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1.
Annu Int Conf IEEE Eng Med Biol Soc ; 2022: 105-108, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-36086086

RESUMO

The camptocormia angle has been established as a strong indicator for evaluating the progress of Parkinson's disease and the efficacy of therapeutical approaches. A wearable setup is proposed to measure the camptocormia angle with the perpendicular method using five inertial sensors. This study identifies suitable inertial measurement unit sensors for mobile long-term measurement. Moreover, a machine-learning approach is presented for segmenting the recorded data into periods with different dominant activities. An artificial neural network was the better classifier compared to a support vector machine to recognize certain common activities in patients with camptocormia. The artificial neural network's accuracy, sensitivity, and F1-score were 92.4 %, 82.9 %, and 82.1 %, respectively. Clinical Relevance- The presented approach is expected to lead to a wearable system for long-term monitoring of the progress of camptocormia, yielding improved parameters compared to the conventional static photo method.


Assuntos
Atrofia Muscular Espinal , Doença de Parkinson , Curvaturas da Coluna Vertebral , Humanos , Atrofia Muscular Espinal/diagnóstico , Redes Neurais de Computação , Doença de Parkinson/diagnóstico , Curvaturas da Coluna Vertebral/diagnóstico
2.
Artigo em Inglês | MEDLINE | ID: mdl-34077362

RESUMO

The importance of body sensor networks to monitor patients over a prolonged period of time has increased with an advance in home healthcare applications. Sensor nodes need to operate with very low-power consumption and under the constraint of limited memory capacity. Therefore, it is wasteful to digitize the sensor signal at a constant sample rate, given that the frequency contents of the signals vary with time. Adaptive sampling is established as a practical method to reduce the sample data volume. In this paper a low-power analog system is proposed, which adjusts the converter clock rate to perform a peak-picking algorithm on the second derivative of the input signal. The presented implementation does not require an analog-to-digital converter or a digital processor in the sample selection process. The criteria for selecting a suitable detection threshold are discussed, so that the maximum sampling error can be limited. A circuit level implementation is presented. Measured results exhibit a significant reduction in the average sample frequency and data rate of over 50% and 38% respectively.

3.
Morphologie ; 102(336): 12-20, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28893491

RESUMO

OBJECTIVE OF THE STUDY: The objective of the present study is to assess the mechanical behavior of trabecular bone based on microCT imaging and micro-finite-element analysis. In this way two methods are detailed: (i) direct determination of macroscopic elastic property of trabecular bone; (ii) inverse approach to assess mechanical properties of trabecular bone tissue. PATIENTS: Thirty-five females and seven males (forty-two subjects) mean aged (±SD) 80±11.7 years from hospitals of Assistance publique-Hôpitaux de Paris (AP-HP) diagnosed with osteoporosis following a femoral neck fracture due to a fall from standing were included in this study. MATERIALS AND METHODS: Fractured heads were collected during hip replacement surgery. Standardized bone cores were removed from the femoral head's equator by a trephine in a water bath. MicroCT images acquisition and analysis were performed with CTan® software and bone volume fraction was then determined. Micro-finite-element simulations were per-formed using Abaqus 6.9-2® software in order to determine the macroscopic mechanical behaviour of the trabecular bone. After microCT acquisition, a longitudinal compression test was performed and the experimental macroscopic Young's Modulus was extracted. An inverse approach based on the whole trabecular bone's mechanical response and micro-finite-element analysis was performed to determine microscopic mechanical properties of trabecular bone. RESULTS: In the present study, elasticity of the tissue was shown to be similar to that of healthy tissue but with a lower yield stress. CONCLUSION: Classical histomorphometric analysis form microCT imaging associated with an inverse micro-finite-element method allowed to assess microscopic mechanical trabecular bone parameters.


Assuntos
Osso Esponjoso/fisiopatologia , Elasticidade , Fraturas do Fêmur/fisiopatologia , Osteoporose/fisiopatologia , Fraturas por Osteoporose/fisiopatologia , Acidentes por Quedas , Idoso , Idoso de 80 Anos ou mais , Fenômenos Biomecânicos , Osso Esponjoso/ultraestrutura , Módulo de Elasticidade , Feminino , Cabeça do Fêmur/fisiopatologia , Cabeça do Fêmur/ultraestrutura , Análise de Elementos Finitos , Humanos , Masculino , Paris , Estresse Mecânico , Microtomografia por Raio-X
4.
J Phys Chem C Nanomater Interfaces ; 121(44): 24657-24668, 2017 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-29152034

RESUMO

The adsorption of molecular acceptors is a viable method for tuning the work function of metal electrodes. This, in turn, enables adjusting charge injection barriers between the electrode and organic semiconductors. Here, we demonstrate the potential of pyrene-tetraone (PyT) and its derivatives dibromopyrene-tetraone (Br-PyT) and dinitropyrene-tetraone (NO2-PyT) for modifying the electronic properties of Au(111) and Ag(111) surfaces. The systems are investigated by complementary theoretical and experimental approaches, including photoelectron spectroscopy, the X-ray standing wave technique, and density functional theory simulations. For some of the investigated interfaces the trends expected for Fermi-level pinning are observed, i.e., an increase of the metal work function along with increasing molecular electron affinity and the same work function for Au and Ag with monolayer acceptor coverage. Substantial deviations are, however, found for Br-PyT/Ag(111) and NO2-PyT/Ag(111), where in the latter case an adsorption-induced work function increase of as much as 1.6 eV is observed. This behavior is explained as arising from a face-on to edge-on reorientation of molecules in the monolayer. Our calculations show that for an edge-on orientation much larger work-function changes can be expected despite the prevalence of Fermi-level pinning. This is primarily ascribed to a change of the electron affinity of the adsorbate layer that results from a change of the molecular orientation. This work provides a comprehensive understanding of how changing the molecular electron affinity as well as the adsorbate structure impacts the electronic properties of electrodes.

5.
BMC Musculoskelet Disord ; 18(1): 350, 2017 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-28810851

RESUMO

BACKGROUND: To investigate the effect of intra-articular injection of Chitosan (Cs) added to hyaluronic acid (HA) on subchondral bone during osteoarthritis (OA), microarchitectural parameters and mineral density were measured in a rabbit model of early OA. A novel hybrid hydrogel adding reacetylated Cs of fungal origin to HA was compared to high molecular weight HA commercial formulation. METHOD: Eighteen rabbits underwent unilateral anterior cruciate ligament transection (ACLT) and were divided into three groups (Saline-group, HA-group and Hybrid-group) depending on the intra-articular injection compound. Eight contralateral knees were used as non-operated controls (Contralateral-group). Micro-computed tomography was performed six weeks post-ACLT to study subchondral bone microarchitectural parameters and mineral density at an early stage of OA development. RESULTS: Cartilage thickness mean value was reduced only in Saline-group compared to Contralateral-group. When the Hybrid-group was compared to Saline-group, subchondral bone microarchitectural parameters (trabecular thickness and trabecular bone volume fraction) were significantly changed; subchondral bone plate and trabecular bone mineral densities (bone mineral density and tissue mineral density) were reduced. When the Hybrid-group was compared to HA-group, subchondral bone microarchitectural parameters (subchondral plate thickness and trabecular thickness) and trabecular bone mineral densities (bone mineral density and tissue mineral density) were significantly decreased. CONCLUSION: Conclusion: Compared to HA alone, the novel hybrid hydrogel, constituted of Cs added to HA, enhanced microarchitectural parameters and mineral density changes, leading to subchondral bone loss in a rabbit model of early experimental OA.


Assuntos
Lesões do Ligamento Cruzado Anterior/diagnóstico por imagem , Lesões do Ligamento Cruzado Anterior/tratamento farmacológico , Quitosana/administração & dosagem , Viscossuplementação/métodos , Animais , Ligamento Cruzado Anterior , Injeções Intra-Articulares/métodos , Masculino , Coelhos , Distribuição Aleatória , Resultado do Tratamento , Microtomografia por Raio-X/métodos
6.
Vet Parasitol ; 214(1-2): 139-43, 2015 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-26518644

RESUMO

In the last decade there have been numerous reports of anthelmintic resistant cyathostomins in many parts of the world. The objective of the present study was to evaluate the efficacy of the commercially available anthelmintics against cyathostomin egg shedding in the Mid-Atlantic region of the United States. A total of 989 horses from 67 different farms located in southeastern Pennsylvania, northern Delaware, and northeastern Maryland were treated with fenbendazole, oxibendazole, pyrantel pamoate, ivermectin, or moxidectin at their recommended dosages. Fecal egg count reduction testing was used to determine the efficacy of each anthelmintic on those horses with fecal egg counts of ≥ 200 eggs per gram on the day of treatment (272 horses). Decreased efficacy (reduction of strongyle-type fecal egg counts by less than 90%) was found for fenbendazole, oxibendazole, and pyrantel pamoate, with only 6%, 21% and 43% of horses showing reductions of greater than 90%, respectively. The macrocyclic lactones showed high efficacy in all horses sampled in this study. The decreased anthelmintic efficacy detected in this study adds further evidence for the existence of resistant cyathostomins throughout much of the eastern United States. Findings from this study can be used to create a more sustainable approach for parasite control programs.


Assuntos
Anti-Helmínticos/uso terapêutico , Doenças dos Cavalos/parasitologia , Contagem de Ovos de Parasitas/veterinária , Animais , Resistência a Medicamentos , Fezes/parasitologia , Helmintos/efeitos dos fármacos , Doenças dos Cavalos/tratamento farmacológico , Cavalos , Óvulo/efeitos dos fármacos , Estados Unidos/epidemiologia
8.
IEEE Trans Biomed Circuits Syst ; 5(3): 253-61, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23851476

RESUMO

This paper presents a low-noise front-end amplifier with configurable gain, targeting the recording of small signals, such as the electrocardiogram (ECG) or electroneurogram (ENG). The circuit consists of a continuous-time input stage using lateral bipolar transistors realized in complementary metal-oxide semiconductor (CMOS) technology followed by a switched-capacitor integrating stage. The voltage gain is adjustable by varying the phase delay between two system clocks. Simulated and measured results for a chip fabricated in 0.35-µm CMOS technology are reported. The amplifier occupies an active area of 0.064 mm(2), yields a nominal gain of 630 V/V with more than a 50-dB tuning range, less than 16 nVrms/√Hz input noise and a common-mode rejection of more than 97 dB. Its power consumption is 280 µW with a ±1.5-V supply.

9.
Phys Rev Lett ; 104(24): 246805, 2010 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-20867325

RESUMO

The adsorption of the molecular acceptor hexaazatriphenylene-hexacarbonitrile on Ag(111) was investigated as function of layer density. We find that the orientation of the first molecular layer changes from a face-on to an edge-on conformation depending on layer density, facilitated through specific interactions of the peripheral molecular cyano groups with the metal. This is accompanied by a rehybridization of molecular and metal electronic states, which significantly modifies the interface and surface electronic properties, as rationalized by theoretical modeling.

10.
Phys Chem Chem Phys ; 12(26): 7184-93, 2010 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-20485783

RESUMO

Searching for new pi-conjugated charge-transfer systems, the electronic structure of a new acceptor-donor pair derived from coronene (C(24)H(12)) was investigated by ultraviolet photoelectron spectroscopy (UPS). The acceptor coronene-hexaone (C(24)H(6)O(6), in the following abbreviated as COHON) and the donor hexamethoxycoronene (C(30)H(24)O(6), abbreviated as HMC) were adsorbed as pure and mixed phases on gold substrates. At low coverage, COHON adsorption leads to the appearance of a charge-transfer induced interface state 1.75 eV below the Fermi energy. At multilayer coverage the photoemission intensity of the interface state drops and the valence spectrum of neutral COHON appears. The sample work function decreases from 5.3 eV (clean Au) to 4.8 eV (monolayer) followed by an increase to 5.6 eV (multilayer). The formation of a significant interface dipole due to charge-transfer at the metal-organic interface is possibly accompanied by a change in molecular orientation. HMC on Au exhibits no interface state and the sample work function decreases monotonically to ca. 4.8 eV (multilayer). The UPS spectra of individual donor and acceptor multilayers show good agreement with density functional theory modeling. In donor/acceptor mixed films the photoemission signal of the donor (acceptor) shifts to higher (lower) binding energy. This trend is predicted by the calculation and is anticipated when charge is transferred from donor to acceptor. We propose that mixed films of COHON and HMC constitute a weak charge-transfer system.

11.
Br J Surg ; 96(12): 1422-8, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19918855

RESUMO

BACKGROUND: The aim of this study was to evaluate the results of endoscopic lumbar sympathectomy for plantar hyperhidrosis. METHODS: A total of 178 endoscopic resections of the lower sympathetic lumbar trunk were carried out in 90 patients (59 men, 31 women) with severe plantar hyperhidrosis. The clinical results, including morbidity and satisfaction rates, were evaluated. Follow-up examination was carried out for all patients after a mean follow-up of 24 (range 3-45) months. RESULTS: All procedures were carried out endoscopically. There were no deaths and only three patients had a postoperative complication. All patients had evidence of postoperative sympathetic denervation of the feet. In 87 patients (97 per cent) hyperhidrosis was eliminated, but in three (3 per cent) it recurred. Compensatory sweating occurred in 40 patients (44 per cent), postsympathectomy neuralgia in 38 (42 per cent) and one man suffered temporary loss of ejaculation. A total of 86 patients (96 per cent) were very, or partly, satisfied with the result, and 83 (92 per cent) would have the procedure repeated if required. CONCLUSION: Endoscopic lumbar sympathectomy was a safe and effective option for patients with severe plantar hyperhidrosis.


Assuntos
Endoscopia/métodos , Doenças do Pé/cirurgia , Hiperidrose/cirurgia , Plexo Lombossacral/cirurgia , Simpatectomia/métodos , Adolescente , Adulto , Idoso , Análise de Variância , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dor Pós-Operatória/etiologia , Disfunções Sexuais Fisiológicas/etiologia , Resultado do Tratamento , Adulto Jovem
12.
Cancer Gene Ther ; 16(1): 53-64, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18654609

RESUMO

Tumor necrosis factor (TNF)-alpha is a type-II transmembrane protein that is cleaved by TNF-alpha-converting enzyme (TACE/ADAM-17) to release soluble TNF, a cytokine with potent antitumor properties whose use in clinical applications is limited by its severe systemic toxicity. We found that human cells transfected with vectors encoding TNF without the TACE cleavage site (DeltaTACE-TNF) still released functional cytokine at substantial levels that varied between transfected cell lines of different tissue types. Vectors encoding membrane-associated domains of CD154, another TNF-family protein, conjoined with the carboxyl-terminal domain of TNF, directed higher-level surface expression of a functional TNF that, in contrast to DeltaTACE-TNF, was resistant to cleavage in all cell types. Furthermore, adenovirus vectors encoding CD154-TNF had significantly greater in vivo biological activity in inducing regression of established, syngeneic tumors in mice than adenovirus vectors encoding TNF, and lacked toxicity associated with soluble TNF. As such, CD154-TNF is a novel TNF that appears superior for treatment of tumors in which high-level local expression of TNF is desired.


Assuntos
Adenoviridae , Ligante de CD40/biossíntese , Terapia Genética , Neoplasias Experimentais/terapia , Proteínas Recombinantes de Fusão/biossíntese , Fator de Necrose Tumoral alfa/biossíntese , Animais , Ligante de CD40/genética , Feminino , Células HeLa , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Neoplasias Experimentais/genética , Neoplasias Experimentais/metabolismo , Estrutura Terciária de Proteína/genética , Proteínas Recombinantes de Fusão/genética , Fator de Necrose Tumoral alfa/genética
13.
Med Biol Eng Comput ; 46(10): 1005-18, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18696136

RESUMO

Using a multi-electrode nerve-signal recording cuff and a method of signal processing described previously, activity in axons with different propagation velocities can be distinguished, and the relative amplitude of the small-fibre signals increased. This paper is, largely, an analysis of the selectivity and noise of this system though impedance measurements from an actual cuff are included. The signal processor includes narrow band-pass filters. It is shown that the selectivity and noise both increase with the centre frequencies of these filters. A convenient approach is to make the filter frequencies inversely related to the artificial time delays so that the filter 'Q's are approximately constant and the noise densities are equal for all velocity filters. Numerical calculations, using formulae for this system and for the conventional tripole, based on a fixed cuff size and tissue resistivity, find the number of action potentials per second that must pass through the cuff so that the signal power equals the noise power. For slow fibres (20 m/s), the rate is 14 times lower for the multi-electrode cuff than the tripole, a significant advantage for recording from these fibres.


Assuntos
Eletrodos Implantados , Eletrônica Médica , Neurônios/fisiologia , Amplificadores Eletrônicos , Impedância Elétrica , Eletricidade , Humanos , Processamento de Sinais Assistido por Computador
14.
Chirurg ; 79(12): 1151-61, 2008 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-18523743

RESUMO

BACKGROUND: Thoracic sympathectomy is a valuable treatment option for patients with primary hyperhidrosis. However, controversies exist about the optimal technique of sympathectomy and the association between localisation of the focal hyperhidrosis and postoperative results. PATIENTS AND METHODS: Retrospective analysis was performed on prospectively collected data of 402 thoracic sympathectomies performed in 204 consecutive patients with palmar-plantar (n=123), palmar-axillary (34), isolated axillary (35), and craniofacial (12) hyperhidrosis. The standard procedure was video-assisted thoracoscopic resection of the sympathetic chain from T2 to T4/5. RESULTS: All procedures were performed thoracoscopically without serious perioperative complications. Postoperative morbidity was 2.5% (10/402) including two cases of incomplete Horner's syndrome (0.5%). One hundred forty-three patients were followed for a mean of 21 months (6-86). Palmar hyperhidrosis was eliminated in 100% of cases and axillary hyperhidrosis in 98.5%. There were three axillary recurrences (1.5%). Of all patients, 60% suffered from transient postsympathectomy neuralgia which was mild in the majority of cases. Strong compensatory sweating occurred in 17% of patients with palmar-plantar and palmar-axillary hyperhidrosis and in 53% of patients with isolated axillary hyperhidrosis (P<0.001). In the palmar-plantar and palmar-axillary groups, 92% were very satisfied with the postoperative results, 90% reported increased quality of life, and 93% would repeat the operation. The corresponding numbers in patients with isolated axillary hyperhidrosis were 47%, 44%, and 66%, respectively (P<0.001). CONCLUSION: Video-assisted thoracoscopic resection of the sympathetic chain from T2 to T4-5 is safe and effective and leads in almost 100% of cases to the elimination of palmar and axillary hyperhidrosis. In contrast to the excellent results in patients with palmar-plantar and palmar-axillary hyperhidrosis, outcome in patients with isolated axillary hyperhidrosis was impaired by a high rate of disturbing compensatory sweating.


Assuntos
Axila/inervação , Mãos/inervação , Hiperidrose/cirurgia , Simpatectomia/métodos , Cirurgia Torácica Vídeoassistida/métodos , Adolescente , Adulto , Idoso , Criança , Face/inervação , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Complicações Pós-Operatórias/etiologia , Estudos Prospectivos , Qualidade de Vida , Recidiva , Estudos Retrospectivos
15.
Graefes Arch Clin Exp Ophthalmol ; 245(11): 1735-7, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17674021

RESUMO

BACKGROUND: Posterior scleritis is a potentially blinding inflammatory disorder rarely seen in children. Standard care consists of systemic administration of steroids and immunosuppressants such as methotrexate or ciclosporin A. We describe the case of a young girl suffering from therapy refractory posterior scleritis successfully treated with the tumor necrosis factor (TNF) inhibitor infliximab. METHODS: This study was an interventional case report. The medical chart of a 13-year-old child treated with infliximab (5 mg/kg, 10 applications at a 4-8 week interval) was reviewed for changes of visual acuity, fundoscopy, optic choherence tomography, ultrasound imaging, and adverse events. RESULTS: Infliximab therapy (5 mg/kg, 10 applications at a 4-8 week interval) led to a long-term remission of posterior scleritis after unsuccessful therapy with high dose prednisolone, methotrexate, and ciclosporin A. To date no side effects have been reported. CONCLUSIONS: Administration of infliximab may be considered under appropriate circumstances to treat children with posterior scleritis.


Assuntos
Anti-Inflamatórios/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Esclerite/tratamento farmacológico , Adolescente , Feminino , Humanos , Imunossupressores/uso terapêutico , Infliximab , Esclerite/diagnóstico por imagem , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Ultrassonografia , Acuidade Visual
16.
Surg Endosc ; 21(1): 129-35, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16960674

RESUMO

BACKGROUND: Patients with plantar hyperhidrosis suffer physically and mentally from a disease that often cannot be treated sufficiently using conservative measures. This article reports the authors' experience with endoscopic lumbar sympathectomies for patients with plantar hyperhidrosis. METHODS: Bilateral lumbar sympathectomy was performed for eight patients (3 women and 5 men). A retroperitoneoscopic surgical technique was used, during which the lower lumbar sympathetic trunk was resected after radiologic localization of the lumbar spine, with care taken to protect the cranial lumbar ganglia. RESULTS: All 16 sympathectomies were conducted retroperitoneoscopically, with no intra- or postoperative complications. In all cases, pedal sweat secretion was completely suspended postoperatively. After a 3- to 8-month follow-up period, the anhidrosis persisted in all cases (100%). None of the patients experienced sexual dysfunction. Five patients (62%) reportedly experienced minor compensatory sweating of the torso, and four patients (50%) had postsympathectomy neuralgia. Seven of eight patients were very happy with the postoperative results and would agree to a repeat of the intervention any time. CONCLUSIONS: Retroperitoneoscopic resection of the lower lumbar sympathetic trunk is a safe and effective procedure for obtaining suspension of excessive sweat secretion in patients with plantar hyperhidrosis that cannot be treated with conservative methods.


Assuntos
Endoscopia , , Hiperidrose/cirurgia , Espaço Retroperitoneal , Simpatectomia/métodos , Adaptação Fisiológica , Adulto , Feminino , Seguimentos , Humanos , Região Lombossacral , Neuralgia/etiologia , Satisfação do Paciente , Sudorese , Simpatectomia/efeitos adversos , Resultado do Tratamento
17.
Dev Genes Evol ; 216(10): 565-77, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16604349

RESUMO

The lion's share of studies on regeneration in Plathelminthes (flatworms) has been so far carried out on a derived taxon of rhabditophorans, the freshwater planarians (Tricladida), and has shown this group's outstanding regeneration capabilities in detail. Sharing a likely totipotent stem cell system, many other flatworm taxa are capable of regeneration as well. In this paper, we present the regeneration capacity of Macrostomum lignano, a representative of the Macrostomorpha, the basal-most taxon of rhabditophoran flatworms and one of the most basal extant bilaterian protostomes. Amputated or incised transversally, obliquely, and longitudinally at various cutting levels, M. lignano is able to regenerate the anterior-most body part (the rostrum) and any part posterior of the pharynx, but cannot regenerate a head. Repeated regeneration was observed for 29 successive amputations over a period of almost 12 months. Besides adults, also first-day hatchlings and older juveniles were shown to regenerate after transversal cutting. The minimum number of cells required for regeneration in adults (with a total of 25,000 cells) is 4,000, including 160 neoblasts. In hatchlings only 1,500 cells, including 50 neoblasts, are needed for regeneration. The life span of untreated M. lignano was determined to be about 10 months.


Assuntos
Platelmintos/fisiologia , Regeneração , Animais , Bromodesoxiuridina
18.
Cell Tissue Res ; 325(3): 577-87, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16642372

RESUMO

Neoblasts in Platyhelminthes are the only cells to proliferate and differentiate into all cell types. In Macrostomum lignano, the incorporation of 5'-bromo-2'-deoxyuridine (BrdU) in neoblasts confirmed the distribution of S-phase cells in two lateral bands. BrdU labeling for light and for transmission electron microscopy (TEM) identified three populations of proliferating cells: somatic neoblasts located between the epidermis and gastrodermis (mesodermal neoblasts), neoblasts located within the gastrodermis (gastrodermal neoblasts), and gonadal S-phase cells. In adults, three stages of mesodermal neoblasts (2, 2-3, and 3) defined by their ultrastructure were found. Stage 1 neoblasts where only seen in hatchlings. These stages either were phases within the S-phase of one neoblast pool or were subsequent stages of differentiating neoblasts, each with its own cell cycle. Regular TEM and immunogold labeling provided the basis for calculating the total number of neoblasts and the ratio of labeled to non-labeled neoblasts. Somatic neoblasts represented 6.5% of the total number of cells. Of these, 27% were labeled in S-phase. Of this fraction, 33% were in stage 2, 46% in stage 2-3, and 21% in stage 3. Immunogold labeling substantiated results concerning the differentiation of neoblasts into somatic cells. Non-labeled stage 2 neoblasts were present, even after a 2-week BrdU exposure. Double labeling of mitoses and FMRF-amide revealed a close spatial relationship of mesodermal neoblasts with the nervous system. Immunogold-labeled sections showed that nearly 70% of S-phase cells were in direct contact or within 5 microm from nerve cords.


Assuntos
Platelmintos/crescimento & desenvolvimento , Fase S , Células-Tronco/citologia , Células-Tronco/metabolismo , Animais , Contagem de Células , Imuno-Histoquímica , Platelmintos/anatomia & histologia , Platelmintos/citologia , Platelmintos/ultraestrutura , Células-Tronco/ultraestrutura
19.
Klin Monbl Augenheilkd ; 222(11): 919-22, 2005 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-16308827

RESUMO

BACKGROUND: The diagnosis of the multisystemic Vogt-Koyanagi-Harada (VKH) syndrome including ocular, neurological and dermatological manifestations is difficult due to the absence of diagnostic serological parameters and the variable onset of clinical signs and symptoms in the course of the disease. PATIENT: A 12 year old female patient was admitted to our clinic , presenting with bilateral choroiditis, vitiligo and episodes of headache. After having ruled out an underlying rheumatological or infectious disease, a VKH syndrome was suspected and effectively treated with systemic steroids. The initial diagnosis of VKH syndrome would not have been possible, if the existing diagnostic criteria had been applied. DISCUSSION: As can be seen in the case of our patient, the existing diagnostic criteria of VKH syndrome may prove to be inadequate in diagnosing VKH syndrome, particularly at the onset of the disease. Considering, that early diagnosis and treatment is crucial in improving the outcome of the disease, current diagnostic criteria have been revised. Recent retrospective data suggest a higher sensitivity for the revised diagnostic criteria.


Assuntos
Síndrome Uveomeningoencefálica/classificação , Síndrome Uveomeningoencefálica/diagnóstico , Criança , Diagnóstico Diferencial , Feminino , Humanos , Guias de Prática Clínica como Assunto , Padrões de Prática Médica/normas , Padrões de Prática Médica/tendências , Uveíte/diagnóstico
20.
Med Eng Phys ; 26(6): 531-4, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15234689

RESUMO

Information extracted from whole-nerve electroneurograms, recorded using electrode cuffs, can provide signals to neuroprostheses. However, the amount of information that can be extracted from a single tripole is limited. This communication demonstrates how previously unavailable information about the direction of action potential propagation and velocity can be obtained using a multi-electrode cuff and that the arrangement acts as a velocity-selective filter. Results from in vitro experiments on frog nerves are presented.


Assuntos
Potenciais de Ação/fisiologia , Algoritmos , Diagnóstico por Computador/métodos , Eletrodos Implantados , Microeletrodos , Condução Nervosa/fisiologia , Nervo Isquiático/fisiologia , Amplificadores Eletrônicos , Animais , Desenho de Equipamento , Análise de Falha de Equipamento , Estudos de Viabilidade , Ranidae
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