Medullar Zones Research Articles

МОРФОГЕНЕЗ ЯИЧНИКОВ ЦЫПЛЯТ-БРОЙЛЕРОВ ПРИ ИСПОЛЬЗОВАНИИ КОРМОВОЙ ДОБАВКИ «ЯНТАРНЫЙ ХОЛОДОК»

The aim of research is to study the development of structural and functional features of the reproductive system of broiler chickens using the feed additive Yantarnyj holodok. Research was conducted on broiler chickens of the Ross-308 cross under experimental conditions, while for the experiment, control and experimental groups of 30 heads each were created, starting from the day-old age, broiler chickens of the control group received tap water from vacuum drinkers without adding a feed additive, and chickens of the experimental group were given the feed additive Yantarnyj holodok daily in a dose of 1.5 l / t with drin¬king water until the end of growing. As a main diet, broiler chickens of both groups received compound feed of Ptitsefabrika Artemovskaya LLC. The use of the feed additive Yantarnyj holodok had a positive effect on the live weight gain, which by the end of the experiment was 2,938.10 ± 405.34 g, which was 1.9 % higher than the average value in the control group. 100 % survival of broiler chickens in the experimental group was established. Histological studies revealed the process of gradual improvement of the ovary structure, the formation of its cortical and cerebral zones. At the age of 10 days, the histological structure of the ovary was not formed and represented only the protein coat, and the internal part was represented by chaotically scattered follicles, among which follicles in the pertification state were found. By the 20th day, the cortical and medullar zones of the ovary could be seen. By the 35th day, the formation of egg-bearing mounds with a zone of formed follicles of varying degrees of maturity is observed, but complete maturation of follicles with a formed egg cell was not detected in the studied individuals. The medullar zone of the ovary is rich in blood vessels of different calibers, that is, the vascularization of the ovary of chickens of this age is significantly developed.

Vitinellopsis nov. gen., a new calcareous alga (Chlorophyta, Bryopsidales) from the Silurian of Gotland (Sweden), and the tribe Vitinelleae nov. nom

The algal genus Vitinellopsis nov. gen. is well represented in the Silurian limestones of Gotland (Sweden). This new taxon is interpreted as a calcified codiacean alga (Chlorophyta, Bryopsidales). In the studied material, the calcareous wall of sparry calcite, probably originally aragonitic, appears well preserved. The subcylindrical thallus, with rounded ends, rarely bifurcated, measures up to 27 mm long and 2.5 mm wide. The medullar zone exhibits 4–6 longitudinal, subtly undulating siphons; the subcortical zone shows inflated, vesiculiform radial siphons, and the cortical zone displays small, relatively short acrophorous siphons. The status of the tribe Vitinelleae nomen novum, formerly Bothryelleae, is discussed. Given its abundance, ease of identification, and short stratigraphic range, Vitinellopsis gotlandica nov. gen., nov. sp. may prove useful for regional correlations, facies and paleobiogeographic studies.

Peculiarities of neuroendocrine and metabolic effects of sulfate-chloride sodium-magnesium mineral waters "Myroslava" and "Khrystyna" of Truskavets’ spa in healthy female rats

Background. Earlier we found that the newly created sulfate-chloride sodium-magnesium drinking mineral waters of Truskavets’ spa have similar neuroendocrine and metabolic effects on healthy old female rats significantly different from daily water. The aim of this study is to elucidate the effects of these mineral waters on the neuroendocrine status and metabolism of these animals. Materials and Methods. Experiment was performed on 50 healthy female Wistar rats. Animals of the first group remained intact, using tap water from drinking ad libitum. Rats of the control group for 6 days injected a tap water through the tube at a dose of 1,5 mL/100 g of body mass. The rats of the main groups received the water "Myroslava" and "Khrystyna". The day after the completion of the drinking course in all rats, at first, assessed the state of autonomous regulation by parameters of the HRV. The plasma levels of the hormones of adaptation were determined: corticosterone, triiodothyronine and testosterone (by the ELISA) as well as electrolytes: calcium, magnesium, phosphates, chloride, sodium and potassium; nitric metabolites: creatinine, urea, uric acid, medium molecular polypeptides, bilirubin; lipid peroxidation products and antioxidant enzymes, as well as cholesterol, amylase and glucose. Most of the listed parameters of metabolism were also determined in daily urine. In the adrenals the thickness of glomerular, fascicular, reticular and medullar zones was measured. Results. To identify exactly those parameters, the set of which all four groups of animals differ significantly from each other, the information field of the registered parameters was subjected to discriminant analysis. The program included in the model 8 endocrine and 16 metabolic parameters, information about which is condensed into three roots. The first root reflects directly the SOD and corticosterone and inversely the reticular zone as well as plasma uric acid and glucose. The second root contains information about Nap/Kp ratio, natrihistia, amylasemia, magnesiumuria as well as inversely about kaliemia. The third root reflects directly the triiodothyronine, parathyroid activity, plasma Ca, natriuria and chloriduria as well as urine malondyaldehide. Inversely displays the root information about the testosterone, Ku/Nau ratio, glomerular zone, plasma katalase and Na as well as uricosuria and amylasuria. In the information space of the three discriminant roots, all four groups are quite clearly distinguished. Classification accuracy is 94% (three errors). Conclusion. The newly created sulfate-chloride sodium-magnesium drinking mineral waters of Truskavets resort have specific endocrine and metabolic effects on healthy old female rats with weekly use. This provides a basis for preclinical studies.

Similar neuroendocrine and metabolic effects of sulfate-chloride sodium-magnesium mineral waters "Myroslava" and "Khrystyna" of Truskavets’ spa in healthy female rats

Background. In order to expand the hydro-mineral base of Truskavets’ spa by diluting brine (130 g/L), two new sulphate-chloride sodium-magnesium mineral waters "Myroslava" (5 g/L) and "Khrystyna" (10 g/L) were created. This report is the first in a series of experimental studies of their physiological activity in line with the concepts of neuroendocrine-immune complex and functional-metabolic continuum. Materials and Methods. Experiment was performed on 50 healthy female Wistar rats 220-300 g divided into 4 groups. Animals of the first group remained intact, using tap water from drinking ad libitum. Rats of the control group for 6 days administered a single tap water through the tube at a dose of 1,5 mL/100 g of body mass. The rats of the main groups received the water "Myroslava" and "Khrystyna". The day after the completion of the drinking course in all rats assessed the state of autonomous regulation by parameters of the HRV. The plasma levels of the hormones of adaptation were determined: corticosterone, triiodothyronine and testosterone (by the ELISA); as well as electrolytes, nitric metabolites, lipid peroxidation products and antioxidant enzymes as well as cholesterol, glucose, amylase and middle mass molecules. Most of the listed parameters of metabolism as well as 17-ketosteroids were determined in daily urine. In the adrenal glands the thickness of glomerular, fascicular, reticular and medullar zones was measured. Results. To identify exactly those parameters, the set of which three groups of animals differ significantly from each other, the information field of the registered parameters was subjected to discriminant analysis. The program included in the model 6 endocrine and 11 metabolic parameters, as well as glomerular filtration. Conclusion. The newly created sulfate-chloride sodium-magnesium drinking mineral waters of Truskavets’ spa have similar neuroendocrine and metabolic effects on healthy old female rats significantly different from daily water.

Role of the neuroendocrine complex in immunotropic effects of nitrogenous metabolites in rats

Background. We have previously shown that nitrogenous metabolites have immunomodulatory effects, both suppressor and enhancing, both in healthy rats and in humans exposed to pathogenic influences. The immunomodulatory effect of bilirubin is probably mediated through aryl hydrocarbon receptors, and uric acid through TL- and adenosine receptors of immune cells. The question of mediators of the immunomodulatory action of urea and creatinine remains open. We hypothesized the mediating role of mediators of the autonomic nervous system and adaptive hormones. The aim of this study is to analyze the relationships between the parameters of nitrogenous metabolites and the parameters of the autonomic nervous and endocrine systems, on the one hand, and between neuroendocrine and immune parameters - on the other hand. Material and methods. Experiment was performed on 60 healthy female Wistar rats. The plasma levels and urinary excretion of the nitrogenous metabolites, HRV and endocrine (corticosterone, triiodothyronine and testosterone plasma levels, calcitonin, parathyroid and mineralocorticoid activities, the thickness of glomerular, fascicular, reticular and medullar zones of adrenals) parameters as well as parameters of immunity were determined. Results. According to the results of canonical correlation analysis, the modulating effects of nitrogenous metabolites on neuroendocrine parameters are quite pronounced and almost identical in terms of bilirubin (R=0,603), creatinine (R=0,602), uric acid (R=0,599) and urea (R=0,586). Taken together, nitrogenous metabolites determine neuroendocrine parameters by 71,5% (R=0,845; χ2(84)=179; p<10-6). Triiodothyronine, fascicular and medullar areas of the adrenal glands, vagal tone and calcitonin activity were the most susceptible to nitrogenous metabolites. In turn, neuroendocrine parameters determine the parameters of immunity, subject to exposure to nitrogenous metabolites, by 95,8% (R=0,979; χ2(264)=405; p<10-6). Conclusion. Previously identified immunomodulatory effects of nitrogenous metabolites are realized, perhaps, through the factors of the autonomic nervous and endocrine systems.

Spectrophotometric Color Measurement to Assess Temperature of Exposure in Cortical and Medullar Heated Human Bones: A Preliminary Study.

Heated-bone color changes may provide information about temperature of exposure, with interest for anthropologists and forensic experts. The aim of this study was to assess heat-induced color changes by spectrophotometry in cortical and medullar human bones heated at different temperatures and times. CIELAB (International Commission on Illumination-LAB) color parameters (L*, a*, and b*) and whiteness (WI) and yellowness (YI) indexes were obtained by spectrophotometry in the cortical and medullar zones of 36 bone sections exposed at 200, 400, 600, and 800 °C for 30 and 60 min. The accuracy of color-based temperature estimations was evaluated by Receiver Operating Characteristics (ROC) analysis. Chromaticity a* showed the best significant discrimination power with the area under the ROC curve (AUC) values ranged from 0.9 to 1.0 in cortical zones and 0.7 to 1.0 in medullar zones for all temperatures of exposures and both time of exposures. Chromaticity b*, and WI and YI indexes showed an AUC of 1.0 at 400, 600, and 800 °C for 30 and 60 min in the cortical and medullar zones. The spectrophotometric color parameters provided a highly accurate estimation of the temperature of exposure to discriminate between temperatures and exposure times in the cortical and medullar zones. Spectrophotometric bone color measurement in cortical and medullar zones can be an objective and reproducible method to estimate the temperature of exposition, and it can be considered useful for forensic and anthropological purposes.

Features of the state of neuro-endocrine factors of adaptation under different options of uric acid metabolism in healthy female rats

Background. As part of the project "Physiological activity of uric acid", we previously identified 4 variants-clusters of uricemia and uricosuria both in rats and in humans. It was shown that the clusters differ from each other in the constellation of immunity parameters, which to one degree or another correlate with uricemia and uricosuria. The aim of this study was to identify autonomic and endocrine adaptogenic factors, the combination of which differentiates previously formed quantitative and qualitative variants of uric acid metabolism in rats. Materials and Methods. Experiment was performed on 58 healthy female Wistar rats 220-300 g. The serum and urine levels of the uric acid, calcium, phosphates, sodium and potassium were determined. The neuro-endocrine status evaluated by the HRV parameters; serum levels of the hormones such as corticosterone, triiodothyronine and testosterone; daily excretion of 17-ketosteroides; electrolytes markers of mineralocorticoid, parathyroid and calcitonin activities as well as by the thickness of glomerular, fascicular, reticular and medullar zones of the adrenals. Results. The previously identified four variants-clusters of uric acid metabolism differ from each other by a constellation of 10 neuro-endocrine adaptation factors that reflect the state of glucocorticoid, androgenic and catecholamine functions of the adrenal glands, as well as HRV-marker of vagal tone and electrolyte markers of sympatho-vagal balance as well as calcitonin and parathyroid activities. Classification accuracy is 90%. Uricosuria and uricemia are negatively correlated with HRV-markers of sympathetic tone and circulating catecholamines, the level of corticosterone and the thickness of the fascicular zone of the adrenal cortex secreting them, as well as the level of triiodothyronine and the Ca-P marker of calcitonin activity, on the other hand, they are positively correlated with the HRV marker of vagal tone and urinary excretion of 17-ketosteroids. The rate of determination of neuro-endocrine adaptation factors by uric acid is 62%. Conclusion. Uric acid is naturally associated with the state of autonomous and endocrine adaptation factors in healthy female rats.

Elemental systematics of the calcitic skeleton of Corallium rubrum and implications for the Mg/Ca temperature proxy

The high-Mg calcite skeleton of Corallium rubrum was analyzed from living colonies collected from a wide range of depths (15 m to 607 m) and environmental settings in the Mediterranean Sea. An overarching goal was to better understand the calcification process and incorporation of elements into the slow-growing skeleton of both shallow and deep-water specimens, and more specifically, to clarify the veracity of geochemical proxies for reconstructing seawater temperatures. The coral internal structure including growth bands were determined by scanning electronic microscopy (SEM) and petrographic techniques. Trace elements (Li, B, Mg, Sr and Ba) compositions of the coral skeleton were obtained by solution and laser ablation inductively coupled plasma mass spectrometry (ICP-MS). Results show that the skeleton of the deep-water specimens has an internal microstructure similar to shallow-water colonies, with the medullar and the annular zones clearly distinguishable in both shallow and deep-water specimens. In general, the bands of the deep-water samples are very thin and equidistant compared to the irregular banding of the shallow-water specimens. Banding differences relate to the contrasting environmental dynamics, with the shallow-water specimens being exposed to large seasonal fluctuations compared to the relative stable conditions of those inhabiting bathyal depths. The inner medullar and outer annular portions differ in their trace element concentrations: Mg/Ca, Sr/Ca and Li/Ca ratios are higher in the medullar zone and seem to be influenced by growth kinetics, whereas B/Ca and Ba/Ca are similar in both zones and hence unaffected by growth rate. The variability of elemental ratios is lower in the deep-water specimens. Growth bands are highly correlated to Mg/Ca, Sr/Ca and Li/Ca, suggesting common mechanism(s) controlling the incorporation of these elements into the coral skeleton. Mg/Ca ratios were especially depleted in the dark bands. Although the mean Mg/Ca of each specimen is positively correlated to ambient seawater temperature, the intra-annual variations and amplitudes differ and do not correlate to the band widths. These findings suggest that intra- and inter-annual variations of Mg/Ca cannot be used to reconstruct a continuous time-series of long-term seasonal temperature records. However, the mean Mg/Ca composition can serve as a valuable proxy to estimate mean palaeoseawater temperature at a given site within the Mediterranean.

Growth Kinetics and Distribution of Trace Elements in Precious Corals

The concentration and spatial distribution of major (Ca, Mg) and trace elements (Na, Sr, S, Li, Ba, Pb, and U) in different Corallium skeletons (C. rubrum, C. japonicum, C. elatius, C. konojoi) have been studied by electron microprobe (EMP) and laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). EMP data show positive Na-Mg and negative Na-S and Mg-S correlations in all skeletons. LA-ICPMS data display additional Sr-Mg, Li-Mg, and U-Mg positive correlations. Medullar zones in the skeletons, corresponding to fast growing zones, are systematically richer in Mg, Na, Sr, Li, and U and poorer in S than the surrounding slow growing zones. These spatial distributions are mostly interpreted in terms of growth kinetics combined with steric effects influencing the incorporation of impurities in biogenic calcites. This interpretation is in agreement with available experimental data on kinetic effects on the incorporation of elements in calcite. At a different scale, annual growth rings in annular slow growing zones show oscillations in Mg, Na, Sr, and S. These chemical oscillations probably result from growth rate variations: fast growth would produce rings enriched in Mg, Sr, and Na, while slow growth would produce rings enriched in Ca, S and organic matter. From previous studies in C. rubrum, the Mg-rich rings would develop during the spring to fall period while the S-rich rings would form immediately after (late fall and winter). Analytical traverses performed in annular zones of different Corallium skeletons indicate that Mg, Na, Sr, Li, and U decrease from core to rim. This observation indicates that radial growth rate decreases as the colony gets older. Contrary to Mg, Na, Sr, Li, S, and U, barium and lead concentrations are identical in medullar and annular zones and appear independent of growth kinetics. Thus, concentrations in Corallium skeletons could provide indications on Ba and Pb contents in the oceans. Barium and lead concentrations are higher in Mediterranean than in Pacific precious corals, these two elements can be used to discriminate C. rubrum from C. japonicum, and contribute enforcing regulations on the trade of precious corals.

Morphogenesis of human fetal thymus during weeks 22–27 of development

Distinctive features of human fetal thymus morphogenesis in early ontogeny in the case of uncomplicated pregnancy have been characterized. A steady increase of thymus dimensions and weight occurred concomitantly to differentiation of morphofunctional zones within the organ. Cell differentiation in the subcapsular and inner cortical zones of the thymus lobes was manifested as changes in parameters of expression of T-lymphocyte antigens CD1, CD2, and CD3 and ultrastructural features of reticuloepithelial cells (REC) type I and II forming a microenvironment for lymphocytes. RECs of the medullar zone formed a glomerular syncytium with desmosomal interepithelial contacts by week 22 of fetal development. Small lymphocytes predominated among thymocytes (66%). Hassall's corpuscles, the structural correlates of morphological and functional maturity, predominated in the fetal thymuses during developmental weeks 25-27.

Retracted: Enhanced bone regeneration with a novel synthetic bone substitute in combination with a new natural cross‐linked collagen membrane: radiographic and histomorphometric study

4Bone is a fully synthetic bioactive bone substitute composed of 60% hydroxyapatite (HA) and 40% beta-tricalcium phosphate (ß-TCP). This study aimed to investigate the effect of resorbable collagen membranes (RCM) on critical size defects in rabbit tibiae filled with this novel biphasic calcium phosphate at 15, 30, 45, and 60 days by radiological and histomorphometric analysis. Three critical size defects of 6 mm diameter were created in both tibiae of 20 New Zealand rabbits and divided into three groups according to the filling material: Group A (4Bone), Group B (4Bone plus RCM), and Group C (unfilled control group). At each of the four study periods, five rabbits were sacrificed. Anteroposterior and lateral radiographs were taken. Samples were processed for observation under light microscopy. At the end of treatment, radiological analysis found that cortical defect closure was greater in Group B than Group A, and radiopacity was clearly lower and more heterogeneous in Group A cortical defects than in Group B. There was no cortical defect closure in Group C. Histomorphometric evaluation showed significant differences in newly formed bone and cortical closure in Group B compared with Groups A and C, with the presence of higher density newly formed bone in cortical and medullar zones. Biphasic calcium phosphate functioned well as a scaffolding material allowing bone ingrowth and mineralization. The addition of absorbable collagen membranes enhanced bone gain compared with non-membrane-treated sites. This rabbit study provides radiological and histological evidence confirming the suitability of this new material for guided tissue regeneration of critical defects.

Retracted: Influence of Biphasic β‐TCP with and without the use of collagen membranes on bone healing of surgically critical size defects. A radiological, histological, and histomorphometric study

The aim of this study was to investigate, by means of radiological and histomorphometric analysis, the effect of resorbable collagen membranes on critical size defects (CSD) in rabbit tibiae filled with biphasic calcium phosphate. Three CSD of 6mm diameter were created in both tibiae of 20 New Zealand rabbits and divided into three groups according to the filling material: Group A (Ossceram), Group B (Ossceram plus Alveoprotect membrane), and Group C (unfilled control group). Five animals from each group were sacrificed after 15, 30, 45, and 60days. Anteroposterior and lateral radiographs were taken. Samples were processed for observation under light microscopy. At the end of treatment, radiological analysis found that cortical defect closure was greater in Group B than Group A, and radiopacity was clearly lower and more heterogeneous in the Group A cortical defects than in Group B. There was no cortical defect closure in Group C. Histomorphometric evaluation showed significant differences in newly formed bone and cortical closure in Group B compared with Groups A and C, with the presence of higher density newly formed bone in cortical and medullar zones. There was no cortical defect closure or medullar bone formation in Group C. Biphasic calcium phosphate functioned well as a scaffolding material allowing mineralized tissue formation. Furthermore, the addiction of absorbable collagen membranes enhanced bone gain compared with non-membrane-treated sites.

Abstract 448: Mechanisms involved in the tumor-induced thymic involution.

Abstract The thymus is a central lymphoid organ critical for the development and maintenance of an effective peripheral T cell repertoire. Most important, it provides a specialized environment for the selection of rearranged clones that will function appropriately in the adaptive immune response. T cell maturation progresses through well-defined stages in which proliferation, differentiation, and apoptosis are central to the selection of a functional TCR repertoire. During mammary tumorigenesis, there is a profound thymus involution associated with a severe depletion of the most abundant subset of thymocytes, CD4+CD8+ double positive (DP) immature cells. Thymic involution has been observed in several model systems; including graft-vs-host disease, aging, and tumor development, however, the precise mechanisms involved in this phenomenon remain poorly defined. Previous results from our laboratory have reported that the severe thymic atrophy and impaired T cell development seen in mammary tumor bearers are associated with a profound decrease in thymus size accompanied by a disrupture of the normal thymic architecture, an arrest in at least two steps of T cell differentiation, and an increase in thymic apoptosis in tumor-bearers. In our studies we have used the murine D1-DMBA-3 mammary tumor model to elucidate the exact mechanisms associated to the tumor-induced impaired T cell development and thymic involution. We have found that the disruption in the thymic architecture of tumor bearers appears to be related to a downregulated expression of hepatocyte growth factor in the medullar zone of the thymus. Moreover, the progressive increase of apoptosis in thymocytes during the tumor development is associated to a downregulation of Bcl-xL and A1, two important molecules that control programmed cell death. Additionally, the impaired T cell development observed during the tumor-induced thymic involution is associated to a profound decrease of IL-7 and IL-15, two crucial cytokines involved in T cell development; a downregulation in the expression of most of the Jak/Stat signaling proteins; and an increased expression of several suppressor of cytokine signaling (SOCS) members. Our data provides the bases for understanding the mechanisms associated to the impaired T cell development and thymic involution present in the thymuses of tumor bearers. Citation Format: Roberto Carrio-Jardines, Vijaya Iragavarapu-Charyulu, Stephania Libreros, Ramón A. García-Areas, Marta Torroella-Kouri, Diana M. Lopez. Mechanisms involved in the tumor-induced thymic involution. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 448. doi:10.1158/1538-7445.AM2013-448

Histological and Immunohistochemical Study on Iberian Red Deer (Cervus elaphus hispanicus) Haemal Nodes

Haemal nodes are capsulated, lymphoid organs with haemal circulation. Their parenchyma is distributed in primary and secondary lymphatic nodes in the cortical and medullar zones. In these zones the lymphatic tissue may adopt a cord-like shape and it is composed by plasma cell, macrophages and B and T lymphocytes. Blood circulates through the sinuses situated underneath the capsule, around the trabeculae and in the marrow.

CARACTERIZACIÓN HISTOLÓGICA DEL TIMO EN FETOS DE ALPACA

The objective of the present study was to study the cytoarchitectural structure of the cervical and thoracic segments of thymus in alpaca (Lama pacos) fetuses. For this purpose, 10 fetuses between 40-190 days of gestation were collected form the local slaughterhouse. At day 40, the developing thymus has acinar cytoarchitectural morphology, infiltrated by a few lymphoid cells surrounded by mesenchymal cells. At day 60, the cervical segment looks like a «follicular» lymphoid, densely populated by thymocytes, whereas the thoracic region has a cystic appearance with short trabecular projections. Cortex and medulla differentiation starts in the posterior cervical and thoracic segments by day 100 and in the anterior cervical segments by day 130, and is well established by day 165. The thymic capsule remained as a double cellular layer of lax connective tissue. Subcapsular and trabecular blood vessels have fenestrated endothelium. Erythroblastic cells were observed by day 100 in the cortex and subcapsule zones. Medullar Hassall’s corpuscles were observed by day 100, and the epithelial reticular cell barrier in the cortical medullar zone was observed by day 130.

Вплив стрептозотоциніндукованого діабету та неповної глобальної ішемії мозку на апоптоз у тимусі щурів

The influence of incomplete global ischemia-reperfusion of the brain on the activity of pro- and antiapoptotic processes in the thymocytes by the intensity of p53 and Bcl-2 - proteins expressions has been investigated. It has been shown that in the cortical zone of thymus of rats with a four-month diabetes, as well as in the control rats and rats with diabetes mellitus after brain ischemia, the antiapoptotic processes are dominated. In the medullar zone of the gland in rats with diabetes, complicated and uncomplicated with brain ischemia-reperfusion the antiapoptotic mechanisms predominate too, but to a lesser extent than in the cortical zone.

Nano to macroscale biomineral architecture of red coral (Corallium rubrum)

Different techniques have been used to characterize the physical and chemical structure of the red coral calcitic skeleton. A section normal to the axis of the skeleton shows a medullar zone surrounded by a circular domain composed of concentric rings. Growth rings are revealed by the cyclic variation of organic matter (OM) and Mg/Ca ratio. These growth rings are annual; thus, both OM and Mg/Ca ratio can be used to date red coral colonies. Growth rings display wavelets. The internal structure of each wavelet results from the stacking of layers with tortuous interfaces. Tortuosity is due to the presence of microprotuberances. Interfaces between layers may display sharp discontinuities indicative of interruption of the mineralizing process. SEM and TEM studies show that each layer is made of (1) fibers, organized or not in fan-shaped structures; and (2) submicrometer (apparently mono-) crystalline units. Fibers are superstructures made of submicrometer units possibly assembled by an oriented aggregation mechanism. HRTEM studies show that in spite of displaying single-crystal scattering behavior, the submicrometer crystalline units are made of 2-5 nm nanograins again possibly aggregated by a mechanism of oriented attachment. Thus, submicrometer crystalline units and polycrystalline fibers can be both defined as mesocrystals. The red coral skeleton is a hierarchically organized organic-inorganic composite that exhibits porosity and structural and compositional order on length scales from the nanoscale to the macroscale.

Presumable role of plasmodesmata in floral signal transduction in shoot apical meristems of rudbeckia and perilla plants

The number of plasmodesmata was calculated per 1 μm of cell wall length in the central and medullar zones of shoot apical meristems (SAM) in the course of floral transition in a long-day (LD) plant Rudbeckia bicolor Nutt. and a short-day plant Perilla nankinensis Lour. Under the day length unfavorable for flowering (control), the numbers of plasmodesmata differed in the central and medullar zones of SAM, which produce the reproductive organs and stems, respectively. Besides, the numbers of plasmodesmata in the central zone of perilla SAM considerably differed between the anticlinal and periclinal cell walls of the first and second cell layers. Following the photoperiodic induction (PI) with eight LD in rudbeckia and twelve SD in perilla favorable for floral transition, the numbers of plasmodesmata considerably increased in the anticlinal and periclinal cell walls of the first and second cell layers of the central zone; meanwhile in the medullar zone, the numbers of plasmodesmata dropped down following PI. These data show that floral transition presumably involves the activation of cell-to-cell interactions and enhances the signal transduction in SAM.

ADAMTS-1 is involved in normal follicular development, ovulatory process and organization of the medullary vascular network in the ovary

To clarify the role of disintegrin-like and metalloproteinase with thrombospondin type I motifs-1 (ADAMTS-1) in ovarian function, we examined abnormalities in ovulatory processes, folliculogenesis and the vascular system of ADAMTS-1 null ovaries. First, when immature female mice were treated with pregnant mare serum gonadotropin (PMSG)/human chorionic gonadotropin (hCG), the number of ovulated oocytes was markedly decreased in ADAMTS-1 null mice in comparison to ADAMTS-1 (+/-) controls. The proportion of anovulated follicles to total mature follicles was significantly higher in ADAMTS-1 null females when compared with controls. The numbers of growing follicles at each stage were counted. The number of follicles at type 5b (late preantral) and later stages was markedly reduced in ADAMTS-1 null mice, irrespective of gonadotropin treatment (no gonadotropins, PMSG alone or PMSG/hCG). These data demonstrate that impairment of ovarian function to ovulate oocytes in ADAMTS-1 null mice occurs at two different levels: in the development of growing follicles and ovulatory processes. Furthermore, ADAMTS-1 null ovaries included a number of unusual atretic follicles that showed no sign of oocyte degeneration but lost the surrounding granulosa cell layers and were considered to be derived from type 4 or 5a follicles. These results suggest that ADAMTS-1 is important for follicular development beyond the type 4 and/or 5a and for maintaining normal granulosa cell layers in follicles. Finally, the number of large blood vessels in the medullar zone was significantly decreased in ADAMTS-1 null mice ovaries, suggesting that ADAMTS-1 is also involved in the organization of the medullary vascular network.

Contribution of γ glutamyl transpeptidase to oxidative damage of ischemic rat kidney

A variety of mechanisms have been considered in the pathogenesis of the cell damage occurring in the kidney that is undergoing transient ischemia. However, little information is available about the role of oxidative stress in building up the tissue injury in the hypoxic organ during short-term ischemia. After a standard brief period (25 min) of unilateral kidney ischemia in rats, pretreated or not with acivicin (60 micromol/L/kg i.v.), tissue samples from both ischemic and not ischemic kidneys were obtained to measure malondialdehyde (MDA) and glutathione (GSH) content, gamma glutamyl transpeptidase (GGT) activity by spectrophotometry, localization and intensity of enzyme activity, and tissue damage by histochemistry. GGT activity was found to be increased in both cortical and medullar zones of the ischemic kidneys, where the GSH level was only slightly decreased and the MDA level, in contrast, was markedly increased; in parallel, the cytosolic volume of the proximal tubular (PT) cells showed a significant increment. The animal pretreatment with acivicin, a specific inhibitor of GGT, besides preventing the up-regulation of the enzyme during ischemia, afforded good protection against the observed changes of MDA and GSH tissue levels, as well as of tubular cell volume. Ex vivo data supporting a net pro-oxidant effect of up-regulated GGT during short-term ischemia of rat kidney have been obtained. The enzyme stimulation appears to contribute to the renal morphological damage exerted by a brief hypoxic condition at the level of PT cells. The actual impact on kidney function by GGT-dependent oxidative damage during transient ischemia and the potential protective action of GGT inhibitors require subsequent investigation.