The arrangement of ciliated sensory cells in Spadella (Chaetognatha)

Author(s):  
Q. Bone ◽  
A. Pulsford

The arrangement of the ciliary sensory organs regularly arrayed on the body is re-described, and it is concluded that these are what are visible as bristles in life. On the head and tail region there are, in addition, stout single cilia, which contain multiple internal tubules, and on the head alone, there are presumed sensory cells which contain cilia within invaginations of the cell surface. Small bunches of pointed bristles occur scattered over the body surface; these are entirely distinct from the sensory cilia.

Mixotricha is a large polymastigote flagellate from the gut of the termite Mastotermes darwiniensis . Its behaviour and fine structure are described in detail. A study of the method of locomotion, using cinematography, has shown that the four flagella are used not to propel the organism but to steer it; movements are brought about by the co-ordinated undulations of many thousands of spirochaetes which cover most of the body surface. The spirochaetes are attached to small brackets, of complex internal structure, which arise in rows from the cell surface. In addition to one or more spirochaetes, each bracket is also associated with an extracellular bacterium. The fine structures of both spirochaetes and bacteria are described. A network of fibrous strands lies immediately below the cell surface, each of its meshes being associated with one of the over-lying brackets. The cytoplasm contains great numbers of vacuoles, as well as dictyosomes and rough-surfaced membranes. The membranes forming these structures, as well as the membranes of the nuclear envelope and the plasma membrane, are all triple-layered but differ in dimensions and appearance. The rough-surfaced membranes are always associated with intra­-cellular bacteria. The taxonomic position of Mixotricha is discussed in the light of the findings on its structure and behaviour.


2021 ◽  
Vol 28 (5) ◽  
pp. 291-308
Author(s):  
Tatjana Nikolayevna Dujsebayeva ◽  
Natalia Ananjeva ◽  
Aaron M. Bauer

The skin, as the interface of the body with the outside world, is directly exposed to the impacts of the environment. We have examined the microstructure of scale surfaces and the numerical distribution and morphology of skin sensory organs (SSO) in Australian limbless lizards of the family Pygopodidae. We have shown that the hairy sensory organs, as complex morphological structures, are a stable characteristic of the scale integument of pygopodids. This feature reflects their relationship to geckos and is shared homoplastically with some iguanian families (Dactyloidae, Leiosauridae, Opluridae, Chamaeleonidae). At the same time, scale micro-ornamentation as an elementary morphological structure is more plastic and, although the basic spinulate pattern is dominant, other variants occur on the scales of the serpentine body of pygopodids. We accept the spinules of MiO and the hairs of SSO as homologous structures at the cellular level since they are both derivatives of the Oberhäutchen cell surface. We propose to characterize the hair-bearing SSO of gekkotan and iguanian lizards as Oberhäutchen hairy sensory organs (ObHSO). Domination of SP MiO and presence of ObHSO in the integument of Gekkota and several families of Iguania, and sporadic occurrence of SP MiO in autarchoglossan taxa provide justification for regarding these characters as plesiomorphic. We characterize the high abundance (iterative state) of SSO in the scales of the head of pygopodids as representing the phenomenon of «overiteration», in which the phylogenetically established condition is enhanced by functional demands on the organism.


Author(s):  
Q. Bone ◽  
A. C. G. Best

Various workers during the past century have figured sensory cells bearing cilia amongst the ordinary non-ciliated epidermal cells of the body surface. Similar sensory cells were also found on the buccal cirrhi, and on the velar tentacles at the entry to the atrium. This earlier work at the light microscope level was summarized by Franz (1923) in his excellent review. More recently Schulte & Riehl (1977) have re-examined the innervation of the oral region and buccal cirrhi at the ultrastructural level, and observed two types of sensory cell in these regions, distinguished by their apical structure. They suggest that these are both secondary sensory neurons (as Franz had previously surmised), but their figures hardly make this suggestion convincing. In this note we show that there is probably only a single type of sensory cell amongst the epidermal cells of the body surface and buccal cirrhi; that it synapses at its base with incoming axons of central cells, and that a different type is indeed found in amphioxus, but only in the velar tentacles.


1990 ◽  
Vol 29 (04) ◽  
pp. 282-288 ◽  
Author(s):  
A. van Oosterom

AbstractThis paper introduces some levels at which the computer has been incorporated in the research into the basis of electrocardiography. The emphasis lies on the modeling of the heart as an electrical current generator and of the properties of the body as a volume conductor, both playing a major role in the shaping of the electrocardiographic waveforms recorded at the body surface. It is claimed that the Forward-Problem of electrocardiography is no longer a problem. Several source models of cardiac electrical activity are considered, one of which can be directly interpreted in terms of the underlying electrophysiology (the depolarization sequence of the ventricles). The importance of using tailored rather than textbook geometry in inverse procedures is stressed.


Author(s):  
Shirazu I. ◽  
Theophilus. A. Sackey ◽  
Elvis K. Tiburu ◽  
Mensah Y. B. ◽  
Forson A.

The relationship between body height and body weight has been described by using various terms. Notable among them is the body mass index, body surface area, body shape index and body surface index. In clinical setting the first descriptive parameter is the BMI scale, which provides information about whether an individual body weight is proportionate to the body height. Since the development of BMI, two other body parameters have been developed in an attempt to determine the relationship between body height and weight. These are the body surface area (BSA) and body surface index (BSI). Generally, these body parameters are described as clinical health indicators that described how healthy an individual body response to the other internal organs. The aim of the study is to discuss the use of BSI as a better clinical health indicator for preclinical assessment of body-organ/tissue relationship. Hence organ health condition as against other body composition. In addition the study is `also to determine the best body parameter the best predict other parameters for clinical application. The model parameters are presented as; modeled height and weight; modelled BSI and BSA, BSI and BMI and modeled BSA and BMI. The models are presented as clinical application software for comfortable working process and designed as GUI and CAD for use in clinical application.


2021 ◽  
Vol 116 ◽  
pp. 103915
Author(s):  
Chihiro Iiyama ◽  
Fuyu Yoneda ◽  
Masaya Tsutsumi ◽  
Shigeyuki Tsutsui ◽  
Osamu Nakamura

Dermatology ◽  
2021 ◽  
pp. 1-9
Author(s):  
María Luisa Peralta-Pedrero ◽  
Denisse Herrera-Bringas ◽  
Karla Samantha Torres-González ◽  
Martha Alejandra Morales-Sánchez ◽  
Fermín Jurado Santa-Cruz ◽  
...  

<b><i>Background:</i></b> Vitiligo has an unpredictable course and a variable response to treatment. Furthermore, the improvement of some vitiligo lesions cannot be considered a guarantee of a similar response to the other lesions. Instruments for patient-reported outcome measures (PROM) can be an alternative to measure complex constructions such as clinical evolution. <b><i>Objective:</i></b> The aim of this study was to validate a PROM that allows to measure the clinical evolution of patients with nonsegmental vitiligo in a simple but standardized way that serves to gather information for a better understanding of the disease. <b><i>Methods:</i></b> The instrument was created through expert consensus and patient participation. For the validation study, a prospective cohort design was performed. The body surface area affected was measured with the Vitiligo Extension Score (VES), the extension, the stage, and the spread by the evaluation of the Vitiligo European Task Force assessment (VETFa). Reliability was determined with test-retest, construct validity through hypothesis testing, discriminative capacity with extreme groups, and response capacity by comparing initial and final measurements. <b><i>Results:</i></b> Eighteen semi-structured interviews and 7 cognitive interviews were conducted, and 4 dermatologists were consulted. The instrument Clinical Evolution-Vitiligo (CV-6) was answered by 119 patients with a minimum of primary schooling. A wide range was observed in the affected body surface; incident and prevalent cases were included. The average time to answer the CV-6 was 3.08 ± 0.58 min. In the test-retest (<i>n</i> = 53), an intraclass correlation coefficient was obtained: 0.896 (95% CI 0.82–0.94; <i>p</i> &#x3c; 0.001). In extreme groups, the mean score was 2 (2–3) and 5 (4–6); <i>p</i> &#x3c; 0.001. The initial CV-6 score was different from the final one and the change was verified with VES and VETFa (<i>p</i> &#x3c; 0.05, <i>n</i> = 92). <b><i>Conclusions:</i></b> The CV-6 instrument allows patient collaboration, it is simple and brief, and it makes it easier for the doctor to focus attention on injuries that present changes at the time of medical consultation.


2021 ◽  
Vol 22 (3) ◽  
pp. 1030
Author(s):  
Melanie Leroux ◽  
Martial Boutchueng-Djidjou ◽  
Robert Faure

In 2021, the 100th anniversary of the isolation of insulin and the rescue of a child with type 1 diabetes from death will be marked. In this review, we highlight advances since the ingenious work of the four discoverers, Frederick Grant Banting, John James Rickard Macleod, James Bertram Collip and Charles Herbert Best. Macleoad closed his Nobel Lecture speech by raising the question of the mechanism of insulin action in the body. This challenge attracted many investigators, and the question remained unanswered until the third part of the 20th century. We summarize what has been learned, from the discovery of cell surface receptors, insulin action, and clearance, to network and precision medicine.


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