scholarly journals Effects of malleable kinetochore morphology on measurements of intrakinetochore tension

Open Biology ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 200101
Author(s):  
Fioranna Renda ◽  
Valentin Magidson ◽  
Irina Tikhonenko ◽  
Rebecca Fisher ◽  
Christopher Miles ◽  
...  
Keyword(s):  
Light Microscopy ◽  
Large Scale ◽  
Computational Modelling ◽  
Human Cells ◽  
Elastic Recoil ◽  
Indian Muntjac ◽  
Scale Length ◽  
Conventional Light Microscopy

The distance between fluorescent spots formed by various kinetochore proteins (delta) is commonly interpreted as a manifestation of intrakinetochore tension (IKT) caused by microtubule-mediated forces. However, large-scale changes of the kinetochore architecture (such as its shape or dimensions) may also contribute to the value of delta. To assess contributions of these non-elastic changes, we compare behaviour of delta values in human kinetochores with small yet mechanically malleable kinetochores against compound kinetochores in Indian muntjac (IM) cells whose architecture remains constant. Due to the micrometre-scale length of kinetochore plates in IM, their shape and orientation are discernible in conventional light microscopy, which enables precise measurements of IKT independent of contributions from changes in overall architecture of the organelle. We find that delta in IM kinetochores remains relatively constant when microtubule-mediated forces are suppressed by Taxol, but it prominently decreases upon detachment of microtubules. By contrast, large decreases of delta observed in Taxol-treated human cells coincide with prominent changes in length and curvature of the kinetochore plate. These observations, supported by computational modelling, suggest that at least 50% of the decrease in delta in human cells reflects malleable reorganization of kinetochore architecture rather than elastic recoil due to IKT.

scholarly journals kSHREC ‘Delta’ reflects the shape of kinetochore rather than intrakinetochore tension

2019 ◽  
Author(s):  
Fioranna Renda ◽  
Valentin Magidson ◽  
Irina Tikhonenko ◽  
Christopher Miles ◽  
Alex Mogilner ◽  
...  
Keyword(s):  
Light Microscopy ◽  
Computational Modelling ◽  
Human Cells ◽  
Thin Layers ◽  
Indian Muntjac ◽  
Delta Change ◽  
Conventional Light Microscopy

AbstractDistance between fluorescent spots formed by various kinetochore proteins (‘Delta’) is proposed to reflect the level of intrakinetochore tension (IKT). However, larger-scale changes in the kinetochore architecture may also affect Delta. To test this possibility, we measure Delta in long kinetochores of Indian muntjac (IM) whose shape, size, and orientation are discernable in conventional light microscopy. We find that architecture of IM kinetochores and the value of Delta change minimally when microtubule-mediated forces are suppressed by Taxol. In contrast, large decreases of Delta observed in Taxol-treated human cells coincide with prominent changes in length and shape of the kinetochore. We also find that inner and outer kinetochore proteins intermix within a common spatial compartment instead of forming separate thin layers. These observations, supported by computational modelling, suggest that changes in Delta reflect changes in the kinetochore shape rather than the level of IKT.

scholarly journals A Comparative Study Between Smartphone-Based Microscopy and Conventional Light Microscopy in 1021 Dermatopathology Specimens

2016 ◽  
Vol 140 (1) ◽  
pp. 86-90 ◽  
Author(s):  
Richard R. Jahan-Tigh ◽  
Garrett M. Chinn ◽  
Ronald P. Rapini
Keyword(s):  
Light Microscopy ◽  
Cell Carcinoma ◽  
Sensitivity And Specificity ◽  
Performance Characteristics ◽  
University Hospital ◽  
Inflammatory Conditions ◽  
Skin Cancers ◽  
And Performance ◽  
Nonmelanoma Skin Cancers ◽  
Conventional Light Microscopy

Context The incorporation of high-resolution cameras into smartphones has allowed for a variety of medical applications including the use of lens attachments that provide telescopic, macroscopic, and dermatoscopic data, but the feasibility and performance characteristics of such a platform for use in dermatopathology have not been described. Objective To determine the diagnostic performance of a smartphone microscope compared to traditional light microscopy in dermatopathology specimens. Design A simple smartphone microscope constructed with a 3-mm ball lens was used to prospectively evaluate 1021 consecutive dermatopathology cases in a blinded fashion. Referred, consecutive specimens from the community were evaluated at a single university hospital. The performance characteristics of the smartphone platform were calculated by using conventional light microscopy as the gold standard. The sensitivity and specificity for the diagnosis of melanoma, nonmelanoma skin cancers, and other miscellaneous conditions by the phone microscopy platform, as compared with traditional light microscopy, were calculated. Results For basal cell carcinoma (n = 136), the sensitivity and specificity of smartphone microscopy were 95.6% and 98.1%, respectively. The sensitivity and specificity for squamous cell carcinoma (n = 94) were 89.4% and 97.3%, respectively. The lowest sensitivity was found in melanoma (n = 15) at 60%, although the specificity was high at 99.1%. The accuracy of diagnosis of inflammatory conditions and other neoplasms was variable. Conclusions Mobile phone–based microscopy has excellent performance characteristics for the inexpensive diagnosis of nonmelanoma skin cancers in a setting where a traditional microscope is not available.

BDV-syndrome: An emerging syndrome with profound obesity and neurodevelopmental delay resembling Prader-Willi syndrome

2021 ◽  
Author(s):  
Elisabeth Bosch ◽  
Moritz Hebebrand ◽  
Bernt Popp ◽  
Theresa Penger ◽  
Bettina Behring ◽  
...  
Keyword(s):  
Clinical Features ◽  
Large Scale ◽  
Hypogonadotropic Hypogonadism ◽  
Computational Modelling ◽  
Prader Willi Syndrome ◽  
Loss Of Function ◽  
Human Phenotype ◽  
Neurodevelopmental Delay ◽  
Missense Variants ◽  
Severely Obese

Abstract Context CPE encodes carboxypeptidase E, an enzyme which converts proneuropeptides and propeptide hormones to bioactive forms. It is widely expressed in the endocrine and central nervous system. To date, four individuals from two families with core clinical features including morbid obesity, neurodevelopmental delay and hypogonadotropic hypogonadism, harbouring biallelic loss-of-function CPE variants, were reported. Objective We describe four affected individuals from three unrelated consanguineous families, two siblings of Syrian, one of Egyptian and one of Pakistani descent, all harbouring novel homozygous CPE loss-of-function variants. Methods After excluding Prader-Willi syndrome, exome sequencing was performed in both Syrian siblings. The variants identified in the other two individuals were reported as research variants in a large scale exome study and in ClinVar database. Computational modelling of all possible missense alterations allowed assessing CPE tolerance to missense variants. Results All affected individuals were severely obese with neurodevelopmental delay and other endocrine anomalies. Three individuals from two families shared the same CPE homozygous truncating variant c.361C>T, p.(Arg121*), while the fourth carried the c.994del, p.(Ser333Alafs*22) variant. Comparison of clinical features with previously described cases and standardization according to the Human Phenotype Ontology indicated a recognisable clinical phenotype, which we termed Blakemore-Durmaz-Vasileiou (BDV) syndrome. Computational analysis indicated high conservation of CPE domains and intolerance to missense changes. Conclusions Biallelic truncating CPE variants are associated with BDV syndrome, a clinically recognisable monogenic recessive syndrome with childhood-onset obesity, neurodevelopmental delay, hypogonadotropic hypogonadism and hypothyroidism. BDV syndrome resembles Prader-Willi syndrome. Our findings suggested that missense variants may also be clinically relevant.

Experimental study of laser beam transmission and power accounting in a large scale length laser plasma

2000 ◽  
Vol 7 (8) ◽  
pp. 3388-3398 ◽  
Author(s):  
J. D. Moody ◽  
B. J. MacGowan ◽  
R. L. Berger ◽  
K. G. Estabrook ◽  
S. H. Glenzer ◽  
...  
Keyword(s):  
Experimental Study ◽  
Laser Beam ◽  
Laser Plasma ◽  
Large Scale ◽  
Beam Transmission ◽  
Scale Length

scholarly journals Cyanoprokaryotes biodiversity in nine shallow Bulgarian wetlands

2019 ◽  
Vol 2 ◽  
Author(s):  
Blagoy Uzunov ◽  
Maya Stoyneva-Gärtner ◽  
Georg Gärtner ◽  
Mariana Radkova ◽  
Katerina Stefanova
Keyword(s):  
Light Microscopy ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Molecular Methods ◽  
Geographical Pattern ◽  
Algal Toxins ◽  
The Real ◽  
Total Phytoplankton ◽  
Toxigenic Strains ◽  
Conventional Light Microscopy

The results from the investigation of the phytoplankton in nine shallow wetlands, situated in Central and Eastern Bulgaria, conducted in the frame of recent projects related to identifying harmful algal blooms and algal toxins in the country are demonstrated. Therefore, the focus is on the cyanoprokaryotes and their toxigenic species in particular. The species were identified using conventional light microscopy, while for distinguishing the toxigenic species and strains PCR-based molecular methods were applied. Cyanoprokaryotes comprised about 30% of the total phytoplankton biodiversity of the studied wetlands and were unevenly spread among them. The presence and spread of toxigenic strains in the studied wetlands also did not show any strong geographical pattern. Taxonomic problems related with the evaluation of the real cyanoprokaryotic biodiversity and potential alien or invasive character of the morphospecies are discussed.

Confocal Microscopy in Comparison with Electron and Conventional Light Microscopy

1987 ◽  
pp. 59-81 ◽  
Author(s):  
H.T.M. VAN DER VOORT ◽  
J.A.C. VALKENBURG ◽  
E.A. VAN SPRONSEN ◽  
C.L. WOLDRINGH ◽  
G.J. BRAKENHOFF
Keyword(s):  
Confocal Microscopy ◽  
Light Microscopy ◽  
Conventional Light Microscopy
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