The comparison of biological effects of bacterial and synthetic melanins in neuroblastoma cells.

Melanins belong to a group of pigments of different structure and origin. They can be produced synthetically or isolated from living organisms. A number of studies have reported testing of various melanins in neurological studies providing different outcomes. Because the structure of melanins can have an effect on obtained results in cell toxicity studies, we present here our original study which aimed to compare the biological effects of bacterial melanin (biotechnologically obtained from B. thuringiensis) with that of synthetic melanin in neuroblastoma cells. Both melanins were structurally characterized in detail. After melanin treatment (0-200 µg/mL), cell viability, glutathione levels, cell morphology and respiration were assessed in SH-SY5Y cells. The structural analysis showed that bacterial melanin is more hydrophilic according to the presence of larger number of -OH moieties. After melanin treatment, we found that synthetic melanin at similar dosage caused always larger cell impairment compared to bacterial melanin. In addition, more severe toxic effect of synthetic melanin was found in mitochondria. In general, we conclude that more hydrophilic, bacterial melanin induced lower toxicity in neuroblastoma cells in comparison to synthetic melanin. Our findings can be useable for neuroscientific studies estimating the potential use for study of neuroprotection, neuromodulation or neurotoxicity.

Assessing the frequency of adverse reactions induced by melanin-containing formulations used for the management of solar dermatitis.

BACKGROUND: Melanin from different sources is widely used by many manufacturers to produce cosmetics and sunscreens. Research data show a wide spectrum of biological activities of melanin including the protection against UV radiation and oxidants. According to the research evidence, the topical use of melanin is more effective against inflammation than the hydrocortisone. The most common side effects of topical melanin ointment are local itching, burning, and moderate hyperemia. AIM OF THE STUDY: The purpose of this work is to describe the adverse outcomes of melanin-containing formulas in patients with solar dermatitis, and to compare the frequency of adverse reactions with data from different research reports. METHODS: A Pharmacovigilance questionnaire was developed to assess potential adverse events attributable to the use of melanin ointment. We used a modified survey tool created by Jaber and coauthors. This survey of melanin application documents validated reports of adverse events manifested by objective skin changes. MEDLINE (Ovid); MEDLINE In-Process Citations & Daily Update (Ovid); PubMed (NLM) (Internet); Embase (Ovid); and Cochrane Database of Systematic Reviews were searched for the evidence on adverse reactions of topical melanin application. RESULTS: The responses documented in this survey show reliability and safety of melanin formula used for the photoprotection and treatment of solar dermatitis. Most symptoms encountered in those using melanin were consistent with exposure to excessive amount (more than 4 times per day) of the compound applied topically. Of the total 534 survey responses received, 74% reported no adverse events. A total of 140 completed adverse event reports. Melanin ointment was being administered for the indications of photo injury (burns) in 75%, photodermatitis in 18%, and solar eczematous dermatitis in 7% of patients. Data were compared with rates from other reports. CONCLUSION: We have no evidence that the chemical structure of melanin varies with currently available products, used locally or in other countries, nor that any such variability played any role in the events reported here. Further studies are required to compare the adverse events of topical melanin formulas containing melanins of different origin.

Psychometric and Logometric Properties of the Armenian Version of Augmentative and Alternative Communication Assessment Questionnaire: Assessing Reliability and Validity.

The study describes the development of the AAC-Arm questionnaire and its initial psychometric and logometric testing for reliability and validity. Psychometric and logometric principles were used to develop an assessment questionnaire capable of evaluating the communication state domains important to patients with neurological disorders. The hypothesized domains were to include (1) auditory function, (2) speech function (3) cognitive functions (4) sensorimotor function, and (5) activities of daily living (ADL). An initial pool of 78 questions was pilot-tested for clarity in 10 patients; following factor analysis, the number of questions was reduced to 39-items. Then the questionnaire was subjected to reliability and validity testing. Factor analysis supported the 5 hypothesized domains. Test-retest reliability using Spearman's correlation demonstrated substantial agreement, ranging from 0.72 for the ADL domain to 0.92 for the auditory function domain. In testing for internal consistency, Cronbach's alphas ranged from 0.86 for-the ADL domain to 0.96 for the cognitive function domain. Correlation between domains gave evidence of construct validity. In comparing similar domains in the AAC questionnaire, a moderate correlation (range 0.33-0.83) for the ADL and sensorimotor function scales were found. The correlation was more positive between the other domains. Testing of reliability for the phraseological, syntactic and semantic competence indices showed good positive correlation between initial and retest scores. The questions in the AAC questionnaire have undergone rigorous psychometric and logometric testing, and the tool is an appropriate instrument for the assessment of neurological patients with communication deficit. The psycholinguistic assessment provides with the main weight of data for successful communication therapy.

Effectiveness and Determinant Variables of Augmentative and Alternative Communication Interventions in Cerebral Palsy Patients with Communication Deficit: a Systematic Review.

PURPOSE: Assess the effectiveness of augmentative and alternative communication (AAC) interventions in patients with CP and to reveal determinant variables of main intervention outcomes: receptive and expressive language. RESEARCH STRATEGIES: The search was performed in following databases: MEDLINE (Ovid); PubMed (NLM); Embase (Ovid); Cochrane Database of Systematic Reviews; Cumulative Index to Nursing and Allied Health Literature; Database of Abstracts of Reviews of Effects; Cochrane Central Register of Controlled Trials; Health Technology Assessment database and PEDro. SELECTION CRITERIA: Full-text and peer-reviewed studies in English studying the effectiveness of AAC in patients with cerebral palsy were included. Studies with patients (<18 years) diagnosed with CP were included. DATA ANALYSIS: A narrative analysis was conducted to evaluate the efficacy of AAC methods. A random-effects model meta-analysis was used to assess determinants of AAC intervention outcomes. RESULTS: The online database and manual reference search revealed 445 records. Nine studies investigating a total of 294 subjects with CP met predefined eligibility criteria: 4 studies with single subject, multiple baseline research designs, 3 longitudinal cohort studies, 1 case control study and 1 case series. Results revealed moderate-quality evidence that AAC interventions improve the receptive and expressive communication skills in patients with CP. The random-effects model meta-analysis revealed the power of identified determinant variables affecting the AAC intervention outcomes. CONCLUSION: Diversity of CP patients requires proper analysis of determinant variables to ensure the efficacy of AAC assessment and intervention. More studies of high methodological and practical quality assessing the efficacy of AAC interventions are needed to clarify the evidence.

Effectiveness and Determinant Variables of Augmentative and Alternative Communication Interventions in Cerebral Palsy Patients with Communication Deficit: a Systematic Review

ABSTRACT Purpose Assess the effectiveness of augmentative and alternative communication (AAC) interventions in patients with CP and to reveal determinant variables of main intervention outcomes: receptive and expressive language. Research strategies The search was performed in following databases: MEDLINE (Ovid); PubMed (NLM); Embase (Ovid); Cochrane Database of Systematic Reviews; Cumulative Index to Nursing and Allied Health Literature; Database of Abstracts of Reviews of Effects; Cochrane Central Register of Controlled Trials; Health Technology Assessment database and PEDro. Selection criteria Full-text and peer-reviewed studies in English studying the effectiveness of AAC in patients with cerebral palsy were included. Studies with patients (<18 years) diagnosed with CP were included. Data analysis A narrative analysis was conducted to evaluate the efficacy of AAC methods. A random-effects model meta-analysis was used to assess determinants of AAC intervention outcomes. Results The online database and manual reference search revealed 445 records. Nine studies investigating a total of 294 subjects with CP met predefined eligibility criteria: 4 studies with single subject, multiple baseline research designs, 3 longitudinal cohort studies, 1 case control study and 1 case series. Results revealed moderate-quality evidence that AAC interventions improve the receptive and expressive communication skills in patients with CP. The random-effects model meta-analysis revealed the power of identified determinant variables affecting the AAC intervention outcomes. Conclusion Diversity of CP patients requires proper analysis of determinant variables to ensure the efficacy of AAC assessment and intervention. More studies of high methodological and practical quality assessing the efficacy of AAC interventions are needed to clarify the evidence.

Diffusion weighted image documented cerebral ischemia in the postprocedural period following pipeline embolization device with shield technology treatment of unruptured intracranial aneurysms: a prospective, single center study.

OBJECTIVE: Acute ischemic stroke and silent cerebral infarctions following pipeline embolization device (PED) treatment of intracranial aneurysms have been estimated to occur in 3-6% and in 50.9-90% of patients respectively. The PED with Shield technology (PED-Shield) incorporates a surface phosphorylcholine polymer to reduce the thrombogenicity of the implant. We sought to determine the incidence of diffusion weighted image (DWI) documented cerebral ischemia after PED-Shield treatment of unruptured intracranial aneurysms. METHODS: This prospective study involved a single center series of consecutive patients treated for an unruptured intracranial aneurysm with the PED-Shield. All participants underwent clinical evaluation on admission, after the procedure, at discharge, and 30 days following treatment. Brain MRI was obtained within 72 hours of the procedure. Ischemic lesions identified on DWI sequences where examined as to their number, size, and location in relation to the procedure. RESULTS: Over 12 months, 33 patients harboring 38 intracranial aneurysms were treated with the PED-Shield in 36 procedures. Neither mortality nor clinically evident ischemic events were noted in the 30 day postprocedural period. DWI documented, silent cerebral ischemia occurred in six patients (18.18%) after six procedures (16.66%). No statistically significant risk factors for postprocedural silent cerebral ischemia were identified. CONCLUSION: We demonstrated a reduced rate of silent cerebral infarcts following PED-Shield treatment of intracranial aneurysms than previously reported with other endovascular treatment modalities and with the previous device generations. Further research is necessary to evaluate our results and to identify methods to reduce the incidence of postprocedural cerebral ischemic events.

Rapid scanning wide-field clutter elimination in epi-optoacoustic imaging using comb LOVIT.

Epi-style optoacoustic (OA) imaging provides flexibility by integrating the irradiation optics and ultrasound receiver, yet clutter generated by optical absorption near the probe obscures deep OA sources. Localised vibration tagging (LOVIT) retrieves OA signal from images that are acquired with and without a preceding ultrasonic pushing beam: Radiation force leads to a phase shift of signals coming from the focal area resulting in their visibility in a difference image, whereas clutter from outside the pushing beam is eliminated. Disadvantages of a single-focus approach are residual clutter from inside the pushing beam above the focus, and time-intensive scanning of the focus to retrieve a large field-of-view. To speed up acquisition, we propose to create multiple foci in parallel, forming comb-shaped ARF patterns. By subtracting OA images obtained with interleaved combs, this technique moreover results in greatly improved clutter reduction in phantoms mimicking optical, acoustic and elastic properties of breast tissue.

Detection of Ca(2+)-dependent acid phosphatase activity identifies neuronal integrity in damaged rat central nervous system after application of bacterial melanin.

The study aims to confirm the neuroregenerative effects of bacterial melanin (BM) on central nervous system injury using a special staining method based on the detection of Ca(2+)-dependent acid phosphatase activity. Twenty-four rats were randomly assigned to undergo either unilateral destruction of sensorimotor cortex (group I; n = 12) or unilateral rubrospinal tract transection at the cervical level (C3-4) (group II; n = 12). In each group, six rats were randomly selected after surgery to undergo intramuscular injection of BM solution (BM subgroup) and the remaining six rats were intramuscularly injected with saline (saline subgroup). Neurological testing confirmed that BM accelerated the recovery of motor function in rats from both BM and saline subgroups. Two months after surgery, Ca(2+)-dependent acid phosphatase activity detection in combination with Chilingarian's calcium adenoside triphosphate method revealed that BM stimulated the sprouting of fibers and dilated the capillaries in the brain and spinal cord. These results suggest that BM can promote the recovery of motor function of rats with central nervous system injury; and detection of Ca(2+)-dependent acid phosphatase activity is a fast and easy method used to study the regeneration-promoting effects of BM on the injured central nervous system.

Bacterial melanin promotes recovery after sciatic nerve injury in rats.

Bacterial melanin, obtained from the mutant strain of Bacillus Thuringiensis, has been shown to promote recovery after central nervous system injury. It is hypothesized, in this study, that bacterial melanin can promote structural and functional recovery after peripheral nerve injury. Rats subjected to sciatic nerve transection were intramuscularly administered bacterial melanin. The sciatic nerve transected rats that did not receive intramuscular administration of bacterial melanin served as controls. Behavior tests showed that compared to control rats, the time taken for instrumental conditioned reflex recovery was significantly shorter and the ability to keep the balance on the rotating bar was significantly better in bacterial melanin-treated rats. Histomorphological tests showed that bacterial melanin promoted axon regeneration after sciatic nerve injury. These findings suggest that bacterial melanin exhibits neuroprotective effects on injured sciatic nerve, contributes to limb motor function recovery, and therefore can be used for rehabilitation treatment of peripheral nerve injury.

Initial training facilitates posttraumatic motor recovery in rats after pyramidal tract lesion and in conditions of induced regeneration.

Training induces plastic changes within the normal and injured brain. Experiments were performed on 48 albino rats. Part of the experimental animals were initially trained to a balancing instrumental conditioned reflex (ICR). Unilateral bulbar pyramidotomy performed in all rats caused contralateral hemiparesis. To make the study results more reliable, recovery of motor skills was evaluated also in conditions of stimulated regeneration. The obtained results indicate that preoperative training in rats contributes to the accelerated recovery of learned motor skills.

Bacterial melanin crosses the blood-brain barrier in rat experimental model.

BACKGROUND: Bacterial melanin has been proven to stimulate regeneration after CNS lesions. The purpose of this study was to test, whether bacterial melanin can enter the brain via the blood-brain barrier (BBB). METHODS: Bacterial melanin (BM) was radioactively labeled by the iodobead method and used to test the BBB permeability after systemic injection into rats. The unidirectional influx rate from the blood was calculated by multiple-time regression analysis. A subgroup of the animals was co-injected with non-labeled BM to determine if BM has a saturable transport across the BBB. The levels of radioactivity were determined in the serum and tissues. Arterial blood was sampled to obtain the level of I-BM at different time points after injection. After systemic perfusion with saline, animals were decapitated and brain, spinal cord, liver and kidney samples were obtained and homogenized to test the I-BM level. RESULTS: Study results showed that radioactively-labeled bacterial melanin crossed the BBB, was enzymatically stable in blood and in brain parenchyma. Entry to brain was reduced when non-labeled BM was also present. Circulating melanin entered all regions of the CNS but the uptake was higher in lumbar spinal cord, thalamus, hypothalamus and substantia nigra. Liver and kidneys had high uptake rates of BM. CONCLUSIONS: These results show that bacterial melanin has saturable transport across the BBB and selectively targets some CNS regions. Such transport may contribute to the neuroprotective action of bacterial melanin.

Neuroprotective action of bacterial melanin in rats after corticospinal tract lesions.

Experiments were performed on 48 albino rats. Part of the experimental animals were initially trained to a balancing instrumental conditioned reflex (ICR). Unilateral bulbar pyramidotomy performed in all rats caused contralateral hemiparesis. On the next day following the operation 24 rats were injected intramuscularly with bacterial melanin solution. 12 of these rats were initially trained to ICR. Recovery periods of ICR and paralyzed hindlimb movements were registered for melanin injected rats (n=24) and for operated rats, not treated with melanin (n=24). In rats injected with bacterial melanin the posttraumatic recovery is shorter than in animals not treated with melanin. The fastest and complete recovery was registered in rats initially trained to ICR and injected after the operation with bacterial melanin. Electrophysiological experiments were performed in transected animals treated with melanin, transected animals without melanin treatment and intact animals. Spiking activity of motoneurons was registered in lumbar motoneurons of rats in response to high frequency stimulation above the corticospinal tract transection. Spiking activity was very similar in motoneurons of melanin injected and intact or non operated animals. In animals, not dosed with bacterial melanin after the operation, areactivity or no change in firing rate was registered in response to stimulus. Stimulation of the corticospinal tract of melanin injected rats produced potentiation of the motoneuronal firing rate and is an evidence of regeneration in corticospinal tract. Similarity in spiking activity of intact and melanin injected rats shows the recovery of conductance in pyramidal tract. Morphohistochemical examination was carried out to confirm the results of behavioral and electrophysiological experiments. Medulla slices were prepared to trace the regeneration of nerve fibers. Examination of transection area revealed that bacterial melanin increases vascularization, dilates the capillaries in nervous tissue and stimulates the process of sprouting.