A physiological essay on the thymus gland

Abstract

de gli altri Jilosoji Peripatetici, hanno creduto esser fallacie, e ingmmi dei cristalli quelle, che altri hanno ammirate per operazioni stupende:^Happily, we have well nigh outgrown this indolent traditionalism in science. The microscope is so thoroughly identified with all recent progress in Physiology, that practical men cannot refuse to recognise its value as an instrument of research. It is now pretty generally felt and acknowledged, that assuming in different observers equal familiarity with the microscope, and equal care in its employment-what one anatomist discovers, another may readily verify. To this test the Author of the present Essay will cheerfully submit the result of his labours ; wishing his observations to be received only so far as they are confirmed by others, who may investigate the subject with the same care as he has given to it, and with the same freedom from previous bias. Mere details of micrometry, and the like, are interesting only in proportion to what flows from them. Fortunately, most of the facts in minute anatomy here recorded are important, both in their analogies, and in the consequences which they involve ; their application is, in most instances, so obvious that the reader will hardly comi^lain reference to the thymus ;-" Dicitur pomum granatum, sive culcitra, quia super ipsam sedet vena chilis et arteria in directo cordis, in loco ubi vena ascendit ad cor." HISTORICAL INTRODUCTION. 3 and was asserted in the early works of the Italian anatomists. Berengario'^da Carpi, while adopting the common belief, seems to have had some notion of the differences produced in the gland by age. Guinther^professedly followed Galen; and Vesa-lius^, in this instance, bowed to the authority which he elsewhere successfully opposed. Etienne^Valverde^Colombo®, Plater and Bauhin®, in the same century, Avith Riolan^, Vesling^°, de Marchettis", Bartholin^'^, de Muralto'^and Bidloo*^, in the next, successively repeated the doctrine, either in its original form, or with some trifling modification. A different theory, though one ascribing to the gland an equally mechanical use, was first suggested by Bidloo, in the thesis just quoted, and has been supported by Pozzi^^, 1 A. J. Bereng. Carpi Isagoge brevis, Bonon. 1523, fol. 33,-" certa adenosa caro, quaj est culcitra seu stragulum vence. .. ab auctoribus niorum et timum vocatur, et a vulgatibus nominatur animella et lacticinium ... est in cibariis usitatis saporosi gustus, maxime ilia quse reperitur in vitulis et hcedis lactantibus." Job. Guintberi Anat. institut. ex Galeni sententia. Par. 1536, lib. ii. (Annales du Museum, tom. xviii.) 1® Pozzi, Orat. dum et Commerc. Anat. Bonon. 1732. Modifications of the mechanical theory. 1® Th. Bartholin (in his Anat. quartum renovata, Leidoe, 1673) states, that he observed the fluid in 1652. ii' J. D. Horstius, jun. (Epist. med. decas. Franc. 1656, p. 85) says, that he has seen it so turgid with milk (lacte adeo intumescentem) " ut primo intuitu apostematis suspicio oboriretur." 15 Gul. Harveius, Epist. ad Riolanum ...

Leptin protects mice from starvation-induced lymphoid atrophy and increases thymic cellularity in ob/ob mice

“…Consistent with previous reports (8,(9)(10)(11)(12), the thymus underwent the most profound reduction in weight and cellularity with starvation. Whereas the mass of nonlymphoid organs (kidney and liver) were unaffected by leptin treatment during fasting, we have shown that exogenous leptin, administered only during the period of fasting, was able to completely protect against the thymic atrophy induced by acute starvation.…”

“…Lymphoid atrophy has long been recognized as a prominent feature of starvation in animals and humans (8)(9)(10)(11)(12)(13)(14); our findings now suggest that the reduction in plasma leptin concentration with fasting is of prime importance in its pathogenesis. Consistent with previous reports (8,(9)(10)(11)(12), the thymus underwent the most profound reduction in weight and cellularity with starvation.…”

“…These changes affect the thymus in particular (8)(9)(10)(11)(12)(13)(14). We have found that prevention of the starvation-induced reduction in plasma leptin concentration by exogenous administration of recombinant leptin was able to protect normal mice from this "nutritional thymectomy."…”

“…Lymphoid atrophy is a well-recognized consequence of nutritional deprivation in animals, including humans (8)(9)(10)(11)(12)(13)(14). This disproportionate loss of lymphoid tissue with starvation is particularly pronounced in the thymus, which has been designated "the barometer of malnutrition" (9).…”

Non responding Ludwig’s angina due to starvation and PEM: review of literature and a case report

“…Thymus has been termed as sensitive barometer of malnutrition. 17 Changes in thymus due to malnutrition includes decreased size and weight, loss of corticomedullary differentiation and lymphoid cells decrease in number. Reduced cell mediated immunity is due to reduction in mature fully differentiated T lymphocytes which in turn is due to reduction in serum thymic factor activity in malnutrition.…”