Distribution and morphology of ghrelin-immunopositive cells in the thymus of the African ostrich / Distribución y morfología de células inmunopositivas de la ghrelina en el timo de la avestruz africana

Ghrelin, an endogenous ligand for the growth hormone secretagogue receptor, has been detected in the thymus of multiple vertebrates. However, little is known about its distribution in the thymus of the African ostrich. In this study, we evaluated the distribution and morphological characteristics of ghrelin-producing cells in the thymus of the African ostrich. Our results revealed that the thymus consists of a capsule and a parenchyma, which comprises the cortex and medulla. Compared to the cortex, the medulla had a fewer number of thymocytes and a greater number of epithelial cells. Additionally, three thymic corpuscles were identified. Ghrelin-immunopositive (ghrelin-ip) cells were detected both in the cortex and medulla of the African ostrich thymus, specifically within epithelial cells and thymic corpuscles. On the other hand, no ghrelin-ip cells were detected within thymocytes. These results clearly demonstrate the presence of ghrelin-ip cells in the thymus of the African ostrich.

La ghrelina, un ligando endógeno para el receptor secretor de la hormona del crecimiento, se ha detectado en el timo de múltiples vertebrados. Sin embargo, poco se sabe sobre su distribución en el timo de la avestruz africana. En este estudio se evaluó la distribución y características morfológicas de las células productoras de ghrelina en el timo de la avestruz africana. Nuestros resultados revelaron que el timo consiste en una cápsula y un parénquima, que comprende la corteza y la médula. En comparación con la corteza, se observó un número menor de timocitos en la médula y un mayor número de células epiteliales. Además, se identificaron tres corpúsculos tímicos. Se detectaron células inmunopositivas a la ghrelina (ghrelin-ip) tanto en la corteza como en la médula del timo de la avestruz africana, específicamente dentro de células epiteliales y corpúsculos tímicos. Por otra parte, no se detectaron células ghrelin-ip dentro de los timocitos. Estos resultados demuestran claramente la presencia de células ghrelin-ip en el timo de la avestruz africana.

Morfologia e biometria do timo em araras dos gêneros Ara e Anodorhynchus / Morphology and biometry of the thymus gland in macaw of Ara and Anodorhynchus genera

Foram utilizados 12 exemplares de Ara ararauna - seis fêmeas e seis machos -, cinco exemplares de Ara chloropterus (uma fêmea e quatro machos) e dois exemplares de Anodorhynchus hyacinthinus - uma fêmea e um macho -, todos adultos, doados por criadouro particular, após óbito natural. Os lobos foram dissecados e medidos com paquímetro - comprimento x largura x espessura - e analisados quanto ao peso, à topografia e à morfologia individual. Independentemente do gênero, foram identificados, em 17 casos (89,5%), lobos tímicos nos antímeros cervicais esquerdo e direito, e em oito casos (42,1%), lobos na cavidade celomática. Os lobos apresentaram formatos alongados - 52,6% -, arredondados - 21,1% - ou ovalados - 15,8% -, posicionados preferencialmente ventromedialmente ao longo do plexo vasculoneural do pescoço, com número médio de cinco lobos por antímero, tamanho médio de 0,49cm de comprimento, 0,12cm de largura e 0,05cm de espessura e peso médio de 0,076g.

Twelve samples of Ara ararauna - six females and six males -, five samples of Ara chloropterus (one female and four males) and two samples of Anodorhynchus hyacinthinus (one female and one male), all adults from a Breeding Park, were used after natural death. The lobes were dissected and measured with electronic calliper (length x width x thickness) and analyzed taking their weight, topography and individual morphology into account. Regardless of gender, 89.5% of the cases presented timic lobes in the left and right cervical antimere, and 42.1% of the cases presented lobes in the celomatic cavity. The lobes were shown in shapes - long (52.6%), round (21.1%) or oval (15.8%), positioned mostly ventromedially, along the neurovascular plexus of the neck, with an average of five lobes per antimere, and an average size of 0.49cm length, 0.12cm width, and 0.05cm thick and average weight of 0.076g.

effect of Nigella sativa on the thymus of young and adult rats: Histological, immunohistochemical, and morphometric study

The thymic microenvironment plays a central role in T-cell differentiation. Involution of the thymus begins relatively early in life, resulting in decreased immunity. Nigella sativa is known for its immunopotentiating effects. The aim of the study was to elucidate the effect of N. sativa on the structure of the thymus in young and mature adult rats. Twenty-eight male Wistar albino rats were divided into two groups: group I and group II. Group I was further divided into subgroup Ia and subgroup Ib. Subgroup Ia included seven 1-month-old young rats weighing 50-60 g that received plain water by gavage for 15 days. Subgroup Ib included seven young rats that received 2 ml/kg body weight of 1% petroleum ether extract of N. sativa by gavage for 15 days. Group II was further divided into subgroup IIa and subgroup IIb. Subgroup IIa included seven mature 12-month-old adult rats weighing 600-650 g that received plain water by gavage for 15 days. Subgroup IIb included seven mature adult rats that received 2 ml/kg body weight of 1% petroleum ether extract of N. sativa by gavage for 15 days. Thymi from different subgroups were processed for histological, immunohistochemical, and morphometric studies. In subgroup Ib, the thymus of N. sativa-treated rats revealed a significant increase in the number of CD3-positive cells in the cortex. Some CD3-positive cells were seen in the medulla. In subgroup IIa, signs of thymic involution in the form of expansion of perivascular spaces containing adipocytes and stromal cells with a significant decrease in the number of CD3-positive cells were noticed. In addition, CI cells non reticular thymulin secreting cells along the capillaries were detected. In N. sativa-treated adult rats [subgroup IIb], restoration of the normal stroma and parenchyma occurred. Moreover, a significant increase in the number of CD3-positive cells in the cortex and medulla with an increase in the secretory activity of reticuloepithelial cells was noticed. Oral administration of the petroleum ether extract of N. sativa for 15 days to young and mature adult rats results in enhanced proliferation of thymocytes and increased activity of reticuloepithelial cells

Aspectos morfométricos do timo em gatos domésticos (Felis domesticus) / Morphometric aspects of the thymus in domestic cats (Felis domesticus)

O timo é um órgão linfático primário que desenvolve sua atividade em organismos jovens. Apesar de sua função ser responsável por mecanismos fundamentais na aquisição das defesas e conseqüentes respostas orgânicas, ela ainda não está totalmente esclarecida, nem tampouco as bases morfológicas que respondem por tais funções, como o processo de desenvolvimento e involução do órgão. Objetivou-se analisar e caracterizar os aspectos morfológicos do timo, tais como seu tamanho e volume, e aspectos histológicos do timo em gatos, correlacionando o sexo e o desenvolvimento etário. Doze timos provenientes de fetos de gatos domésticos (Felis domesticus) sem raça definida (SRD), machos e fêmeas, separados em três grupos etários. O timo apresentou-se com uma coloração rosa-pálida e com duas porções, a torácica e a cervical, sendo que cada uma delas possuía um lobo direito e um lobo esquerdo em sua maioria. A porção torácica localizava-se em região de mediastino cranial, entre os pulmões e à base do coração. E a porção cervical estendia-se além das costelas em sentido cranial, estando localizada ventralmente à traqueia. A estrutura celular do timo demonstrou-se organizada com a presença de agregados concêntricos, os chamados corpúsculos tímicos, formados por células epiteliais, sustentada por uma cápsula de tecido conjuntivo de onde partiam septos que ao penetrar no órgão dividia-o em lóbulos. Ocorreram variações significativas quanto à lobação e as dimensões do timo entre indivíduos da mesma faixa etária, e entre sexos diferentes. Os valores relativos ao comprimento, espessura e largura, de maneira geral, apresentaram aumento, em conformidade ao desenvolvimento dos animais, mas com diferenças entre os sexos.

The thymus is a primary lymphatic organ that develops its activity in young organisms. But despite its function is fundamental mechanisms responsible for the acquisition and subsequent body defenses, it is not yet fully understood, neither the morphological basis accounting for such functions as the process of development and the organ involution. The objective was to analyze and characterize the morphology of the thymus, such as its size and volume, and histological aspects of the thymus in cats, correlating sex and age development. Twelve foetus of mongrel domestic cats (Felis domesticus), males and females, divided into three age groups. The thymus presented two parts with a pale pink color, the thoracic and cervical portion; each has a right lobe and a left lobe mostly. The thoracic portion was located in the region of cranial mediastinum, between the lungs and the heart base. And the cervical portion extended beyond the ribs cranially and is located ventral to the trachea. The thymus cellular structure was shown by the presence of organized concentric aggregates, named Hassall's corpuscles, formed by epithelial cells, supported by a connective tissue capsule that penetrated the parenchyma dividing it into lobules. Significant changes with number of lobes and thymus size between individuals of the same age, and between sex. The values for length, thickness and width, in general, showed an increase, according to the development of animals, with differences between sex.

Efectos del ácido fólico sobre algunas variables morfométricas del timo de ratas adolescentes con síndrome fetal alcohólico / Effects of folic acid on some morphometric variables of the thymus of adolescent rats with fetal alcohol syndrome

Se pretende determinar los efectos protectores sobre el timo de ratas adolescente con síndrome fetal alcohólico experimental, para lo cual se utilizaron 24 ratas Wistar adolescentes y gestantes divididas en 4 grupos: A) tratadas con etanol, B) tratadas con etanol y ácido fólico, C) tratadas solo con ácido fólico y D) grupo no tratado. El tratamiento se extendió durante toda la gestación hasta el parto. Se tomaron 2 crías por cada madre. A las crías se les practicó la eutanasia a los 35 días de vida posnatal. Se extrajo el timo y se obtuvieron cortes de 4 micrómetros y se colorearon con H/E. Se utilizó el programa digital para morfometría Image Tool. Se midieron las áreas de la corteza y médula del timo, así como la relación entre ambas variables. Se realizó ANOVA de 2 vías. El área de la corteza del timo fue significativamente menor en el grupo tratado con etanol en relación con el resto de los grupos. Los hijos de las madres tratadas con ácido fólico mostraron los valores mayores en el área de la corteza, y el grupo tratado con etanol y ácido fólico mostró un patrón muy similar al control. Se concluyó que el etanol provoca cambios histopatológicos evaluados como atrofia de la corteza del timo y que el ácido fólico suministrado a la madre durante la gestación tiene efecto protector sobre esta anomalía

The study is intended to determine the protective effects of folic acid on the thymus of adolescent rats with experimental fetal alcohol syndrome. To this end, 24 adolescent and pregnant Wistar rats were used, which were divided in 4 groups: A) treated with ethanol, B) treated with ethanol and folic acid, C) treated only with folic acid, and D) not treated. Treatment extended throughout the entire gestation period until delivery. Two offspring were chosen from each mother. The offspring were euthanized at 35 days of postnatal life. The thymus was extracted and 4-micrometer cutouts were obtained, which were colored with H/E. The digital program Image Tool was used for morphometry. Measurements were taken of areas of the thymic cortex and medulla, and the relationship between the two variables was determined. A two-way ANOVA was performed. The thymic cortex area was significantly smaller in the group treated with ethanol than in the other groups. Offspring of mothers treated with folic acid showed the highest cortex area values, and the group treated with ethanol and folic acid exhibited a pattern very similar to the control group. It was concluded that ethanol brings about histopathological changes evaluated as thymic cortex atrophy, and that the folic acid administered to mothers during gestation has a protective effect over this abnormality

Vascularização arterial dos lobos torácicos do timo em fetos de suínos da Linhagem C40 / Arterial vascularization of the thoracic lobes of the thymus in stillborns of the lineage C40

As origens e distribuições das artérias que vascularizaram os lobos torácicos do timo foram estudadas em fetos de 30 suínos da linhagem C40, sendo 12 machos e 18 fêmeas. Os exemplares tiveram o sistema arterial preenchido com solução aquosa a 50 por cento de Neoprene Látex corado e, em seguida, foram submetidos à fixação em solução aquosa a 10 por cento de formaldeído. Os lobos torácicos do timo foram vascularizados por ramos diretos das artérias torácica interna direita (63,33 por cento) e esquerda (53,33 por cento), subclávia esquerda (3,33 por cento), vertebral esquerda (3,33 por cento), cervical superficial direita (3,33 por cento) e esquerda (3,33 por cento), carótida comum esquerda (3,33 por cento), coronária direita (3,33 por cento) e pelos troncos braquiocefálico (33,33 por cento) e costocervical (3,33 por cento). Observaram-se ainda os ramos indiretos das artérias torácica interna direita (70 por cento) e esquerda (76,67 por cento), subclávia esquerda (23,33 por cento), cervical superficial esquerda (3,33 por cento) e do arco aórtico (6,67 por cento).

The origins and distributions of the arteries that vascularization the thoracic lobes of the thymus, right and left, were studied in 30 swine of the lineage C40, fetus, being 12 males and 18 females. The animals had the arterial system filled with aqueous colored solution in a 50 percent of Neoprene Latex, and than were fixed in 10 percent aqueous solution formaldehyde. The thoracic lobes of thymus were vascularization by direct branches of the right (53.33 percent) and left (63.33 percent) internal thoracic arteries, left subclavian (3.33 percent), left vertebral (3.33 percent), right (3.33 percent) and left (3.33 percent) superficial cervical, left common carotid (3.33 percent), right coronary (3.33 percent) and brachiocephalic trunk (33.33 percent) and costocervical trunk (3.33 percent). The right internal thoracic arteries (70 percent) and left internal thoracic (76.67 percent), left subclavian (23.33 percent), left superficial cervical (3.33 percent) of the aortic arch (6.67 percent) provided indirect branches for the correspondent thoracic lobes of the thymus in each side.

Características morfométricas do desenvolvimento do timo em cães / Morphometric characteristics of thymus development in dogs

O timo é um órgão de grande importância imunológica durante a vida fetal e o período neonatal. Ele é o precursor da linfopoiese e apresenta alta atividade linfopoiética, sendo também o maior órgão linfóide durante a vida intrauterina e até o nascimento. Neste estudo, os aspectoso morfológicos do desenvolvimento prenatal de timos de cães foram descritos em fetos de diferentes idades e sexos. Vinte e quatro fetos de cães domésticos, sem raça definida, machos e fêmeas, foram divididos em 4 grupos etários. O timo apresentou-se composto por dois lobos unidos por um tecido de conexão, com coloração rósea, localizados no espaço mediastinal cranial. A porção cranial estendeu-se pouco além do primeiro par de costelas. As células que formavam o parênquima do timo estavam bem organizadas. Agrega dos concêntricos chamados Corpúsculos de Hassal foram observados, envolvidos por uma delgada cápsula de tecido conjuntivo que é espessada por tecido adiposo. O tamanho dos vasos aumentou gradativamente com a idade dos fetos, sendo maior nos animais próximos ao nascimento. Os timos das fêmeas apresentaram maior volume (Vref) e dimensões de tamanho que nos machos.

The thymus is an organ with great immunological relevance during foetus life and neonatal period, It is the predecessor of lymphopoiesis and shows high lymphopoietic activity, being also the largest lymphoid organ during intrauterine life and at birth. In this study, the morphological aspects of the prenatal development of dog thymus were described in foetus of different ages and sexes. Twenty-four foetus of mongrel domestic dogs, males and females, were divided into four age groups. The thymus presented two lobes linked by a rose-colored tissue connection that was localized in the cranial mediastinal space. The cranial portion protrudes slightly beyond the first pair of ribs. The cells that formed the thymus parenchyma were well organized. Concentric aggregates named Hassal corpuscles were observed, involved by a thin capsule of connective tissue thickened by adipose tissue. The vessels size gradually increased with the foetus age, being larger in animals that were closer to birth. The volume (Vref) and size parameters of female thymus were larger than in males.

Vascularização arterial dos lobos cervicais do timo em fetos de suínos da linhagem C40 / Arteries of the cervical wolves of the thymus in stillborns hogs of the lineage C40

O timo é o órgão linfóide que atua no desenvolvimento pós-natal e manutenção da competência imunológica dos animais. Apresenta-se desenvolvido desde a fase final do período pré-natal até o início da puberdade, sendo neste período o maior órgão linfóide e o de maior função linfopoiética. Por causa desta importância, objetivou-se estudar a vascularização arterial da parte cervical do timo da linhagem suína C40, cujas características zootécnicas tem produzido crescente interesse econômico na sua exploração. Para tanto, utilizou-se 30 fetos de suínos (machos e fêmeas com diferentes idades) provenientes de abortos e coletados em criatórios das regiões do Triângulo Mineiro e Alto Paranaíba-MG. Após injeção dos sistemas arteriais e posterior dissecação, verificou-se que os lobos cervicais do timo, de ambos os antímeros, mostraram-se na fase fetal divididos em porções craniais e caudais, unidas por um istmo e estendendo-se desde as glândulas mandibulares até a margem cranial do primeiro par de costelas. Os lobos cervicais tímicos dos antímeros direito e esquerdo foram irrigados pelas artérias subclávia, carótida comum, tireóidea caudal, tireóidea cranial, cervical superficial, laríngea caudal, laríngea cranial. Os lobos cervicais tímicos do antímero direito foram irrigados pelas mesmas artérias do antímero contralateral, excetuando-se a artéria subclávia.

The thymus is a lymphoid structure of great importance for young animals, excellently acting on the after-birth development and maintenance of their immunologic ability. It has been shown well-developed from the final phase of the prenatal period through the beginning of puberty, and is the largest lymphoid structure with high lymphopoietic function during that period. The objective was to study the arterial vascularization of the cervical part of the thymus of C40 pigs, to supply morphologic information for this structure in animals that are of economical importance in Brazil, and to furnish subsidies for comparative anatomy. Thirty pig embryos, males and females, were used originating from cases of abortion and natural death. Both sides of the cervical lobes of the thymus were found divided during the fetal phase into cranial and caudal portions, joined by an isthmus and situated along the medial face of the mandibulary glands up to the cranial edge of the first pair of ribs. Characteristic for each side of the thymus vascularization is that the cervical lobes of the left side were found irrigated by Arteria subclavia, A. carotida communis, A. thyreoidea caudalis, A. thyreoidea cranialis, A. thyreoidea cervicalis superficialis, A. laryngea caudalis, and A. laryngea cranialis. The cervical thymus lobes of the right side were irrigated by A. carotida communis, A. thyreoidea caudalis, A. thyreoidea cranialis, A. thyreoidea cervicalis superficialis, A. laryngea caudalis, and A. laryngea cranialis.

Evaluación del tamaño del timo: validez y confiabilidadde la ecografía del timo en niños / Assessment of the size of the thymus: validity and reliability of ultrasonography of the thymus in children

El propósito del trabajo fue establecer la validez y confiabilidad de la Ecografía del Timo en niños menores de 6 años de edad, de ambos sexos, en la actualidad es una de las herramientas que puede evaluar la función de la respuesta inmunitaria en forma confiable yno invasiva. Metodos. La validez de la ultrasonografía del timo, es demostrada frente aun patrón de oro, en niños fallecidos se ejecutó la ecografía vs. la Anatomía Patológica (Grupo 1); y en otros niños la ecografía vs. laTomografía Axial Computarizada (TAC)(Grupo 2). La confiabilidad, fue evaluada a nivel intra observador (Grupo 3), se evaluó su estado nutricional mediante: peso para talla, peso para la edad, talla para la edad. A todos los niños, con evaluación de la TAC yla confiabilidad se les realizó un examen y un cuestionario de tipo clínico pediátrico. Resultados. Tanto la evaluación por anatomía patológica (n=5), como por tomografía axial computarizada (n=4) vs. la ecografía del timo no muestran diferencias estadísticamente signifi cativas en la mediciones realizadas en el tamaño del timo en los niños evaluados. En el grupo 3 (n=15), el índice de correlación intraclase es de 0.96. Se realizaron los cálculos de One-way ANOVA + test de Scheffe y elanálisis de varianza (ANOVA). Conclusion. La validez de la ecografía del timo en niños es adecuada, esuna herramienta que “mide lo que dice medir”. La confi abilidad intraobservador, establece un índice de correlación casi perfecto conun personal adecuadamente entrenado para medir con la ecografía el timo en niños.

Abstract. Evaluation of the thymus size: validity and reliableness of thymussonography in children. Introduction. The porpuse of this paper was to stablish the validity and the reliableness of thymus sonography in children under 6 years of age of both sexes. At present, thymus songraphy is one of the tools for assessing the function of the immune response by means of a reliable and non-invasive method. Methods. The validity of thymus ultrasongraphy is demonstrated in front of a gold standard, in dead children, sonography was performed and compared to pathological anatomy (group 1); and in other children, sonography was compared to computerized axial tomography (TAC) (group 2). The reliableness was evaluated at the intraobserver level (group 3). The children ́s nutritional status was assessed by: weight for height; weight for age; and height for age. On all children with TAC and reliableness evaluation a clinical exam was performed and a paediatric clinic questionnaire was fi lled out. Results. The evaluation by pathological anatomy (n=5) as well as the computerized axial tomography as compared to thymus sonography did not show statistically signifi cant differences in the measurements of thymus size. In group 3 (n=15), the intraobserver correlation index was 0.96. Statistical analysis was performed using one-way ANOVA + test of a Scheffé and analysis of variance (ANOVA). Conclusion.The validity of the thymus sonography in children is adequate, it is a tool that “measures what it says it measures”. The intraobserver reliableness establishes an almost perfect correlation index in a well trained person for measuring thymus size by sonography in children.

T-lymphocyte subsets and thymic size in malnourished infants in Egypt: a hospital-based study

Thymus size was assessed ultrasonographically and correlated to the percentage of CD4 and CD8 T-lymphocytes in peripheral blood in 32 infants with protein-energy malnutrition [PEM] and compared with 14 healthy control infants. The study revealed thymus atrophy in patients with PEM, especially the oedematous type, accompanied by changes in the peripheral lymphocyte subsets. These changes were reversible after nutritional rehabilitation. However, they may affect the immune status of PEM patients and may require a longer duration of nutrition rehabilitation than required for recovery of anthropometric measures. We recommend proper assessment of the immune functions of PEM patients during nutritional rehabilitation until full recovery

Morphometric analysis of the thymus of puppies infected with the Snyder Hill Strain of canine distemper virus / Análise morfométrica do timo de cães filhotes infectados com a amostra Snyder Hill do vírus de cinomose canina

The thymic morphometry analysis was used for determining apoptosis and atrophy of the thymus of eight puppies inoculated with canine distemper virus (CDV). Three healthy dogs were used as negative controls. Sections, 5æm thick, were stained by HE and Shorr, and the latter were evaluated by morphometry. CDV nucleoprotein was detected by immunohistochemistry. Morphometric results confirmed lymphoid hypotrophy in CDV inoculated dog thymuses, more stroma, less parenchyma and higher apoptotic index/field than negative control (not inoculated) puppies. Apoptosis plays a role in the mechanism of thymus atrophy that develops in canine distemper.

Determinaram-se a apoptose e a atrofia no timo de oito cães novos, inoculados experimentalmente com o vírus de cinomose. Três cães saudáveis foram usados como controle negativo. Secções coradas pelo Shorr foram avaliadas por morfometria. A nucleoproteína viral foi detectada por imunoistoquímica. Os resultados morfométricos confirmaram a hipotrofia e mostraram que o timo dos cães inoculados tinha mais estroma, menos parênquima e maior índice apoptótico/campo que o dos animais-controle. Pode-se concluir que a apoptose desempenha importante papel no mecanismo de hipotrofia tímica que se desenvolve na cinomose.

Ecografía del timo / Thymus sonography

El presente trabajo pretende ubicar en cadena de valor a un órgano con múltiples incidencias en varias patologías que complican el crecimiento y desarrollo de neonatos, lactantes y niños en algunos casos con incidencia extendida a la adultez, toda vez que los linfocitos T (timocitos) tienen alto impacto inmunológico. Desde el advenimiento de la ultrasonografía médica es posible el estudio del timo, relacionándolo en un contexto clínico y otros estudios diagnósticos por imágenes.

A prospective study of prenatal and postnatal development of thymus of Deshi chicken.

Thymus was one of the primary lymphoid organs along with the bursa in birds. The growth of the thymus of deshi chicken (Gallus Domesticus) from prenatal embryonic day fifteen (ED15) to postnatal day ninety (D90) were studied. In macroscopic study, it was found as a paired, lobulated gland, one half of which was located on either side of the neck. Each half consists of six to eight, flattened, ovoid to elongated, pale white to yellowish white lobes of varing size and shape of lymphoid tissue lying in the sub-dermal connective tissue of the neck. Histologically, the thymus of deshi chicken at embryonic day fifteen was covered by a very thin connective tissue capsule from which septa arises and divides the gland into lobes and lobules. The lobules were homogenous, small in size and the cortex and medulla were demarcated. Lobules have developing Hassall's corpuscles and they were of uniform shape and size. The lobules become well developed with advancing age. The cortex gradually becomes thicker and was packed with large lymphocytes. Hassall's corpuscles became larger and there number increases at postnatal period (D90) in the medulla of the thymus. The growth and development of thymus at each stage of the study period were found to be significantly high. The present finding of thymus of deshi chicken was found similar to the adult hybrid chicken. The study also indicates that the chicken thymic cell population, structure & functions was similar to the human thymus histologically. It was also found that the chicken embryo allows easy experimental access to all the stages of the thymic development so the present study will be helpful for experimentation on lymphoid organs and to understand pathophysiology of immunological diseases of human.

Características clínicas de 217 pacientes Miasténicos clasificados de acuerdo con la histología del Timo / Clinical characteristics in 217 myasthenic patients classified according to the histology of the thymus

Estudio retrospectivo de 217 pacientes con miastenia gravis, timectomizados. De los pacientes de la serie, 189 (87,1 por ciento) presentaron alguna alteración histológica y en 28 (12,9 por ciento) se encontró un timo sin anormalidades patológicas. La hiperplasia tímica fue la alteración más frecuente (73,7 por ciento), en tanto que la presencia de timoma fue menos común (13,4 por ciento). Las principales características clínicas halladas en el grupo con hiperplasia fueron la presentación de la enfermedad por debajo de los 30 años, mercado predominio del sexo femenino y baja frecuencia de complicaciones de la timectomía. En la mayoría de los casos con timoma, el inicio de la miastenia ocurrió después de la cuarta década. En estos casos hallamos formas más severas de la miastenia, mayor número de complicaciones de la timectomía y más alta mortalidad posoperatoria. También se destacan los beneficios de la timectomía sobre otros tratamientos

Histological and histochemical studies of the efect of castration on the thymus gland and muscles of male albino rat

Forty animals were used at the ages of one, five, nine months and one year. They were divided into eight groups, four control and four experimental groups. The experimental groups were castrated and sacrificed 14 days after castration. The thymus and skeletal muscle were examined using some histological and histochemical procedures. It was found that castration delayed the rate of involution of the thymus and returned the thymus back to features nearly similar to those of younger animals. It was also found that castration caused marked reduction in size and number of muscle fibers. Dispersion and homogenous degeneration in some muscle fibers were observed with an increase in the amount of adipose connective tissue among the muscle fibers, especially in castrated rats of old ages

Alteraçöes no peso e celularidade do timo de camundongos tratados com dieta parenteral: comparaçäo com o jejum / Weight and celullarity alterations of mice thymus gland treated with parenteral nutrition: comparison with fasting

O peso e a celularidade do timo foram estudados em camundongos C 57 BL/6 com 8 semanas de idade, tratados durante 48 horas com dieta parenteral (DP), jejum, injeçöes de salina, e raçäo comum e água "ad libitum". Os resultados mostraram que a DP levou a uma perda de peso do timo proporcionalmente maior que a perda de peso corporal e que a perda de peso do fígado. A comparaçäo entre os grupos mostrou que a proporçäo dessa perda em relaçäo ao peso corporal foi semelhante entre os animais submetidos à DP e ao jejum. Por outro lado, o número de timócitos foi muito mais elevado nos animais tratados com a DP que naqueles submetidos ao jejum, embora muito menor que nos animais alimentados "ad libitum".

Immunoendocrine interrelationship--effect of ovariectomy on spleen and thymus in mouse.

Increase in the weights of spleen were observed 15 days after ovariectomy in adult as well as immature mice. However, no corresponding change was recorded in the splenocyte count. Morphological alterations in the shape of germinal centres was noted after ovariectomy in adult and immature mice. Increase in weight of the thymus could be demonstrated in adult mice only, with a concomitant enlargement of cortical and medullary region.