Overlapping stimulation of subthalamic nucleus and dentato-rubro-thalamic tract in Parkinson's disease after deep brain stimulation.

BACKGROUND: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) reduces tremor, rigidity, and akinesia. According to the literature, the dentato-rubro-thalamic tract (DRTt) is verified target for DBS in essential tremor; however, its role in the treatment of Parkinson's disease is only vaguely described. The aim of our study was to identify the relationship between symptom alleviation in PD patients and the distance of the DBS electrode electric field (EF) to the DRTt. METHODS: A single-center retrospective analysis of patients (N = 30) with idiopathic Parkinson's disease (PD) who underwent DBS between November 2018 and January 2020 was performed. DRTt and STN were visualized using diffusion-weighted imaging (DWI) and tractography protocol of magnetic resonance (MR). The EF was calculated and compared with STN and course of DRTt. Evaluation of patients before and after surgery was performed with use of UPDRS-III scale. The association between distance from EF to DRTt and clinical outcomes was examined. To confirm the anatomical variation between DRTt and STN observed in tractography, white matter dissection was performed with the Klingler technique on ten human brains. RESULTS: Patients with EF overlapping STN and DRTt benefited from significant motor symptoms improvement. Anatomical findings confirmed the presence of population differences in variability of the DRTt course and were consistent with the DRTt visualized by MR. CONCLUSIONS: DRTt proximity to STN, the main target in PD DBS surgery, confirmed by DWI with tractography protocol of MR combined with proper predefined stimulation parameters may improve efficacy of DBS-STN.

The effect of metallic substrates on the optical properties of monolayer MoSe2.

Atomically thin materials, like semiconducting transition metal dichalcogenides (S-TMDs), are highly sensitive to the environment. This opens up an opportunity to externally control their properties by changing their surroundings. Photoluminescence and reflectance contrast techniques are employed to investigate the effect of metallic substrates on optical properties of MoSe2 monolayer (ML). The optical spectra of MoSe2 MLs deposited on Pt, Au, Mo and Zr have distinctive metal-related lineshapes. In particular, a substantial variation in the intensity ratio and the energy separation between a negative trion and a neutral exciton is observed. It is shown that using metals as substrates affects the doping of S-TMD MLs. The explanation of the effect involves the Schottky barrier formation at the interface between the MoSe2 ML and the metallic substrates. The alignment of energy levels at the metal/semiconductor junction allows for the transfer of charge carriers between them. We argue that a proper selection of metallic substrates can be a way to inject appropriate types of carriers into the respective bands of S-TMDs.

Readout of a dopant spin in the anisotropic quantum dot with a single magnetic ion.

Owing to exchange interaction between the exciton and magnetic ion, a quantum dot embedding a single magnetic ion is a great platform for optical control of individual spin. In particular, a quantum dot provides strong and sharp optical transitions, which give experimental access to spin states of an individual magnetic ion. We show, however, that physics of quantum dot excitons also complicate spin readout and optical spin manipulation in such a system. This is due to electron-hole exchange interaction in anisotropic quantum dots, which affects the polarisation of the emission lines. One of the consequences is that the intensity of spectral lines in a single spectrum are not simply proportional to the population of various spin states of magnetic ion. In order to provide a solution of the above problem, we present a method of extracting both the spin polarisation degree of a neutral exciton and magnetic dopant inside a semiconductor quantum dot in an external magnetic field. Our approach is experimentally verified on a system of CdSe/ZnSe quantum dot containing a single Fe2+ ion. Both the resonant and non-resonant excitation regimes are explored resulting in a record high optical orientation efficiency of dopant spin in the former case. The proposed solutions can be easily expanded to any other system of quantum dots containing magnetic dopants.

Comparison of magneto-optical properties of various excitonic complexes in CdTe and CdSe self-assembled quantum dots.

We present a comparative study of two self-assembled quantum dot (QD) systems based on II-VI compounds: CdTe/ZnTe and CdSe/ZnSe. Using magneto-optical techniques we investigated a large population of individual QDs. The systematic photoluminescence studies of emission lines related to the recombination of neutral exciton X, biexciton XX, and singly charged excitons (X(+), X(-)) allowed us to determine average parameters describing CdTe QDs (CdSe QDs): X-XX transition energy difference 12 meV (24 meV); fine-structure splitting δ1=0.14 meV (δ1=0.47 meV); g-factor g = 2.12 (g = 1.71); diamagnetic shift γ=2.5 µeV T(-2) (γ =1.3 µeV T(-2)). We find also statistically significant correlations between various parameters describing internal structure of excitonic complexes.

Serum neuron specific enolase - a novel indicator for neuropsychiatric systemic lupus erythematosus?

OBJECTIVE: Neuropsychiatric (NP) lupus, a common manifestation of systemic lupus erythematosus (SLE), is still insufficiently understood, in part, because of the lack of specific biomarkers. Neuron specific enolase (NSE), an important neuronal glycolytic enzyme, shows increased serum levels following acute brain injury, and decreased serum levels in several chronic disorders of the nervous system, including multi infarct dementia, multiple sclerosis and depression. The aim of the study was to evaluate serum NSE levels in SLE patients with and without nervous system involvement, and in healthy controls, and to assess the correlation of NSE serum levels of patients with neuropsychiatric systemic lupus erythematosus (NPSLE) with clinical parameters. METHODS: The study comprised 47 SLE patients and 28 controls. SLE activity was assessed using the Systemic Lupus Activity Measure (SLAM). A neurologist and a psychiatrist examined all patients. NP involvement was diagnosed according to strict NPSLE criteria proposed by Ainiala and coworkers, as modification to American College of Rheumatology (ACR) nomenclature and case definitions. NSE serum levels were determined by use of an immunoassay. RESULTS: Mean NSE serum concentrations in patients with NPSLE were significantly lower than in non-NPSLE patients (6.3 ± 2.6 µg/L vs. 9.7 ± 3.3 µg/L, p < 0.01) and in controls (8.8 ± 3.3 µg/L, p < 0.05). There were significant negative correlations between NSE serum levels and SLE activity (r = -0.42, p < 0.05) and the number of NPSLE manifestations diagnosed (-0.37; p = 0.001). CONCLUSION: Decreased serum concentrations of NSE may reflect chronic neuronal damage with declined metabolism of the nervous tissue in patients with NPSLE.

Designing quantum dots for solotronics.

Solotronics, optoelectronics based on solitary dopants, is an emerging field of research and technology reaching the ultimate limit of miniaturization. It aims at exploiting quantum properties of individual ions or defects embedded in a semiconductor matrix. It has already been shown that optical control of a magnetic ion spin is feasible using the carriers confined in a quantum dot. However, a serious obstacle was the quenching of the exciton luminescence by magnetic impurities. Here we show, by photoluminescence studies on thus-far-unexplored individual CdTe dots with a single cobalt ion and CdSe dots with a single manganese ion, that even if energetically allowed, nonradiative exciton recombination through single-magnetic-ion intra-ionic transitions is negligible in such zero-dimensional structures. This opens solotronics for a wide range of as yet unconsidered systems. On the basis of results of our single-spin relaxation experiments and on the material trends, we identify optimal magnetic-ion quantum dot systems for implementation of a single-ion-based spin memory.

[Apomorphine in advanced Parkinson disease]. / Apomorfina w zaawansowanej chorobie Parkinsona.

Apomorphine is the most potent dopamine receptor agonist and its symptomatic effectiveness is comparable to levodopa. Subcutaneous apomorphine is rapidly and completely absorbed. Plasma peak concentrations are achieved after 5-15 minutes and onset of clinical effect is within 20 minutes. Apomorphine intermittent subcutaneous injections are effective as rescue therapy for unpredictable off periods in advanced Parkinson disease (PD). More often apomorphine is administered as a subcutaneous infusion which secures the continuous dopaminergic stimulation. The benefit on 'off' periods is consistent across all studies, but dyskinesia improvement is not so obvious. Two infusion therapies (apomorphine and intraduodenal levodopa) and deep brain stimulation (DBS) are effective in advanced PD patients with untreatable motor complications. Apomorphine infusions should be considered in patients unable to undergo DBS because of cognitive impairment and neurosurgical contraindications.

The clinical and neuroimaging studies in Holmes tremor.

AIM: Holmes tremor (HT) is a combination of rest, postural and action tremor. A parallel dysfunction of cerebello-thalamic and nigrostriatal pathways seems necessary to produce this kind of tremor. We present the clinical and neuroimaging study verifying that hypothesis. MATERIAL AND METHODS: A total of 10 patients: five male, five female, fulfilling consensus criteria were included. Demographic, clinical and neuroimaging data (MRI = 9; CT = 1, SPECT with the use of 123-I-FP CIT: DaTSCAN in six patients to assess the presynaptic dopaminergic nigrostriatal system involvement, indices of asymmetry for ligand uptake for each striatum were calculated) were analyzed. RESULTS: Hemorrhage was the most frequent etiology and thalamus - the most commonly involved structure. Contrary to the previous reports, the visual assessment did not reveal remarkable interhemispheric differences of DaTSCAN uptake. Quantitative measurements showed only minimal differences. CONCLUSIONS: It is open to debate whether nigrostriatal pathway damage is crucial for the phenomenology of HT. Alternative hypothesis is presented that HT represents the heterogeneous spectrum of tremors with similar phenomenology, but different pathophysiology.

A VEGF-A splice variant defective for heparan sulfate and neuropilin-1 binding shows attenuated signaling through VEGFR-2.

The development of functional blood and lymphatic vessels requires spatio-temporal coordination of the production and release of growth factors such as vascular endothelial growth factors (VEGFs). VEGF family proteins are produced in multiple isoforms with distinct biological properties and bind to three types of VEGF receptors. A VEGF-A splice variant, VEGF-A(165)b, has recently been isolated from kidney epithelial cells. This variant is identical to VEGF-A(165) except for the last six amino acids encoded by an alternative exon. VEGF-A(165)b and VEGF-A(165) bind VEGF receptors 1 and 2 with similar affinity. VEGF-A(165)b elicits drastically reduced activity in angiogenesis assays and even counteracts signaling by VEGF-A(165). VEGF-A(165)b weakly binds to heparan sulfate and does not interact with neuropilin-1, a coreceptor for VEGF receptor 2. To determine the molecular basis for altered signaling by VEGF-A(165)b we measured VEGF receptor 2 and ERK kinase activity in endothelial cells in culture. VEGF-A(165) induced strong and sustained activation of VEGF receptor 2 and ERK-1 and -2, while activation by VEGF-A(165)b was only weak and transient. Taken together these data show that VEGF-A(165)b has attenuated signaling potential through VEGF receptor 2 defining this new member of the VEGF family as a partial receptor agonist.

Botulinum toxin type A for upper limb spasticity following stroke: an open-label study with individualised, flexible injection regimens.

Current antispastic medications are unsatisfactory for spasticity treatment, but botulinum toxin type A (BTX-A) shows promise as a new therapeutic option. This open-label, prospective study aimed to assess the effectiveness of BTX-A in improving functional mobility in the early post-stroke population using an individualised, flexible range of doses and targeted muscle groups. Twenty-one stroke patients (13 male, 8 female) were enrolled and injected with BTX-A (Botox, Allergan, mean dose: 255 U; range: 185-300) according to individual spasticity patterns. Assessments were made at baseline and weeks 2, 4, 6, 10 and 16 post-treatment. Outcome measures comprised: Modified Ashworth Scale (MAS), finger flexion scale (Bhakta), MRC scale, Physician's Rating Scale (PRS), Nine Hole Peg Test (9HPT), Motor Assessment Scale, Clinical Global Impression (CGI), Global Assessment of Spasticity (GASS) and Visual Analogue Scale (VAS) for pain assessment. Statistically significant improvements in muscle tone as determined by the MAS were found in all areas (except arm) till week 16 (p<0.05). Finger positioning improved for the study duration, whilst muscle power increased only slightly in specific muscles. PRS revealed significant improvements to week 10 and slight improvement in 9HPT performance in selected patients was observed. Motor Assessment Scale results were statistically significant for arm, hand and advanced hand functions, although the overall functional benefit was mild. GASS and CGI results also showed improvement. Pain was present only in 11 patients and did not significantly improve following treatment. Individualised BTX-A injection regimens may be an effective, reversible and safe new treatment option for patients with spasticity. Nevertheless, functional improvement may be reached only in selected patients.

Lower extremity prostheses.

This article discusses the technical and medical difficulties involved in the proper fitting of prostheses on the lower extremity. The factors determining the success of a prosthesis include the quality of the stump, the skill of prosthesis socket fabrication, and the proper ordering of components, as well as rehabilitation supervised by experts and professional care for the amputee.

Orthoses of the upper limb.

This article presents the medical indications and contemporary technological capabilities in the orthotic treatment of the upper limb. The devices that today constitute an integral part of therapeutic procedures are presented, as well as the potential created by the application of low-temperature thermoplastic materials. Therapeutic success is conditioned by professional cooperation between the physician, the kinesitherapist, the orthotic technician, and the patient.

Foot orthoses: therapeutic potential and technical aspects.

This article discusses the indications and typical technical difficulties encountered in the use of foot orthoses, especially shoe inserts and prescription shoes.

Upper limb prostheses.

This article discusses the technical and medical difficulties involved in managing prostheses of the upper limb. The level of amputation governs the type of prosthesis construction chosen, but does not affect emotional acceptance. The factors determining therapeutic success include the quality of the stump, the skill involved in prosthetic socket fabrication, and the proper selection of modular components, as well as good rehabilitation and professional care for the patient with amputated upper limb.

Gene targeting in Arabidopsis.

Precise modification by gene targeting (GT) provides an important tool for studies of gene function in vivo. Although routine with many organisms, only isolated examples of GT events have been reported for flowering plants. These were at low frequencies precluding reliable estimation of targeting efficiency and evaluation of GT mechanisms. Here we present an unambiguous and straightforward system for detection of GT events in Arabidopsis using an endogenous nuclear gene encoding protoporphyrinogen oxidase (PPO), involved in chlorophyll and heme syntheses. Inhibition of PPO by the herbicide Butafenacil results in rapid plant death. However, the combination of two particular mutations renders PPO highly resistant to Butafenacil. We exploited this feature for selection of GT events by introducing the mutations into the PPO gene by homologous recombination. We have estimated the basal GT frequency to be 2.4 x 10(-3). Approximately one-third of events were true GT (TGT) leading to the anticipated modification of the chromosomal PPO copy. The remaining events could be classified as ectopic GT (EGT) arising by modification of vector DNA by the chromosomal template and its random integration into the Arabidopsis genome. Thus the TGT frequency in our experimental setup is 0.72 x 10(-3). In view of the high efficiency of Arabidopsis transformation, GT experiments of a reasonable size followed by a PCR screen for GT events should also allow for modification of non-selectable targets. Moreover, the system presented here should contribute significantly to future improvement of GT technology in plants.

Elevated levels of intrachromosomal homologous recombination in Arabidopsis overexpressing the MIM gene.

The Arabidopsis MIM gene encodes a protein belonging to the SMC family (structure maintenance of chromosomes) which is required for intrachromosomal homologous recombination (ICR). Both ICR and MIM gene expression are enhanced by DNA-damaging treatments, suggesting that MIM is a factor limiting DNA repair by homologous recombination (HR) under genotoxic stress. We tested this hypothesis by measuring the levels of recombination in the mim mutant under genotoxic stress, using methyl methanesulfonate. Although the mutant clearly showed diminished basal and induced levels of ICR, enhancement of ICR by DNA-damaging treatments was similar to that observed in the wild type. This suggests that the MIM gene product is required for DNA repair by HR, but is not critical for HR induction. To determine whether enhanced availability of MIM would increase basal HR levels in Arabidopsis, we examined ICR frequencies in transgenic Arabidopsis strains overexpressing the MIM gene after ectopic insertion of additional MIM copies. Two independent lines showed a twofold increase in ICR frequency relative to the wild type. Thus MIM is required for efficient ICR in plants, and its manipulation can be used to change homologous recombination frequencies. Since MIM is one of the components responsible for chromatin dynamics, our results suggest that the chromatin environment determines the frequency of homologous recombination.

Function of the rabbit supraspinatus muscle after large detachment of its tendon: 6-week, 3-month, and 6-month observation.

Thirty rabbits were anesthetized, and the supraspinatus tendon was detached from the greater tuberosity and the infraspinatus and subscapularis tendons. After 6 weeks (group A), 3 months (group B), and 6 months (group C), in vivo evaluation of twitch tension and fatigue index was done. Next, scapulas with muscles were examined with computed tomography. The most prominent decrease of twitch tension and fatigue index was noted during the first 6 weeks. The twitch tension and fatigue index after 2 and 4 minutes of the muscle operated on expressed as a percentage of the values developed by healthy contralateral nonoperated muscle were 58.2%, 34.5%, and 32.7% at the beginning of stimulation, 45.4%, 35.3%, and 26.7% after 2 minutes, and 42.5%, 32.6%, and 18.5% after 4 minutes of stimulation, respectively, in groups A, B, and C. Computed tomography examination showed fatty degeneration of the supraspinatus averaging 1.85 (group A), 2.28 (group B), and 2.43 (group C). Moderate infraspinatus fatty degeneration was noted in all groups. There was no significant fatty degeneration of subscapularis muscle.

Principles for awarding and fitting orthopedic devices and current views on terminology and classification.

This article presents excerpts from statues and regulations governing the legal aspects of providing orthopedic devices. The author suggests that the rules of the Committee on Prosthetics and Orthotics of the American Academy of Orthopaedic Surgeons be applied for the classification and terminology of orthopedic devices.

[The phenomena of irradiating pain in rotator cuff tear: quantitative analysis]. / Fenomen promieniujacego bólu w uszkodzeniu stozka rotatorów--analiza ilosciowa.

The aim of this study was the quantitative analysis of the phenomena of pain radiation in the case of rotator cuff tear. The clinical material concerns 97 patients, age range from 45 to 86 years. Radiating pain was noted in 33 cases; radiation into distal part of arm--12.4%, elbow--9.3%, forearm--6.2%, hand--1%, hand and thumb 2.1%, 5th finger--1.0%, neck--1.0% and into axilla--1.0%. The radiation of pain was provoked by one finger pressure over tender point (84.8%) or by impingement sign (15.2%). Next the impingement test was performed and additionally supplemented by intraarticular lidocaine injection in 5 cases. Radiation of pain disappeared completely in 26 cases, partly in 6 and persisted in one.

Serial SFEMG studies of orbicularis oculi muscle after the first administration of botulinum toxin.

Serial single fiber electromyography (SFEMG) examinations of orbicularis oculi muscle in patients with blepharospasm or hemifacial spasm treated with botulinum toxin injections were performed. The aim of the study was to evaluate the impairment of neuromuscular transmission, to follow reinnervation after botulinum toxin administration and to find out whether there was a relationship between SFEMG parameters and clinical symptoms. Examinations were performed before injection, during early and late remission of symptoms, and after recurrence of the involuntary movement. Severe impairment of neuromuscular transmission, as revealed by increased jitter and increased presence of abnormal potential pairs and pairs with blocking, was found in early remission, but fiber density remained unchanged when compared with pretreatment values. In late remission, increased fiber density was registered for the first time. The recurrence of involuntary movements was related to the further increase of fiber density and tendency to normalization of jitter parameters. The study therefore suggests that formation of new neuromuscular junctions and their functional maturation is responsible for muscle recovery after botulinum toxin administration.