• Title/Summary/Keyword: medical laser

Search Result 720, Processing Time 0.028 seconds

CO2 Laser Microsurgery for Type 1 Posterior Glottic Stenosis Misdiagnosed as Bronchial Asthma: A Case Report

  • Ju, Yeo Rim;Park, Hyoung Sik;Lee, Sang Joon;Woo, Seung Hoon
    • Medical Lasers
    • /
    • v.9 no.1
    • /
    • pp.79-83
    • /
    • 2020
  • This paper reports a case of type 1 posterior glottic stenosis in a 60-year-old woman that was misdiagnosed as bronchial asthma. The patient was intubated at another hospital after ingesting herbicide and extubated seven days later. Although her voice changed, she had not received treatment at that time. She visited a local internal medicine clinic when her condition deteriorated to the point of dyspnea, but several months of treatment for bronchial asthma failed to improve her symptoms. Upon admission to the author's hospital, a laryngoscopic examination revealed a type 1 posterior glottic stenosis, which was removed surgically using a CO2 laser.

Application of Photobiomodulation in Hearing Research: Animal Study

  • Lee, Jae-Hun;Jung, Jae Yun
    • Medical Lasers
    • /
    • v.9 no.1
    • /
    • pp.1-5
    • /
    • 2020
  • Hearing organs have unique characteristics and have a role in processing external sensory signals. Sensory hair cells and nerve fibers in the organ of Corti can be damaged by various causes and they do not regenerate themselves. Medication used for clinical treatment for the inner ear is limited due to the anatomical structure of the inner ear. Photobiomodulation (PBM) is a therapeutic approach that uses various sources of light and the success of PBM therapy is highly reliant on the parameters of the light sources. The positive effects of PBM have been reported in various clinical fields. This paper summarizes the previously reported research on PBM for the treatment of hearing damage in animal models.

Brief Retrospect on the Use of Photobiomodulation (PBM) Therapy for Augmented Bone Regeneration (ABR)

  • Padalhin, Andrew Reyes
    • Medical Lasers
    • /
    • v.10 no.1
    • /
    • pp.15-21
    • /
    • 2021
  • As technology advances at a rapid rate, innovations in regenerative medicine will eventually include the use of energy-based therapeutics, such as low intensity-pulsed ultrasound stimulation (LIPUs), pulsed electromagnetic field stimulation (PMFs), and low-level laser/light therapy (LLLt) or photobiomodulation therapy (PBMt). Among these treatments, LLLt/PBMt attracted significant attention by the turn of the century, as evidenced by the numerous publications compared to LIPUs and PMFs, particularly for augmented bone regeneration (ABR). This is a testament of how the maturation of technology and scientific knowledge leads to latent compounded applications, even when the value of a technique is reliant on empirical data. This article reviews some of the notable investigations using LLLt/PBMt for bone regeneration published in the past decade, focusing on how this type of therapy has been utilized together with the existing regenerative medicine landscape.

Enamel pretreatment with Er:YAG laser: effects on the microleakage of fissure sealant in fluorosed teeth

  • Memarpour, Mahtab;Kianimanesh, Nasrin;Shayeghi, Bahareh
    • Restorative Dentistry and Endodontics
    • /
    • v.39 no.3
    • /
    • pp.180-186
    • /
    • 2014
  • Objectives: The purpose of this in vitro study was to evaluate the microleakage and penetration of fissure sealant in permanent molar teeth with fluorosis after pretreatment of the occlusal surface. Materials and Methods: A total of 120 third molars with mild dental fluorosis were randomly divided into 6 groups (n = 20). The tooth surfaces were sealed with an unfilled resin fissure sealant (FS) material. The experimental groups included: 1) phosphoric acid etching (AE) + FS (control); 2) AE + One-Step Plus (OS, Bisco) + FS; 3) bur + AE + FS; 4) bur + AE + OS + FS; 5) Er:YAG laser + AE + FS; and 6) Er:YAG laser + AE + OS + FS. After thermocycling, the teeth were immersed in 0.5% fuchsin and sectioned. Proportions of mircoleakage (PM) and unfilled area (PUA) were measured by digital microscope. Results: Overall, there were significant differences among all groups in the PM (p = 0.00). Group 3 showed the greatest PM, and was significantly different from groups 2 to 6 (p < 0.05). Group 6 showed the lowest PM. Pretreatment with Er:YAG with or without adhesive led to less PM than bur pretreatment. There were no significant differences among groups in PUA. Conclusions: Conventional acid etching provided a similar degree of occlusal seal in teeth with fluorosis compared to those pretreated with a bur or Er:YAG laser. Pretreatment of pits and fissures with Er:YAG in teeth with fluorosis may be an alternative method before fissure sealant application.

Characterization of Porcine Tissue Perforation Using High-Power Near-Infrared Laser at 808-nm Wavelength (808 nm 파장의 고출력 근적외선 레이저 조사 시 돼지 조직의 천공 특성 연구)

  • Kim, Seongjun;Cho, Jiyong;Choi, Jaesoon;Lee, Don Haeng;Kim, Jung Kyung
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.37 no.9
    • /
    • pp.807-814
    • /
    • 2013
  • A fundamental study on laser-tissue interaction was conducted with the aim of developing a therapeutic medical device that can remove lesions on the intestinal wall by irradiating a high-power 808-nm infrared laser light incorporated in an endoscopic system. The perforation depth was linearly increased in the range of 1~4 mm in proportional to laser output (3~12 W) and irradiation time (5~20 s). We demonstrated that the perforation depth during laser irradiation was varied according to the tissue property of each extracted porcine organ. The measurement of the temperature distribution suggests that the energy is localized in the irradiation spot and transferred to deep tissue, which protects the surrounding tissue from thermal injury. These results can be used to set the driving parameters for a laser incision technique as an alternative to conventional surgical interventions.

The Development of 63nm Diode Laser System for Photodynamic Therapy of Cancer (광역학적 암치료를 위한 635nm 다이오드 레이저 시스템 개발)

  • 임현수
    • Journal of Biomedical Engineering Research
    • /
    • v.24 no.4
    • /
    • pp.319-328
    • /
    • 2003
  • The purpose of this paper is to develop a medical laser system using the semiconductor diode laser in order to photodynamic cancel therapy as a light source. The ideal light source for photodynamic therapy would be a homogeneous nondiverging light with variable spot size and specific wavelength with stability. After due consideration in this point, in this paper, we used a diode laser resonator of 635nm wavelength. The development laser system have a statistical laser out beam with accuracy control using the constant current control of method and clinic-friendly with compact. In order to protect the diode resonator from the over-current, the rush-current and electrical fault, we specially designed. The most importance therapeutic factor are the radiation mode for cancer therapy. So we developed the radiation mode of CW(Continuous Wave), long pulse, short pulse, and burst pulse and can adjust the exposure time from several milli-second to several minute. The experimental result shows that laser beam power was increased linear from 10mW to 300mW according to the increasing input current and the increasing exposure time. The developed new compact diode laser system have a stability of output power and specific wavelength with easy control and transportable for many applications of PDT.

Effect of Infra-red laser irradiation on pain relive in rats (적외선 레이저 자극이 흰쥐의 진통 작용에 미치는 영향)

  • Lee In-Hak
    • The Journal of Korean Physical Therapy
    • /
    • v.9 no.1
    • /
    • pp.89-96
    • /
    • 1997
  • The purpose of this study was to determine the effect of Ga-Al-As (Gallium-Aluminum-Arsenid) laser radiation on the tail-flick latency in rat. Thirty Sprague-Dawley male and female rats Were divided into five groups : that is control, laser 15sec radiation, laser 30sec radiation, laser 60sec radiation, and Tramadol Hcl injection groups. The continuous Ga-Al-As laser with, wave length 780-830nm and diameter of probe in the 3mm, averse output of 100mw radiation was applied to the meridian point(Gv 1 : Governing vessel) of the rats. Tail-flick latency were measured with hot plate at $55^{\circ}C$ : before treatment and immediately, 30 minutes, 1 hour, 2 hours, 24 hours, 24 hours and 48 hours after treatment. The result were as follows ; 1. The tail-flick latency according to time varition, control group was not significance. 2. The tail-flick latency according to time varition, laser 15 sec irradiate rats in post-treared was significance(P<0.05). 3. The tail-flick latency according to time varition, laser 30 sec irradiate rats group was not significance. 4. The tail-flick latency according to time varition, laser 60 sec irradiate rats in post 30 minute was significance(P<0.05). 5. The tail-flick latency according to time varition, Tramadol Hcl injection rats in post-treated (P<0.05), post 30 minute(P<0.05), post 60 minute (P<0.01) and 2 hour(P<0.05) was significance. This study suggest that Ga-Al-As (Gallium-Aluminum-Arsenid) laser applied to meridian point of the rat with 15 sec, 30 sec, and 60 set radiation could induc no analgesic effect, but Tramadol Hcl injection rat is good analgesic effect.

  • PDF

Analysis of the Gene Expression by Laser Captured Microdissection (I): Minimum Conditions Required for the RNA Extraction from Oocytes and Amplification for RT-PCR (Laser Captured Microdissection을 이용한 유전자 발현에 대한 연구 (I): RT-PCR을 위한 난자의 RNA 추출 및 증폭을 위한 최소한도의 확립)

  • Park, Chang-Eun;Ko, Jung-Jae;Cha, Kwang-Yul;Lee, Kyung-Ah
    • Clinical and Experimental Reproductive Medicine
    • /
    • v.28 no.3
    • /
    • pp.183-190
    • /
    • 2001
  • Objective: Recently, microdissection of tissue sections has been used increasingly for the isolation of morphologically identified homogeneous cell populations, thus overcoming the obstacle of tissue complexity for the analysis cell-specific expression of macromolecules. The aim of the present study was to establish the minimal conditions required for the RNA extraction and amplification from the cells captured by the laser captured microdissection. Methods : Mouse ovaries were fixed and cut into serial sections (7 im thickness). Oocytes were captured by laser captured microdissection (LCM) method by using PixCell $II^{TM}$ system. The frozen sections were fixed in 70% ethanol and stained with hematoxylin and eosin, while the paraffin sections were stained with Multiple stain. Sections were dehydrated in graded alcohols followed by xylene and air-dried for 20 min prior to LCM. All reactions were performed in ribonuclease free solutions to prevent RNA degradation. After LCM, total RNA extraction from the captured oocytes was performed using the guanidinium isothiocyanate (GITC) solution, and subsequently evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR) for glyceraldehyde-3-phosphate-dehydrogenase (GAPDH). Results: With the frozen sections, detection of the GAPDH mRNA expression in the number of captured 25 oocytes were not repeatable, but the expression was always detectable from 50 oocytes. With 25 oocytes, at least 27 PCR cycles were required, whereas with 50 oocytes, 21 cycles were enough to detect GA PDH expression. Amount of the primary cDNA required for RT-PCR was reduced down to at least 0.25 $\grave{i}$ l with 50 oocytes, thus the resting 19.75 il cDNA can be used for the testing other interested gene expression. Tissue-to-slide, tissue-to-tissue forces were very high in the paraffin sections, thus the greater number of cell procurement was required than the frozen sections. Conclusion: We have described a method for analyzing gene expression at the RNA level with the homogeneously microdissected cells from the small amount of tissues with complexity. We found that LCM coupled with RT-PCR could detect housekeeping gene expression in 50 oocytes captured. This technique can be easily applied for the study of gene expression with the small amount of tissues.

  • PDF

Generation of FISH Probes Using Laser Microbeam Microdissection and Application to Clinical Molecular Cytogenetics

  • Shim, Sung-Han;Kyhm, Jee-Hong;Chung, Sung-Ro;Kim, Seung-Ryong;Park, Moon-Il;Lee, Chul-Hoon;Cho, Youl-Hee
    • Journal of Microbiology and Biotechnology
    • /
    • v.17 no.7
    • /
    • pp.1079-1082
    • /
    • 2007
  • Chromosome microdissection and the reverse FISH technique is one of the most useful methods for the identification of structurally abnormal chromosomes. In particular, the laser microbeam microdissection (LMM) method allows rapid isolation of a target chromosome or a specific region of chromosomes without damage of genetic materials and contamination. Isolated chromosomes were directly amplified by the degenerate oligonucleotide-primed polymerase chain reaction (DOP-PCR), and then the FISH probes labeled with spectrum green- or spectrum red-dUTP were generated by nick-translation. Whole chromosome painting (WCP) probes were successfully generated from only 5 copies of the chromosome. With this method, we produced 24 WCP probes for each human chromosome. We also tried to characterize a marker chromosome, which seemed to be originated from chromosome 11 on conventional banding technique. The marker chromosomes were isolated by the LMM method and analyzed by reverse FISH. We elucidated that the marker chromosome was originated from the short arm of chromosome 5 ($5p11{\to}pter$). A fully automated and computer-controlled LMM method is a very simple laboratory procedure, and enables rapid and precise characterization of various chromosome abnormalities.

Comparative Study of p53 Mutation and Oncoprotein Expression in Gastric Adenocarcinoma (미세절편으로 얻은 위암 조직세포에서 p53 유전자의 돌연변이와 종양단백 발현에 관한 연구)

  • Kim Chul;Joo Jai Kyun;Choi Chan;Kim Young Jin
    • Journal of Gastric Cancer
    • /
    • v.3 no.3
    • /
    • pp.145-150
    • /
    • 2003
  • Purpose: The p53 tumor suppressor gene is believed to play a pivotal role in preventing the uncontrolled cellular growth characteristic of cancer. Mutation of the p53 gene represent one of the most common genetic alterations in human cancers, and the acquisition of such defects is strongly associated with tumor progression and metastasis. The aim of this study was to evaluate the relation between p53 immunoreactivity and the mutation of p53 gene in gastric adenocarcinoma obtained by laser capture microscope. Materials and Methods: Formalin fixed paraffin embedded tissue specimens were obtained from 20 patients who underwent surgery for gastric cancer. According to UICC TNM system, 3 of the cases were Ia, 2 cases II, 4 cases IIIa, 5 cases IIIb, and 6 cases IV. Results: Immunohistochemical staining revealed eight cases as negative (less than $10\%$), twelve cases as postive (more than $10\%$). The locations of mutations were as follows; 7 cases had point mutation at exon 4, and 3 cases point mutation at exon 8. There was no mutation at exon 5, 6, 7 and 9. The mutation was observed in 1 case out of 8 p53 oncoprotein negative cases, and 7 cases out of 12 p53 positive cases. The mutation was more common in p53 positive cases (P<0.05), However, there was no significant correlation between p53 mutation observed by DNA sequencing after laser capture microdissection and expression of p53 oncoprotein. Conclusion: These result suggest that he expression of p53 oncoprotein not to be related to the mutation of p53 gene at exons 4 through 9 in gastric cancer.

  • PDF