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1.
J Oral Maxillofac Surg ; 82(4): 449-460, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38336352

RESUMO

PURPOSE: This study investigates whether the intraoral approach to mandibular open reduction and internal fixation, through exposure to the oral cavity's microbiome, results in higher infection rates compared to the extraoral approach, thus addressing a critical public health concern, potentially offering an opportunity to reduce health-care costs, and aiming to guide effective clinical practice. METHODS: In this systematic review with meta-analyses, a review of the literature was conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. A comprehensive literature search was conducted using Embase and PubMed for articles published between 1989 and 2023. Inclusion criteria targeted studies on open reduction and internal fixation mandibular fractures comparing intraoral and extraoral approaches and reporting infection rates. Exclusion criteria eliminated non-English articles, case reports, and studies with insufficient approach-specific data. The primary outcome was the postoperative infection rate, with surgical approach as the predictor. Covariates such as age, sex, diabetes, and smoking status were included when reported. Data were analyzed using R software, employing random-effects models due to anticipated heterogeneity (I2 statistics). RESULTS: From 61 studies, 11 provided direct comparisons involving 1,317 patients-937 intraoral and 380 extraoral. Infection rates were 5.9% for intraoral and 10% for extraoral approaches. Pooled relative risk was 0.94 [95% confidence interval, 0.63, 1.39], suggesting no significant risk difference. Prevalence of infections was estimated at 9% for intraoral and 6.1% for extraoral procedures, with significant heterogeneity (I2 = 84% for intraoral and 56% for extraoral). CONCLUSION: Our meta-analysis found no significant difference in infection rates between the two approaches. There is opportunity to expand on reporting complication rates comparing the various approaches to mandibular fixation. Until these data are presented, surgeon preference may dictate the operative approach to expose the mandible for reduction and fixation.


Assuntos
Fixação Interna de Fraturas , Fraturas Mandibulares , Infecção da Ferida Cirúrgica , Humanos , Fraturas Mandibulares/cirurgia , Infecção da Ferida Cirúrgica/epidemiologia , Infecção da Ferida Cirúrgica/etiologia , Fixação Interna de Fraturas/métodos , Redução Aberta/métodos , Boca/microbiologia , Boca/lesões
2.
Rhinology ; 61(1): 12-23, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36323438

RESUMO

BACKGROUND: Chemosensory dysfunction (CD) has been reported as a common symptom of SARS-CoV-2 infection, but it is not well understood whether and for how long changes of smell, taste and chemesthesis persist in infected individuals. METHODOLOGY: Unselected adult residents of the German federal state of Schleswig-Holstein with Polymerase Chain Reaction (PCR)-test-confirmed SARS-CoV-2 infection were invited to participate in this large cross-sectional study. Data on the medical history and subjective chemosensory function of participants were obtained through questionnaires and visual analogue scales (VAS). Olfactory function (OF) was objectified with the Sniffin Sticks test (SST), including threshold (T), discrimination (D) and identification (I) test as well as summarized TDI score, and compared to that in healthy controls. Gustatory function (GF) was evaluated with the suprathreshold taste strips (TS) test, and trigeminal function was tested with an ampoule containing ammonia. RESULTS: Between November 2020 and June 2021, 667 infected individuals (mean age: 48.2 years) were examined 9.1 months, on average, after positive PCR testing. Of these, 45.6% had persisting subjective olfactory dysfunction (OD), 36.2% had subjective gustatory dysfunction (GD). Tested OD, tested GD and impaired trigeminal function were observed in 34.6%, 7.3% and 1.8% of participants, respectively. The mean TDI score of participants was significantly lower compared to healthy subjects. Significant associations were observed between subjective OD and GD, and between tested OD and GD. CONCLUSION: Nine months after SARS-CoV-2 infection, OD prevalence is significantly increased among infected members of the general population. Therefore, OD should be included in the list of symptoms collectively defining Long-COVID.


Assuntos
COVID-19 , Transtornos do Olfato , Adulto , Humanos , Pessoa de Meia-Idade , Estudos Transversais , Transtornos do Olfato/epidemiologia , Transtornos do Olfato/etiologia , Transtornos do Olfato/diagnóstico , SARS-CoV-2 , Síndrome de COVID-19 Pós-Aguda , Olfato , Distúrbios do Paladar/epidemiologia , Distúrbios do Paladar/etiologia
3.
Int J Mol Sci ; 23(24)2022 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-36555129

RESUMO

The blood-brain barrier (BBB) controls brain homeostasis; it is formed by vascular endothelial cells that are physically connected by tight junctions (TJs). The BBB expresses efflux transporters such as P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP), which limit the passage of substrate molecules from blood circulation to the brain. Focused ultrasound (FUS) with microbubbles can create a local and reversible detachment of the TJs. However, very little is known about the effect of FUS on the expression of efflux transporters. We investigated the in vivo effects of moderate acoustic pressures on both P-gp and BCRP expression for up to two weeks after sonication. Magnetic resonance-guided FUS was applied in the striatum of 12 rats. P-gp and BCRP expression were determined by immunohistochemistry at 1, 3, 7, and 14 days postFUS. Our results indicate that FUS-induced BBB opening is capable of (i) decreasing P-gp expression up to 3 days after sonication in both the treated and in the contralateral brain regions and is capable of (ii) overexpressing BCRP up to 7 days after FUS in the sonicated regions only. Our findings may help improve FUS-aided drug delivery strategies by considering both the mechanical effect on the TJs and the regulation of P-gp and BCRP.


Assuntos
Barreira Hematoencefálica , Neoplasias , Ratos , Animais , Barreira Hematoencefálica/metabolismo , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Projetos Piloto , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Células Endoteliais/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias/metabolismo , Encéfalo/metabolismo , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Microbolhas
4.
Infection ; 49(6): 1277-1287, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34642875

RESUMO

PURPOSE: Over the course of COVID-19 pandemic, evidence has accumulated that SARS-CoV-2 infections may affect multiple organs and have serious clinical sequelae, but on-site clinical examinations with non-hospitalized samples are rare. We, therefore, aimed to systematically assess the long-term health status of samples of hospitalized and non-hospitalized SARS-CoV-2 infected individuals from three regions in Germany. METHODS: The present paper describes the COVIDOM-study within the population-based cohort platform (POP) which has been established under the auspices of the NAPKON infrastructure (German National Pandemic Cohort Network) of the national Network University Medicine (NUM). Comprehensive health assessments among SARS-CoV-2 infected individuals are conducted at least 6 months after the acute infection at the study sites Kiel, Würzburg and Berlin. Potential participants were identified and contacted via the local public health authorities, irrespective of the severity of the initial infection. A harmonized examination protocol has been implemented, consisting of detailed assessments of medical history, physical examinations, and the collection of multiple biosamples (e.g., serum, plasma, saliva, urine) for future analyses. In addition, patient-reported perception of the impact of local pandemic-related measures and infection on quality-of-life are obtained. RESULTS: As of July 2021, in total 6813 individuals infected in 2020 have been invited into the COVIDOM-study. Of these, about 36% wished to participate and 1295 have already been examined at least once. CONCLUSION: NAPKON-POP COVIDOM-study complements other Long COVID studies assessing the long-term consequences of an infection with SARS-CoV-2 by providing detailed health data of population-based samples, including individuals with various degrees of disease severity. TRIAL REGISTRATION: Registered at the German registry for clinical studies (DRKS00023742).


Assuntos
COVID-19 , Qualidade de Vida , COVID-19/complicações , Humanos , Pandemias , SARS-CoV-2 , Resultado do Tratamento , Síndrome de COVID-19 Pós-Aguda
5.
IEEE Trans Biomed Eng ; 71(6): 1770-1779, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38198257

RESUMO

BACKGROUND: Nociceptive pain is required for healthy function, yet, neuropathic pain (disease or injury) can be severely debilitating. Though a wide-array of treatment options are available, they are often systemic and/or invasive. As a promising neuromodulation treatment, Focused ultrasound (FUS) is a noninvasive and highly spatially-targeted technique shown to stimulate neural activity, yet, effects on pain signaling are currently unknown. OBJECTIVE: Develop and validate a method for studying FUS nerve stimulation modulation of pain-evoked neural responses in vivo. METHODS: We developed a high-resolution functional ultrasound (fUS) method capable of mapping cortical responses in healthy and neuropathic pain mice in response to FUS neuromodulation treatment. RESULTS: FUS-evoked hemodynamic responses are correlated with the intensity of peripheral neuromodulation. We confirm functional connectivity is altered in neuropathic mice and demonstrate that FUS can modulate neuropathic pain-evoked hemodynamics. CONCLUSIONS: The findings presented herein provides evidence for an FUS-based nerve pain method and validates the fUS technique developed for monitoring pain-evoked hemodynamics. SIGNIFICANCE: We anticipate that the findings presented herein describe a noninvasive and flexible nerve modulation technique for pain mitigation, furthering evidence for clinical translation.


Assuntos
Neuralgia , Animais , Neuralgia/terapia , Neuralgia/diagnóstico por imagem , Neuralgia/fisiopatologia , Camundongos , Masculino , Camundongos Endogâmicos C57BL , Mapeamento Encefálico/métodos , Terapia por Ultrassom/métodos , Ultrassonografia/métodos
6.
Ultrasound Med Biol ; 50(3): 332-340, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38105118

RESUMO

OBJECTIVE: The objective of this study was to investigate the effect of FUS on autonomic nervous system activity, including heart and respiratory rates, and to separate the thermal modulation from combined thermal and mechanical FUS effects. METHODS: The thalamus and hypothalamus of wild-type mice were sonicated with a continuous-wave, 2 MHz FUS transducer at pressures of 425 and 850 kPa for 60 seconds. Cardiac and respiratory rates were monitored as signs of autonomic nervous activity. FUS-induced changes in autonomic activity were compared to FUS targeted to a spatially-distant motor region and to laser-induced heating. RESULTS: FUS delivered to the primary target over the thalamus and hypothalamus at 850 kPa reversibly increased the respiratory rate by 6.5±3.2 breaths per minute and decreased the heart rate by 3.2±1.8 beats per minute. No significant changes occurred in this region at 425 kPa or when targeting the motor regions at 850 kPa. Laser heating with the same temperature rise profile produced by 850 kPa sonication resulted in cardiorespiratory modulation similar to that of FUS. CONCLUSIONS: FUS is capable of reversibly and non-invasively modulating cardiorespiratory activity in mice. Localized changes in temperature may constitute the main cause for this activity, though further investigation is warranted into the distinct and complementary mechanisms of mechanically- and thermally-induced FUS neuromodulation. Close monitoring of vital signs during FUS neuromodulation may be warranted to monitor systemic responses to stimulation.


Assuntos
Taxa Respiratória , Tálamo , Camundongos , Animais , Temperatura
7.
IEEE Trans Biomed Eng ; 70(4): 1150-1161, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36191094

RESUMO

Harmonic motion imaging (HMI) is an ultrasound-based elasticity imaging technique that utilizes oscillatory acoustic radiation force to estimate the mechanical properties of tissues, as well as monitor high-intensity focused ultrasound (HIFU) treatment. Conventionally, in HMI, a focused ultrasound (FUS) transducer generates oscillatory tissue displacements, and an imaging transducer acquires channel data for displacement estimation, with each transducer being driven with a separate system. The fixed position of the FUS focal spot requires mechanical translation of the transducers, which can be a time-consuming and challenging procedure. In this study, we developed and characterized a new HMI system with a multi-element FUS transducer with the capability of electronic focal steering of ±5 mm and ±2 mm from the geometric focus in the axial and lateral directions, respectively. A pulse sequence was developed to drive both the FUS and imaging transducers using a single ultrasound data acquisition (DAQ) system. The setup was validated on a tissue-mimicking phantom with embedded inclusions. Integrating beam steering with the mechanical translation of the transducers resulted in a consistent high contrast-to-noise ratio (CNR) for the inclusions with Young's moduli of 22 and 44 kPa within a 5-kPa background while the data acquisition speed is increased by 4.5-5.2-fold compared to the case when only mechanical movements were applied. The feasibility of simultaneous generation of multiple foci and tracking the induced displacements is demonstrated in phantoms for applications where imaging or treatment of a larger region is needed. Moreover, preliminary feasibility is shown in a human subject with a breast tumor, where the mean HMI displacement within the tumor was about 4 times lower than that within perilesional tissues. The proposed HMI system facilitates data acquisition in terms of flexibility and speed and can be potentially used in the clinic for breast cancer imaging and treatment.


Assuntos
Técnicas de Imagem por Elasticidade , Humanos , Módulo de Elasticidade , Elasticidade , Eletrônica , Movimento
8.
Ultrasound Med Biol ; 49(8): 1768-1779, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37202245

RESUMO

OBJECTIVE: Ultrasound elasticity imaging techniques aim to provide a non-invasive characterization of tissue mechanical properties to detect pathological changes and monitor disease progression. Harmonic motion imaging (HMI) is an ultrasound-based elasticity imaging technique that utilizes an oscillatory acoustic radiation force to induce localized displacements and estimate relative tissue stiffness. Previous studies have applied a low amplitude modulation (AM) frequency of 25 or 50 Hz in HMI to assess the mechanical properties of different tissue types. In this study, we investigate the dependence of AM frequency in HMI and whether the frequency can be adjusted based on the size and mechanical properties of the underlying medium for enhanced image contrast and inclusion detection. METHODS: A tissue-mimicking phantom with embedded inclusions at different sizes and stiffnesses was imaged within a range of AM frequencies from 25 to 250 Hz at 25-Hz step size. DISCUSSION: The AM frequency at which the maximum contrast and CNR are achieved depends on the size and stiffness of the inclusions. A general trend shows that contrast and CNR peak at higher frequencies for smaller inclusions. In addition, for some inclusions with the same size but different stiffnesses, the optimized AM frequency increases with the stiffness of the inclusion. Nevertheless, there is a shift between the frequencies at which the contrast peaks and those with maximum CNR. Finally, in agreement with the phantom findings, imaging an ex-vivo human specimen with a 2.7-cm breast tumor at a range of AM frequencies showed that the highest contrast and CNR are achieved at the AM frequency of 50 Hz. CONCLUSION: These findings indicate that the AM frequency can be optimized in different applications of HMI, especially in the clinic, for improved detection and characterization of tumors with different geometries and mechanical properties.


Assuntos
Técnicas de Imagem por Elasticidade , Neoplasias , Humanos , Ultrassonografia , Elasticidade , Técnicas de Imagem por Elasticidade/métodos , Imagens de Fantasmas
9.
HIV Clin Trials ; 13(6): 308-23, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23195669

RESUMO

PURPOSE: Women comprise ≯50% of HIV-infected patients, yet safety, tolerability, and efficacy data in women taking antiretrovirals (ARVs) are limited. Lopinavir/ ritonavir (LPV/r)-anchored regimens are globally the most widely prescribed HIV-1 protease inhibitor regimens. The objective was to investigate the safety and efficacy of LPV/r-based therapy in women. METHODS: A database query yielded all available data in HIV-1-infected subjects receiving LPV/r-based triple-ARV regimens from randomized clinical trials lasting ≥48 weeks from Abbott or Abbott-supported AIDS Clinical Trials Group studies. Efficacy (HIV-1 RNA levels, CD4+ T-cell counts) and safety and tolerability (treatment discontinuation, treatment-related adverse events [AE], and clinical laboratory abnormalities) at 48 weeks were assessed for total women, women by age (≥50, <50 years) and body mass index (BMI; <25, ≥25 to <30, ≥30 kg/m2), and sex. RESULTS: Nine hundred ninety-two women initiated LPV/r-based therapy (of whom 79.2% were ARV-naïve), with 83.6% completing 48 weeks of treatment. There were 75.5% of women who achieved a threshold of HIV RNA <400 copies/mL by intent-to-treat, non-completer equals failure (ITT, NC = F) analysis, with a mean ± SE CD4+ T-cell count increase of 191.6 ± 4.92 cells/mm3 from baseline. Women aged ≥50 versus <50 years had higher incidence of moderate-to-severe treatment-related AEs and certain laboratory abnormalities, better virologic response (HIV RNA <400 copies/mL by ITT, NC = F), similar immunologic responses, and similar overall incidence of treatment discontinuations. Higher incidences of certain moderate-to-severe treatment-related AEs and laboratory abnormalities occurred in women with BMI ≥30 kg/m2; however, no effect of BMI on efficacy or discontinuation was observed. CONCLUSIONS: LPV/r-based regimens were efficacious and well-tolerated in women without marked differences based on age and BMI categories evaluated.


Assuntos
Síndrome da Imunodeficiência Adquirida/tratamento farmacológico , Inibidores da Protease de HIV/administração & dosagem , HIV-1 , Lopinavir/administração & dosagem , Ritonavir/administração & dosagem , Síndrome da Imunodeficiência Adquirida/imunologia , Síndrome da Imunodeficiência Adquirida/virologia , Fatores Etários , Índice de Massa Corporal , Contagem de Linfócito CD4 , Quimioterapia Combinada , Feminino , Humanos , Lopinavir/efeitos adversos , Masculino , RNA Viral/análise , Ritonavir/efeitos adversos
10.
Materials (Basel) ; 15(18)2022 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-36143638

RESUMO

Several recent studies have attempted to formulate printable cementitious materials to meet the printing requirements, but these materials are designed to work with specific printing equipment and printing configurations. This paper aims to systematically develop and perform characterization of a commercially available ultra-high-performance concrete-class material (UHPC) modified to be printable. Four percentages of superplasticizer were used (100%, 94%, 88%, 82%) to adjust the UHPC mixture for 3D-printing requirements. A superplasticizer amount of 88% was considered adequate to meet the requirements. Several fresh and hardened properties of UHPC were measured experimentally: shape-retention ability and green strength were investigated in fresh state, and compressive and flexural strength were evaluated in three loading directions to evaluate the anisotropic effects. Furthermore, the strength of the interlayer bond was investigated. The UHPC developed in this study met the criteria for extrudability, buildability, and shape retention to ensure printability. In comparison with mold-cast UHPC, printed UHPC exhibited superior flexural performance (15-18%), but reduced compressive strength (32-56%). Finally, the results demonstrated that a commercially available UHPC-class material can be used for 3DCP, which possesses all necessary properties, both fresh and hardened.

11.
Pneumologie ; 65(1): 19-20, 2011 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-20925021

RESUMO

We report on a 67-year-old male patient who had undergone treatment for renal cell carcinoma 19 years previously. A CT scan showed a solitary enlarged lymph node in the right upper paratracheal region. A specimen was obtained by endobronchial ultrasound with transbronchial needle aspiration. Cytological analysis revealed lymph node metastasis of the late relapsing renal cell carcinoma.


Assuntos
Carcinoma de Células Renais/diagnóstico por imagem , Carcinoma de Células Renais/secundário , Neoplasias Renais/diagnóstico por imagem , Neoplasias Renais/cirurgia , Recidiva Local de Neoplasia/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Traqueia/diagnóstico por imagem , Idoso , Carcinoma de Células Renais/cirurgia , Humanos , Linfonodos/diagnóstico por imagem , Metástase Linfática , Masculino , Recidiva Local de Neoplasia/prevenção & controle , Resultado do Tratamento
13.
Pneumologie ; 65(4): 203-7, 2011 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-21267814

RESUMO

PURPOSE: The aim of this retrospective study was to compare patient characteristics, treatment patterns and treatment results in two groups of patients with limited disease (LD) and extensive disease (ED) small-cell lung cancer (SCLC) in 2004 - 2005 vs. 2007 - 2008. PATIENTS AND METHODS: We included all patients with LD or ED SCLC in this retrospective analysis who were diagnosed in our department in the periods 2004 - 2005 and 2007 - 2008. We collected data on patient characteristics, chemotherapy, radiotherapy, treatment response and median survival. Statistical analyses were separately performed for patients in LD and ED SCLC. RESULTS: 109 patients had LD SCLC. The response rate on first-line therapy was 74 %. More than half of the cases had recurrent disease. Second-line treatment was given to about two thirds of these patients. Third-line therapy was administered in around 15 % of all cases. Prophylactic cranial irradiation was performed more frequently from 2007 - 2008. The median survival was 17 months. There were no statistically significant differences regarding patient characteristics and treatment results. ED SCLC was present in 188 patients. The response rate was around 68 %. All patients relapsed, second-line therapy was administered in half of these cases; third-line therapy in 10 % of all cases. No statistically significant differences were detected between the two time frames. Median survival was 10 months. CONCLUSION: Overall, no statistically significant differences were present for patients with LD and ED SCLC in 2004 - 2005 vs. 2007 - 2008. Prophylactic cranial irradiation was employed more frequently in LD SCLC from 2007.


Assuntos
Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/terapia , Carcinoma de Pequenas Células do Pulmão/mortalidade , Carcinoma de Pequenas Células do Pulmão/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Análise de Sobrevida , Taxa de Sobrevida , Resultado do Tratamento
14.
Artigo em Inglês | MEDLINE | ID: mdl-32746236

RESUMO

Focused ultrasound (FUS)-based viscoelastic imaging techniques using high frame rate (HFR) ultrasound to track tissue displacement can be used for mechanistic monitoring of FUS neuromodulation. However, a majority of techniques avoid imaging during the active push transmit (interleaved or postpush acquisitions) to mitigate ultrasound interference, which leads to missing temporal information of ultrasound effects when FUS is being applied. Furthermore, critical for clinical translation, use of both axial steering and real-time (<1 s) capabilities for optimizing acoustic parameters for tissue engagement are largely missing. In this study, we describe a method of noninterleaved, single Vantage imaging displacement within an active FUS push with simultaneous axial steering and real-time capabilities using a single ultrasound acquisition machine. Results show that the pulse sequence can track micron-sized displacements using frame rates determined by the calculated time-of-flight (TOF), without interleaving the FUS pulses and imaging acquisition. Decimation by 3-7 frames increases signal-to-noise ratio (SNR) by 15.09±7.03 dB. Benchmarking tests of CUDA-optimized code show increase in processing speed of 35- and 300-fold in comparison with MATLAB parallel processing GPU and CPU functions, respectively, and we can estimate displacement from steered push beams ±10 mm from the geometric focus. Preliminary validation of displacement imaging in humans shows that the same driving pressures led to variable nerve engagement, demonstrating important feedback to improve transducer coupling, FUS incident angle, and targeting. Regarding the use of our technique for neuromodulation, we found that FUS altered thermal perception of thermal pain by 0.9643 units of pain ratings in a single trial. Additionally, 5 [Formula: see text] of nerve displacement was shown in on-target versus off-target sonications. The initial feasibility in healthy volunteers warrants further study for potential clinical translation of FUS for pain suppression.


Assuntos
Nervo Mediano , Transdutores , Humanos , Dor , Sensação , Ultrassonografia
15.
Ultrasound Med Biol ; 47(9): 2759-2767, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34176702

RESUMO

Focused ultrasound (FUS) has been used to non-invasively elicit or inhibit motor neuronal activity in the mouse peripheral nervous system in vivo. However, less is known about whether FUS elicits immune system responses associated with peripheral sensory neuronal activity. In this study, we sought to determine that non-invasive ultrasound image-guided FUS can elicit the neurogenic axon reflex of peripheral nerves in the mouse sciatic nerve. The local vasodilation in the plantar view of the hind paw detected with a high-resolution laser Doppler imager indicated neurogenic flare responses after FUS stimulation. The effects of FUS were compared with control groups, where a distinct pattern of blood flow changes was observed only in FUS-elicited neurogenic flare responses. The findings indicate that image-guided FUS elicits local axon reflexes in vivo with a high degree of specificity and penetration depth.


Assuntos
Nervos Periféricos , Reflexo , Animais , Camundongos , Neurônios , Nervos Periféricos/diagnóstico por imagem , Ultrassonografia , Vasodilatação
16.
Ultrasound Med Biol ; 47(4): 998-1013, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33455808

RESUMO

Ultrasound can modulate activity in the central nervous system, including the induction of motor responses in rodents. Recent studies investigating ultrasound-induced motor movements have described mostly bilateral limb responses, but quantitative evaluations have failed to reveal lateralization or differences in response characteristics between separate limbs or how specific brain targets dictate distinct limb responses. This study uses high-resolution focused ultrasound (FUS) to elicit motor responses in anesthetized mice in vivo and four-limb electromyography (EMG) to evaluate the latency, duration and power of paired motor responses (n = 1768). The results indicate that FUS generates target-specific differences in electromyographic characteristics and that brain targets separated by as little as 1 mm can modulate the responses in individual limbs differentially. Exploiting these differences may provide a tool for quantifying the susceptibility of underlying neural volumes to FUS, understanding the functioning of the targeted neuroanatomy and aiding in mechanistic studies of this non-invasive neuromodulation technique.


Assuntos
Encéfalo/efeitos da radiação , Movimento/efeitos da radiação , Ondas Ultrassônicas , Estimulação Acústica , Animais , Eletromiografia , Membro Anterior/fisiologia , Membro Posterior/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Músculo Esquelético/fisiologia , Tempo de Reação
17.
Artigo em Inglês | MEDLINE | ID: mdl-34713274

RESUMO

Ultrasound attenuation through soft tissues can produce an acoustic radiation force (ARF) and heating. The ARF-induced displacements and temperature evaluations can reveal tissue properties and provide insights into focused ultrasound (FUS) bio-effects. In this study, we describe an interleaving pulse sequence tested in a tissue-mimicking phantom that alternates FUS and plane-wave imaging pulses at a 1 kHz frame rate. The FUS is amplitude modulated, enabling the simultaneous evaluation of tissue-mimicking phantom displacement using harmonic motion imaging (HMI) and temperature rise using thermal strain imaging (TSI). The parameters were varied with a spatial peak temporal average acoustic intensity (I spta ) ranging from 1.5 to 311 W.cm-2, mechanical index (MI) from 0.43 to 4.0, and total energy (E) from 0.24 to 83 J.cm-2. The HMI and TSI processing could estimate displacement and temperature independently for temperatures below 1.80°C and displacements up to ~117 µm (I spta <311 W.cm-2, MI<4.0, and E<83 J.cm-2) indicated by a steady-state tissue-mimicking phantom displacement throughout the sonication and a comparable temperature estimation with simulations in the absence of tissue-mimicking phantom motion. The TSI estimations presented a mean error of ±0.03°C versus thermocouple estimations with a mean error of ±0.24°C. The results presented herein indicate that HMI can operate at diagnostic-temperature levels (i.e., <1°C) even when exceeding diagnostic acoustic intensity levels (720 mW.cm-2 < I spta < 207 W.cm-2). In addition, the combined HMI and TSI can potentially be used for simultaneous evaluation of safety during tissue elasticity imaging as well as FUS mechanism involved in novel ultrasound applications such as ultrasound neuromodulation and tumor ablation.

18.
Artigo em Inglês | MEDLINE | ID: mdl-32746182

RESUMO

Passive acoustic mapping enables the spatiotemporal monitoring of cavitation with circulating microbubbles during focused ultrasound (FUS)-mediated blood-brain barrier opening. However, the computational load for processing large data sets of cavitation maps or more complex algorithms limit the visualization in real-time for treatment monitoring and adjustment. In this study, we implemented a graphical processing unit (GPU)-accelerated sparse matrix-based beamforming and time exposure acoustics in a neuronavigation-guided ultrasound system for real-time spatiotemporal monitoring of cavitation. The system performance was tested in silico through benchmarking, in vitro using nonhuman primate (NHP) and human skull specimens, and demonstrated in vivo in NHPs. We demonstrated the stability of the cavitation map for integration times longer than 62.5 [Formula: see text]. A compromise between real-time displaying and cavitation map quality obtained from beamformed RF data sets with a size of 2000 ×128 ×30 (axial [Formula: see text]) was achieved for an integration time of [Formula: see text], which required a computational time of 0.27 s (frame rate of 3.7 Hz) and could be displayed in real-time between pulses at PRF = 2 Hz. Our benchmarking tests show that the GPU sparse-matrix algorithm processed the RF data set at a computational rate of [Formula: see text]/pixel/sample, which enables adjusting the frame rate and the integration time as needed. The neuronavigation system with real-time implementation of cavitation mapping facilitated the localization of the cavitation activity and helped to identify distortions due to FUS phase aberration. The in vivo test of the method demonstrated the feasibility of GPU-accelerated sparse matrix computing in a close to a clinical condition, where focus distortions exemplify problems during treatment. These experimental conditions show the need for spatiotemporal monitoring of cavitation with real-time capability that enables the operator to correct or halt the sonication in case substantial aberrations are observed.


Assuntos
Acústica , Microbolhas , Algoritmos , Animais , Barreira Hematoencefálica/diagnóstico por imagem , Ultrassonografia
19.
Sci Rep ; 11(1): 15043, 2021 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-34294761

RESUMO

An emerging approach with potential in improving the treatment of neurodegenerative diseases and brain tumors is the use of focused ultrasound (FUS) to bypass the blood-brain barrier (BBB) in a non-invasive and localized manner. A large body of pre-clinical work has paved the way for the gradual clinical implementation of FUS-induced BBB opening. Even though the safety profile of FUS treatments in rodents has been extensively studied, the histological and behavioral effects of clinically relevant BBB opening in large animals are relatively understudied. Here, we examine the histological and behavioral safety profile following localized BBB opening in non-human primates (NHPs), using a neuronavigation-guided clinical system prototype. We show that FUS treatment triggers a short-lived immune response within the targeted region without exacerbating the touch accuracy or reaction time in visual-motor cognitive tasks. Our experiments were designed using a multiple-case-study approach, in order to maximize the acquired data and support translation of the FUS system into human studies. Four NHPs underwent a single session of FUS-mediated BBB opening in the prefrontal cortex. Two NHPs were treated bilaterally at different pressures, sacrificed on day 2 and 18 post-FUS, respectively, and their brains were histologically processed. In separate experiments, two NHPs that were earlier trained in a behavioral task were exposed to FUS unilaterally, and their performance was tracked for at least 3 weeks after BBB opening. An increased microglia density around blood vessels was detected on day 2, but was resolved by day 18. We also detected signs of enhanced immature neuron presence within areas that underwent BBB opening, compared to regions with an intact BBB, confirming previous rodent studies. Logistic regression analysis showed that the NHP cognitive performance did not deteriorate following BBB opening. These preliminary results demonstrate that neuronavigation-guided FUS with a single-element transducer is a non-invasive method capable of reversibly opening the BBB, without substantial histological or behavioral impact in an animal model closely resembling humans. Future work should confirm the observations of this multiple-case-study work across animals, species and tasks.


Assuntos
Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/efeitos da radiação , Neuronavegação/métodos , Ondas Ultrassônicas , Animais , Comportamento Animal , Transporte Biológico/efeitos da radiação , Biomarcadores , Barreira Hematoencefálica/diagnóstico por imagem , Cognição , Imageamento por Ressonância Magnética , Microbolhas , Modelos Animais , Primatas , Característica Quantitativa Herdável
20.
HIV Med ; 11(4): 232-8, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20002783

RESUMO

BACKGROUND: Pregnancy may alter protein binding (PB) of highly bound protease inhibitors due to changes in plasma concentrations of albumin and alpha-1 acid glycoprotein (AAG). Small changes in PB can greatly impact the fraction of drug unbound (FU) exerting pharmacological effect. We report lopinavir (LPV) PB during third trimester (antepartum, AP) compared to > or =1.7 weeks postpartum (PP) to determine if FU changes compensate for reduced total concentrations reported previously. METHODS: P1026s enrolled women receiving LPV/ritonavir, soft gel capsules 400/100 mg or 533/133 mg twice daily. LPV FU, albumin and AAG were determined AP and PP. RESULTS: AP/PP samples were available from 29/25 women respectively with all but one woman receiving the same dose AP/PP. LPV FU was increased 18% AP vs. PP (mean 0.96+/-0.16% AP vs. 0.82+/-0.21% PP, P=0.001). Mean protein concentrations were reduced AP (AAG=477 mg/L; albumin=3.28 mg/dL) vs. PP (AAG=1007 mg/L; albumin=3.85 mg/dL) (P<0.0001 for each comparison). AAG concentration correlated with LPV binding. Total LPV concentration did not correlate with LPV FU AP or PP. However, higher LPV concentration PP was associated with reduced PB and higher FU after adjustment for AAG. CONCLUSIONS: LPV FU was higher and AAG lower AP vs. PP. The 18% increase in LPV FU AP is smaller than the reduction in total LPV concentration reported previously and is not of sufficient magnitude to eliminate the need for an increased dose during pregnancy.


Assuntos
Proteínas de Fase Aguda/metabolismo , Infecções por HIV/tratamento farmacológico , Inibidores da Protease de HIV/metabolismo , HIV-1 , Complicações Infecciosas na Gravidez/tratamento farmacológico , Pirimidinonas/metabolismo , Adolescente , Adulto , Terapia Antirretroviral de Alta Atividade , Quimioterapia Combinada , Feminino , Infecções por HIV/metabolismo , Inibidores da Protease de HIV/administração & dosagem , Humanos , Lopinavir , Gravidez , Complicações Infecciosas na Gravidez/metabolismo , Terceiro Trimestre da Gravidez , Estudos Prospectivos , Ligação Proteica , Pirimidinonas/administração & dosagem , Ritonavir/administração & dosagem , Adulto Jovem
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