Advent Of Laser Research Articles

The Different Biopsy Techniques

Preimplantation genetic testing needs access to genomic DNA in order to execute a genetic test on a preimplantation embryo. Normally a few cells must be extracted or ‘biopsied’ from the embryo to achieve this. Embryo biopsy evolved from attempts in the 1960s and early 1970s to sex farm animal embryos to now utilizing it to screen and select human embryos based on Ploidy, or avoid monogenic disorders. In October 1989, the first clinical cleavage stage biopsies and single cell PGT to determine the sex of the embryos were conducted. It has now evolved to utilize Trophectoderm cells. The advent of Laser has allowed the biopsy process to shift away from mechanical and chemical hatching and techniques also now involve Laser to separate the cells from the blastocyst. Here is a short summary of the different biopsy stages. Polar Body Biopsy : — Polar bodies are small cells produced during the process of oogenesis (egg development) in females. — Since polar bodies contain genetic material from the egg, they can be biopsied to indirectly infer the genetic status of the egg. — This technique is less common and has limitations, but it can be used in certain situations. Blastomere Biopsy (Day 3 Biopsy) : — Performed on the third day after fertilization when the embryo has around 8 cells. — A single cell (blastomere) is removed from the embryo for genetic testing. — Mosaicism cannot be ruled out thus questioning the efficacy of this technique. Trophectoderm Biopsy (Day 5-7 Biopsy) : — Performed at the blastocyst stage, typically on the fifth or sixth day of embryonic development. — Usually, 5-10 cells from the trophectoderm are removed for genetic testing. — This technique is now gold standard and allows determination of mosaicism. The embryo biopsy revolution’s 30-year saga is still unfolding, and non-invasive genetic testing holds potential to revolutionize the way embryos are tested for genetic disorders.

Application of Laser in Dentistry – A Literature Review

The advent of laser has completely changed the concept of dental treatment and has become one of the most interesting technologies in dental practice. Lasers have been widely employed clinically for soft tissue and hard tissue procedures such as debridement of caries, cysts, tumors, ulcers; cavity preparation, gingivectomy, crown lengthening, frenectomy, pulpotomy, and several other treatments. They claim to aid healing and reduce, pain and inflammation. Lasers are considered an effective tool to enhance efficacy, specificity, ease, and comfort.

Renal Amyloidosis

The kidney is the organ most commonly involved in systemic amyloidosis. This study reports the largest clinicopathologic series of renal amyloidosis. This study provides characteristics of 474 renal amyloidosis cases evaluated at the Mayo Clinic Renal Pathology Laboratory from 2007 to 2011, including age, sex, serum creatinine, proteinuria, type of amyloid, and tissue distribution according to type. The type of amyloid was Ig amyloidosis in 407 patients (85.9%), AA amyloidosis in 33 (7.0%), leukocyte chemotactic factor 2 amyloidosis in 13 (2.7%), fibrinogen A α chain amyloidosis in 6 (1.3%), Apo AI, Apo AII, or Apo AIV amyloidosis in 3 (0.6%), combined AA amyloidosis/Ig heavy and light chain amyloidosis in 1 (0.2%), and unclassified in 11 (2.3%). Laser microdissection/mass spectrometry, performed in 147 cases, was needed to determine the origin of amyloid in 74 of the 474 cases (16%), whereas immunofluorescence failed to diagnose 28 of 384 light chain amyloidosis cases (7.3%). Leukocyte chemotactic factor 2 amyloidosis and Apo AI, Apo AII, or Apo AIV amyloidosis were characterized by diffuse interstitial deposition, whereas fibrinogen A α chain amyloidosis showed obliterative glomerular involvement. Compared with other types, Ig amyloidosis was associated with lower serum creatinine, higher degree of proteinuria, and amyloid spicules. In the authors' experience, the vast majority of renal amyloidosis cases are Ig derived. The newly identified leukocyte chemotactic factor 2 amyloidosis form was the most common of the rarer causes of renal amyloidosis. With the advent of laser microdissection/mass spectrometry for amyloid typing, the origin of renal amyloidosis can be determined in >97% of cases.

Historical remarks on the birth of the ligand field diagrams and the advent of laser

Tanabe and Sugano's personal accounts are given for the birth of the Tanabe-Sugano diagrams and the advent of laser.

LASIK and Surface Ablation in the Modern Era: Trends and Novel Applications

Refractive laser surgery has become one of the most successful and commonly performed elective ophthalmic procedures. Since the introduction of photorefractive keratectomy, followed closely by the advent of laser in situ keratomileusis, the field of laser refractive surgery has continued to rapidly evolve. Surgical techniques are constantly refined to improve patient outcomes and minimize complications, and technology continues to advance to provide more precise and customizable treatment options. New applications of refractive procedures continually emerge in the literature. Breakthroughs in the field have led to novel applications of refractive procedures that may offer options to patients that previously had been considered poor surgical candidates. It is important for the clinician to maintain awareness of the current trends and new developments in refractive surgery to provide appropriate counseling and treatment for their patients.

A more cost effective and rapid high percentage germ‐line transmitting chimeric mouse generation procedure via microinjection of 2‐cell, 4‐cell, and 8‐cell embryos with ES and iPS cells

The long-standing traditional method of delivering embryonic stem (ES) cells adjacent to the inner cell mass (ICM) of blastocysts to generate chimeras improved with the advent of laser- or Piezo assisted 8-cell embryo microinjection. Building on this technology but omitting either the laser or the Piezo to penetrate the zona pellucida and making use of earlier embryonic stages (2-cell and 4-cell), we were able to significantly speed up and economize our ES cell microinjection and chimera production throughput. We demonstrate here that embryonic (ES) and induced pluripotent stem (iPS) cells can stay fully pluripotent when delivered into 2-cell- and 4-cell-stage embryos, long before they would naturally be incorporated into the ICM of a blastocyst (E3.5) and give rise to high percentage and germline transmitting chimeras.

Laser-assisted microdissection, techniques and applications in pathology (Review)

Innovations in molecular medicine provided sophisticated tools for analysis of the pathogenesis of diseases. Much emphasis is put on examination of alterations in affected organ systems. However, since in vivo tissues are inherently complex mixtures of different cell types, specific molecular data on individual cell populations are difficult to obtain. The advent of laser assisted microdissection (LAM) now allows efficient isolation of pure cell populations and even of single cells from mixed tissues. The most promising aspect of LAM is its combination with different molecular downstream analyses of microdissected cells at the levels of the genome, the transcriptome and the proteome. This review focuses on the two basic techniques of laser-assisted microdissection and on its applications in molecular pathology.

Thermal consequences of photorefractive keratectomy.

Photorefractive keratectomy (PRK) is still a widely used method for the correction of refractive error despite the advent of laser in situ keratomileusis (LASIK). However, both procedures are associated with significant side effects such as corneal haze and regression. Several factors have been implicated in the etiology of haze, one of which is thermal loading of the cornea. The purpose of this study was to investigate the temperature changes occurring during PRK when performed at different ablation depths. Noncontact, color-coded ocular thermography was performed with an infrared detector apparatus during PRK ablation on 19 ovine corneas. Five different refractive corrections were carried out ranging from -2.00 diopters (D) (ablation depth, 31.2 microm) to -10.00 D (ablation depth, 137.9 microm). A temperature rise at the corneal surface was demonstrated in all 19 corneas. The mean rise in temperature was 7.35 +/- 1.13 degrees C with a maximum rise in temperature of 8.97 degrees C. A positive correlation was found between the refractive correction and the peak rise in temperature (r2 = 0.57, p< 0.0001). The rate of temperature change was greater for smaller treatments than for larger treatments (r2 = 0.79, p < 0.0001). Corneas undergoing larger treatments were subject to greater rises in temperature for longer periods of time. This study suggests that the cornea undergoes a significant rise in temperature as a result of the PRK process. Further investigation is required to determine what effect this thermal loading has on the corneal wound healing response after PRK.

Applications of laser desorption and electrospray ionization mass spectrometry at the transition between clusters and colloids.

The advent of laser desorption/ionization and electrospray ionization techniques in mass spectrometry has enabled the study of large metal carbonyl cluster anions. These new methods provide both molecular weight and structural information and allow the study of cluster mixtures whose characteristics approach those of colloids.