specifier according to DSM-5 and 2.4% (95% CI=1.4-3.5%) were diagnosed with SAD. When applying the ICD-10 criteria 1.9% (95% CI=0.9-2.8%) fulfilled SAD diagnostic criteria. The prevalence of fall-winter depression according to the Kasper-Rosenthal criteria was determined to be 3.5%. The criteria was fulfilled by 15.1% for subsyndromal SAD (s-SAD). We did not find any statistically significant gender differences in prevalence rates. When using the DSM-5 as a gold standard for the diagnosis of SAD, diagnosis derived from the SPAQ yielded a sensitivity of 31.8% and a specificity of 97.2%. Subjects with SAD had significantly higher scores on the SDS and higher rates of sick leave and days with reduced productivity than healthy subjects.

CONCLUSIONS

Prevalence estimates for SAD with the SHQ are lower than with the SPAQ. Our data are indicative of the substantial burden of disease and the socioeconomic impact of SAD. This epidemiological data shows a lack of gender differences in SAD prevalence. The higher rates of females in clinical SAD samples might, at least in part, be explained by lower help seeking behaviour in males.

[ICF-based Assessments to Evaluate Need and Success in the Treatment of Patients With Mental Disorders - A Systematic Review]

AIMS

The aim of the study is to provide a systematic overview of assessment instruments that refer conceptually to the International Classification of Functioning, Disability, and Health (ICF) and can be used in the context of mental disorders.

METHODS

We conducted a systematic literature search in the scientific databases (EMBASE, Medline, PsycInfo, PSYNDEX) and screened relevant conference proceedings since 2001. From abstracts fitting our inclusion criteria we reviewed full texts. Identified assessments were compared regarding their operationalization of the ICF.

RESULTS

Out of 440 identified abstracts we selected 8 assessment instruments for interviewer-, proxy- or self-assessment. Two were generic and six disease-specific scales. Differences pertain to the extent as well as coverage and operationalization of the ICF.

CONCLUSION

Existing instruments differ in psychometric properties and operationalization of the ICF. This review might help clinicians to select ICF-based assessments.

In vitro biomechanical comparison of a newly designed interlocking nail system to a standard DCP. Testing of cat femora in an osteotomy gap model

OBJECTIVE

To describe a newly designed interlocking nail system (Targon® Vet System, TVS) tested in a model of diaphyseal femoral fractures in cats.

MATERIAL AND METHODS

Introduction of the TVS and presentation of the system components. Evaluation of application range and biomechanical testing of the TVS in cadaver bones under cyclic loading until fatigue failure occurred. The first two test groups compared the influence of implantation and immediate removal of the TVS locking bolts and six holes created by 2.0 mm cortical screws on the stability of feline femora. In the third group the two fixation systems were compared to each other with implants in place in an osteotomy gap model. The failure mode was statistically compared for each group (p < 0.05).

RESULTS

Femora after implantation and removal of the bolts of the TVS were significantly stiffer than after implantation and removal of the six 2.0 mm cortical screws. In the osteotomy gap model, femora with the TVS in place failed some- what later, but not statistically significant, than the opposite femur of the same cat with the 2.0 8-hole DCP in place.

CONCLUSION AND CLINICAL RELEVANCE

Using this testing method, stability of the TVS seems to be biomechanically comparable to conventional osteosynthesis plate systems. Therefore the TVS may be an encouraging alternative to conventional osteosynthesis systems in diaphyseal fractures, offering several advantages without the need for extensive specialized equipment.

[Acute calcinosis of the hand in an infant]

We report on an acute calcinosis in infants as a differential diagnosis to a trauma or an infect of the wrist.

[Scaphoid fracture in motocross riders]

Motocross racing is a demanding motorcycling discipline with significant physiological and psychological demands. Upper extremity injuries are frequently encountered. Interestingly, motocross riders present with a significantly stronger left arm, even if the left hand is not dominant. This difference is attributed to the use of the clutch lever with the left hand, which is more frequent in motocross than in Enduro or desert rally. The wrist has been reported to be involved especially among motocross racers in contrast to road racing. Besides wrist fractures, scaphoid fractures have been previously without a detailed analysis of the injury mechanism. We report on three patients suffering scaphoid fractures caused by extreme hyperextension of the wrist during landing after a motocross jump. Two patients presented late three months following the initial trauma (both Herbert type C fractures), while one motocross athlete with a B 2-type scaphoid fracture was admitted to wrist surgery within a week. The B 2-type fracture was treated with open reduction and Herbert-screw fixation, while the C-type fractures were treated by Herbert-screw fixation in addition to a cortico-cancellous bone graft. Within ten weeks after the surgery the patients were back in sport at their given preoperative level. Hyperextension rather than wrist flexion appears as the predominant mechanism of wrist injuries in motocross riders. A more axial impact on the wrist is more likely to produce a radial fracture during the landing phase. Preventive strategies are internal muscular wrist stabilisation using eccentric training and external stabilisation by rigid gloves allowing only limited hyperextension.

Peripheral glial cell differentiation from neurospheres derived from adipose mesenchymal stem cells

Mesenchymal stem cells derived from bone marrow and adipose tissue are being considered for use in neural repair because they can differentiate after appropriate induction in culture into neurons and glia. The question we asked was if neurospheres could be harvested from adipose-derived stem cells and if they then could differentiate in culture to peripheral glial-like cells. Here, we demonstrate that adipose-derived mesenchymal stem cells can form nestin-positive non-adherent neurosphere cellular aggregates when cultured with basic fibroblast growth factor and epidermal growth factor. Dissociation of these neurospheres and removal of mitogens results in expression of the characteristic Schwann cell markers S100 and p75 nerve growth factor receptor and GFAP. The simultaneous expression of these glia markers are characteristic features of Schwann cells and olfactory ensheathing cells which have unique properties regarding remyelination and enhancement of axonal regeneration. When co-cultured with dorsal root ganglion neurons, the peripheral glial-like cells derived from adipose mesenchymal stem cells aligned with neuritis and stimulated neuritic outgrowth. These results indicate that neurospheres can be generated from adipose-derived mesenchymal stem cells, and upon mitogen withdrawal can differentiate into peripheral glial cells with neurotrophic effects.

[Fractures of the wrist and hand. Principles of conservative treatment]

Over the last years, many special instruments and implants were designed for operative treatment of fractures of the wrist and hand. Therefore, conservative treatment of these injuries became old-fashioned in the eyes of most patients and surgeons. Nevertheless, conservative treatment of nondislocated stable fractures of the wrist and hand usually shows better clinical results than operative treatment does. On the other hand, conservative treatment of displaced fractures is very difficult. The key to success is thorough knowledge of the use of casts, splints, and functional therapy and good patient compliance to avoid complications. Opportunities for conservative treatment of fractures of the wrist and hand are herein described.

Ersatzoperationen bei Ausfall motorischer Funktionen an der Hand

Nerve injuries in the upper extremity can result in severe disability. In the last three decades, progress in microsurgical techniques has improved the outcome for nerve injuries and if the prognosis is reasonably good, nerve repair should usually be performed prior to tendon transfer procedures. However, above all proximal lesions of peripheral nerves such as high radial nerve palsy still often yield unsatisfactory results, despite a technically well-executed nerve repair. Prognosis further depends on the time interval since the injury and also on the age of the patient, as the regenerative process is delayed in older patients. The indication for tendon transfers strongly depends on the personal and professional profiles of the individual patient. Tendon transfer procedures alleviate the suffering from functional hand impairment providing a superior alternative to permanent external splints. Tendon transfers are usually secondary procedures for replacing function after evaluation of the functional motor loss. Numerous transfer procedures have been described for every nerve trunk of the upper extremity, their prognosis depending mainly on the extent and pattern of nerve loss, local effects of the trauma (e.g. involvement of soft tissues, joints), and the physiological characteristics of the transferred muscle. Even if the results of the tendon transfers may finally be less satisfactory in cases of complex nerve damage than in isolated motor nerve lesions, they offer a valuable functional benefit, often being the only possibility to restore hand function. Although regrettably underused, tendon transfer improve upper extremity function in more than 70% of patients with cervical spinal cord injury. Reconstruction of key elements such as wrist extension, key grip between the thumb and the index finger, or digital flexion and extension leads to highly improved use of the tetraplegic hand and thus provides new mobility and independence from the help of others. This article presents an overview of the most common procedures to restore hand function in peripheral nerve injuries and tetraplegia in order to provide a systematic approach for decision making.

Lipomas after blunt soft tissue trauma: are they real? Analysis of 31 cases

BACKGROUND

Soft tissue trauma and lipomas are common occurrences in surgical practice. Lipomas are defined as benign tumours of adipose tissue with so far unexplained pathogenesis and aetiology. A link between preceding blunt soft tissue trauma at the site of the tumour and the formation of lipomas has been described earlier. These soft tissue tumours have been named 'post-traumatic lipomas'.

OBJECTIVES

In a retrospective review, to analyse all patients with benign adipose tissue tumours treated at our institution between August 2001 and January 2007.

METHODS

All cases were reviewed regarding medical history, magnetic resonance imaging findings, intraoperative findings, clinical chemistry and histology.

RESULTS

In 170 patients presenting with lipomas, 34 lipomas in 31 patients were identified as post-traumatic. The mean +/- SD age of the patients with post-traumatic lipomas was 52 +/- 14.5 years. The mean time elapsed between soft tissue trauma and lipoma formation was 2.0 years (range 0.5-5). Twenty-five of the 31 patients reported an extensive and slowly resolving haematoma after blunt tissue trauma at the site of lipoma formation. The mean +/- SD body mass index was 29.0 +/- 7.6 kg m(-2). Fourteen of 31 patients presented with an elevated partial thromboplastin time. Eleven of 34 lipomas were found on the upper extremities, five on the lower extremities, 13 on the trunk, and two on the face. All tumours were located subcutaneously, superficial to the musculofascial system. Thirty-three lipomas were removed by surgical excision and one by liposuction following an incisional biopsy. Histological examination revealed capsulated and noncapsulated benign adipose tissue in all 34 tumours.

CONCLUSIONS

The existence of a pathogenic link between blunt soft tissue trauma and the formation of post-traumatic lipomas is still controversial. Two potential mechanisms are discussed. Firstly, the formation of so-called post-traumatic 'pseudolipomas' may result from a prolapse of adipose tissue through fascia induced by direct impact. Alternatively, lipoma formation may be explained as a result of preadipocyte differentiation and proliferation mediated by cytokine release following soft tissue damage after blunt trauma and haematoma formation.

Gefäßchirurgische Interventionen und plastisch-rekonstruktive Chirurgie

Despite the high prevalence of arterial occlusive disease, only a few studies have investigated the benefit of interventions to recanalize extremity arteries prior to plastic operations to close chronic wounds. The purpose of this study was to investigate the correlation of simple clinical examinations and apparative diagnostics of arterial occlusive disease of the lower extremity in patients with chronic wounds and to evaluate the benefit of vascular procedures to optimize wound perfusion before surgical closure. A total of 150 individuals with chronic wounds were included in this retrospective study. All patients underwent palpation of their foot pulses, Doppler sonography, and measurement of occlusive pressure. Positive results were tested by angiography. All patients with peripheral extremity vessel occlusion underwent vascular interventions prior to plastic operations for definitive wound closure. In all 34 patients with missing foot pulses, the clinical diagnosis of arterial occlusion could be confirmed by angiography. Peripheral recanalization and improved wound perfusion could be achieved in all patients. Arterial insufficiency could be diagnosed rapidly and safely using simple clinical examination such as palpation of foot pulses or measurement of occlusive pressures combined with Doppler sonography. Thus this simple and straightforward algorithm helped to secure the success of surgical therapy by shortening the time until wound-healing and reducing the psychosocial burden on the patient and financial costs to the health care system.

Hirudo medicinalis-Anwendungen in der plastischen und rekonstruktiven Mikrochirurgie - eine Literaturübersicht

Medical leech therapy has enjoyed a renaissance in the world of reconstructive microsurgery during recent years. Especially venous congestion is decreased using hirudo medicinalis application such as following replantation of amputated fingers or congested flaps. They provide a temporary relief to venous engorgement whilst venous drainage is re-established. Living in symbiosis with Aeromonas hydrophila, who can digest the sixfold blood meal related to their body weight, and a broad number of anticoagulant agents such as the thrombin inhibitor hirudin, apyrase as well as collagenase, hyaluronidase, Factor Xa inhibitor and fibrinase I and II, leeches decrease venous congestion. Laser Doppler flowmetry could demonstrate a significant increase in superficial skin perfusion following leech application 16 mm around the biting zone. Following the initial blood meal accounting for about 2.5 ml, the anticoagulant effect of the various leeches enzymes follows within the next 5-6 hours, which both account for the beneficial effects. Infection associated with leech therapy is a documented complication of leech application, with reported incidences ranging from 2.4 to 20 % and a chinolone antibiotic is currently recommended to face the potential Aeromonas hydrophila infection. Anemia is a second adverse effect during medicinal leech application which has to be taken account with repetitive blood samples. Besides the successful applications of leeches in various applications in plastic and reconstructive microsurgery, randomized-controlled trials are pending to elucidate the value of hirudo medicinalis according to evidence-based criteria above from case series and case studies.

Demyelinating diseases and potential repair strategies

Demyelination is associated with a number of neurological disorders including multiple sclerosis (MS), spinal cord injury and nerve compression. MS lesions often show axon loss and therefore reparative therapeutic goals include remyelination and neuroprotection of vulnerable axons. Experimental cellular transplantation has proven successful in a number of demyelination and injury models to remyelinate and improve functional outcome. Here we discuss the remyelination and neuroprotective potential of several myelin-forming cells types and their behavior in different demyelination and injury models. Better understanding of these models and current cell-based strategies for remyelination and neuroprotection offer exciting opportunities to develop strategies for clinical studies.

[Lymphadenectomy of the inguinal region and pelvis]

The draining lymph nodes of extra-abdominal tumors and malignant lesions of the lower extremity are located in the groin and iliac region. Malignancies with lymphatic drainage into this region include tumors of the anorectum, penis and vulva, skin (melanoma, squamous cell carcinoma), and soft tissue sarcomas. Current clinical research in biology, routes of lymphatic spread, and the possibility of marking the sentinel lymph node has directed lymphadenectomy strategy toward differential procedures, depending on the type of underlying malignancy. The spectrum of lymphadenectomy includes diagnostic lymph node removal of clinically enlarged nodes, removal of the sentinel node, and radical lymphadenectomy. Lymphadenectomy can also be indicated as a palliative procedure. The indications also depend on the type of tumor, previous treatment, and disease prognosis. This review presents the current state of indications and surgical techniques of inguinal and iliacal lymphadenectomy.

Resektion der infizierten Achillessehne

BACKGROUND

Structural full-thickness defects of the Achilles tendon represent a severely disabling injury which should be treated by reconstruction. This study presents functional outcomes from standardised follow-up of non-reconstructed Achilles tendons with soft tissue coverage alone.

PATIENTS AND METHODS

Seven patients were treated with various techniques of soft tissue reconstruction without restoration of the Achilles tendon. After a mean of 11 months postoperatively, the lower extremity was evaluated generally with regard to function, AOFAS score (ankle and hindfoot), and isokinetic torque testing by the Biodex system.

RESULTS

All patients showed high mobility, muscle strength, and range of motion at follow-up. The average AOFAS score was 84.7 (maximum 100), and the torque loss in plantar flexion was 44.5% on average compared to the uninvolved side and thus comparable with results after secondary tendon reconstruction.

CONCLUSION

After complete loss of the Achilles tendon, compensatory techniques can hinder significant loss of torque and endurance, compared with secondary tendon reconstruction, allowing unsupported mobility and even top athletic performance.

Diagnostik und Therapie posttraumatischer Pseudolipome

BACKGROUND

Both trauma and lipomas are frequently encountered in day-to-day clinical practice. Although lipomas are defined both clinically and pathologically as benign fatty tissue tumours, their aetiology is still not clear.

METHODS

In this study 19 patients with 23 posttraumatic lipomas were analysed retrospectively with reference to ultrasound and MRI diagnosis, history, laboratory results and histopathological investigations.

RESULTS

The mean age of the patients was 50.5 years (+/-15.5). The causative soft tissue trauma dated back an average of 2.6 years. When the histories were taken, 16 of the 19 patients reported vast, slow-resorbing posttraumatic haematomas. Nine of the 23 lipomas were sited in the upper extremity, 3 in the lower extremity, 9 in the trunk and 2 in the face. All were located epifascially. In 22 cases the lipomas were excised, and in 1 case the lipoma was removed by liposuction. Histological examination demonstrated capsulated benign fatty tissue tumours in 19 cases and uncapsulated benign fatty tissue tumours in 4. The average body mass index (BMI) was 29 kg/m(2). Removal of the tumour resulted in a good aesthetic result in all patients.

CONCLUSIONS

The link between a blunt soft tissue injury and the development of a posttraumatic lipoma is still the subject of controversy; there are two mechanisms that seem more likely than any others proposed: (1) the "pseudolipoma" as the result of a prolapse of fatty tissue as an immediate result of trauma and (2) the development of a lipoma by way of differentiation of pre-adipocytes mediated by cytokines released by a posttraumatic haematoma. There appears to be a correlation between an increased partial thromboplastin time (PTT) and the development of posttraumatic lipomas. The generalised increase in the volume of body fat documented by the elevated BMI supports the idea that lipomas arise from the prolapse of adipose tissue. However, there is no single mechanistic explanation for the development of posttraumatic lipomas. They are probably caused by multiple factors and not by isolated pathological mechanisms.

[Breast cancer -- plastic surgical strategies for the treatment of tumour infiltration of the thoracic wall and brachial plexus]

Extensive locoregional recurrency or metastatic involvement of brachial plexopathy is a condition that is often associated with advanced systemic breast cancer. In the past the role of surgeon was restricted due to a scepticism as to whether any benefit will be provided for the patient. In the recent 25 years however safe and refined plastic surgical approaches have been developed that provide more options to treat even complex recurrent disease. The strategy of plastic surgery in an interdisciplinary approach of gynecology, oncology and radiotherapy as well as thoracic surgery is outlined.

[Toxic epidermal necrolysis. A case for the burn intensive care unit]

Toxic epidermal necrolysis is a rare but life-threatening exfoliating disease of the skin and mucous membranes, commonly considered a drug sensitivity reaction. In this review of the literature we discuss the epidemiology, etiology, and pathology. We show diagnostic problems and current treatment strategies. Many of the problems associated with the disease, such as wound infection, sepsis, nutritional support, and pain management, are similar to problems in severely burned patients. Burn centers provide optimal logistics and knowledge to diagnose and treat this serious disease entity.

Skin toxicity induced by wet heat

Pieces of human skin from the skin bank were heated in an autoclave for 1 or 5 min at temperatures 80, 90, 100, 110 and 135 degrees C. The pieces were then homogenized and the homogenates were injected intraperitoneally into groups of mice. The amount injected was either a quantity equivalent to 50 or 75% of the mouse body surface area. Fourteen separate experiments were carried out, each one with a variety of temperatures. Mortality in the groups of mice was recorded by the 8th day. Control mice received homogenates of skin heated to no more that 38 degrees C and out of a total of 104 control mice there were only 4 deaths. In contrast homogenates of skin heated to 135 degrees C killed from 80 to 100% of the mice in different groups, averaging 92%. Skin heated to 110 degrees C killed from 33 to 90% of the mice in different groups, averaging 63%. Skin heated to 100 degrees C killed from 0 to 80% of the mice in different groups, averaging 33%. Temperatures of 80 and 90 degrees C killed no more than 10% of the mice in any group, averaging less than 3%. One minute of heating seemed to be sufficient to induce the toxic effect in the skin. These findings indicated that wet heat application to skin was capable of inducing toxicity in a fashion similar to that demonstrated many years ago with hotter dry temperatures applied to skin for 15s. That application was shown to induce polymerization of skin cell membrane lipid proteins rendering them toxic. In this study, increasing toxicity appeared similarly to depend on the quantity of wet heat input as illustrated by the range of increasing temperatures. The relatively lower temperatures of scalding versus flame burns can accomplish similar dangerous effects; it is simply a quantitative matter of heat input.

Treatment of extensive toxic epidermal necrolysis in children

OBJECTIVE

Toxic epidermal necrolysis (TEN) is a rare but life-threatening disease of the skin and mucous membranes. We report our experience in the treatment of pediatric TEN patients with early debridement of necrotic skin and coverage with human allograft skin.

METHODS

From 1984 to 2000, 15 children (6 girls, 9 boys, 7.2 +/- 1.5 years) with a histologic diagnosis of TEN and involvement of >30% total body surface area were treated at the Shriners Hospitals for Children in Galveston. All were treated in a specialized pediatric burn intensive care unit after our standard treatment protocol, including operative debridement of sloughing skin and allografting within 24 hours of admission. Outcome parameters were mortality, length of hospital stay, wound healing, clinical complications, causative drugs, corticosteroid use, and delay in referral to a burn center.

RESULTS

Taking a new medication (antibiotics, anticonvulsive drugs) was associated with all cases of TEN. Patients who were treated with early debridement and coverage with allograft skin showed no wound infection, and overall mortality was 7%. Total length of hospital stay was 26 +/- 3 days. Long-term sequelae were changes in skin pigmentation (100%), ophthalmologic problems (40%), and diffuse itching early after wound healing (53%).

CONCLUSION

Although a rare disease in children, TEN was managed successfully in a burn center environment, using early debridement and wound coverage with allograft skin as a biological dressing. The use of corticosteroids and referral patterns seems unchanged during the past 2 decades, indicating an additional need for information and education about the disease.

Finding and evaluating clinical practice guidelines

Clinical practice guidelines are valuable, clinical decision-making aids for preventive, diagnostic, therapeutic, and palliative patient care. This article identifies ways to access clinical practice guidelines and discusses evaluative criteria for identifying gold-standard evidence-based practice guidelines. Finally, clinicians are reminded of crucial questions to ask before applying any guidelines to patient care.

Liposomal IGF-1 gene transfer modulates pro- and anti-inflammatory cytokine mRNA expression in the burn wound

The use of systemic IGF-1 has been shown to attenuate the postburn hypermetabolic response and improve burn wound healing. Local IGF-1 gene therapy, however, promotes re-epithelialization in the burn wound without the side-effects associated with systemic delivery. We tested the hypothesis that these beneficial effects are due to changes in local cytokine production. Adult male Sprague-Dawley rats received a 40% total body surface area full-thickness scald burn and randomly received a subcutaneous injection at the burn wound margin of saline or cationic liposomes containing a IGF-1 cDNA construct. Animals were killed at 1, 4, 7 and 10 days after burn trauma. Skin biopsies at the wound border were harvested for total RNA extraction. Cytokine mRNA expression was determined using a multi-probe RNase protection assay. Data are presented as means +/- s.e.m. Statistical analysis used the unpaired t-test or Mann-Whitney test where appropriate. Significance was accepted at P < 0.05. Treatment of the burn wound with liposomal IGF-1-cDNA transfer decreased IL-1beta mRNA levels on day 10 after burn trauma from five-fold burn-induced increases compared with sham-treated rats, to near the control values present in unburned skin samples. Similarly, there was an eight-fold increase in TNF-alpha mRNA expression on postburn day 10 that was abrogated by IGF-1 gene therapy. Local IGF-1 gene transfer attenuates the mRNA expression of the inflammatory cytokines IL-1beta and TNF-alpha in the burn wound. This change may improve burn wound healing by decreasing prolonged local inflammation.

Cell proliferation, apoptosis, NF-kappaB expression, enzyme, protein, and weight changes in livers of burned rats

Thermal injury has been shown to alter gut epithelium and heart myocyte homeostasis by inducing programmed cell death. The effect of thermal injury on hepatocyte apoptosis and proliferation, however, has not been established. The purpose of this study was to determine whether a large thermal injury increases liver cell apoptosis and proliferation and whether these changes were associated with alterations in hepatic nuclear factor kappaB (NF-kappaB) expression and changes in liver enzymes and amount of protein. Sprague-Dawley rats received a 40% total body surface area scald burn or sham burn. Rats were killed and livers were harvested at 1, 2, 5, and 7 days after burn. Liver cell apoptosis was determined by terminal deoxyuridine nick end labeling (TUNEL) assay and cell proliferation by immunohistochemistry for proliferating cell nuclear antigen. Hepatic NF-kappaB expression was determined by Western blot, and total hepatic protein content was determined by protein assay. Protein concentration decreased after burn compared with sham controls (P < 0.05). Liver cell apoptosis, proliferation, and NF-kappaB expression in hepatocytes increased in burned rats compared with controls (P < 0.05). It was concluded that thermal injury induces hepatic cell apoptosis and proliferation associated with an increase in hepatic NF-kappaB expression and a decrease in hepatic protein concentration.

Modern burn care

In the United States nearly 2 million people are burned every year; about 100,000 burns are moderate to severe and require hospitalization and about 5,000 deaths occur because of burns. The overall improvement in mortality and outcome of patients with severe burn trauma over the last decades can be attributed to the following: (1) emergency medical treatment with aggressive early resuscitation, (2) respiratory care and treatment of inhalation injury, (3) control of infection, (4) early burn wound excision and grafting, and (5) modulation of the hypermetabolic response to trauma. The authors present the major developments and changes in burn care regimens concerning emergency medical treatment, focusing on the requirement of early fluid resuscitation, criteria for hospital admission, and referral to burn centers. Also discussed are changes in respiratory management of burn patients and therapy of inhalation injury, infection control measurements, early burn wound excision and wound coverage, and the nutritional and pharmacological modulation of the hypermetabolic response to trauma. All these burn therapy regimens need to be continuously reassessed in clinical use and further improved to achieve still better outcome and quality of life for burn victims.