The histopathalogical effects of retinoic acid on the tissues

The aim of this study is to sum up the important information that has emerged from the last 10 years of experimental investigations over the effects of retinoic acid (RA) on embryonic structure and adult tissues. Administration of exogenous RA can affect the connective tissues including enhancement of myeloid compartment and suppression of erythroid cells and conversion of hematopoietic stem cells to erythroid progenitors. Also, it is able to induce osteogenic differentiation of stem cells derived from adipose tissues and etc. Examining the neural tissue highlighted that disruption of RA signaling in the adult leads to degeneration of motor neurons and development of some diseases. In vitro administration of All-Trans Retinoic Acid (ATRA) increased dendritic growth and synaptophysin puncta intensity and increased expressions of neuronal nuclei, neuron specific enolase, synaptophysin. RA also promotes expression of a marker of mature astrocytes. On muscular tissue, it can inhibit proliferation of smooth muscle cells (SMC) while promoting differentiation of SMC in vitro instead. The ATRA stimulates skeletal myogenesis while inhibiting cardiomyogenesis and hypertrophy and proliferation of cultured neonatal cardiomyocytes and cardiofibroblasts. In addition, differences in levels of embryonic RA may contribute to variability in great artery anomalies. In epithelial tissue, the squamous epithelium exposed to ATRA showed the columnar differentiation independent to proliferation. Also RA seems able to rescue the regeneration process of injured gut and revealing a better wound healing of the intestine undergone intra-operative radiotherapy. It can interrupt the process of progressive fibrosis, enhancements of the langerhans islets, exocrine pancreas, modulate the health of the mammary glands and repairs the lung cell. Thus, differences in levels of endogenous RA in embryonic and adult tissues may contribute to anomalies and pathogenesis of disease, furthermore RA has paradoxical effects on the parts forming the connective and muscles tissue in equal conditions.     

Light and electron microscopic studies on the effect of a contraceptive drug on the stomach of mouse

The present study was an investigation of the effect of the contraceptive drug, Nordette, on the stomach of the mouse when administered daily at a recommended therapeutic dose rate of 0.0026 mg kg(-1) for 30 days. Extensive light and electron microscopic changes were noticed. The drug caused enlargement in the all types of cells. The oxyntic cells appeared hypertrophied with irregular cell boundaries, enlarged nuclei and faintly stained cytoplasm. Their cytoplasm contained irregularly distributed mitochondria with dense matrix, decreased rER, obviously increased sER, disorganized intracellular canaliculi and some lysosomes. The peptic cells appeared enlarged and contained hypertrophied rough endoplasmic reticulum and an increase amount of ribosomes and secretory granules. There was an increase in the amount of the secretory granules in the lumen of the gastric gland. The mucus cells at the upper region of the gastric gland were greatly decreased. Smooth muscle fibers showed enlargement and degeneration. The submucosa and lamina propria showed vacuolation. The most pathological effects were restricted to the obvious decrease of the lymphoid cells in the submucosa and lamina propria. Dilatation and congestion of the blood vessels and blood capillaries were noticed. Blood capillaries lined by enlarged endothelial cells containing enlarged heterochromatic nuclei.     

Effects of Polygonum aviculare herbal extract on sperm parameters after EMF exposure in mouse

Electromagnetic fields with high energy same as ionizing radiation inserts their destructive effects via free radical production. Using antioxidants or herbal plants with antioxidants components could diminish hazardous effects of EMF. Polygonum aviculare has a high amount of phenolic and flavonoid and proved that has antioxidants effects. The aim of this study was to evaluate the effects of Polygonum aviculare herbal extract on sperm parameters after EMF exposure in mouse. Twenty four male mice, 8 weeks divided to 4 groups (one control and three experimental groups). Control group didn't receive EMF exposure. EMF group mice received 3 mT EMF during 2 months, 4 h daily and 5 days weekly. Polygonum aviculare group received 50 mg kg(-1) herbal extract during 2 months and poly -EMF group received 3 mT EMF during 2 months, 4 h daily and 5 days weekly and 50 mg kg(-1) herbal extract during 2 months. After 2 months the mice sacrificed with cervical dislocation and sperm obtained from tail of epididymis and motility and morphology of them were analyzed. Sperm analysis results showed that in group with Polygonum aviculare, morphology and motility of sperm developed (p < 0.05). Present results showed that EMF can reduce motility of sperm and treatment of Polygonum aviculare after EMF exposure developed sperm quality after EMF exposure.     

腰果树分泌道超微结构的研究

用透射电镜技术研究了腰果树（Ａｎａｃａｒｄｉｕｍ ｏｃｃｉｄｅｎｔａｌｅ Ｌ．）末端小枝次生韧皮部分泌道的结构，着重研究了上皮细胞中的亲锇物质的形成、积累和排出，这些亲锇物质是分泌道的主要产物。观察表明，在充分发育的上皮细胞中，大量亲锇物质出现在细胞质、内质网潴泡和质体中。在细胞质中可以看到大量直径为２０～３０ｎｍ的亲锇的微粒，看来它们能聚集成为大小不等的亲锇物质的团块。这些亲锇物质的团块常常附着     

Morphological changes of rabbit lacrimal gland cells from amiodarone administration

Background: Amiodarone is a drug that is used for treatment of cardiac arrhythmia after cardiac ischemia. This drug as beta blocker decreases arrhythmia rate but it has many side effects on different tissues. Since there are rare reports about changes of lacrimal glands, this research has been carried out to study the morphological and ultrastructural changes of lacrimal gland cells after amiodarone administration. Methods: Male rabbits (n = 14) were divided into control and experimental groups. Experimental group were intra peritoneally injected with a daily single dose of 80 mg/kg amiodarone for two weeks. The control group only received normal saline. At the end of the injection period, the two groups were anesthetized and perfused with Karnovsky's fixative. The lacrimal glands were removed, fixed and then prepared for light and electron microscopic studies. Quantitative studies on lacrimal gland cell micrographs were performed by point counting method. The results were statistically compared between the two groups. Results: Light microscopic observation showed many secretory granules in the cytoplasm of the lacrimal gland cells, which were also seen in the lumen of acini. Ultrastructure study of these cells showed the presence of inclusions in their cytoplasm with homogenous and dense structure. In quantitative analysis, the volume fractions (Vv) of mitochondria and nucleus to the cell showed no differences between the two groups but the Vv of euchromatin to the nucleus was different (P<0.05 ). Conclusion: The presented results show adverse effects of amiodarone on rabbit lacrimal gland cells.     

Variation in testicular histology of the spiny tailed lizard Uromastyx aegyptius microlepis during hibernation and active periods

The testicular histology of the lizard, Uromastyx aegyptius microlepis were varied considerably during hibernation and activity periods, reaching maximum values in summer. The onset of winter induces testicular regression, reduced testis size, testis diameter, diameter and epithelial height of the seminiferous tubules and epididymal epithelial height. Animals exhibit testicular recrudescence during late winter (February and March) and maximum testicular volume occurred during June. The period of maximal testicular volume was positively correlated with increasing ambient temperature. The summer season induces the testicular activity in contrast with the winter season in which the activity decreased and the testes were collapsed. Spermatocytogenesis is active in early spring and the major portion of the seminiferous epithelium comprises spermatids in various stages of maturation and their luminae were filled with spermatozoa. The size of the interstitial cells is direct correlated with changes occurring in epididymis and seminiferous epithelium. Most interstitial cell nuclei show clear regression when spermatocytogenesis were diminishes.     

Effects of in vitro brevetoxin exposure on apoptosis and cellular metabolism in a leukemic T cell line (Jurkat)

Harmful algal blooms (HABs) of the toxic dinoflagellate, Karenia brevis, produce red tide toxins, or brevetoxins. Significant health effects associated with red tide toxin exposure have been reported in sea life and in humans, with brevetoxins documented within immune cells from many species. The objective of this research was to investigate potential immunotoxic effects of brevetoxins using a leukemic T cell line (Jurkat) as an in vitro model system. Viability, cell proliferation, and apoptosis assays were conducted using brevetoxin congeners PbTx-2, PbTx-3, and PbTx-6. The effects of in vitro brevetoxin exposure on cell viability and cellular metabolism or proliferation were determined using trypan blue and MTT (1-(4,5-dimethylthiazol-2-yl)-3,5-diphenylformazan), respectively. Using MTT, cellular metabolic activity was decreased in Jurkat cells exposed to 5 – 10 μg/ml PbTx-2 or PbTx-6. After 3 h, no significant effects on cell viability were observed with any toxin congener in concentrations up to 10 μg/ml. Viability decreased dramatically after 24 h in cells treated with PbTx-2 or -6. Apoptosis, as measured by caspase-3 activity, was significantly increased in cells exposed to PbTx-2 or PbTx-6. In summary, brevetoxin congeners varied in effects on Jurkat cells, with PbTx-2 and PbTx-6 eliciting greater cellular effects compared to PbTx-3.     

Cell and nuclear degradation in root meristems following exposure of potatoes (Solanum tuberosum L.) to salinity

Summary In many plant species, it has been demonstrated at the whole plant level that supplemental Ca²⁺ alleviates the effects of salinity stress. These effects have been attributed to physiological processes, but there are no reports of the effects of supplemental Ca²⁺ on preventing nuclear damage to the root meristematic cells following exposure to NaCl salinity. Two in vitro cultured potato (Solanum tuberosum L.) cultivars, analysed by fluorescent microscopy and flow cytometry, showed a similar pattern of salinity-induced changes to the nuclei of root meristematic cells. Damage occurring after only a few hours was followed by nuclear degradation at 24 h. Flow cytometry histograms showed a reduction in G1 and G2 nuclei and an increase in degraded nuclei, in NaCl-stressed roots. Salinity-induced nuclear degradation was alleviated by the addition of CaCl₂.     

Okadaic Acid Toxin at Sublethal Dose Produced Cell Proliferation in Gastric and Colon Epithelial Cell Lines

The aim of this study was to analyze the effect of Okadaic Acid (OA) on the proliferation of gastric and colon epithelial cells, the main target tissues of the toxin. We hypothesized that OA, at sublethal doses, activates multiple signaling pathways, such as Erk and Akt, through the inhibition of PP2A. To demonstrate this, we carried out curves of doses and time response against OA in AGS, MKN-45 and Caco 2 cell lines, and found an increase in the cell proliferation at sublethal doses, at 24 h or 48 h exposure. Indeed, cells can withstand high concentrations of the toxin at 4 h exposure, the time chosen considering the maximum time before total gastric emptying. We have proved that this increased proliferation is due to an overexpression of Cyclin B, a cyclin that promotes the passage from G2 to mitosis. In addition, we have demonstrated that OA induces activation of Akt and Erk in the three cells lines, showing that OA can activate pathways involved in oncogenesis. In conclusion, this study contributes to the knowledge about the possible effects of chronic OA consumption.     

Effects of Ethephon on Aerenchyma Formation in Rice Roots

The effects of ethephon on the constitutive aerenchyma formation in roots were studied with a rice variety Yangdao 6 as material. The number of air spaces formed by disintegrated cells in mediopellis increased significantly with the rising ethephon concentrations, whereas superoxide dismutase (SOD) activity showed downward trends. Compared with the control, the expression levels of xyloglucan endotransglycosylase (XET) gene were markedly higher both at the apical 10 mm and distal parts of roots in 100 mg/L ethephon treated plants. The accumulation of XET was supposed to be associated with the aerenchyma development. Furthermore, earlier cortical cell death was observed under the ethephon treatments, and most of nuclei of cells at 4 mm from the root apex disintegrated with many Golgi apparatus, mitochondria and membrane- bound vesicles around the cell wall.     

The effects of altered ultrasound parameters on the recovery of sciatic nerve injury

Background: Initial studies have shown that low-energy ultrasound stimulates living tissue cells to reduce regeneration or speed up their recovery. The purpose of this study was to examine the effects of various ultrasound parameters on the speed of recovery in injured sciatic nerves NMRI.Methods: NMRI mice (n = 200) with injured left paw, caused by crushing their sciatic nerves, were randomly selected. The animals were exposed to ultrasound radiation with various frequencies, intensities, and exposure time. They were allocated into 20 groups (19 treatment and 1 control groups). Sciatic functional index (SFI) test was used to evaluate the difference between the groups with respect to functional efficiency of the sciatic nerve and its recovery. SFI ، (P=0.000).Results: The results of SFI test obtained from the 14^th day showed a significant difference among the groups (P<0.05). On the 14^th day after treatment, one of the groups (US11) recovered up to 90%..Conclusion: Altered ultrasound exposure parameters had more favorable outcomes compared with our previous work.Key Words: Sciatic nerve, Ultrasonic therapy, Regeneration     

Effects of Salinity Stress on the Seminal Root Tip Ultrastructures of Rice Seedlings (Oryza sativa L.)

Abstract

Growth and structural changes in the seminal root tip of rice seedlings (Oryza sativa L. cv. Nipponbare) in response to NaCl salinity were studied. Seedlings were grown in agar medium with 0, 0.1, 0.3, 1.0, 2.0 and 3.0% NaCl(agar culture), and in water with 0, 0.01, 0.03, 0.06 and 0.1% NaCl (water culture). Seedling growth was significantly suppressed by higher concentrations of NaCl. The effect of NaCl appeared faster in water culture than in agar culture. In both agar and water cultures, root growth was markedly suppressed over shoot growth. Under saline conditions, epidermis, cortex and root cap cells appear to be damaged to a greater extent than the meristem and stelar cells. The most notable ultrastructural change in response to salinity was the development and increment of vacuoles, which seem to provide a space for accumulation of excess ions. Many electron dense deposits were observed in the larger vacuoles of the epidermal and cortical cells. Under saline conditions, cell wall thickening of the epidermis, an increase in endoplasmic reticulum, myelin figures, less compact Golgi bodies and inhibited production of Golgi vesicles were also observed.     

茶尺蠖雄成虫生殖系统形态学与组织学观察

通过常规解剖和石蜡切片显微技术对茶树主要害虫之一茶尺蠖（Ectropis obliqua Prout）雄成虫的内外生殖器官进行了形态观察和结构特征的定位描述。茶尺蠖雄成虫外生殖器由抱握器、背兜、爪形突和阳具组成;内生殖器由1个精巢、1对贮精囊、1对输精管、1对附腺和单个射精管组成,组织结构与鳞翅目其他种基本一致;经切片观察发现,精巢由8个呈辐射状精巢小管组成,它们之间被一薄层结缔组织分隔开,其内分布大量的精原细胞、精母细胞和成熟的精子束;贮精囊和输精管内均充满液体,其中贮精囊内可见大量的精子束。描述茶尺蠖雄成虫生殖系统结构特征,明确精子束在组织内的填充状态等特征,对其田间预测预报、系统发育,以及种间鉴定等均有一定的指导意义。     

Cell size in Russet Burbank potato tubers with various levels of nitrogen and soil moisture tensions

Russet Burbank potatoes were grown at levels of added nitrogen of 0, 135, and 270 kg/ha and soil moisture tensions (SMT) of 0.5 and 1.0 atm. With all combinations, there was a consistent gradient of larger to smaller starch-storage parenchyma cells from stem end to bud end of mature tubers. Stem and bud ends of tubers grown at a SMT of 0.5 atm with N had smaller cortical and pith (innermost medullary or water-core) cells than did ends of tubers grown without N. Perimedullary tissues of bud ends of tubers receiving N likewise contained smaller cells than did corresponding tissues of tubers grown without N. No pronounced differences in cell size were found in tissues from the midsections. In bud-end tissue of tubers grown at a SMT of 1.0 atm, there were no consistent differences in cell size with respect to N levels. However, pith, perimedullary, and cortical tissues of the midsections and stem ends of tubers receiving N had smaller cells than did corresponding tissues from tubers without N. The different patterns of cell size in tubers grown at different SMT indicate that the effects of N may be influenced by soil moisure.     

Some anatomical and physiological potato tuber characteristics and their relationship to hollow heart

The inception site of hollow heart (HH) and possible relationships between HH and physiological or anatomical characteristics of tubers were investigated. Scanning electron micrographs revealed cells at the site of HH inception were physically rather than enzymatically degraded. Transmission electron micrographs of tuber pith cells from non hollow (NH) tubers showed cell wall and cytoplasm width varied among cultivars but were not related to HH resistance. Water potential of NH tuber tissues at the pith, bud, center and stem end of 3 cultivars and one selection varying in resistance to HH was determined. Although the water potential gradually became less negative as tubers advanced in maturity, no differences were found in water potential between pith cells in various parts of tubers or among cultivars. Tuber pith cells increased in size concomitant with tuber growth. In all tubers pith cells were largest in the center and stem end and smallest in the bud end, but differences in mean pith cell size among cultivars were not related to HH susceptibility. However, within a cultivar the bud, center, and stem end pith cells of HH tubers were all smaller than the corresponding pith cells from similarly sized NH tubers.     

花生感染条纹病毒(PStV)后叶片细胞超微结构研究

花生接种PStV后30d取叶片进行超薄切片置于电镜下观察,在花37和白沙1016两个品种发病叶片的叶肉细胞中均发现有多种形状的内含体和病毒粒子的存在;内含体多发现于细胞核周围,有风轮状、柬状、管状和环状等;病毒粒子以柬状或拟晶格状存在,且以高感品种白沙1016叶肉细胞内的含量较多。PStV对叶绿体和线粒体等细胞器的结构有破坏作用,表现为叶绿体畸形,类囊体片层减少,基粒缩小且排列不整齐,并有大量淀粉粒累积,部分线粒体出现肥大和自溶。此外,感病细胞的膜系统松弛,有膜溶解现象,上述病理结构变化均以高感品种白沙1016表现的更为明显。     

Differentiation of Umbilical Cord Lining Membrane-Derived Mesenchymal Stem Cells into Endothelial-Like Cells

Background: Stem cell therapy for the treatment of vascular-related diseases through functional revascularization is one of the most important research areas in tissue engineering. The aim of this study was to investigate the in vitro differentiation of umbilical CL-MSC into endothelial lineage cells. Methods: In this study, isolated cells were characterized for expression of MSC-specific markers and osteogenic and adipogenic differentiation. They were induced to differentiate into endothelial-like cells and then examined for expression of the endothelial-specific markers, karyotype, and functional behavior of cells. Results: Isolated cells expressed MSC-specific markers and differentiated into adipocytes and osteoblasts. After endothelial differentiation, they expressed CD31, vWF, VE-cadherin, VEGFR1, and VEGFR2 at both mRNA and protein level, but their morphological changes were not apparent when compared with those of undifferentiated cells. There were no significant changes in karyotype of differentiated cells. Furthermore, angiogenesis assay and LDL uptake assay showed that differentiated cells were able to form the capillary-like structures and uptake LDL, respectively. Conclusion: The results indicated that umbilical CL-MSC could differentiate into functional endothelial-like cells. Also, they are suitable for basic and clinical studies to cure several vascular-related diseases. Key Words: Endothelial differentiation, Endothelial-like cells, Mesenchymal stem cells, Umbilical cord lining membrane     

Effect of Phlorofucofuroeckol A and Dieckol Extracted from Ecklonia cava on Noise-induced Hearing Loss in a Mouse Model

One of the well-known causes of hearing loss is noise. Approximately 31.1% of Americans between the ages of 20 and 69 years (61.1 million people) have high-frequency hearing loss associated with noise exposure. In addition, recurrent noise exposure can accelerate age-related hearing loss. Phlorofucofuroeckol A (PFF-A) and dieckol, polyphenols extracted from the brown alga Ecklonia cava, are potent antioxidant agents. In this study, we investigated the effect of PFF-A and dieckol on the consequences of noise exposure in mice. In 1,1-diphenyl-2-picrylhydrazyl assay, dieckol and PFF-A both showed significant radical-scavenging activity. The mice were exposed to 115 dB SPL of noise one single time for 2 h. Auditory brainstem response(ABR) threshold shifts 4 h after 4 kHz noise exposure in mice that received dieckol were significantly lower than those in the saline with noise group. The high-PFF-A group showed a lower threshold shift at click and 16 kHz 1 day after noise exposure than the control group. The high-PFF-A group also showed higher hair cell survival than in the control at 3 days after exposure in the apical turn. These results suggest that noise-induced hair cell damage in cochlear and the ABR threshold shift can be alleviated by dieckol and PFF-A in the mouse. Derivatives of these compounds may be applied to individuals who are inevitably exposed to noise, contributing to the prevention of noise-induced hearing loss with a low probability of adverse effects.     

Protective Effect of Flavonoids from a Deep-Sea-Derived Arthrinium sp. against ox-LDL-Induced Oxidative Injury through Activating the AKT/Nrf2/HO-1 Pathway in Vascular Endothelial Cells

Oxidized low-density lipoprotein (ox-LDL)-induced oxidative injury in vascular endothelial cells is crucial for the progression of cardiovascular diseases, including atherosclerosis. Several flavonoids have been shown cardiovascular protective effects. Recently, our research group confirmed that the novel flavonoids isolated from the deep-sea-derived fungus Arthrinium sp., 2,3,4,6,8-pentahydroxy-1-methylxanthone (compound 1) and arthone C (compound 2) effectively scavenged ROS in vitro. In this study, we further investigated whether these compounds could protect against ox-LDL-induced oxidative injury in endothelial cells and the underlying mechanisms. Our results showed that compounds 1 and 2 inhibited ox-LDL-induced apoptosis and adhesion factors expression in human umbilical vein vascular endothelial cells (HUVECs). Mechanistic studies showed that these compounds significantly inhibited the ROS level increase and the NF-κB nuclear translocation induced by ox-LDL. Moreover, compounds 1 and 2 activated the Nrf2 to transfer into nuclei and increased the expression of its downstream antioxidant gene HO-1 by inducing the phosphorylation of AKT in HUVECs. Importantly, the AKT inhibitor MK-2206 2HCl or knockdown of Nrf2 by RNA interference attenuated the inhibition effects of these compounds on ox-LDL-induced apoptosis in HUVECs. Meanwhile, knockdown of Nrf2 abolished the effects of the compounds on ox-LDL-induced ROS level increase and the translocation of NF-κB to nuclei. Collectively, the data showed that compounds 1 and 2 protected endothelial cells against ox-LDL-induced oxidative stress through activating the AKT/Nrf2/HO-1 pathway. Our study provides new strategies for the design of lead compounds for related cardiovascular diseases treatment.