大鼠肾小体发育的生长曲线

目的：探讨大鼠肾小体发育中体积生长曲线的变化规律。方法：采用连续切片技术,光镜观察并结合体视学分析方法,对不同发育阶段大鼠肾小体的体积进行测量,定量研究肾小体体积的变化规律。结果：胚龄16 d 时逗号小体及 S 小体出现,胚龄18 d,出现了Ⅲ期和Ⅳ期肾小体,生后7 d,逗号小体及 S 小体消失,肾小体的体积从胚龄18 d 到生后40 d 大约增大86倍。结论：大鼠肾小体于胚龄16 d 发生,生后40 d 达到成年水平。     

GAP-43免疫反应神经纤维对发育中大鼠脾脏支配的研究

本实验用免疫组化方法研究了含生长相关蛋白（GAP－43）的神经纤维在新生、幼年、成年大鼠脾脏的分布及发育规律、结果显示，在出生第1d，GAP－43免疫反应阳性神经纤维团簇即出现于尚在形成中的白髓（原基）中．根据形态可将它们分粗直和细网两种类型．至生后第10d，随着脾脏的迅速发育，GAP－43免疫反应阳性神经纤维的密度也达最高峰，它们大量出现于脾脏的血管系统周围和白、红髓内，其形态演变为具有膨体的细纤维．在生后20d，除脾脏的血管周围外，GAP－43阳性纤维密度有所下降，只出现于脾小体和被膜等结构内。在成年大鼠脾脏，除上述部位外，阳性纤维明显见于发育成熟的小梁中。本研究发现，GAP－43免疫反应阳性神经纤维密度在脾脏发育各阶段有所不同，以生后第10d为最多．本研究还就含GAP－43神经在发育中脾脏的分布规律与含TH能神经成分做了比较．     

雄性大鼠大脑半球白质及其内有髓神经纤维老年改变的侧别差异

目的 探讨雄性大鼠左右大脑半球白质及其内有髓神经纤维是否存在显著性差异,以及每侧大脑半球白质及其内有髓神经纤维的老年性改变是否一致.方法运用透射电子显微镜和体视学方法分别对5只年轻(6～8月龄)和4只老年(18月龄)雄性Long-Evans大鼠左侧、右侧大脑半球白质体积及白质内有髓神经纤维体积、长度和直径进行定量研究.结果年轻组大鼠和老年组大鼠左右大脑半球白质体积及白质内有髓神经纤维体积、长度和直径均不存在显著性差异.每侧大脑半球白质及其内有髓神经纤维总长度和总体积均随年龄增加而降低,右侧半球白质体积、右侧半球白质内有髓神经纤维总体积和左侧半球白质内有髓神经纤维总长度随年龄增长分别显著性降低32.9%、28.6%和49.3%.结论正常年轻和老年雄性Tong-Evans大鼠两侧大脑半球的白质及其内有髓神经纤维均不存在显著性侧别差异.老年雄性Long-Evans大鼠右侧大脑半球白质体积、右侧大脑半球白质内有髓神经纤维的总体积和左侧大脑半球白质内有髓神经纤维总长度存在显著老年性改变.     

大鼠大脑白质及白质内有髓神经纤维的性别与年龄差异

目的:研究正常年轻和中老年组雌雄性大鼠大脑白质及白质内有髓神经纤维之间的性别差异,并探讨大脑发育过程中性别差异随年龄增加的改变。方法:运用透射电子显微镜和体视学方法对6~8月龄的年轻Long-Evans大鼠及18月龄同种中老年大鼠大脑白质及其有髓神经纤维进行定量研究。结果:年轻组雄性大鼠大脑白质、有髓神经纤维及其髓鞘的总体积均显著大于雌性,而中老年组雌性大鼠大脑白质、有髓神经纤维体积密度、有髓神经纤维及其髓鞘的总体积均显著大于雄性。结论:年轻组及中老年组大鼠大脑白质、白质内有髓神经纤维及其髓鞘总体积均存在性别差异,随着年龄的增长,雄性大鼠大脑白质及白质内有髓神经纤维体积的减少较雌性更为明显。     

大鼠海马结构内有髓神经纤维老年性改变的体视学研究

目的 探讨雌性Long-Evans大鼠海马结构及其内有髓神经纤维的老年性改变。 方法 运用透射电子显微镜和体视学方法分别对5只青年(6月龄)、5只中老年(18月龄)和6只老年(28月龄)雌性Long-Evans大鼠海马结构及其内有髓神经纤维进行定量研究。 结果 青年组、中老年组和老年组大鼠的海马结构总体积,海马结构内有髓神经纤维的体积分数和总体积,有髓神经纤维的长度密度和有髓神经纤维平均直径均未见显著性改变。中老年组大鼠海马结构内有髓神经纤维总长度与青年组相比增加了63.6%,老年组有髓神经纤维总长度与中老年组相比下降了47.5%,老年组有髓神经纤维总长度与青年组比较下降了13.8%。 结论 本研究结果进一步支持正常老年大脑的有髓神经纤维存在广泛性老年改变。     

正常Wistar大鼠脾器官内结构组分相关性的体视学研究

本文对12只正常成年Wistar大鼠碑器官内组分间的关系,进行了体视学参数的定量探讨。首次定量地阐明脾中动脉周围淋巴鞘的体积密度、脾小体的体积密度、白髓的体积密度、缘带的体积密度、白髓和缘带的体积密度与脾内中央动脉的长度密度均无相关(P>0.25)。白髓的体积密度与缘带的体积密度无相关(P>0.05)。小梁和被膜的体积密度与红髓的体积密度无相关(P>0.10)。这提示脾由功能上相互独立的几个组分构成,为脾功能的研究提供了定量形态学资料。     

大鼠肾小体发生发育的形态学变化

目的:探讨大鼠肾小体发生发育过程中的形态变化规律。方法:采用光镜、电镜技术并结合体视学测量方法,对不同发育阶段大鼠肾小体进行形态观察和体视学计量。结果:大鼠肾小体的发育经过了逗号小体、S小体、Ⅲ期和Ⅳ期肾小体4个阶段,从胚龄18d到生后40d肾小体的体积大约增大86倍,肾小体的数目大约增大7倍,生后7d之后基本稳定。结论:大鼠肾小体发生始于胚龄16d,肾小体的体积于生后40d达到成年水平,肾小体的数目在生后7d达到高峰。     

短期丰富生存环境对中老年雌性大鼠海马结构及其内有髓神经纤维的影响

目的 探讨短期丰富生存环境干预对中老年雌性大鼠海马结构及其内有髓神经纤维的影响。 方法 将20只14月龄的雌性SD大鼠随机分为丰富生存环境组和标准环境组,每组各10只,对丰富生存环境组的动物给予4个月丰富生存环境干预, 标准环境组于普通标准环境下饲养4个月;然后每组各随机选取5只,采用Morris水迷宫对大鼠的空间学习能力进行测试,然后运用透射电子显微镜和体视学方法分别对大鼠大脑海马结构及其内有髓神经纤维进行定量研究。 结果 短期丰富生存环境组中老年雌性大鼠与标准环境组相比,其空间学习能力明显增强;丰富生存环境组海马结构内有髓神经纤维总长度和总体积分别显著增加了43.4%和47.4%,且有髓神经纤维总长度的增加主要是由于细小直径的有髓神经纤维长度增加所致。海马结构总体积和海马结构内有髓神经纤维直径未见改变。 结论 4个月丰富生存环境干预对于14月龄雌性大鼠空间学习能力、海马内有髓神经纤维均有显著性影响。     

摄入不同剂量过量碘大鼠脾脏的形态学改变

目的对摄入不同剂量过量碘的大鼠脾脏进行形态学研究,探讨碘过量对大鼠机体免疫功能的影响。方法断乳1个月Wistar大鼠18只,雌雄各半,分为适碘组(NI)、10倍碘组(10HI组)和100倍碘组(100HI组)。给以不同浓度碘化钾水喂养3个月后,处死取脾脏并称重,对脾脏进行光镜下观察,并对脾小结、生发中心、动脉周鞘和边缘区进行体视学定量分析,对脾脏边缘区免疫细胞进行超微结构观察。结果与正常组比较,10HI组和100HI组大鼠脾脏绝对重量和脾脏指数未见明显改变,10HI组大鼠脾脏脾小结、生发中心、动脉周鞘和边缘区体密度未见明显改变,脾脏免疫细胞超微结构未见明显改变。100HI组大鼠脾脏脾小结、生发中心、动脉周鞘和边缘区体密度明显增加,脾脏免疫细胞超微结构出现明显改变,即呈现功能活跃的表现。结论低剂量过量碘摄入对大鼠免疫功能未产生明显影响,高剂量过量碘摄入可引起大鼠免疫功能亢进。     

小鼠肾小体的生长曲线

目的:探讨小鼠肾脏发生发育过程中肾小体体积的增长规律。方法：光镜下应用体视学方法对生前和生后小鼠肾脏中各发育阶段的肾小体体积进行测量。结果：胚龄14d时，逗号小体和S小体出现，生后7d消失。胚龄16d时，Ⅲ、Ⅳ期肾小体出现，其体积从胚龄16d到生后40d大约增大70倍。结论：小鼠肾小体于胚龄14d发生，从生后7d到生后40d体积增长迅速。     

Distribution and identity of the earliest proliferating progeny of colony-forming cells in regenerating murine spleen and bone marrow

A study was made of the sites of development and the types of cells found in very early hemopietic colomes in the mouse spleen. Two, 3, and 4 days after transplantation, the proliferating descendants of transplanted bone-marrow cells were identified on radioautographs of spleen sections and on spleen and bone-marrow smears of supralethally irradiated recipient mice which were injected with ³H-TdR at 12, 6, and 0.5 hours before sacrifice. Surprisingly the spleens of nontransplanted, irradiated mice contained proliferating medium and large lymphocytes in the white pulp which increased in numbers during the observation period. The early descendants of transplanted cells that lodged in the spleen could be clearly distinguished from the labeled indigenous cells because they formed discrete nodules or colonies beneath the splenic capsule or in the vicinity of venules and trabeculae of the red pulp. These cells were identifiable on day 2 as transitional cells or unknown hemopoietic blasts and on day 4 included early erythroid cells and small lymphocytes. There was evidence for the traffic of ³H-TdR-labeled cells through the splenic sinusoids.     

Localization in the rat spleen of carbon-laden macrophages introduced into the splenic artery: a subpopulation of macrophages entering the white pulp

Heavily carbon-laden (HC) macrophages, largely derived from the red pulp of the donor spleen, were injected into the splenic artery of recipient rats. Immediately after injection, HC macrophages were found only in the marginal sinus and in the splenic cords. With time after injection, they appeared successively at the periphery of the white pulp, in the deeper white pulp, and finally in and near the germinal centers, suggesting migration of HC macrophages from the marginal sinus towards the germinal centers. The number of HC macrophages in and near the germinal centers reached a peak at 12 h. Most of the HC macrophages in the white pulp were spherical or ovoid in shape with a diameter of 7-11 microns in sections, having an eccentric round or oval nucleus often with a distinct nucleolus and a cap-like or horseshoe-like cytoplasm filled with carbon. When immunostained with monoclonal antibodies against rat macrophage subpopulations, more than 90% of HC macrophages in the white pulp were found to be ED1+2-3-. A population of the same type of macrophages, both in morphology and phenotype, were found in the red pulp of the donor spleen. They were different from the major residents, red pulp scavenger macrophages, which were ED1+2+3- and larger in size and irregular in shape. These results suggest the presence of a distinct subpopulation of macrophages which actively migrate into the splenic white pulp including the germinal centers. A discharge of transferred macrophages from the red pulp to the general circulation is also suggested.     

Repopulation of lymph nodes and spleen in thymus chimeras after lethal irradiation and bone marrow transplantation: dependence on the age of the thymus

CAP and Lewis rats were thymectomized and received a syngeneic thymus graft followed by lethal irradiation and syngeneic bone marrow transplantation. In three groups (A: recipient 15 months old, thymus graft 3 months old; B: recipient 3 months old, thymus graft 15 months old; C: recipient and thymus graft both 3 months old), we performed an immunohistologic analysis of the splenic white and red pulp and the paracortical zone of the lymph nodes. The repopulation of these regions was demonstrated with monoclonal antibodies that react with Thy-1 positive cells, peripheral T cells, T helper cells, and T non-helper cells. In the splenic red pulp, more Thy-1 positive lymphocytes were found in group B than in group C. The proportion of T lymphocytes and T helper lymphocytes in the region of the periarteriolar lymphocyte sheath of the splenic white pulp was higher when a young thymus was transplanted (groups A and C) than when an old one was (group B). In contrast, in the splenic red pulp, more T lymphocytes were found in group A than in groups B and C. In the paracortical zone of the lymph nodes, this was demonstrable only for group C versus group B. The proportion of T non-helper lymphocytes in the region of the splenic red pulp was higher in group B than in group C. These results indicate that the repopulation of lymph nodes and spleen after transplantation of an old thymus is delayed, quantitatively reduced, and qualitatively different (more T non-helper lymphocytes).     

Age-related difference by IgG subclass in the response of mice to allogeneic spleen cells.

Inbred mice of various strains, 3–4 months of age and 16 months or older, were given primary injections of allogeneic spleen cells to observe the time of appearance and relative levels of alloantibodies of IgG1 and IgG2 class. In 3–4 month old C3H mice injected with BALB/c spleen cells, IgG2 alloantibodies were present on day 6, before the appearance of alloantibodies of IgG1 class. The IgG2 class alloantibodies then continued to increase in level until day 12. IgG1 class antibodies, which appeared after day 6, also increased during this period. When C3H mice at 16 months of age were similarly injected a difference in response was found in that IgG2 class alloantibodies did not increase in level after the appearance of those of the IgG1 class, but IgG1 class alloantibodies increased until day 12, as in the young mice. At intermediate ages smaller effects in the same directions were observed. Young BALB/c mice injected with C3H spleen cells gave responses similar to those of the young C3H mice. At 16 months, however, the response was not different from that of the young BALB/c mice. At older ages (19–25 months) the response of BALB/c mice was similar to that of the 16-month-old C3H mice described above. CBA mice of various ages which were injected with BALB/c spleen cells showed effects similar to that of the BALB/c mice in that a change of response seen in the older CBA mice, similar to that of the other two strains, did not appear at 16 months of age but did appear later (20–24 months).     

Age-dependent changes in the cellularity and ultrastructure of the spleen of Fischer F344 rats

The age-related changes in the cellularity (cells/gram of tissue) of the spleens and thymuses of Fischer F344 male rats were determined. A decline in the weight of the thymus with age was observed as previously reported by others. The decline was most drastic between 4 and 20 months of age. The spleen, however, increased in weight with age. The increase was almost linear between 4 and 30 months of age. Yet when the number of cells recovered from each organ as a function of age was determined, a decrease for both the thymus and the spleen was observed with increasing age. It was surprising to find that fewer cells were recovered from the spleens of old animals even though the weight of the spleen of the old animals was greater than the spleens from the younger animals. The ultrastructure of the splenic white pulp of rats ranging from 4 to 30 months of age was studied to determine the possible cause for the age-related decrease in cellularity of the spleen. The white pulp of the 4-month-old rats contained a large number of small lymphocytes, and the number of cells was found to decrease with increasing age. The 30-month-old animals had less than 20% the number of lymphocytes in the white pulp as the 4-month-old animals, and the white pulp exhibited an increased number of reticular cells and macrophages with enlarged cytoplasm. The decreased cellularity and increased structural disturbance might be significant in the age-related decline of spleen lymphocyte functions.     

Studies on the syngeneic mixed lymphocyte reaction. II. Decline in he syngeneic mixed lymphocyte reaction with age.

The syngeneic mixed lymphocyte reaction (SMLR) is the proliferative response of T lymphocytes cultured with syngeneic non-T lymphocytes. In previous studies, we found that the SMLR reaches adult level of activity at 4 weeks of age in BALB/c mice. We now report that the SMLR declines with age in this strain. The decline was first documented at 12 months of age, when non-T spleen cells were less able to stimulate young adult T cells than were non-T cells from 2 to 3 month-old mice. Splenic T cells from 12 month old mice were as responsive as splenic T cells from 2 to 3 months old mice. By 24 months of age, mice had no significant SMLR activity. Splenic T cells from 24 month old mice did not respond and splenic non-T cells did not stimulate SMLR when cultured with cells from young adult mice. Finally, suppressor cells were demonstrated in spleen cells preparations from 24 month old mice and may explain or contribute to the impaired SMLR in these animals.     

Only a small proportion of splenic B cells in adults are short-lived virgin cells

A cohort of newly produced virgin B cells was followed from the marrow to the spleen of non-immunized clean rats, which showed minimal antigen-driven proliferation of B cells in their spleens. The progenitors of this cohort of virgin cells were labeled in vivo over 12 h with the thymidine analogue 5-bromo-2′-deoxyuridine (BrdUrd) and their non proliferating progeny left the marrow 2-3 days later. This coincided with the arrival of labeled B cells in the red pulp and T zones of the spleen. These appear to be short-lived as few remained a week after the label was given. The short-lived newly produced virgin B cells can only comprise a minority of splenic B cells, for it is shown that only 20% of splenic B cells are found in the red pulp and T zone. It is calculated that newly produced virgin B cells are likely to make up between 5% and 10% of splenic B cells. In the marginal zones and follicular mantle respective medians of 3.3% and 1.8% were already labeled at 1 day from the start of the BrdUrd pulse. The appearance of these cells seems likely to result from antigen-driven B cell proliferation outside the marrow, for labeled virgin B cells have not started to leave the marrow at this stage. During day 2 and 3 the proportion of labeled follicular mantle B cells rose to 3.4%, which might in part reflect the recruitment of newly produced virgin B cells to the pool of recirculating follicular B cells. After day 3 in the follicles and day 1 in the marginal zones the proportion of labeled cells did not vary significantly through day 7. This appears to confirm the comparative longevity of the cells in these zones, which contain 80% of the non-proliferating splenic B cells of adult rats.     

MORPHOLOGICAL STUDIES OF THE SPLEEN IN SPLENOMEGALIC LIVER CIRRHOSIS COMPARING WITH THE SPLEEN IN IDIOPATHIC PORTAL HYPERTENSION (SO-CALLEDBANTI'S SYNDROME WITHOUT LIVER CIRRHOSIS)

Morphological changes of the spleen in splenomegalic liver cirrhosis (SLG) were studied. Comparisons with the normal spleen and the spleen of idiopathic portal hypertension (IPH) were made by (1) light microscopy with histometry, (2) scanning electron microscopy (SEM) with histometry, and (3) SEM of the spleen vascular replica. Hlstometrical studies by light microscopy showed that in both SLG and IPH, the white pulp volume was decreased in random units of splenic tissue but increased in the whole spleen, whereas the red pulp volume was increased both in random units of splenic tissue and in the whole spleen. The increase in the total volume of the white pulp was less marked in SLG than in IPH. SEM histometry demonstrated in the red pulp an increase in small venous sinuses and narrowing of the Billroth cord in SLG and IPH. Narrowing of the Billroth cord was more marked in SLG than in IPH. SEM of the white pulp showed channels formed by reticulum cells around the central artery in SLC and IPH. The channels are thought to correspond to so-called "follikulare Fibroadenie" or periarterial fibrosis. The spleen vascular replica demonstrated open arterial termination into the tissue spaces in the Billroth cord in SLG, IPH and the normal. Venous sinuses were arranged in bundles in SLC and IPH.     

Monoclonal antibodies against mouse splenic stromal cells

A panel of rat monoclonal antibodies directed against mouse splenic stromal cells were isolated. These monoclonal antibodies were Immunohistochemically divided into four groups which reacted with non-lymphoid cells of the murine spleen; (1) in the white pulp, (11) at the marginal zone, (111) in the red pulp, and (IV) on the endothelium of splenic blood vessels. These monoclonal antibodies were studied Immunohistochemically In lymphoid organs by means of light and electron microscopy. Monoclonal antibodies SS-4 (group I) reacted with fibroblastic reticulum cells that were distributed only in the white pulp of the spleen and In the follicular areas of lymph nodes. The SS-4 staining cell, In clustered splenic stromal cells, formed colonies which Included a small number of Thy-1 positive lymphocytes. Therefore, we concluded that SS4 staining stromal cells comprise the lymphoid cornpartment. In contrast, monoclonal antibodies SS-1, SS-3 and SS-5 (group II) reacted with dendritic shaped cells in the marginal zone of the spleen. Examination of splenic extra-medullary hematopolesis in mice rescued by bone marrow transplantation after lethal irradiation revealed that SS-3 and SS-5 reacted with dendritic shaped stromal cells in clonal nodules of engrafted marrow in the red pulp. SS-3 and SS-5 staining cells could not be observed in physiologic hematopoiesis of non-transplanted mice. It was suggested that SS3 and SS-5 staining stromal cells are Involved in primitive hematopoiesls. Monoclonal antibodies SS2, SS-6 and SS-7 (group 111) mainly reacted with dendritic cells and macro-phages in the red pulp. Monoclonal antibodies SS-8 and SS-9 (group IV) reacted with endothelial cells of blood vessels and sinuses. These findings of heterogeneity in mouse splenic stromal cells are further evidence that specific micro-envlronments are composed by speclalired stromal cells.     

The role of lymphoid tissue inducer cells in splenic white pulp development

CD4(+)CD3(-) lymphoid tissue inducer (LTi) cells are crucial for the development and organisation of lymph nodes and gut associated lymphoid tissues. In this report, we characterise their appearance in the developing spleen and highlight their importance in relation to the development of splenic T cell zones. LTi cells were detected in embryonic spleen from embryonic day 13, although their progenitors were present at embryonic day 12. These cells clustered initially around splenic blood vessels in a lymphotoxin (LT)-independent manner, but up-regulation of VCAM-1 expression on stromal cells associated with the blood vessels was LT dependent. After birth, T cell colonisation of these clusters to form nascent white pulp areas was also LT dependent. Transfer experiments reconstituting RAG(-/-) mice with either WT or LTalpha(-/-) splenocytes demonstrated that lymphocyte expression of LT was not essential for the organisation of a discrete CD3(+) T cell zone with localised podoplanin and CCL21 expression. Our studies indicate that a combination of LT signals from LTi cells and LT-independent signals from lymphocytes is sufficient for expression of podoplanin and CCL21 on splenic T cell zone stroma and subsequent T cell organisation.