scholarly journals Experimental Evaluation of an Interferometric Light Microscopy Particle Counter for Titering and Characterization of Virus Preparations

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 939
Author(s):  
Vesa Turkki ◽  
Elisa Alppila ◽  
Seppo Ylä-Herttuala ◽  
Hanna P. Lesch
Keyword(s):  
Light Microscopy ◽  
Virus Particle ◽  
High Concentration ◽  
Particle Counter ◽  
Characterization Methods ◽  
Virus Particles ◽  
Standard Curve ◽  
Counting Device ◽  
Conventional Light Microscopy

Virus particle concentration is a critical piece of information for virology, viral vaccines and gene therapy research. We tested a novel nanoparticle counting device, “Videodrop”, for its efficacy in titering and characterization of virus particles. The Videodrop nanoparticle counter is based on interferometric light microscopy (ILM). The method allows the detection of particles under the diffraction limit capabilities of conventional light microscopy. We analyzed lenti-, adeno-, and baculovirus samples in different concentrations and compared the readings against traditional titering and characterization methods. The tested Videodrop particle counter is especially useful when measuring high-concentration purified virus preparations. Certain non-purified sample types or small viruses may be impossible to characterize or may require the use of standard curve or background subtraction methods, which increases the duration of the analysis. Together, our testing shows that Videodrop is a reasonable option for virus particle counting in situations where a moderate number of samples need to be analyzed quickly.

CHARACTERIZATION OF INSECT SENSE ORGANS AND OPTICAL CLEARING OF WHOLE- MOUNT PREPARATIONS USING diI IN FIXED TISSUES

1993 ◽  
Vol 175 (1) ◽  
pp. 299-303
Author(s):  
S. N. Zill ◽  
S. F. Frazier ◽  
D. L. Macfarland ◽  
S. E. Fish
Keyword(s):  
Light Microscopy ◽  
Peripheral Nerves ◽  
Lipid Solubility ◽  
Sensory Receptors ◽  
Sense Organs ◽  
Neuronal Membranes ◽  
Carbocyanine Dye ◽  
Whole Mount ◽  
Conventional Light Microscopy

Studies of invertebrate sensory receptors have been greatly aided by the use of compounds, such as cobalt salts, which can diffuse or be transported in peripheral nerves, to characterize morphologically and to label identified exteroceptive and proprioceptive sense organs (Braunig et al. 1981). However, most of these methods require the maintenance of live preparations, which can be difficult when attempting to fill axons over long distances. We have mapped sense organs of the cockroach leg using the carbocyanine dye, diI. This lipid-soluble dye, recently developed for use in vertebrates (Honig and Hume, 1989), diffuses passively in neuronal membranes and can be used in fixed tissues. However, because of its lipid solubility, it has the disadvantage that it dissolves in standard organic clearing agents. We have developed methods of applying diI and clearing cockroach preparations that permit the visualization of both sensory neuron somata under fluorescent illumination and their associated cuticular specializations by conventional light microscopy. These experiments have confirmed the location of many receptors previously identified by serial sectioning and light microscopy (Dresden and Nijenhuis, 1958; Nijenhuis and Dresden, 1952, 1956). We have also mapped sense organs on the distal leg segments and demonstrated the widespread presence of multiply innervated, chemoreceptor-like sense organs on all segments of the cockroach mesothoracic and metathoracic legs.

scholarly journals Quantitation of HER2/neu Expression in Primary Gastroesophageal Adenocarcinomas Using Conventional Light Microscopy and Quantitative Image Analysis

2012 ◽  
Vol 136 (6) ◽  
pp. 610-617 ◽  
Author(s):  
Jennifer Jeung ◽  
Roshan Patel ◽  
Lizette Vila ◽  
Dara Wakefield ◽  
Chen Liu
Keyword(s):  
Breast Cancer ◽  
Image Analysis ◽  
Light Microscopy ◽  
Scoring System ◽  
Growth Factor Receptor ◽  
Tumor Grade ◽  
Quantitative Image ◽  
Epidermal Growth ◽  
Conventional Light Microscopy

Context.—Human epidermal growth factor receptor 2 (HER2/neu) is overexpressed in a proportion of gastroesophageal (GE) adenocarcinomas, and trastuzumab treatment results in significant improvement in overall survival in patients with HER2/neu-overexpressing GE tumors. Grading of HER2/neu expression in GE tumors and its clinical application is different from that of breast cancer. HER2/neu immunohistochemistry (IHC) image analysis (IA), widely used in breast cancer, has not been studied in GE tumors. Objective.—To evaluate the correlation between manual HER2/neu IHC scoring and HER2/neu IHC image analysis in GE adenocarcinomas with characterization of associated clinicopathologic features. Design.—Tumor grade, growth pattern, and stage were evaluated in 116 cases of primary GE adenocarcinoma biopsy and resection specimens. Using anti-HER2/neu antibody and the proposed HER2/neu scoring system for gastric cancer, HER2/neu IHC expression was recorded after manual scoring and automated IA interpretation. Results.—HER2/neu overexpression (IHC 3+) was detected in 19% (10 of 54) of gastric tumors, and overall correlation between manual HER2/neu IHC interpretation and IA interpretation was 78% (42 of 54). HER2/neu overexpression (IHC 3+) was detected in 26% (16 of 62) of GE junction tumors, and the overall correlation between manual HER2/neu IHC interpretation and IA interpretation was 84% (52 of 62). Conclusions.—The HER2/neu IHC scoring system for GE adenocarcinomas differs from that of breast carcinoma. Automated IA, validated for scoring of HER2/neu IHC in breast cancer, has a low correlation between HER2/neu IHC 2+ and IHC 3+ cases scored by conventional light microscopy and cannot be reliably used in the interpretation of HER2/neu IHC expression in GE adenocarcinomas.

Spontaneous Production of Type C Virus Particles in a Culture Derived from Rat Embryo Cells

1972 ◽  
Vol 30 ◽  
pp. 288-289
Author(s):  
Elizabeth S. Priori ◽  
T. Shigematsu ◽  
B. Myers ◽  
L. Dmochowski
Keyword(s):  
Virus Particle ◽  
Mouse Embryo ◽  
Calf Serum ◽  
Embryo Cell ◽  
Virus Particles ◽  
Extracellular Virus ◽  
Mouse Embryo Cell ◽  
Mature Virus Particle ◽  
Embryo Cells ◽  
Type C

Spontaneous release of type C virus particles in long-term cultures of mouse embryo cells as well as induction of similar particles in mouse embryo cell cultures with IUDR or BUDR have been reported. The presence of type C virus particles in cultures of normal rat embryos has not been reported.NB-1, a culture derived from embryos of a New Zealand Black (NB) rat (rats obtained from Mr. Samuel M. Poiley, N.C.I., Bethesda, Md.) and grown in McCoy's 5A medium supplemented with 20% fetal calf serum was passaged weekly. Extracellular virus particles similar to murine leukemia particles appeared in the 22nd subculture. General appearance of cells in passage 23 is shown in Fig. 1. Two budding figures and one immature type C virus particle may be seen in Fig. 2. The virus particles and budding were present in all further passages examined (currently passage 39). Various stages of budding are shown in Figs. 3a,b,c,d. Appearance of a mature virus particle is shown in Fig. 4.

Electron Microscope Study of RNA's of Paramyxoviruses

1972 ◽  
Vol 30 ◽  
pp. 196-197
Author(s):  
Ruchama Baum ◽  
J.T. Seto
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Electron Microscope Study ◽  
Sendai Virus ◽  
Sodium Dodecyl ◽  
Rna Molecules ◽  
Virus Particles ◽  
Molecular Weights ◽  
Length Measurements

The ribonucleic acid (RNA) of paramyxoviruses has been characterized by biochemical and physiochemical methods. However, paramyxovirus RNA molecules have not been studied by electron microscopy. The molecular weights of these single-stranded viral RNA molecules are not known as yet. Since electron microscopy has been found to be useful for the characterization of single-stranded RNA, this investigation was initiated to examine the morphology and length measurements of paramyxovirus RNA's.Sendai virus Z strain and Newcastle disease virus (NDV), Milano strain, were used. For these studies it was necessary to develop a method of extracting RNA molecules from purified virus particles. Highly purified Sendai virus was treated with pronase (300 μg/ml) at 37°C for 30 minutes and the RNA extracted by the sodium dodecyl sulfate (SDS)-phenol procedure.

Characterization of submicrometer fluid Inclusions in minerals by Analytical/Transmission Electron Microscopy and electron diffraction

1990 ◽  
Vol 48 (4) ◽  
pp. 424-424
Author(s):  
George Guthrie ◽  
David Veblen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Electron Diffraction ◽  
Light Microscopy ◽  
Fluid Inclusions ◽  
Energy Dispersive Spectrometer ◽  
Analytical Transmission Electron Microscopy ◽  
Transmission Electron

The nature of a geologic fluid can often be inferred from fluid-filled cavities (generally <100 μm in size) that are trapped during the growth of a mineral. A variety of techniques enables the fluids and daughter crystals (any solid precipitated from the trapped fluid) to be identified from cavities greater than a few micrometers. Many minerals, however, contain fluid inclusions smaller than a micrometer. Though inclusions this small are difficult or impossible to study by conventional techniques, they are ideally suited for study by analytical/ transmission electron microscopy (A/TEM) and electron diffraction. We have used this technique to study fluid inclusions and daughter crystals in diamond and feldspar.Inclusion-rich samples of diamond and feldspar were ion-thinned to electron transparency and examined with a Philips 420T electron microscope (120 keV) equipped with an EDAX beryllium-windowed energy dispersive spectrometer. Thin edges of the sample were perforated in areas that appeared in light microscopy to be populated densely with inclusions. In a few cases, the perforations were bound polygonal sides to which crystals (structurally and compositionally different from the host mineral) were attached (Figure 1).

Management and engineering solutions to improve stripping equipment efficiency in Chernogorksy open pit mine

2018 ◽  
pp. 36-48
Author(s):  
G. N. Shapovalenko ◽  
S. N. Radionov ◽  
V. V. Gorbunov ◽  
V. A. Khazhiev ◽  
V. Yu. Zalyadnov ◽  
...  
Keyword(s):  
Open Pit Mine ◽  
Open Pit ◽  
High Concentration ◽  
Open Pit Mines ◽  
Blasting Operation ◽  
Internal Dump ◽  
Mining Conditions ◽  
Mining Front ◽  
Comparison Of Equipment

Chernogosky open pit mine integrates truck-and-shovel system of mining with overburden rehandling to internal dump with a set of walking excavators for rehandling of overburden to mined-out area of the pit. It is possible to improve efficiency of stripping in the conditions of Chernogorsky OPM by reducing percentage of stripping with more expensive handling system. The relevant research and solutions to this effect are presented in this article. Comparative characterization of mining conditions and parameters of mining systems applied is given for open pit mines Chernogorsky, Turnui, Nazarovsky, Vostochno-Beisky and Izykh. The comparative analysis points at the need to account for difficulty of mining and process sites in comparison of equipment productivity. High concentration of mining machines, which is conditioned by narrow mining front and simultaneous operation of five faces, as well as blasting operation implemented every 1-2 days, are recognized as the main constraints of excavator capacity in mining with direct dumping in Chernogorsky open pit mine. The management and engineering solutions implemented in the mine and resulted in higher efficiency of draglines are described.

scholarly journals Focused ultrasound in neuro-oncology: the role of the Focused Ultrasound Foundation in driving adoption and innovation

2021 ◽  
Author(s):  
Emily C. Whipple ◽  
Camille A. Favero ◽  
Neal F. Kassell
Keyword(s):  
Drug Delivery ◽  
Brain Tumors ◽  
Focused Ultrasound ◽  
Clinical Evidence ◽  
Neurological Injury ◽  
High Concentration ◽  
Potential Applications ◽  
Tumor Agent

Abstract Introduction Intra-arterial (lA) delivery of therapeutic agents across the blood-brain barrier (BBB) is an evolving strategy which enables the distribution of high concentration therapeutics through a targeted vascular territory, while potentially limiting systemic toxicity. Studies have demonstrated lA methods to be safe and efficacious for a variety of therapeutics. However, further characterization of the clinical efficacy of lA therapy for the treatment of brain tumors and refinement of its potential applications are necessary. Methods We have reviewed the preclinical and clinical evidence supporting superselective intraarterial cerebral infusion (SSJACI) with BBB disruption for the treatment of brain tumors. In addition, we review ongoing clinical trials expanding the applicability and investigating the efficacy of lA therapy for the treatment of brain tumors. Results Trends in recent studies have embraced the use of SSIACI and less neurotoxic chemotherapies. The majority of trials continue to use mannitol as the preferred method of hyperosmolar BBB disruption. Recent preclinical and preliminary human investigations into the lA delivery of Bevacizumab have demonstrated its safety and efficacy as an anti-tumor agent both alone and in combination with chemotherapy. Conclusion lA drug delivery may significantly affect the way treatment are delivered to patients with brain tumors, and in particular GBM. With refinement and standardization of the techniques of lA drug delivery, improved drug selection and formulations, and the development of methods to minimize treatment-related neurological injury, lA therapy may offer significant benefits for the treatment of brain tumors.

Characterization of Iranian Moarraque glazes by light microscopy, SEM-EDX and voltammetry of microparticles

2008 ◽  
Vol 9 ◽  
pp. e50-e54 ◽  
Author(s):  
María Teresa Doménech-Carbó ◽  
Antonio Doménech-Carbó ◽  
Dolores Julia Yusá-Marco ◽  
Hossein Ahmadi
Keyword(s):  
Light Microscopy ◽  
Voltammetry Of Microparticles
Sign in / Sign up

Export Citation Format

Share Document