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Ultrasonics Sonochemistry Nov 2022The strength of cell adhesion is important in understanding the cell's health and in culturing them. Quantitative measurement of cell adhesion strength is a significant...
The strength of cell adhesion is important in understanding the cell's health and in culturing them. Quantitative measurement of cell adhesion strength is a significant challenge in bioengineering research. For this, the present study describes a system that can measure cell adhesion strength using acoustic streaming induced by Lamb waves. Cells are cultured on an ultrasound transducer using a range of preculture and incubation times with phosphate-buffered saline (PBS) just before the measurement. Acoustic streaming is then induced using several Lamb wave intensities, exposing the cells to shear flows and eventually detaching them. By relying upon a median detachment rate of 50 %, the corresponding detachment force, or force of cell adhesion, was determined to be on the order of several nN, consistent with previous reports. The stronger the induced shear flow, the more cells were detached. Further, we employed a preculture time of 8 to 24 h and a PBS incubation time of 0 to 60 min, producing cell adhesion forces that varied from 1.2 to 13 nN. Hence, the developed system can quantify cell adhesion strength over a wide range, possibly offering a fundamental tool for cell-based bioengineering.
Topics: Cell Adhesion; Acoustics; Mechanical Phenomena
PubMed: 36257212
DOI: 10.1016/j.ultsonch.2022.106204 -
Biochemical and Biophysical Research... Jul 2021Sperm head-to-head agglutination is a well-known known phenomenon in mammalian and non-mammalian species. Although several factors have been reported to induce sperm...
Sperm head-to-head agglutination is a well-known known phenomenon in mammalian and non-mammalian species. Although several factors have been reported to induce sperm agglutination, information on the trigger and process of sperm detachment from the agglutination is scarce. Since hyperactivated motility is involved in bovine sperm detachment from the oviduct, we focused on caffeine, a well-known hyperactivation inducer, and aimed to determine the role of caffeine in sperm detachment from agglutination. Agglutination rate of bovine sperm was significantly decreased upon incubation with caffeine following pre-incubation without caffeine. Additionally, we observed that bovine sperm were detached from agglutination only when the medium contained caffeine. The detached sperm showed more asymmetrical flagellar beating compared to the undetached motile sperm, regardless of whether before or after the detachment. Intriguingly, some sperm that detached from agglutination re-agglutinated with different sperm agglutination. These findings indicated caffeine as a trigger for sperm detachment from the agglutination in bull. Furthermore, another well-known hyperactivation inducer, thimerosal, also significantly reduced the sperm agglutination rate. Overall, the study demonstrated the complete process of sperm detachment from sperm head-to-head agglutination and proposed that hyperactivated motility facilitates sperm detachment from another sperm. These findings would provide a better understanding of sperm physiology and fertilization process in mammals.
Topics: Animals; Caffeine; Cattle; Male; Progesterone; Sperm Agglutination; Sperm Head; Spermatozoa; Thimerosal
PubMed: 34049203
DOI: 10.1016/j.bbrc.2021.05.060 -
IScience May 2021Beginning of metastasis, cancer cells detach from the primary tumor and they can survive even under loss of anchorage; however, the detachment-elicited mechanisms have...
Beginning of metastasis, cancer cells detach from the primary tumor and they can survive even under loss of anchorage; however, the detachment-elicited mechanisms have remained unknown. Here, we found that Na,K-ATPase α3-isoform (α3NaK) in human cancer cells is dynamically translocated from intracellular vesicles to the plasma membrane when the attached cells are detached and that this mechanism contributes to the survival of the detached (floating) cancer cells. α3NaK was detected in the plasma membrane of floating cancer cells in peritoneal fluids of patients, while it was in the cytoplasm of the cells in primary tumor tissues. On cancer cell detachment, we also found the focal-adhesion-kinase-dependent Ca response that induces the α3NaK translocation via nicotinic acid adenine dinucleotide phosphate pathway. Activation of AMP-activated protein kinase was associated with the translocated α3NaK in the plasma membrane. Collectively, our study identifies a unique mechanism for survival of detached cancer cells, opening up new opportunities for development of cancer medicines.
PubMed: 33997694
DOI: 10.1016/j.isci.2021.102412 -
Retina (Philadelphia, Pa.) Jun 2023To report the anatomical and functional outcomes of medium-term perfluoro-n-octane (PFO) tamponade as a rescue procedure in very complex retinal detachments (RDs). (Review)
Review
PURPOSE
To report the anatomical and functional outcomes of medium-term perfluoro-n-octane (PFO) tamponade as a rescue procedure in very complex retinal detachments (RDs).
METHODS
We reviewed the case records of 35 consecutive patients who underwent vitrectomy for very complex RDs due to diverse etiologies. The surgical complexity was so graded because of the intraoperative failure to ascertain complete retinal reattachment; perfluoro-n-octane was used as rescue tamponade for 2 to 4 weeks. The second intervention included additional membrane peeling, retinectomy, endophotocoagulation, and gas/silicone oil tamponade. The minimum follow-up was 3 months after the final intervention: the primary outcome was retinal reattachment and the secondary outcome was change in best-corrected visual acuity (BCVA).
RESULTS
The most common presentations were severe trauma with retinal incarceration, preretinal and subretinal hemorrhage, or chronic/recurrent RDs with anterior proliferative vitreoretinopathy. Preoperative BCVA was ≤counting fingers in 31 (88.6%) patients. Complete retinal attachment without any tamponade was achieved in 33 (94.3%) eyes. best-corrected visual acuity improved in 30 (85.7%) eyes: 16 (45.7%) had BCVA ≥20/200 and 21 (60%) regained ambulatory vision (≥5/200). Two eyes developed keratopathy, and four needed antiglaucoma medications.
CONCLUSION
We achieved excellent anatomical outcomes and acceptable functional outcomes in nearly inoperable RDs with few side effects. Medium-term perfluoro-n-octane tamponade can be used as a salvage procedure in very complex RDs where intraoperative reattachment cannot be ensured.
Topics: Humans; Retinal Detachment; Visual Acuity; Retina; Retinal Diseases; Vitrectomy; Fluorocarbons; Treatment Outcome; Retrospective Studies; Silicone Oils
PubMed: 36791344
DOI: 10.1097/IAE.0000000000003763 -
International Ophthalmology Clinics Jul 2022
Topics: Choroidal Effusions; Fluorescein Angiography; Humans; Retinal Detachment
PubMed: 35752890
DOI: 10.1097/IIO.0000000000000436 -
Acta Ophthalmologica Mar 2021Retinoschisis (RS), rhegmatogenous retinal detachment (RRD) and combined RS retinal detachment (RSRD) may resemble clinically and pose a diagnostic challenge. This study...
PURPOSE
Retinoschisis (RS), rhegmatogenous retinal detachment (RRD) and combined RS retinal detachment (RSRD) may resemble clinically and pose a diagnostic challenge. This study investigates the role of the fundus autofluorescence (AF) in differentiating RS, RRD and RSRD.
METHODS
Fundus AF changes of 34 eyes diagnosed with RRD, 30 eyes with RS and 12 eyes with RSRD were retrospectively analysed. Ultra-widefield AF (UW-AF) image intensities obtained with the Optomap 200Tx were interpreted as hypo-, hyper- and isoautofluorescent or a mixed pattern with hypo- and hyperautofluorescence over and at the posterior margin (PM) of RRD, RS and RSRD.
RESULTS
All RS eyes revealed isoautofluorescence over the area of RS, and nine eyes (30%) showed hypoautofluorescent PM. Among RRD, acute (≤2 weeks) and chronic (>2 weeks) RRD demonstrated distinct AF characteristics. Sixty-two per cent of RRD eyes had acute RRD. From those, 16 eyes (76%) demonstrated hypoautofluorescence over the detached area and 19 (90%) eyes with hyperautofluorescent PM. Sixty-two per cent of chronic RRD eyes demonstrated isoautofluorecence over the detached area. Eight RSRD eyes (67%) revealed hyperautofluorescence in the detached area. The positive predictive value (PPV) for hypoautofluorescence over the area of subretinal fluid (SRF) in RRD was 95%. The PPV for hyperautofluorescence over the area of SRF in RSRD was 100% and for isoautofluorescence for schitic area in RSRD and RS was 76%.
CONCLUSION
The UW-AF can be a useful non-invasive adjuvant tool to distinguish between RRD, RS and RSRD. Hypo- or hyperautofluorescence over the area of interest and hyperautofluorescent PM indicates the presence of SRF.
Topics: Adult; Aged; Female; Fluorescein Angiography; Follow-Up Studies; Fundus Oculi; Humans; Male; Middle Aged; Retina; Retinal Detachment; Retinoschisis; Retrospective Studies; Scleral Buckling; Tomography, Optical Coherence; Visual Acuity
PubMed: 32602221
DOI: 10.1111/aos.14521 -
Cytotechnology Apr 2019Low intensity (< 2 V/cm (peak to peak voltage/cm)), high frequency (10-30 MHz), and 10 min alternating electric fields (sine wave with no DC component) induce...
Low intensity (< 2 V/cm (peak to peak voltage/cm)), high frequency (10-30 MHz), and 10 min alternating electric fields (sine wave with no DC component) induce non-contact and enzyme-free cell detachment of anchorage-dependent cells directly from commercially available cell culture flasks and stack plates. 0.25 V/cm, 20 MHz alternating electric field for 10 min at room temperature (RT) induced maximum detachment and separated 99.5 ± 0.1% (mean ± SEM, n = 6) of CHO-K1 and 99.8 ± 0.2% of BALB/3T3 cells from the culture flasks. Both vertical and lateral alternating electric field applications for 10 min at RT detach the CHO-K1 cells from 25 cm culture flasks. The alternating electric field application induced cell detachment is almost noncytotoxic, and over 90% of the detached cells remained alive. The alternating electric field applied CHO-K1 cells for 90 min showed little or no lag phase and immediately enter exponential phase in cell growth. Combination of the 20 MHz alternating electric field and enzymatic treatment for 4 min at 37 °C showed synergetic effect and quickly detached human induced pluripotent stem cells from a laminin-coated culture flask compared with the only enzymatic treatment. These results indicate that the rapid cell detachment with both the electric field application and the enzymatic treatment could be applied to subcultures of cells that are susceptible to prolonged enzymatic digestion damage for mass culture of sustainable clinical use.
PubMed: 30783819
DOI: 10.1007/s10616-019-00307-4 -
Indian Journal of Ophthalmology Apr 2022Detaching a rectus muscle irreparably destroys its ciliary artery circulation which also supplies the anterior segment of the eye.
BACKGROUND
Detaching a rectus muscle irreparably destroys its ciliary artery circulation which also supplies the anterior segment of the eye.
PURPOSE
To educate strabismus surgeons about a method of detaching a muscle without compromising anterior segment circulation.
SYNOPSIS
A limbal based conjunctival incision is made. The muscle is identified, separated from its attachments and secured with 6-0 Vicryl. The anterior ciliary vessel supplying it is isolated by making a small snip incision in the muscle capsule with delicate blunt dissection parallel to the anterior ciliary artery The muscle is detached from its original insertion. The muscle is tied to sclera at the intended point of recession. The intact anterior ciliary artery, thus will continue to function, untouched.
HIGHLIGHTS
We recommend pre-placing the sutures in the muscle and also in the sclera at the point of reattachment to avoid possible stretching and breaking of anterior ciliary vessels at the time of muscle detachment and also to dissect the artery free from muscle several millimeters more than the intended recession in order to spare the anterior ciliary circulation in strabismus surgery.
VIDEO LINK
https://youtu.be/Bn050Ihu9rU.
Topics: Conjunctiva; Humans; Ischemia; Oculomotor Muscles; Sclera; Strabismus; Surgical Wound
PubMed: 35326085
DOI: 10.4103/ijo.IJO_629_22 -
Journal of Endodontics Feb 2016Disruption of the matrix of endodontic biofilms will aid in their removal from a root canal. Therefore, the aim of this study was to investigate the efficacy of EDTA and...
INTRODUCTION
Disruption of the matrix of endodontic biofilms will aid in their removal from a root canal. Therefore, the aim of this study was to investigate the efficacy of EDTA and a modified salt solution (MSS) to detach bacteria from biofilms.
METHODS
Forty-eight-hour-old Enterococcus faecalis biofilms were grown on glass coverslips and then treated for 1 hour by immersion in 17% EDTA or MSS. Phosphate-buffered saline served as a negative control. Then, residual biofilm cells on the substrate and the detached cells in the supernatant were collected. Viability was verified by the colony-forming unit (CFU) counting method. Propidium monoazide (PMA) treatment in conjunction with quantitative polymerase chain reaction (qPCR) was also performed to detect the presence of E. faecalis 16S ribonucleic RNA genes. Data were analyzed using 1-way analysis of variance and Tukey or Kruskal-Wallis and Dunn tests. The Pearson R test evaluated the correlation between results from CFU and PMA (α = 5%).
RESULTS
qPCR showed that EDTA detached 99% of biofilm cells, and MSS detached 94% of biofilm cells (both P < .001). In contrast to EDTA, MSS was highly antimicrobial. The treatment promoted an ample log 7 reduction of the attached cells (P < .001), and almost no live cells were detected in the supernatant (P < .001). Positive correlations between CFU and qPCR with PMA were observed (r = 0.959 and r = 0.729).
CONCLUSIONS
EDTA detached cells in biofilms with a minor antimicrobial effect. Besides a great antimicrobial effect, MSS also detached biofilm cells. These dispersals of biofilms give insights into new endodontic biofilm removal strategies.
Topics: Anti-Infective Agents; Biofilms; Dental Pulp Cavity; Edetic Acid; Enterococcus faecalis; Microbial Viability; Real-Time Polymerase Chain Reaction; Root Canal Irrigants; Sodium Chloride; Sorbic Acid
PubMed: 26723483
DOI: 10.1016/j.joen.2015.11.017 -
Scientific Reports Mar 2020To describe the 25-year surgical trends, long-term outcomes and risk factors affecting the outcomes of giant retinal tear-related rhegmatogenous retinal detachments...
To describe the 25-year surgical trends, long-term outcomes and risk factors affecting the outcomes of giant retinal tear-related rhegmatogenous retinal detachments (GRT-RRD). Patients' demographics, pre-operative characteristics, risk factors, operative procedures and post-operative outcomes were collected and divided into three groups - Group A: 1991 to 2015 (overall); Group B: 1991 to 2005, and Group C: 2006 to 2015. Functional and anatomical successes were monitored over a 5-year period. Multivariate logistic regression analysis was performed to identify the risk factors related to functional and anatomical success.127 eyes of 127 patients were included in the study. At 5 year, 69.4% patients had visual acuity (VA) < logMAR 1.0 with 87.5% primary anatomical success rate. While the functional outcome remained the same between group B and C, there was an increase in the anatomical success from 89.7% to 100%, albeit not statistically significant. Patients with worse presenting VA, 150 degrees or more of giant retina tear, macula-detached status and presence of PVR were associated with VA of> logMAR 1.0 (all p < 0.05). The types of surgery (TPPV vs combined SB/TPPV), number of breaks, lens extraction and additional cryotherapy were not associated with the functional or anatomical success. In conclusion, the GRT-RRD functional and structural outcomes were comparable between 1991-2005 and 2006-2015, albeit a statistically insignificant improvement of anatomical outcome over the past 25 years. Worse presenting VA, 150 degrees or more of giant retinal tear, detached macula and presence of PVR were associated with poorer visual outcome.
Topics: Cohort Studies; Female; Humans; Male; Postoperative Complications; Recurrence; Regression Analysis; Retinal Detachment; Retinal Perforations; Retrospective Studies; Risk Factors; Scleral Buckling; Time Factors; Treatment Outcome; Visual Acuity; Vitrectomy; Vitreoretinopathy, Proliferative
PubMed: 32214123
DOI: 10.1038/s41598-020-61592-0