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Bacteria
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
Microbes are free-living, predominantly single cell organisms that are ubiquitous in nature. One ounce of rich garden soil may contain 60 billion living organisms; yet only about ten percent of the over 2000 identified species of bacteria are known to cause disease. Microbes are too small to be seen with the naked eye; i.e., they require the aid of a microscope or other magnifying device for direct observation. However, large populations of a specific microbe can be cultivated or grown into colonies in the laboratory and then observed directly. For example: a one-ounce yeast cake contains approximately 300 billion individual cells—a number higher than the world′s human population—and is observable; whereas a single yeast cell cannot be seen. Consider that it is the summation of all the organisms′ physical, chemical, and biological attributes—all of which are conferred by the genetic complement within the cell—that determines whether the cell can live or die in an environment where it arrives.
Communicable, infectious and parasitic conditions
Published in Jackie Musgrave, Health and Wellbeing for Babies and Children, 2022
Infections are caused by micro-organisms, which can be defined as living organisms that are not visible to the naked eye. This fact is of course one of the reasons why infections can spread with relative ease, it is simply because the micro-organisms cannot be seen, therefore, viruses, bacteria and fungi, which cause infections can enter the body in several ways without detection.
Visual Hallmarks of Cancer
Published in Jeremy R. Jass, Understanding Pathology, 2020
In fact, by the time one has examined a specimen of cancer by naked eye and low power microscopic examination, the diagnosis is usually certain. However, another important entity is still available for study: the malignant cell itself. A normal cell of the body performs a specialised function and this is mirrored by a recognisable light microscopic structure. The size, shape and staining pattern of a cancer cell is different from its normal counterpart. The nucleus is generally larger than normal and occupies a greater proportion of the cytoplasm. The chromatin opens up from its usual uniformly dense state (heterochromatin) to form coarse clumps and condensations beneath the nuclear membrane (hyperchromatism) with intervening finely dispersed euchromatin. The nuclei vary in size, shape and staining characteristics (pleomorphism) (Fig. 26). In malignant cells nucleoli are increased in size and number, reflecting the increased protein synthetic activity of the cell. One may be able to observe an unusually large number of cells in the process of division (mitosis). Appearances at the level of the individual cell are called cytological, as opposed to histological features at the tissue level. There is now an increasing tendency to achieve a cytological diagnosis of cancer by aspirating tiny fragments of tissue through a fine needle. While the information obtained will be less detailed and comprehensive than that achieved through a larger surgical biopsy, it will often be sufficient to guide further treatment.
Molecular tissue profiling by MALDI imaging: recent progress and applications in cancer research
Published in Critical Reviews in Clinical Laboratory Sciences, 2021
Pey Yee Lee, Yeelon Yeoh, Nursyazwani Omar, Yuh-Fen Pung, Lay Cheng Lim, Teck Yew Low
Histopathological staining, immunohistochemistry (IHC) and optical microscopy are the contemporary gold standards for diagnosing and staging of tumors [1]. These methods can achieve sub-micron spatial resolution, with the latest technology offering fine structural details on the order of 100 nm [2]. These techniques are commonly performed by highly trained and skilled pathologists who examine stained tumor tissues under light microscopy for morphological aberrations. However, microscopic assessment of cancer tissues is often hampered by the heterogeneity of cancer cells and the difficulty in detecting early-stage tumors by the naked eye [3]. As well, IHC analysis is restricted to a few target proteins at any one time and is limited by the availability of specific antibodies (Table 1). It has been well established that aberrant molecular events are important hallmarks of cancer and are linked to multiple facets of tumorigenesis [4]. As such, these molecular changes may serve as useful indicators to assist cancer diagnosis and sub-classification as well as to provide additional prognostic and therapeutic details. In fact, many molecular techniques, such as polymerase chain reaction (PCR), microarray and sequencing have revolutionized traditional pathology by detecting molecular alterations that could supplement the histopathological data for cancer patient management [5].
Reverse transcription-loop mediated isothermal amplification (RT-LAMP) assay for detection of AhR receptor responsive xenobiotics
Published in Toxicology Mechanisms and Methods, 2021
Deeksha Sharma, Payal Rani, Suneel Kumar Onteru, Partha Roy, Rakesh Kumar Tyagi, Surya Pratap Singh, Dheer Singh
RT-LAMP reaction was performed at optimized concentration of RNA 50 ng at different concentration of TCDD (5, 10 and 15 pg/mL) in granulosa cells against CYP1A1 with the incorporation of a colorimetric dye HNB to the reaction mixture. After 60 min, the target template was successfully amplified in the target-contained sample, with no amplification in the no target control (NTC; Figure 3(a)). We observed the color change by naked eye at all different concentrations. However, maximum change was observed at 10 pg/mL concentration of TCDD. We also took absorbance of RT-LAMP amplified product and obtained significantly more absorbance at 10 pg/mL (Figure 3(b)). In all cases, we could distinguish RT-LAMP-positive condition from one sample to another sample by simply observing the color change of the reaction mixture.
Management of a patient’s gait abnormality using smartphone technology in-clinic for improved qualitative analysis: A case report
Published in Physiotherapy Theory and Practice, 2018
William R. VanWye, Donald L. Hoover
Although the implementation of smartphone video capture may initially appear novel, there is a lack of scientific evidence showing in-clinic integration of this technology by clinicians. Furthermore, the naked eye has limitations for assessing human motion, including observation of walking. Previous research has established that the use of video technology improves gait analysis, especially for less-experienced clinicians. Technology has advanced to allow in-clinic assessment by incorporating the use of readily available video capture using smartphones. This technology and its applications can improve diagnosis and treatment with minimal addition of cost or time. Future studies should address whether video capture for gait analysis using smartphone technology improves a clinician’s ability to diagnose and treat orthopaedic conditions, including the use of HTRS in cases of triple arthrodesis.