scholarly journals Estimating residence times of lymphocytes in ovine lymph nodes

2019 ◽  
Author(s):  
Margaret M. McDaniel ◽  
Vitaly V. Ganusov
Keyword(s):  
Lymph Nodes ◽  
Mathematical Models ◽  
Experimental System ◽  
The Body ◽  
Lymphoid Tissues ◽  
Residence Times ◽  
Lymphocyte Migration ◽  
Entry Rate ◽  
Lymphocyte Recirculation

AbstractThe ability of lymphocytes to recirculate between blood and secondary lymphoid tissues such as lymph nodes (LNs) and spleen is well established. Sheep have been used as an experimental system to study lymphocyte recirculation for decades and multiple studies exist documenting accumulation and loss of intravenously (i.v.) transferred lymphocytes in efferent lymph of various ovine LNs. Yet, surprisingly little work has been done to accurately quantify the dynamics of lymphocyte exit from the LNs and to estimate the average residence times of lymphocytes in ovine LNs. In this work we developed a series of mathematical models based on fundamental principles of lymphocyte recirculation in the body and specifically, on how lymphocytes enter and exit lymph nodes in non-inflammatory (resting) conditions. We fitted these models to data from several independent experiments. Our analysis suggested that in sheep, recirculating lymphocytes spend on average 3 hours in the spleen and 20 hours in skin or gut-draining LNs with a distribution of residence times in LNs following a skewed gamma (lognormal-like) distribution. The latter result is in contrast which recent suggestions that the distribution of residence times of naive T cells in murine LNs is exponential and that lymphocyte residence times depend on the LN type (e.g., gut- vs. skin-draining). Our mathematical models also suggested an explanation for a puzzling observation of the long-term persistence of i.v. transferred lymphocytes in the efferent lymph of the prescapular LN (pLN); the model predicted that this is a natural consequence of long-term persistence of the transferred lymphocytes in circulation. We also found that lymphocytes isolated from the skin-draining pLN have a two-fold increased entry rate into the pLN as opposed to the mesenteric (gut-draining) LN (mLN). Likewise, lymphocytes from mLN had a three-fold increased entry rate into the mLN as opposed to entry rate into pLN. Importantly, these cannulation data could not be explained by preferential retention of cells in LNs of origin. Taken together, our work illustrates the power of mathematical modeling in describing the kinetics of lymphocyte migration in sheep and provides quantitative estimates of lymphocyte residence times in ovine LNs.

scholarly journals Efficient Transendothelial Migration of Latently HIV-1-Infected Cells

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1589
Author(s):  
Reou Tanabe ◽  
Yuko Morikawa
Keyword(s):  
Lymph Nodes ◽  
Stromal Cells ◽  
Cell Subset ◽  
Transendothelial Migration ◽  
The Body ◽  
Lymphoid Tissues ◽  
Latently Infected ◽  
Infected Cells ◽  
Hiv 1

A small fraction of HIV-1-infected T cells forms populations of latently infected cells when they are a naive T-cell subset or in transit to a resting memory state. Latently HIV-1-infected cells reside in lymphoid tissues and serve as viral reservoirs. However, whether they systemically recirculate in the body and re-enter the lymphoid nodes are unknown. Here, we employed two in-vitro cell coculture systems mimicking the lymphatic endothelium in lymph nodes and investigated the homing potential, specifically the transendothelial migration (TEM), of two latently HIV-1-infected cell lines (J1.1 and ACH-2). In trans-well coculture systems, J1.1 and ACH-2 showed higher TEM efficiencies than their parental uninfected and acutely infected cells. The efficiency of TEM was enhanced by the presence of stromal cells, such as HS-5 and fibroblastic reticular cells. In an in-vitro reconstituted, three-dimensional coculture system in which stromal cells are embedded in collagen matrices, J1.1 showed slightly higher TEM efficiency in the presence of HS-5. In accordance with these phenotypes, latently infected cells adhered to the endothelial cells more efficiently than uninfected cells. Together, our study showed that latently HIV-1-infected cells enhanced cell adhesion and TEM abilities, suggesting their potential for efficient homing to lymph nodes.

scholarly journals Experimental and mathematical approaches to quantify recirculation kinetics of lymphocytes

2018 ◽  
Author(s):  
Vitaly V. Ganusov ◽  
Michio Tomura
Keyword(s):  
Immune Cells ◽  
Lymphocyte Subsets ◽  
Lymphoid Tissues ◽  
Residence Times ◽  
T And B Cells ◽  
Lymphocyte Recirculation ◽  
Intensive Investigation ◽  
Resting Lymphocytes ◽  
Kinetics Of ◽  
Different Tissues

AbstractOne of the properties of the immune system that makes it different from nervous and en-docrine systems of mammals is the ability of immune cells to migrate between different tissues. Lymphocytes such as T and B cells have the ability to migrate from the blood to secondary lymphoid tissues such as spleen, lymph nodes, and Peyer’s patches, and then migrate back to the blood, i.e., they can recirculate. Recirculation of lymphocytes has been a subject of intensive investigation decades ago with wealth of data on the kinetics of lymphocyte recirculation available. However, these data have not been widely used to estimate the kinetics of recirculation of different lymphocyte subsets in naive and immunized animals. In this paper we review pioneering studies addressing the question of lymphocyte recirculation, overview quantitative approaches that have been used to estimate the kinetics of lymphocyte recirculation, and provide currently published estimates of the residence times of resting lymphocytes in secondary lymphoid tissues of mammals.

scholarly journals THYMUS-DEPENDENT AREAS IN THE LYMPHOID ORGANS OF NEONATALLY THYMECTOMIZED MICE

1966 ◽  
Vol 123 (1) ◽  
pp. 191-204 ◽  
Author(s):  
Delphine M. V. Parrott ◽  
Maria A. B. de Sousa ◽  
June East
Keyword(s):  
Lymph Nodes ◽  
Plasma Cells ◽  
The Body ◽  
Lymphoid Tissues ◽  
Spleen Cells ◽  
Apparent Paradox ◽  
Cell Series ◽  
Thymus Cells ◽  
Thymectomized Mice

Specific areas of lymphocyte depletion, termed thymus-dependent areas, have been delineated in neonatally thymectomized C3H/Bi and F1 (C57BL x C3H/Bi) mice. They occur within the lymphoid follicles of the spleen immediately surrounding the central arterioles, and constitute the mid and deep cortical zones of the lymph nodes. These depleted areas appear in healthy thymectomized mice as early as 3 wk after operation but, in mice which survive for more than 6 to 7 wk, the thymus-dependent areas are repopulated by rapidly dividing pyroninophilic cells, the majority of which are immature plasma cells. Syngeneic thymus cells, labeled in vitro with tritiated adenosine localize preferentially in the thymus-dependent areas after intravenous injection. Similarly labeled spleen cells also accumulate in these areas but, in addition, are distributed at the periphery of splenic follicles and in the outer cortical zone of the lymph nodes. Many more spleen than thymus cells enter the lymphoid tissues and the spleen appears to be the primary target. The apparent paradox that syngeneic thymus cells are less efficient than spleen cells in restoring neonatally thymectomized mice to normality is discussed in the light of these results and possible routes by which the migrating cells could enter the lymphoid tissues are considered. The origin of the plasma cells which repopulate the lymphocyte depleted areas is also discussed. It is concluded that the normal thymus produces cells which contribute directly to the migratory or circulatory lymphocyte population but that there also exists another source of supply for the plasma cell series. These two systems may function synergistically so that the thymus may control, directly or indirectly, the balance of cell populations within the body.

Scanning electron microscopy of freeze-fractured prescapular lymph node of caprine

1984 ◽  
Vol 42 ◽  
pp. 244-245
Author(s):  
O. Faroon ◽  
F. Al-Bagdadi ◽  
T. G. Snider ◽  
C. Titkemeyer
Keyword(s):  
Lymph Node ◽  
Lymph Nodes ◽  
Lymphatic System ◽  
Three Dimensional ◽  
Meat Products ◽  
The Body ◽  
Morphological Data ◽  
The World ◽  
Cellular Constituent ◽  
Scanning Electron

The lymphatic system is very important in the immunological activities of the body. Clinicians confirm the diagnosis of infectious diseases by palpating the involved cutaneous lymph node for changes in size, heat, and consistency. Clinical pathologists diagnose systemic diseases through biopsies of superficial lymph nodes. In many parts of the world the goat is considered as an important source of milk and meat products.The lymphatic system has been studied extensively. These studies lack precise information on the natural morphology of the lymph nodes and their vascular and cellular constituent. This is due to using improper technique for such studies. A few studies used the SEM, conducted by cutting the lymph node with a blade. The morphological data collected by this method are artificial and do not reflect the normal three dimensional surface of the examined area of the lymph node. SEM has been used to study the lymph vessels and lymph nodes of different animals. No information on the cutaneous lymph nodes of the goat has ever been collected using the scanning electron microscope.

Defining the Competence of Psychologists with a View to Public Accountability *

1997 ◽  
Vol 2 (4) ◽  
pp. 293-300 ◽  
Author(s):  
Ype H. Poortinga ◽  
Ingrid Lunt
Keyword(s):  
Scientific Knowledge ◽  
Professional Training ◽  
Professional Competence ◽  
Codes Of Ethics ◽  
The Body ◽  
The European Union ◽  
Rigorous Evaluation ◽  
Judicial Proceedings ◽  
Psychological Knowledge

In national codes of ethics the practice of psychology is presented as rooted in scientific knowledge, professional skills, and experience. However, it is not self-evident that the body of scientific knowledge in psychology provides an adequate basis for current professional practice. Professional training and experience are seen as necessary for the application of psychological knowledge, but they appear insufficient to defend the soundness of one's practices when challenged in judicial proceedings of a kind that may be faced by psychologists in the European Union in the not too distant future. In seeking to define the basis for the professional competence of psychologists, this article recommends taking a position of modesty concerning the scope and effectiveness of psychological interventions. In many circumstances, psychologists can only provide partial advice, narrowing down the range of possible courses of action more by eliminating unpromising ones than by pointing out the most correct or most favorable one. By emphasizing rigorous evaluation, the profession should gain in accountability and, in the long term, in respectability.

EFFECT OF DIFFERENT DOSES OF PREDNISOLONE AND ADRENOCORTICOTROPHIC HORMONE (ACTH) ON LYMPHATIC LUNG CLEARANCE AND ON EXPERIMENTAL SILICOSIS

1970 ◽  
Vol 63 (2) ◽  
pp. 325-337
Author(s):  
Carl-Johan Göthe
Keyword(s):  
Lymph Nodes ◽  
Lymphatic System ◽  
The Body ◽  
Lung Weight ◽  
Lung Clearance ◽  
Dust Transport ◽  
Fine Particulate ◽  
Quartz Dust ◽  
Different Doses ◽  
Stimulation Of

ABSTRACT The effect of three doses of prednisolone and ACTH respectively on the weight of the body, the lungs and the hilar lymph nodes was studied on rats killed one month after the intratracheal (i.t.) injection of 50 mg of fine-particulate quartz. The prednisolone was administered via the drinking water, and the ACTH was injected intraperitoneally during the period between the i.t. injection of quartz dust and the killing of the animals. Prednisolone causes the rats to become cachectic and reduces the weight of the hilar lymph nodes. It also retards the transport of quartz dust from the lungs via the lymphatics. All these effects increase with increasing doses of prednisolone. However, its effect on the lung weight is insignificant. ACTH does not affect the body weight, but retards the weight increase of the lungs and the hilar lymph nodes. These effects increase with increasing doses of ACTH, and seem to be connected with an ability of ACTH to promote the clearance of quartz dust from the lungs and hilar lymph nodes. The method used, however, does not make it possible to differentiate quantitatively between any ACTH effects on the bronchogenie and lymphatic lung-clearance mechanisms. Available data, however, indicate that the stimulation of the dust transport from the lungs and hilar lymph nodes is, at least to some extent, related to the lymphatic system.

STUDIES IN THE SUPPOSED GOITROGENOUS EFFECT OF TAP WATER IN HELSINKI

1960 ◽  
Vol XXXIII (IV) ◽  
pp. 630-636
Author(s):  
F.-E. Krusius ◽  
P. Peltola
Keyword(s):  
Tap Water ◽  
Physiological Saline ◽  
Normal Weight ◽  
The Body ◽  
Iodine Uptake ◽  
Redistilled Water ◽  
Detectable Difference ◽  
Term Administration ◽  
Long Term Experiment

ABSTRACT The study reported here was performed in order to examine the tap water of Helsinki for its alleged goitrogenous effect. In a short-term, 24-hour experiment with rats, kept on an iodine-poor diet, we noticed no inhibition of the 4-hour 131I uptake, as compared with that of animals receiving physiological saline instead of tap water. Two similar groups of rats receiving 1 and 2 mg of mercazole in redistilled water showed a distinct blockage of the 4-hour uptake, which proved the effect of this substance. In a long-term experiment of 5 weeks' duration there was no detectable difference in the body weight, thyroid weight and the 4-hour 131I uptake when the rats receiving tap water or distilled water to which 0.45 per cent of sodium chloride was added were compared with each other. Replacement of tap water by a 10 mg per cent solution of mercazole in redistilled water enlarged the thyroid to double its normal weight and increased the 131I uptake to approximately five times that of the controls. Thus our experiments failed to demonstrate any goitrogenous effect in the tap water of Helsinki. Changes similar to those produced by a long-term administration of mercazole, i. e. an enlargement of the thyroid and an increased thyroidal iodine uptake, have been shown to be due to milk collected from goitrous areas. The observations here reported confirm the importance of milk in the genesis of the goitre endemia of Helsinki. Attention is further called to the fact that a thyroidal enlargement combined with an increased thyroidal iodine uptake cannot always be taken as a sign of iodine deficiency because similar changes may be produced by the administration of goitrogens.

ANALYSIS OF ABDOMINAL TYPHOID INCIDENCE IN THE SOUTH REGION OF THE KYRGYZ REPUBLIC

2020 ◽  
pp. 43-48
Author(s):  
Zakirova J.S. ◽  
Nadirbekova R.A. ◽  
Zholdoshev S.T.
Keyword(s):  
Drinking Water ◽  
Typhoid Fever ◽  
Risk Groups ◽  
The Body ◽  
Kyrgyz Republic ◽  
Radiation Factor ◽  
High Quality ◽  
Two Generations ◽  
Immunological Deficiency

The article analyze the long-term morbidity, spread of typhoid fever in the southern regions of the Kyrgyz republic, and remains a permanent epidemic focus in the Jalal-Abad region, where against the low availability of the population to high-quality drinking water, an additional factor on the body for more than two generations and radiation factor, which we confirmed by the spread among the inhabitants of Mailuu-Suu of nosological forms of the syndrome of immunological deficiency, as a predictor of risk groups for infectious diseases, including typhoid fever.

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