The effect of trauma on the structural-temporal organization of the T-dependent zone of a regional lymph node]

Experiments in 238 white mice have shown that after trauma there was a change in the population density (PD) of immune competent cells in the T-dependent zone of the regional lymph node (LN) both in the center of the deep cortex and in the T-territory adjacent to the germinative center. PD of small lymphocytes increases on the 1st-3rd days after trauma and returns to the initial level by the 4th-5th day. PD of mitotically dividing cells, immunoblasts, plasmablasts, immature and mature plasmocytes dramatically decreased on the 3rd day while an inconsiderable elevation of their PD took place on the 1st day in T-territory. The increased PD of small lymphocytes in the regional LN seems to be associated with their intensified release from the injury focus. The suppressed proliferation and differentiation of the plasmocyte line cells is the reaction to operation stress: in the posttraumatic period the spectral composition of fluctuations of PD of cells and parameters of its rhythmical components (both in the center of the deep cortex and in T-territory) were changed. As a rule, there was a displacement of acrophase and lessening of the rhythm amplitude. The general potency of the process after trauma increased. The amount of circadian components in the spectral composition of rhythmicity and their potency increased which speaks of central hormonal influences becoming greater.     

The temporal organization of the complex nodule in the lymph node

The aim of the work is to study rhythmic processes at tissue level in the lymph nodule and in the T-territory adjacent to it in order to reveal temporal interrelations in functioning the germinative center, crown and T-territory. The lymph nodule sections are stained with methylene green-pyronine. Small and middle lymphocytes, immunoblasts, plasmoblasts, immature and mature plasma cells, mitotic figures are taken into account. Spectral composition and rhythmic parameters are determined for each type of the cells in the ultradian, circadian and infradian ranges. Periods, approaching the circadian one, are revealed in the germinative centers for small lymphocytes and immature plasma cells. Practically, for all plasma cells the functional period near to 7 h is found; this attests the presence of the common synchronous rhythm driver. Phase difference of immunoblast, plasmablast, immature plasma cell fluctuation in the germinative centers makes it possible to suppose the time, necessary to transfer the immunoblast into the plasmablast (1.6-2.6 h) and the plasmablast into the immature plasma cell (3 h). Owing to the knowledge of the spectral composition of the rhythmic and parameters of certain components it is possible to approximate the total course of the process. Combination of fluctuations with various periods results in their recurrence in more prolonged time intervals.     

Effect of trauma on space-time organization of B-dependent area of the regional lymph node cortex

In the experiment performed on 238 non-inbred white mice it has been demonstrated that after trauma in the concha auricularis population density (PD) of immune-competent cells in the germinative center (GC) and in the crown of the regional lymph node (LN) changes. The PD of small lymphocytes increases, and the PD of mitotically dividing cells, immunoblasts, plasmoblasts, immature and mature plasmocytes decreases sharply in both zones. The increase of small lymphocytes PD in the regional LN after the trauma is obviously connected with intensification of their inflow from the lesion focus. Inhibition of proliferation and differentiation of the immune-competent cells in the GC of the crown is a response to the operation stress. During the posttraumatic period both spectral composition and parameters of the constituents of rhythmical alteration of the cells PD change both in the GC and in the crown. As a rule, displacement of acrophase and decrease in amplitude of the rhythm take place. Total power of the process for various types of immune-competent cells alters unequally. In the spectral composition of the rhythmicity amount of circadian components increases, their power increases, too. This demonstrates an increase of central hormonal effects during the posttraumatic period. After trauma fluctuations of the cells PD of the plasmacytic line, as well as in mitotically dividing cells with a 7-hour's period, which has been revealed in intact animals before the trauma, are preserved. This demonstrates a relative independence of the given synchronizer of rhythmicity at a tissue level from any influence of the higher regulatory center.     

Biological rhythms of cells of the lymphoid series in the thymus-dependent zone of lymph nodes

Biological rhythms of density in the lymphoid line cell populations (small and middle lymphocytes, immunoblasts, plasmoblasts, immature and mature plasmocytes) have been investigated in the thymus-dependent zone of the mouse axillary lymph nodes. The observations have been performed for 572 h. The amount of the cells is counted over the nodes of the morphometrical net. The results of the observations are treated by means of the spectral cosinor-analysis. Circadian or similar to it rhythmicity is peculiar for all the types of the cells, besides plasmoblasts. Within the ultradian range rhythmicity of the small lymphocytes, immunoblasts and immature plasmocytes is presented by two components, and that of the plasmoblasts--by one. The complexity of the rhythm components demonstrates that the course of the process during the observation time does not repeat strictly every day running, since periods of the circadian components somewhat fluctuate from 24 h, and periods of the ultracircadian ones--do not make multiple parts from the duration of the circadian periods. The time of picks and troughs of the amount of the cells during successive 24 h also do not coincide with each other, as the circadian and ultradian components interact. During one 24-hour's period the curve does not possess a regular sinusoid form and additional picks and troughs are revealed, since certain oscillations of a higher frequency participate in the process. These data are necessary to estimate reactions at T-immunological response.     

Features of the structure of the regional lymph nodes of the duodenum in monkeys

By means of morphometric methods, duodenal regional lymph nodes were studied in rhesus and lapunder macaques. It was demonstrated that in monkeys the connective tissue framework, cortical plateau, medullary substance, cortical substance, sinuses and follicles are expressed differently. Cellular elements in the lymph nodes analysed in the monkeys subjected to a comparative investigation demonstrated their uneven distribution in the same structural components. Small lymphocytes were predominate cellular elements. There were rather essential differences in the number of plasmic cells, mitotically dividing cells, acidophilic granulocytes, mast cells and macrophages. Certain species differences were demonstrated to exist both in structure and cell composition of the lymph nodes that seemed to depend on some local peculiarities of immunogenic reactions.     

Blood vascular network of the rat lymph node: tridimensional studies by light and scanning electron microscopy

Many aspects of the blood vascular network of the lymph node are unknown, and others need confirmation. We have studied the blood vasculature of rat peripheral lymph nodes by means of carbon perfusion and vascular cast corrosion techniques. At the hilus of the node, an artery gives off arterioles running in medullary cords towards the cortex. Some reach the peripheral cortex directly, branching there into slender cortical vessels. Other arterioles enter the periphery of the deep cortex units, and then head towards the peripheral cortex. Upon reaching it, they curve part way above the center of the deep cortex units and provide slender branches to the overlying peripheral cortex. Dense plexuses of capillaries arise from arterioles in the medullary cords, in the periphery of the deep cortex units, and in the outermost stratum of the extrafollicular zone of the peripheral cortex. In the cortex, the draining high endothelial venules are restricted to the extrafollicular zone and to the periphery of the deep cortex units. At the cortico-medullary junction, these peculiar venules transform into regular medullary venules which form the hilar veins. In contrast, the folliculo-nodules and center of the deep cortex units are little vascularized by a loose capillary network, while no vessels occur in the subsinus layer. These features of the node vascular network are of interest in relation to the node architecture.     

Exploring a biological tissue from atomic to macroscopic scale using synchrotron radiation: example of hair.

A combined approach, using synchrotron radiation-based diffraction and infrared microspectrometry, has been used to study the structure and molecular composition of hair samples. These methods allowed us to get an insight at different structural scales into the composition and structure of hair. Firstly, information about the configuration of amino-acid residues was obtained at atomic scale, secondly, a model was presented for the geometry and the packing of the microfibrils at medium scale and finally different structural zones were evidenced by microdiffraction at macroscopic scale. We also showed that the two main components of hair--proteins and lipids--are not evenly distributed within the fiber. In addition, these two components exhibit different structure, depending upon their location. Moreover, diffraction and microdiffraction data indicate that the cuticle zone is mainly composed of lipid granules, whereas the cortex and the medulla zones are composed primarily of alpha-keratin. Infrared microspectroscopy, using an enhanced lateral resolution thanks to synchrotron radiation, indicates, on one hand, that the protein structure between the cuticle and cortex are different, and on the other hand, that the concentration of lipids, inside the medulla, is much higher than everywhere else. This work emphasizes the complementarity between both techniques, and highlights the potentialities they can offer in the case of various other studies in biology.     

Structure of the small-intestinal lymphoid patches in albino rats at various stages of their development

The following stages in lymphoid patches (LP) development have been revealed: I-1-6, II-7-14, III-15-21, IV-22-30 days; during these periods lymphoid noduli with germinative centers, cupolae and internodular areas are formed. Amount of all kinds of cells in the LP parenchyma and their rearrangement in the zones takes place. In one-month-old rats blast forms predominate in the LP germinative centers, and small lymphocytes--in the zone of small lymphocytes of the noduli and internodular areas. Under conditions of antenatal effect of an antibiotic on the system mother--fetus there is no disturbances in formation of the anatomical structures. However at each stage of development the small intestine LP are not mature, concerning their cellular composition. Amount of cells decreases, their interrelationship changes. Lympho- and plasmocytopoiesis decreases.     

Immunopathology of alkaline phosphataseinduced granulomatous hepatitis in rats

Granulomatous inflammation is a specific type of chronic inflammation in which macrophages and T-cell-mediated immunity to the inciting agent play a pivotal role. In the present study, granulomatous hepatitis was induced in rats by the administration of a single intravenous dose of porcine intestinal alkaline phosphatase. The cellular composition of the hepatic granulomas was analyzed in-situ with a number of recently developed mouse anti-rat monoclonal antibodies to cells of the monocyte-macrophage lineage and lymphocyte subsets. Well-developed granulomas consisted of aggregates of macrophages with central modification into epithelioid cells, a peripheral rim of T- and B-lymphoid cells, including considerable numbers of immunoblasts and plasma cells. In addition, the periphery of the granulomas contained many fat storing cells, a sinusoidal cell type thought to play a central role in hepatic fibrosis. Moreover, intense immunostaining for the extracellular matrix proteins fibronectin and collagen type III was observed at the periphery of the lesions. The granulomas persisted for long periods without eliciting liver cirrhosis. Alkaline phosphatase induced hepatic granulomas in the rat may help to elucidate the contribution of cells of the B-lineage to chronic granulomatous inflammation.     

Differential expression of moesin in cells of hematopoietic lineage and lymphatic systems

 Moesin is a member of the ERM family consisting of ezrin, radixin, and moesin. The protein is located in the plasma membrane similarly to ezrin and radixin, and is thought to regulate cellular movements and morphological changes. Using monoclonal antibody CR-22, the specificity of which against human moesin was confirmed by immunoprecipitation and western blotting analysis, we immunohistochemically stained various formalin-fixed and paraffin-embedded human tissues, in particular, clots of bone marrow and lymphatic tissues, to examine moesin expression in cells of hematopoietic lineage and lymphatic systems. In the bone marrow, moesin was expressed in myeloid cells, while little staining was detected in erythroid cells. Moesin was highly expressed in both the center and the periphery of mature megakaryocytes. In the lymphatic tissues, moesin was strongly expressed by T-lymphocytes in the paracortex. In the mantle zone, the periphery of the germinal center, moesin was expressed by small lymphocytes which were identified as B-lymphocytes. Furthermore, in areas of inflammation, moesin was expressed in both the center and the periphery of neutrophils, whereas in some neutrophils in distant areas, moesin was localized at the cellular periphery. These results suggest that differential expression of moesin in these cells is involved in their morphology and specialized functions. Accepted: 19 December 1997     

The synthesis and localization of crystallins in different cell compartments of the crystalline lens in adult frogs: immunoautoradiographic and immunofluorescent research

The purpose of this study was to analyze immunochemically the synthesis and distribution of tissue-specific proteins, i.e., alpha-, beta- gamma- and rho-crystallins, in morphologically distinct regions of the frog (Rana temporaria L.) lens which consist of cells at various stages of differentiation, maturation and aging. Five such cell compartments can be distinguished in the lens: (1) central zone of lens epithelium (stem/clonogenic cells); (2) equatorial epithelial cells (differentiating cells); (3) lens fibers of the outer cortex (post-mitotic differentiated cells); (4) lens fibers of the deep cortex (cells without nuclei at terminal stage of differentiation); and (5) cells of the lens "nucleus" (cells formed during embryogenesis). Intact lenses and isolated lens epithelium were cultured in vitro in the presence of 35S-methionine. Then lens epithelium, outer and deep cortex, and lens nucleus were extracted with buffered saline and extracts used for immunoautoradiography. Distribution of crystallins in paraffin sections of the whole lens or isolated lens epithelium was studied using indirect immunofluorescence. Synthesis of alpha-crystallins was observed in lens epithelium and cortex, but not in lens nucleus. According to immunohistochemistry, these proteins were absent from central part of the lens epithelium: positive fluorescence was observed only in elongating cells at its periphery and in lens fibers. The data on beta-crystallins are similar except that synthesis of these proteins (traces) was detected also in lens nucleus. Synthesis of gamma-crystallins was detected in lens cortex and nucleus (traces) but not in epithelium. Immunohistochemistry showed that these proteins are absent from all regions of lens epithelium and found only in fiber cells of cortex and nucleus. Rho-crystallin was synthesized in all cell compartments of the adult lens, and all lens cells contained this protein. Our results show that cells of central lens epithelium do not contain alpha- beta- or gamma-crystallins (or the rate of their synthesis is insignificant). While cells are moving towards lens equator and elongating, synthesis of alpha- and beta-crystallins is activated. Gamma-crystallins are synthesized later, first in young lens fibers near lens equator. During embryonic development in amphibia, in contrast, gamma- and beta-crystallins are detected at earlier stages than alpha- and rho-crystallins (Mikha?lov et al., 1988). These data suggest that different mechanisms are involved in differentiation on lens fibers from embryonic precursor cells, on one hand, and from epithelial stem cells of adult lens, on the other.     

Confocal analysis of cytoskeletal organisation within isolated chondrocyte sub-populations cultured in agarose

This study reports the cytoskeletal organisation within chondrocytes, isolated from the superficial and deep zones of articular cartilage and seeded into agarose constructs. At day 0, marked organisation of actin microfilaments was not observed in cells from both zones. Partial or clearly organised microtubules and vimentin intermediate filaments cytoskeletal components were present, however, in a proportion of cells. Staining for microtubules and vimentin intermediate filaments was less marked after 1 day in culture however than on initial seeding. For all three cytoskeletal components there was a dramatic increase in organisation between days 3 and 14 and, in general, organisation was greater within deep zone cells. Clear organisation for actin microfilaments was characterised by a cortical network and punctate staining around the periphery of the cell, while microtubules and vimentin intermediate filaments formed an extensive fibrous network. Cytoskeletal organisation within chondrocytes in agarose appears, therefore, to be broadly similar to that described in situ. Variations in the organisation of actin microfilaments between chondrocytes cultured in agarose and in monolayer are consistent with a role in phenotypic modulation. Vimentin intermediate filaments and microtubules form a link between the plasma membrane and the nucleus and may play a role in the mechanotransduction process.     

Cytoarchitectonics of different areas of the thymus in rats

Correlation of various parts in the gland of white non-inbred 3-month-old male rats has been studied morphometrically. Five zones have been distinguished in the lobe: in the cortex--subcapsular, middle and border-like with medullary substance, in the medulla--border-like with cortical substance, deep zones. A high level of dividing and capable for division poorly differentiated cell forms, especially in the thymic cortex are noted in the gland's contents.     

Cortical upper layer neurons derive from the subventricular zone as indicated by Svet1 gene expression

The cerebral cortex is composed of a large variety of different neuron types. All cortical neurons, except some interneurons, are born in two proliferative zones, the cortical ventricular (VZ) and subventricular (SVZ) zones. The relative contribution of both proliferative zones to the generation of the diversity of the cortical neurons is not well understood. To further dissect the underlying mechanism, molecular markers specific for the SVZ are required. Towards this end we performed a subtraction of cDNA libraries, generated from E15.5 and E18.5 mouse cerebral cortex. A novel cDNA, Svet1, was cloned which was specifically expressed in the proliferating cells of the SVZ but not the VZ. The VZ is marked by the expression of the Otx1 gene. Later in development, Svet1 and Otx1 were expressed in subsets of cells of upper (II-IV) and deep (V-VI) layers, respectively. In the reeler cortex, where the layers are inverted, Svet1 and Otx1 label precursors of the upper and deeper layers, respectively, in their new location. Interestingly, in the Pax6/small eye mutant, Svet1 activity was abolished in the SVZ and in the upper part of the cortical plate while the Otx1 expression domain remained unchanged. Therefore, using Svet1 and Otx1 as cell-type-specific molecular markers for the upper and deep cortical layers we conclude that the Sey mutation affects predominantly the differentiation of the SVZ cells that fail to migrate into the cortical plate. The abnormality of the SVZ coincides with the absence of upper layer cells in the cortex. Taken together our data suggest that while the specification of deep cortical layers occurs in the ventricular zone, the SVZ is important for the proper specification of upper layers.     

Morphometric and histological studies on the adrenal glands of the camel Camelus dromedarius

The adrenal gland of the camel consists of an outer cortex and an inner medulla. The general disposition of the cortex and medulla, however, differs occasionally from that of other mammals. Extensions of medulla could reach as far as the periphery of the cortex. Islet of medullary tissue may be found in sections of the cortex and cortical tissue consisting of all zones of the cortex may occur around arteries or nerves in the medulla. The medulla may be separated from the cortex by connective tissue especially in old camels. The arrangement of noradrenaline-secreting cells is different from that in other ruminants; they are found in groups scattered between the adrenaline-secreting cells. Bundles of smooth muscle occur in venules at the corticomedullary interface. Accessory adrenal glands are found embedded in the renal fat. They are similar in structure to the adrenal gland. The adrenal cortex forms 74% of the volume of the gland and the ratio of the cortex to medulla is 4:1. The zona glomerulosa, fasciculata and reticularis constitute about 13%, 53%, and 29% by volume of the cortex, respectively.     

Changes in human cerebral cortex in various areas of concussion in severe cranio-cerebral injury

In 23 patients with a severe cranial-cerebral trauma the operative material (pieces of the cortex, obtained from the destructive, transitional and relatively preserved zones in the bruise foci with crushing, localized in various lobules of the cerebral hemispheres) has been studied. From 2 h up to 9 days after trauma, changes, characterizing the state of the vascular bed, nervous and glial cells have been followed. In the external area of the transitional zone in 15 patients and in the relatively preserved zone in all the patients reversibly altered nervous cells predominate. Only in the destructive zone in all 23 patients and in the whole transitional zone in 8 patients neurons in all cortical layers are deeply injured and unviable. Certain considerations on differential surgical tactics, when treating the bruise foci with crushing at a severe cranial and cerebral trauma are presented.     

Distinct roles of MLCK and ROCK in the regulation of membrane protrusions and focal adhesion dynamics during cell migration of fibroblasts

We examined the role of regulatory myosin light chain (MLC) phosphorylation of myosin II in cell migration of fibroblasts. Myosin light chain kinase (MLCK) inhibition blocked MLC phosphorylation at the cell periphery, but not in the center. MLCK-inhibited cells did not assemble zyxin-containing adhesions at the periphery, but maintained focal adhesions in the center. They generated membrane protrusions all around the cell, turned more frequently, and migrated less effectively. In contrast, Rho-associated kinase (ROCK) inhibition blocked MLC phosphorylation in the center, but not at the periphery. ROCK-inhibited cells assembled zyxin-containing adhesions at the periphery, but not focal adhesions in the center. They moved faster and more straight. On the other hand, inhibition of myosin phosphatase increased MLC phosphorylation and blocked peripheral membrane ruffling, as well as turnover of focal adhesions and cell migration. Our results suggest that myosin II activated by MLCK at the cell periphery controls membrane ruffling, and that the spatial regulation of MLC phosphorylation plays critical roles in controlling cell migration of fibroblasts.     

Neuronal organization of the periamygdaloid cortex in the cat brain

Neuronal organization of the fields Pmm, Pml2, Pe and epm of the periamygdaloid cortex of the cat brain has been studied by means of Golgi and Nissl methods. The field Pmm essentially differs from other fields of this cortex by primitiveness of its cytoarchitectonic an neuronal organization (two layers uniform by the composition of their neurons are distinguished, the structure of the latter is relatively primitive). In the medial part of this field long axonal rarely branching short dendritic, and in the lateral part--poorly differentiating pyramidal and spindle-like cells predominate. The field Pmm can be considered as a transitional formation between the subcortex (the medial nucleus of the amygdaloid body) and other fields of the periamygdaloid cortex. The fields Pml2, Pe and epm are built more complexly: the cells are organized in 4 layers, more complexly differentiated by their form and size than in the field Pmm and correspondingly more various (long axonal densely branching cells are observed: pyramidal and spindle-like--of the cortical type and bushy--of the subcortical type, as well as long axonal rarely branching reticular cells). The short axonal cells in the fields Pml2, Pe and epm are rather variable in their form, size and direction of axons; in the field Pmm they are less numerous. The field Pmm and the complex of the fields Pml2, Pe and epm are perhaps different in their function, this is evident from different projection of their neurons. Axons of the cells in the field Pmm get into less differentiated and the most ancient medial nucleus of the amygdaloid body and into the ancient system of connections of the latter--terminal strip, and neurons of the fields Pml2, Pe and epm are projected into the basolateral part of the amygdaloid body and into the external capsule--phylogenetically younger structures. Besides, poverty of the axonal collateralies in the long axonal neurons and a small amount and uniformity of the forms of the short axonal cells in the field Pmm and contrary, rich collateralies and variety of short axonal cells in the composition of other fields demonstrate more complex internal integrative function, performing in that composition.     

Organizational levels of the cerebral cortex: An integrated model

We propose a theoretical model of the cerebral cortex which is based on its cellular components and integrates its different levels of organization: (1) cells have general adaptive and memorization properties; (2) cortical columns are repetitive interneuronal circuits which determine an adaptive processing specific to the cerebral cortex; (3) cortical maps effect selective combinations which are very efficient to learn basic behaviourial adaptations such as invariant recognition of forms, visually-guided hand movements, or execution of structured motor programs; (4) the network between cortical areas has a global architecture which integrates successive learning experiences into coherent functions such as the human language.     

Concretions in the human testis are derived from the basal lamina of seminiferous cords

Summary We provide evidence that testicular concretions form exclusively in association with seminiferous cords. Testicular material obtained from 6 patients with various disorders of spermatogenesis was studied by means of light-and electron microscopy. Seminiferous cords in the testes examined form so-called hypoplastic zones. They contain immature Sertoli cells and are surrounded by an unusually thick basal lamina and one or two layers of myofibroblasts. They display extensive coiling and form ring-like structures. Concretions are located at the periphery or in the center of the cords and consist of a hyaline material with an occasional granular core. They are enveloped by Sertoli cells or myofibroblasts. Data presented indicate that concretions may develop within the above-mentioned ring-like structures or in deep indentations of the surrounding connective tissue. Computer-assisted 3-D reconstructions of a seminiferous cord based on 24 serial semithin sections revealec that the majority of concretions communicate with the interstitial tissue through a broad opening comparable to a meso. On the basis of our observations we could demonstrate that concretions are accumulations of basal lamina that occasionally contain remnants of degenerated myofibroblasts. They form outside the cords and belong to the connective tissue compartment. As the components of the basal lamina are thought to be produced by the interaction of Sertoli cells and myofibroblasts we tentatively assume that the development of concretions reflects a disturbance in this complex interaction. We suggest that the presence of concretions refers to a developmental disorder and may be pathognomonic for the occurrence of defective seminiferous cords.Supported by Deutsche Forschungsgemeinschaft (Ho 388/6-1) and Verein zur Förderung der Forschung auf dem Gebiet der Fortpflanzung e.V; Hamburg