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1.
Anesthesiology ; 133(1): 185-194, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-31977524

RESUMO

BACKGROUND: Postoperative pain caused by trauma to nerves and tissue around the surgical site is a major problem. Perioperative steps to reduce postoperative pain include local anesthetics and opioids, the latter of which are addictive and have contributed to the opioid epidemic. Cryoneurolysis is a nonopioid and long-lasting treatment for reducing postoperative pain. However, current methods of cryoneurolysis are invasive, technically demanding, and are not tissue-selective. This project aims to determine whether ice slurry can be used as a novel, injectable, drug-free, and tissue-selective method of cryoneurolysis and resulting analgesia. METHODS: The authors developed an injectable and selective method of cryoneurolysis using biocompatible ice slurry, using rat sciatic nerve to investigate the effect of slurry injection on the structure and function of the nerve. Sixty-two naïve, male Sprague-Dawley rats were used in this study. Advanced Coherent anti-Stokes Raman Scattering microscopy, light, and fluorescent microscopy imaging were used at baseline and at various time points after treatment for evaluation and quantification of myelin sheath and axon structural integrity. Validated motor and sensory testing were used for evaluating the sciatic nerve function in response to ice slurry treatment. RESULTS: Ice slurry injection can selectively target the rat sciatic nerve. Being injectable, it can infiltrate around the nerve. The authors demonstrate that a single injection is safe and selective for reversibly disrupting the myelin sheaths and axon density, with complete structural recovery by day 112. This leads to decreased nocifensive function for up to 60 days, with complete recovery by day 112. There was up to median [interquartile range]: 68% [60 to 94%] reduction in mechanical pain response after treatment. CONCLUSIONS: Ice slurry injection selectively targets the rat sciatic nerve, causing no damage to surrounding tissue. Injection of ice slurry around the rat sciatic nerve induced decreased nociceptive response from the baseline through neural selective cryoneurolysis.


Assuntos
Crioterapia/métodos , Gelo , Bloqueio Nervoso/métodos , Nervo Isquiático , Analgesia , Animais , Axônios/efeitos dos fármacos , Axônios/ultraestrutura , Injeções , Masculino , Bainha de Mielina/efeitos dos fármacos , Bainha de Mielina/ultraestrutura , Nociceptividade , Medição da Dor , Ratos , Ratos Sprague-Dawley , Nervo Isquiático/efeitos dos fármacos , Nervo Isquiático/ultraestrutura , Caminhada
2.
Appl Opt ; 59(25): 7585-7595, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32902458

RESUMO

We present evidence-based design principles for three different UV-C based decontamination systems for N95 filtering facepiece respirators (FFRs) within the context of the SARS-CoV-2 outbreak of 2019-2020. The approaches used here were created with consideration for the needs of low- and middle-income countries (LMICs) and other under-resourced facilities. As such, a particular emphasis is placed on providing cost-effective solutions that can be implemented in short order using generally available components and subsystems. We discuss three optical designs for decontamination chambers, describe experiments verifying design parameters, validate the efficacy of the decontamination for two commonly used N95 FFRs (3M, #1860 and Gerson #1730), and run mechanical and filtration tests that support FFR reuse for at least five decontamination cycles.


Assuntos
Filtros de Ar , Descontaminação/instrumentação , Desenho de Equipamento/métodos , Máscaras , Raios Ultravioleta , Filtros de Ar/microbiologia , Filtros de Ar/virologia , Reutilização de Equipamento , Umidade , Ozônio/síntese química , Ozônio/toxicidade , Temperatura , Raios Ultravioleta/efeitos adversos
3.
Lasers Surg Med ; 52(1): 77-83, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31579971

RESUMO

BACKGROUND AND OBJECTIVES: Laser hair removal is the most common laser therapy and the third most commonly performed procedure with more than one million treatments in United States in 2016. This retrospective study was conducted to assess long-term efficacy and safety of the 755 nm laser for hair removal. STUDY DESIGN/MATERIALS AND METHODS: Nearly, 3,606 laser treatments were performed with the long-pulsed 755 nm wavelength laser equipped with an epidermal cooling device between 1997 and 2005 and were followed till 2013. Standardized assessments were conducted by two treating physicians and patients at two follow-up intervals. At first follow-up, clearance was assessed by two physicians and clearance and satisfaction by patients. At the second follow-up, patients were assessed if hair clearance sustained compared with the first follow-up. RESULTS: Nine hundred and forty-eight patients with Fitzpatrick skin types I-IV were treated with a total of 3,606 laser treatments in this study. The mean age at the beginning of the study was 35 years (±11), 95.1% of patients were female (n = 902) and 4.9% male (n = 46). Five hundred and seventy-four patients received a minimum of three treatments and an average of 5.31 (3-16) treatments on axilla, back, bikini, breast, abdomen, face, lower extremity, or upper extremity region. First, follow-up was conducted 3.9 (±1.5) years after the final laser treatment. Seventy-four percent of these patients received 75-100% clearance as reported by the physician and 48% clearance as reported by the patient. Fifty-two percent of patients reported slower hair growth and 42% change in hair texture. Ninety percent of patients treated on axilla, 82% treated on the bikini area, and 79% treated on lower extremities experienced 75% or more clearance after three treatments. Facial, as well as breast and abdomen treatments, only showed a 66% and 62%, respectively, after three treatments. For these locations, five and more treatments were needed to achieve a quote of 79% (face) or 80% (breast and abdomen) for a 75-100% clearance. Upper extremity and back treatments did not have enough physician ratings to draw conclusions. Long-term adverse events were minimal and were all located on the face (one patient scar, four patients herpes infection). Second follow-up of 173 patients was conducted after 11.5 years (±2.0) and 87.9% of patients reported that their improvement sustained. CONCLUSIONS: The long-pulsed 755 nm alexandrite laser is a safe and efficacious treatment for the reduction of unwanted body hair with permanent results and high patient satisfaction. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.


Assuntos
Remoção de Cabelo/métodos , Lasers de Estado Sólido/uso terapêutico , Terapia com Luz de Baixa Intensidade , Adulto , Feminino , Remoção de Cabelo/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Estudos Retrospectivos , Resultado do Tratamento
4.
Lasers Surg Med ; 51(1): 88-94, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30320907

RESUMO

OBJECTIVE: Lidocaine acts as a local anesthetic by blocking transmembrane sodium channel permeability, but also induces the synthesis of heat shock proteins and sensitizes cells to hyperthermia. A previous study reported two cases of deep focal skin ulceration at points corresponding to depot local lidocaine injection sites after treatment with non-ablative fractional resurfacing and it was hypothesized that lidocaine had focally sensitized keratinocytes to the thermal damage of laser treatment. The objective of this study was to investigate whether lidocaine potentiates hyperthermia damage to both normal and cancerous skin cells using an in vitro model. METHODS: Normal skin cell lines (fibroblasts, keratinocytes), skin cancer cell lines (melanoma, basal cell carcinoma), and a mucosal cancer cell line (cervical carcinoma) were exposed to various concentrations of lidocaine (0-0.3%) with or without hyperthermia (37°C, 42°C). RESULTS: Compared to normal skin cells, we demonstrate that cancer cell lines show significantly increased cell toxicity when a moderate temperature (42°C) and low lidocaine concentrations (0.1-0.2%) are combined. The toxicity directly correlates with a higher percentage of cells in S-phase (28-57%) in the cancer cell lines compared to normal skin cell lines (13-19%; R-square 0.6752). CONCLUSION: These results suggest that lidocaine potentiates thermal sensitivity of cell cycle active skin cells. The direct correlation between cell toxicity and S-phase cells could be harnessed to selectively treat skin and mucosal cancer cells while sparing the surrounding normal tissue. Additional research pre-clinically and clinically using several different heat sources (e.g., lasers, ultrasound, etc.) and lidocaine concentrations is needed to confirm and optimize these results. Lidocaine-enhanced hyperthermia may provide a non-invasive, alterative treatment option for highly proliferating, superficial skin, and mucosal lesions such as cancer or warts. Lasers Surg. Med. 51:88-94, 2019. © 2018 Wiley Periodicals, Inc.


Assuntos
Hipertermia Induzida/métodos , Lidocaína/toxicidade , Neoplasias Cutâneas/tratamento farmacológico , Pele/citologia , Ciclo Celular , Linhagem Celular , Linhagem Celular Tumoral , Sobrevivência Celular , Humanos
5.
Lasers Surg Med ; 50(1): 64-69, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29058788

RESUMO

BACKGROUND AND OBJECTIVE: Ablative fractional laser treatment uses thousands of very small laser beam wounds to damage a fraction of the skin, which stimulates tissue remodeling. Each open micro-wound heals without scarring, but the amount of skin tightening achieved is limited. This animal study was performed to test the hypothesis that immediate temporary closure of fractional laser wounds could increase skin tightening after fractional ablative laser treatment. MATERIALS AND METHODS: Four adult swine were used for the study; 98 square test sites (3 × 3 cm) were tattooed on the abdomen and flanks of each pig. An ablative fractional Erbium:YAG laser (Sciton Profile, Sciton Inc, Palo Alto, CA) was used to treat the test areas. A laser micro-spot fluence of 375 J/cm2 was delivered in 150-250 microseconds pulses, resulting in an array of ablation channels extending 1.5 mm deep into the skin, with a spot size of 250 µm, with 10% treatment density. Immediately following laser exposure the resulting holes were closed using a stretched elastic adhesive dressing, which, when applied, recoiled and compressed the diameter of the ablation holes. The compressive dressings were removed after 7 days. This procedure was compared to removing the same amount of skin (10%) mechanically by specially designed 19 gauge coring needles, as well as to the same laser and coring methods without compression closure. Area and shape of test sites were measured by digital photography before and 28 days after treatment. Data analysis included compensation for animal growth, as measured by increase in the area of the untreated control sites. RESULTS: All treated and control sites healed within a week, without scarring evident at 28 days. Laser treatment combined with compressive wound closure caused significant shrinkage at 28 days compared with untreated control sites. The treated skin area was reduced by 11.5% (P = 0.0001). Needle coring with wound closure produced similar, significant shrinkage (8%, P < 0.0021), whereas laser and needle coring treatment without closure did not result in significant area reduction (P = 0.1289) compared with untreated control sites. CONCLUSION: Significant skin tightening can be achieved by immediate temporary non-invasive wound closure after short pulse Er:YAG fractional ablative laser treatment, as well as after mechanically removing skin with a coring needle. This approach may improve skin tightening after ablative laser treatments. Further clinical studies are necessary to confirm successful application in humans. Lasers Surg. Med. 50:64-69, 2018. © 2017 Wiley Periodicals, Inc.


Assuntos
Terapia a Laser/métodos , Lasers de Estado Sólido/uso terapêutico , Envelhecimento da Pele/efeitos da radiação , Cicatrização/efeitos da radiação , Animais , Feminino , Envelhecimento da Pele/patologia , Suínos
6.
Opt Mater (Amst) ; 80: 197-202, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30692715

RESUMO

Radiation therapy is one of the primary therapeutic techniques for treating cancer, administered to nearly two-thirds of all cancer patients. Although largely effective in killing cancer cells, radiation therapy, like other forms of cancer treatment, has difficulty dealing with hypoxic regions within solid tumors. The incomplete killing of cancer cells can lead to recurrence and relapse. The research presented here is investigating the enhancement of the efficacy of radiation therapy by using scintillating nanoparticles that emit UV photons. UV photons, with wavelengths between 230 nm and 280 nm, are able to inactivate cells due to their direct interaction with DNA, causing a variety of forms of damage. UV-emitting nanoparticles will enhance the treatment in two ways: first by generating UV photons in the immediate vicinity of cancer cells, leading to direct and oxygen-independent DNA damage, and second by down-converting the applied higher energy X-rays into softer X-rays and particles that are more efficiently absorbed in the targeted tumor region. The end result will be nanoparticles with a higher efficacy in the treatment of hypoxic cells in the tumor, filling an important, unmet clinical need. Our preliminary experiments show an increase in cell death using scintillating LuPO4:Pr nanoparticles over that achieved by the primary radiation alone. This work describes the fabrication of the nanoparticles, their physical characterization, and the spectroscopic characterization of the UV emission. The work also presents in vitro results that demonstrate an enhanced efficacy of cell killing with x-rays and a low unspecific toxicity of the nanoparticles.

7.
Lasers Surg Med ; 48(3): 264-9, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26627306

RESUMO

BACKGROUND AND OBJECTIVE: Skin changes are among the most visible signs of aging. Fractional ablative lasers improve skin quality by making small skin wounds that heal rapidly without scarring. While they improve skin texture and discoloration, there is minimal effect on skin laxity. This study was performed to assess skin shrinkage performed by removing multiple small full-thickness skin columns with coring needles combined with wound closure. MATERIALS AND METHODS: In 5 swine 116 squares (3 cm(2) ) were demarcated for treatment and control sites. In treatment sites 10% of the skin was removed by full-thickness skin coring needles (19 gauge) and afterwards closed and compressed with an elastic adhesive dressing. This procedure was compared to puncturing the skin with standard hypodermic needles (without tissue removal) and subsequent closure with compressive dressing. Area and shape of sites were measured before and 28 days after treatment. RESULTS: Test and control sites healed within a week without scarring. Coring with wound closure caused significant shrinkage after 28 days. The treated skin area was reduced by 9% (P < 0.0001) and the direction of shrinkage was influenced by the direction of wound closure. Coring without wound closure and puncturing the skin without tissue removal produced an insignificant 3% decrease in area. CONCLUSION: Significant minimally invasive skin tightening in a preferred direction can be achieved by removing skin with coring needles followed by wound closure. The direction of shrinkage is influenced by the direction of micro-hole closure, irrespective of the skin tension lines. This approach may allow reshaping the skin in a desired direction without scarring.


Assuntos
Ritidoplastia/métodos , Envelhecimento da Pele , Animais , Feminino , Modelos Animais , Agulhas , Rejuvenescimento , Ritidoplastia/instrumentação , Suínos , Técnicas de Fechamento de Ferimentos , Cicatrização
8.
Semin Cutan Med Surg ; 34(1): 42-7, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25922957

RESUMO

Radiation injury to the skin is a major source of dysfunction, disfigurement, and complications for thousands of patients undergoing adjunctive treatment for internal cancers. Despite the great potential for affecting quality of life, radiation injury has received little attention from dermatologists and is primarily being managed by radiation oncologists. During our volunteer work in Vietnam, we encountered numerous children with significant scarring and depigmentation of skin from the outdated use of radioactive phosphorus P32 in the treatment of hemangiomas. This dangerous practice has left thousands of children with significant fibrosis and disfigurement. Currently, there is no treatment for radiation dermatitis. Here, we report a case series using the combination of laser treatment, including pulsed-dye laser, fractional CO2 laser, and epidermal grafting to improve the appearance and function of the radiation scars in these young patients. We hope that by improving the appearance and function of these scars, we can improve the quality of life for these young patients and potentially open up a new avenue of treatment for cancer patients affected with chronic radiation dermatitis, potentially improving their range of motion, cosmesis, and reducing their risk of secondary skin malignancies.

9.
Nat Methods ; 8(4): 347-52, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21399637

RESUMO

Positron emission tomography (PET) neuroimaging and behavioral assays in rodents are widely used in neuroscience. PET gives insights into the molecular processes of neuronal communication, and behavioral methods analyze the actions that are associated with such processes. These methods have not been directly integrated, because PET studies in animals have until now required general anesthesia to immobilize the subject, which precludes behavioral studies. We present a method for imaging awake, behaving rats with PET that allows the simultaneous study of behavior. Key components include the 'rat conscious animal PET' or RatCAP, a miniature portable PET scanner that is mounted on the rat's head, a mobility system that allows considerable freedom of movement, radiotracer administration techniques and methods for quantifying behavior and correlating the two data sets. The simultaneity of the PET and behavioral data provides a multidimensional tool for studying the functions of different brain regions and their molecular constituents.


Assuntos
Comportamento Animal/fisiologia , Mapeamento Encefálico/instrumentação , Encéfalo/fisiologia , Tomografia por Emissão de Pósitrons/instrumentação , Ratos/fisiologia , Animais , Mapeamento Encefálico/métodos
10.
Inflamm Res ; 61(9): 967-76, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22618200

RESUMO

OBJECTIVE: Enzymatically oxygenated lipid products derived from omega-3 and omega-6 fatty acids play an important role in inflammation dampening. This study examined the anti-inflammatory effects of n-6 docosapentaenoic acid-derived (17S)-hydroxy-docosapentaenoic acid (17-HDPAn-6) and (10,17S)-dihydroxy-docosapentaenoic acid (10,17-HDPAn-6) as well as n-3 docosahexaenoic acid-derived 17(R/S)-hydroxy-docosahexaenoic acid (17-HDHA). MATERIALS AND METHODS: The effects of 17-HDPAn-6, 10,17-HDPAn-6 or 17-HDHA on activity and M1/M2 polarization of murine macrophage cell line RAW 264.7 were examined by phagocytosis assay and real-time PCR. To assess anti-inflammatory effects in vivo, dextran sodium sulfate (DSS) colitis was induced in mice treated with 17-HDPAn-6, 10,17-HDPAn-6, 17-HDHA or NaCl. RESULTS: Our results show that 17-HDPAn-6, 10,17-HDPAn-6 and 17-HDHA increase phagocytosis in macrophages in vitro and promote polarization towards the anti-inflammatory M2 phenotype with decreased gene expression of TNF-α and inducible Nitric oxide synthase and increased expression of the chemokine IL-1 receptor antagonist and the Scavenger receptor Type A. Intraperitoneal treatment with 17-HDPAn-6, 10,17-HDPAn-6, or 17-HDHA alleviated DSS-colitis and significantly improved body weight loss, colon epithelial damage, and macrophage infiltration. CONCLUSION: These results suggest that DPAn-6-derived 17-HDPAn-6 and 10,17-HDPAn-6 as well as the DHA-derived 17-HDHA have inflammation-dampening and resolution-promoting effects that could be used to treat inflammatory conditions such as inflammatory bowel disease.


Assuntos
Anti-Inflamatórios/farmacologia , Colite/imunologia , Ácidos Docosa-Hexaenoicos/farmacologia , Ácidos Graxos Insaturados/farmacologia , Macrófagos/efeitos dos fármacos , Animais , Anti-Inflamatórios/uso terapêutico , Linhagem Celular , Colite/tratamento farmacológico , Colite/patologia , Modelos Animais de Doenças , Ácidos Docosa-Hexaenoicos/uso terapêutico , Ácidos Graxos Insaturados/uso terapêutico , Macrófagos/fisiologia , Camundongos , Fagocitose/efeitos dos fármacos
11.
Int J Radiat Biol ; 98(9): 1484-1494, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35020574

RESUMO

PURPOSE: Radiation therapy for cancer is limited by damage to surrounding normal tissues, and failure to completely eradicate a tumor. This study investigated a novel radiosensitizer, composed of lutetium phosphate nanoparticles doped with 1% praseodymium and 1.5% neodymium cations (LuPO4:Pr3+,Nd3+). During X-ray exposure, the particles emit UVC photons (200-280 nm), resulting in increased tumor cell death, by oxygen-independent UVC-induced damage. METHODS AND MATERIALS: Specially designed LuPO4:Pr3+,Nd3+ nanoscintillator particles were characterized by dynamic light scattering, TEM and emission spectroscopy upon excitation. Cell death was determined by reduction in tumor spheroid growth over a 3-week period using a 3 D A549 lung cancer model. Cell cycle was evaluated by flow cytometry and cell death pathways were assessed by Annexin V/PI stain as well as quantify apoptotic bodies. RESULTS: Lung cancer cells expressed no long-term or nonspecific toxicity when incubated with LuPO4:Pr3+,Nd3+ nanoscintillators. In contrast, there was significant growth inhibition of cell spheres treated with 2.5 mg/ml LuPO4:Pr3+,Nd3+ in combination with ionizing radiation (4 or 8 Gy X-ray), compared to radiation alone. Homogeneous distribution of small NPs throughout the entire sphere resulted in more pronounced lethality and growth inhibition, compared to particle distribution limited to the outer cell layers. Growth inhibition after the combined treatment was caused by necrosis, apoptosis and G2/M cell cycle arrest. CONCLUSIONS: Newly designed UVC-emitting nanoscintillators (LuPO4:Pr3+,Nd3+) in combination with ionizing radiation cause tumorsphere growth inhibition by inducing cell cycle arrest, apoptosis and necrosis. UVC-emitting nanoparticles offer a promising new strategy for enhancing local tumor response to ionizing radiation treatment.


Assuntos
Neoplasias Pulmonares , Nanopartículas , Apoptose/efeitos da radiação , Linhagem Celular Tumoral , Humanos , Neoplasias Pulmonares/radioterapia , Necrose , Radiação Ionizante
12.
IEEE Trans Radiat Plasma Med Sci ; 6(5): 583-591, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-36212108

RESUMO

In this study, we used a compact, high-resolution, and MRI-compatible PET camera (VersaPET) to assess the feasibility of measuring the image-derived input function (IDIF) from arteries in the leg with the ultimate goal of enabling fully quantitative PET brain imaging without blood sampling. We used this approach in five 18F-FDG PET/MRI brain studies in which the input function was also acquired using the gold standard of serial arterial blood sampling. After accounting for partial volume, dispersion, and calibration effects, we compared the metabolic rates of glucose (MRglu) quantified from VersaPET IDIFs in 80 brain regions to those using the gold standard and achieved a bias and variability of <5% which is within the range of reported test-retest values for this type of study. We also achieved a strong linear relationship (R2 >0.97) against the gold standard across regions. The results of this preliminary study are promising and support further studies to optimize methods, validate in a larger cohort, and extend to the modeling of other radiotracers.

13.
Lasers Surg Med ; 43(3): 230-5, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21308697

RESUMO

OBJECTIVE: To determine whether the active thermal bystander effect (ATBE) is cell-cycle dependent. MATERIALS AND METHODS: Dividing cells were directly heated for 10 minutes and co-cultured for 24 hours with different bystander cells. We compared the ATBE for dividing and non-dividing human fibroblasts, as well as for dividing human white preadipocytes (HWP) and non-dividing, mature differentiated human white adipocytes. ATBE was assessed as loss of cell viability of the bystander cells by using the MTT assay. Cell-cycle analysis was performed by using flow cytometry. RESULTS: Dividing fibroblasts and preadipocytes showed a significant ATBE (P < 0.008 and P < 0.05) with loss of cell viability of about 10% in the temperature range of 40-48°C. There was no significant difference between the extent of the bystander effect for these two cell populations (P = 0.30). In contrast, non-dividing fibroblasts and mature adipocytes did not generate any ATBE within this temperature range. There was a statistically significant difference in ATBE between dividing and non-dividing cell subpopulations for both fibroblasts (P = 0.003) and preadipocytes (P < 0.001) compared to their non-dividing counterparts. CONCLUSION: These results suggest that the ATBE is a cell-cycle-dependent process which requires actively dividing cells as receiving bystander cells. The cell-cycle dependency of the ATBE could have useful clinical applications in selectively targeting fast growing cells such as tumor cells. Whether the yield of the ATBE can be amplified by synchronizing the exposure to the ATBE with specific phases of the cell cycle remains subject to further investigation.


Assuntos
Adipócitos/fisiologia , Efeito Espectador/fisiologia , Ciclo Celular/fisiologia , Fibroblastos/fisiologia , Temperatura Alta/efeitos adversos , Estresse Fisiológico/fisiologia , Adipócitos/citologia , Divisão Celular/fisiologia , Sobrevivência Celular , Células Cultivadas , Fibroblastos/citologia , Citometria de Fluxo , Humanos
14.
Photochem Photobiol Sci ; 9(12): 1634-9, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20931137

RESUMO

Dyes that bind to DNA, such as Hoechst 33342, are commonly used to visualize chromatin in live cells by fluorescence microscopy. A caveat is that the probes themselves should not perturb cellular responses and under normal conditions the dyes are generally non-toxic. However, researchers are increasingly using computerized time-lapse microscopy (CTLM), where cells stained with fluorescent dyes are often imaged frequently over a period of several days, to follow cellular responses in real time. Little is currently known about possible toxicity of fluorescent DNA dyes under CTLM conditions. In this study we demonstrate that the common live-cell DNA stain Hoechst 33342 can cause apoptosis under CTLM conditions. Although toxicity is evident at long times in the absence of imaging at high dye concentrations, phototoxicity from repeated excitation of the dye in the imaging process is dominant. We show that phototoxicity is a function of the product of light fluence and dye concentration, irrespective of irradiance, frequency and total number of scans. Thus, phototoxicity can be prevented by a combination of dye concentration and imaging procedure that is below this threshold. These quantitative data can be used as a guide to others performing time-lapse microscopy studies with this common live-cell DNA stain and serves as a caution for researchers when using other fluorescent stains under CTLM conditions.


Assuntos
Benzimidazóis/toxicidade , Corantes Fluorescentes/toxicidade , Animais , Apoptose , Benzimidazóis/química , Linhagem Celular , Cromatina/química , DNA/química , Corantes Fluorescentes/química , Microscopia de Fluorescência , Ratos , Fatores de Tempo , Raios Ultravioleta
15.
Radiat Res ; 193(1): 82-87, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31738663

RESUMO

Radiation-resistant hypoxic tumor areas continue to present a major limitation for successful tumor treatment. To overcome this radiation resistance, an oxygen-independent treatment is proposed using UVC-emitting LuPO4:Pr3+ nanoparticles (NPs) and X rays. The uptake of the NPs as well as their effect on cell proliferation was investigated on A549 lung cancer cells by using inverted time-lapse microscopy and transmission electron microscopy. Furthermore, cytotoxicity of the combined treatment of X rays and LuPO4:Pr3+ NPs was assessed under normoxic and hypoxic conditions using the colony formation assay. Transmission electron microscopy (TEM) images showed no NP uptake after 3 h, whereas after 24 h incubation an uptake of NPs was documented. LuPO4:Pr3+ NPs alone caused a concentration-independent cell growth delay within the first 60 h of incubation. The combined treatment with UVC-emitting NPs and X rays reduced the radiation resistance of hypoxic cells by a factor of two to the level of cells under normoxic condition. LuPO4:Pr3+ NPs cause an early growth delay but no cytotoxicity for the tested concentration. The combination of these NPs with X rays increases cytotoxicity of normoxic and hypoxic cancer cells. Hypoxic cells become sensitized to normoxic cell levels.


Assuntos
Lutécio , Nanopartículas , Praseodímio , Tolerância a Radiação/efeitos dos fármacos , Hipóxia Tumoral/efeitos da radiação , Raios Ultravioleta , Células A549 , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Humanos , Tolerância a Radiação/efeitos da radiação
16.
Adv Wound Care (New Rochelle) ; 9(4): 174-183, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32117581

RESUMO

Objective: We recently developed the approach of using "microcolumns" of autologous full-thickness skin tissue for wound repair. The small size of these micro skin tissue columns (MSTCs, ∼0.5 mm in diameter) allows donor sites to heal quickly without scarring. Treatment with MSTCs significantly accelerate wound healing, and suppled various skin cell types and skin structures to replenish the wound volume. This technology is now starting clinical use. In this study, we investigate whether MSTCs may also influence wound healing by releasing soluble signaling factors. Approach: Freshly harvested MSTCs were incubated in culture medium for 24 h. The conditioned medium was collected and tested for its effects on migration and proliferation of human dermal fibroblasts, and its ability to induce tube formation by human umbilical vein endothelial cells (HUVECs). Proteins released into the conditioned medium were characterized by multiplex enzyme-linked immunosorbent assay (ELISA), and compared with medium conditioned by an equivalent mass of intact full-thickness skin. Results: MSTC-conditioned medium increased fibroblast migration and proliferation, as well as HUVEC tube formation. MSTCs released many soluble factors known to play prominent roles in wound healing. A subset of proteins showed significantly different release profiles compared with intact full-thickness skin. Innovation: The technology for harvesting and using MSTCs to augment wound healing was recently developed as an alternative to conventional autologous skin grafting. This study shows that MSTCs could also function as "cytokine factories." Conclusion: In addition to supplying autologous cells to repopulate the wound volume, MSTCs can also function as a source of growth factors and cytokines to further enhance wound healing.


Assuntos
Citocinas/metabolismo , Fibroblastos/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Comunicação Parácrina/fisiologia , Transplante de Pele/métodos , Pele/metabolismo , Cicatrização , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Cicatriz/metabolismo , Meios de Cultivo Condicionados , Citocinas/farmacologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Pele/citologia , Transplante Autólogo/métodos
17.
Plast Reconstr Surg ; 145(4): 725e-733e, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32221206

RESUMO

BACKGROUND: Cryolipolysis is a noninvasive method for removal of subcutaneous fat for body contouring. Conventional cryolipolysis with topical cooling requires extracting heat from subcutaneous fat by conduction across the skin, thus limiting the amount and the location of the fat removed. The authors hypothesized that local injection of a physiological ice slurry directly into target adipose tissue would lead to more efficient and effective cryolipolysis. METHODS: Injectable slurries containing 20 percent and 40 percent ice content were made using common parenteral agents (normal saline and glycerol), then locally injected into the subcutaneous fat of swine. Ultrasound imaging, photography, histological, and gross tissue responses were monitored before and periodically up to 8 weeks after injection. RESULTS: Fat loss occurred gradually over several weeks following a single ice slurry injection. There was an obvious and significant 55 ± 6 percent reduction in adipose tissue thickness compared with control sites injected with the same volume of melted slurry (p < 0.001, t test). The amount of fat loss correlated with the total volume of ice injected. There was no scarring or damage to surrounding tissue. CONCLUSION: Physiological ice slurry injection is a promising new strategy for selective and nonsurgical fat removal.


Assuntos
Contorno Corporal/métodos , Criocirurgia/métodos , Gelo , Gordura Subcutânea/cirurgia , Animais , Contorno Corporal/efeitos adversos , Criocirurgia/efeitos adversos , Feminino , Injeções Subcutâneas/efeitos adversos , Injeções Subcutâneas/métodos , Modelos Animais , Sus scrofa
18.
Int J Radiat Biol ; 85(6): 523-31, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19466639

RESUMO

PURPOSE: Individuals suffering from Fanconi Anemia (FA) exhibit a pronounced hypersensitivity to agents that cause DNA inter-strand crosslinks and frequently also to ionising radiation. However, fibroblast lines derived from FA patients generally show little or no radiosensitivity in vitro. Here, we sought to elucidate the role of the central FA protein D2 (FANCD2) in determining cellular radioresistance. MATERIAL AND METHODS: Clonogenic radiation survival was assessed in an isogenic pair of human fibroblasts with or without wild-type FANCD2 under varying oxygen concentrations. Additional endpoints included single-cell gel electrophoresis, RAD51 foci formation, and apoptosis. RESULTS: At 20% oxygen, there was no reduction in the survival of FANCD2-deficient fibroblasts compared to wild-type complemented cells. However, at 0% oxygen FANCD2-deficient cells were more radiosensitive than wild-type cells. Interestingly, at 3% oxygen, which more closely resembles the physiological environment in human tissues, the difference in radiosensitivity was maintained. Our data also suggest that the increased radiosensitivity of FANCD2-deficient cells seen under conditions of reduced oxygen is associated with apoptotic cell death, but not secondary to a defect in the homologous recombination repair pathway that is required for crosslink repair. CONCLUSIONS: Our data may help explain the previously described discrepancy between the clinical and cellular radiosensitivity of FA patients.


Assuntos
Proteína do Grupo de Complementação D2 da Anemia de Fanconi/deficiência , Fibroblastos/enzimologia , Fibroblastos/efeitos da radiação , Oxigênio/farmacologia , Tolerância a Radiação , Animais , Apoptose/efeitos da radiação , Linhagem Celular , Proteína do Grupo de Complementação D2 da Anemia de Fanconi/metabolismo , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Humanos , Hipóxia/metabolismo , Rad51 Recombinase/genética , Tolerância a Radiação/genética , Radiação Ionizante , Recombinação Genética/efeitos da radiação , Reprodutibilidade dos Testes
19.
J Biomed Biotechnol ; 2008: 821529, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18483568

RESUMO

Genetic or epigenetic inactivation of the pathway formed by the Fanconi anemia (FA) and BRCA1 proteins occurs in several cancer types, making the affected tumors potentially hypersensitive to DNA cross-linkers and other chemotherapeutic agents. It has been proposed that the inability of FA/BRCA-defective cells to form subnuclear foci of effector proteins, such as FANCD2, can be used as a biomarker to aid individualization of chemotherapy. We show that FANCD2 inactivation not only renders cells sensitive to cross-links, but also oxidative stress, a common effect of cancer therapeutics. Oxidative stress sensitivity does not correlate with FANCD2 or RAD51 foci formation, but associates with increased gammaH2AX foci levels and apoptosis. Therefore, FANCD2 may protect cells against cross-links and oxidative stress through distinct mechanisms, consistent with the growing notion that the pathway is not linear. Our data emphasize the need for multiple biomarkers, such as gammaH2AX, FANCD2, and RAD51, to capture all pathway activities.


Assuntos
Proteína do Grupo de Complementação D2 da Anemia de Fanconi/metabolismo , Anemia de Fanconi/metabolismo , Fibroblastos/metabolismo , Histonas/metabolismo , Estresse Oxidativo , Rad51 Recombinase/metabolismo , Transdução de Sinais , Biomarcadores/metabolismo , Linhagem Celular , Humanos
20.
Medicine (Baltimore) ; 97(33): e11914, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30113491

RESUMO

Meralgia paresthetica (MP) is a rare lateral femoral cutaneous nerve-(LFCN)-mononeuropathy. Treatment for this disorder includes conservative and operative approaches; the latter is considered if conservative therapy fails. The most commonly used surgical approaches are decompression/neurolysis and avulsion/neurectomy. However, there are no definitive guidelines on the optimal surgical approach to be used. The purpose of this study was to evaluate the outcome of surgical decompression of the LFCN for the treatment of persistent MP with preservation of sensation along the distribution of the LFCN.We evaluated the outcomes of LFCN procedures performed between 2015 and 2016. A total of 16 surgical decompressions could be identified. Retrospective analysis of prospectively collected patient data was performed, as well as systematic evaluation of the postoperative course, with regular follow-up examinations based on a standardized protocol. Pain was analyzed using an NRS (numeric rating scale). Several postsurgical parameters, including temperature hypersensitivity and numbness in the LFCN region, were compared with the presurgical data.Sixty-nine percent of patients had histories of trauma or surgery, which were designated as the onset of pain. Of these patients, 78% had hip prostheses, 2 had previous falls. Postoperatively, a significant reduction of 6.6 points in the mean NRS pain value was observed. All other evaluated parameters also improved postoperatively. Patient satisfaction was high, with 86% reporting complete satisfaction, and 14% reporting partial satisfaction.Previous studies favor either avulsion/neurectomy as the preferred procedure for MP treatment, or provide no recommendation. Our findings instead confirm the decompression/neurolysis approach as the primary surgical procedure of choice for the treatment of MP, if conservative treatment fails.


Assuntos
Descompressão Cirúrgica/métodos , Síndromes de Compressão Nervosa/cirurgia , Procedimentos Neurocirúrgicos/métodos , Adulto , Descompressão Cirúrgica/efeitos adversos , Feminino , Nervo Femoral/cirurgia , Neuropatia Femoral , Humanos , Masculino , Procedimentos Neurocirúrgicos/efeitos adversos , Dor Pós-Operatória/etiologia , Período Pós-Operatório , Estudos Prospectivos , Estudos Retrospectivos , Resultado do Tratamento
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