Micromorphology of cactus-pear (Opuntia ficus-indica (L.) Mill) cladodes based on scanning microscopies

Cladode ultrastructural features of two prickly and two spineless Opuntia ficus-indica cultivars were examined using environmental scanning electron and atomic force microscopies. Observations focused on cladode as well as spine and glochid surface micromorphologies. Prickly cultivars were characterized by abundant cracked epicuticular wax deposits covering the cladode surface, with an amorphous structure as observed by AFM, while less abundant waxy plates were observed by ESEM on spineless cultivar cladodes. Further AFM observations allowed a rough granular and crystalloid epicuticular wax structure to be distinguished in spineless cultivars. Regarding spine micromorphology, prickly cultivars had strong persistent spines, observed by ESEM as a compact arrangement of oblong epidermal cells with a rough granular structure. However, deciduous spines in spineless cultivars had a broken transversely fissured epidermis covering a parallel arrangement of fibres. Through AFM, the deciduous spine surface presented an irregular hilly and smooth microrelief while persistent spines exhibited rough helical filamentous prints.ESEM and AFM studies of cladode surfaces from prickly and spineless cactus pear cultivars revealed valuable micro-morphological details that ought to be extended to a large number of O. ficus-indica cultivars.     

External morphology of the mouthparts of the whitebacked planthopper Sogatella furcifera (Hemiptera: Delphacidae), with special reference to the sensilla

The whitebacked planthopper, Sogatella furcifera (Horváth), is a major pest of rice in Asia, with the adults and larvae sucking the phloem sap and affecting plant growth. The ultrastructural morphology of the mouthparts, with distribution of sensilla located on the maxillae and labium in adult S. furcifera was observed using scanning electron microscopy and illustrated, with a brief discussion of their taxonomic and putative functional significance. The gross mouthparts comprising an uppermost small cone-shaped labrum, a three-segmented labium with a deep longitudinal groove on the anterior side, and a stylet fascicle consisting of two mandibular and two maxillary stylets, are consistent with the conventional piercing–sucking type of mouth parts found in Hemiptera. The mandibles bear 5 teeth on the external convex region on the distal extremity. Smooth maxillary stylets, interlocked to form a larger food canal and a smaller salivary canal, are asymmetrical only in the internal position of longitudinal carinae and grooves. Two dendritic canals are also found in each maxilla and one in each mandible. The cross-section of the stylet fascicle is oval. The labial tip is a rosette shape. Two types of sensilla trichoides, two types of uniporous peg sensilla, two pairs of sensilla basiconica and a pair of subapical labial sensory organs have been detected at different locations on the labium, specifically the labial tip is divided into dorsal paired sensory fields with 9 pairs of uniporous peg sensilla and 1 pairs of dome-shaped sensilla, and ventral paired sensory fields with 2 pairs of sensilla basiconica.     

Effect of rapid freezing–thawing techniques on the sperm parameters and ultrastructure of Chinese Taihang black goat spermatozoa

Supercooling sperm in liquid nitrogen vapour is a feasible and economic technique for the practical production. The study aimed to reveal the negative effects of this rapid freezing and thawing processes on Taihang black goat spermatozoa and to find out the changing of spermatozoa motility and ultrastructure by using CASA and TEM. Qualified semen samples, which collected from twenty Chinese Taihang black goats using artificial vagina were pooled and investigated the kinematics parameters and ultrastructural morphology. The results showed that freezing–thawing caused a significant reduction in the spermatozoon total motility (P < 0.001), in rapid and medium cell numbers (P < 0.001) and motility parameters (VAP, VSL, VCL, ALH and BCF) (P < 0.01). Immotile spermatozoa number was increased significantly after freezing–thawing (P < 0.001). In the ultrastructural analysis, the shape with a sperm nucleus characterized by ruptures, bend and deformity was observed. The plasma membranes were broken, and nucleoplasm erupted. The mitochondria in the middle piece were disturbed by partial absence or additional accumulations. Swelling, coiling, vacuolization and structural disorganization of mitochondria were also observed. In conclusion, Freezing–thawing procedure has a detrimental effect on motility, membrane integrity and mitochondria of goat spermatozoa. Transmission electron microscopy provides an intuitive observation to investigate deformity spermatozoa.     

Ultrastructural and Intracellular Chemical Changes of a Novel Halophilic Strain V430 of <Emphasis Type="Italic">Staphylococcus saprophyticus</Emphasis> under CaCl<Subscript>2</Subscript> Stress

Observation of the ultrastructural and intracellular chemical changes of CaCl₂-tolerant strains is important both for understanding their adaptation mechanism under high salt stress and for providing theoretical basis of their application in treating high-CaCl₂ wastewaters. A novel strain V 430 isolated by us has been successfully used to decrease the chemical oxygen demand (COD) concentration of diosgenin wastewater from 20 g l⁻¹ to less than 0.5 g l⁻¹. For this study, strain V430 was incubated in culture media of different CaCl₂ concentrations (up to 9.0%). Strain V430 cells incubated in media of high CaCl₂ concentration excreted extracellular substances and accumulated intracellular Ca²⁺ and K⁺ and free amino acids. The levels of intracellular cations and free amino acids increased with increase in CaCl₂ concentration of the medium. The increase in total free amino acids was mostly due to accumulation of glutamic acid. The strain cells under 9.0% CaCl₂ stress took up K⁺ in a short time, while accumulation of Ca²⁺ proceeded over the whole growth process.     

Bidder's organ of Bufo ictericus: a light and electron microscopy analysis

Male toads of the Bufonidae Family have rudimentary ovaries designated Bidder's organs, and if the testes are removed this organ develops into a functional ovary, representing a morphological strategy for the reproduction of the species. The Bidder's organ of Bufo ictericus was examined using routine and histochemical techniques by light microscopy and transmission electron microscopy. Each Bidder's organ presented a typical ovarian morphology, being composed of a cortex and a medulla. Bidderian follicles in different stages of development were visualized in the cortex, where they are better developed. The germ cells exhibit a large oocyte with a round-shaped nucleus. The Bidderian follicles are supported by a loose net of reticular fibers. In the medullar region, collagen fibers were immersed in the matrix rich in blood vessels that also contained a small quantity of neutral glycoproteins rich in hexose and/or sialic acid and carboxylated polymers with a characteristic distribution of glycosaminoglycans. The oocyte and the follicular cells were separated by a narrow space containing microvilli. The oocyte exhibit a well developed smooth endoplasmic reticulum, a poorly developed Golgi apparatus, and occasional lysosomes. Concentric cisternal complexes are often visualized; however, their morphological significance remains unclear. The peroxisomes display a fine granular matrix without a crystalline core, with a weak 3,3′-diaminobenzidine-reaction. Intimate association between peroxisomes, peroxisomes and lipid inclusions was observed in the oocyte, suggesting its participation in yolk metabolism.     

Structural characteristics of the tendinous cord–papillary muscle junction in healthy and hypertensive rats

Although the myotendinous junction (MTJ) of skeletal striated muscle is well known, more detailed studies regarding the structure of the cardiac MTJ are scarce. The objective of the present study was to investigate the morphological characteristics of the MTJ in hearts of healthy and hypertensive (SHR) female rats using histological, ultrastructural and three-dimensional (SEM) methods, as well as to evaluate the expression of vinculin by immunofluorescence. In the two groups, light microscopy showed branching tendinous cords and collagen bundles penetrating the apex of the finger-like projections of the papillary muscle. SEM analysis revealed an enlarged apex of the papillary muscle in SHR which was not observed in healthy animals. The loss of force transmission appears to be compensated by the amplified connection between the papillary muscle and valvular collagen. A large number of intercalated disks close to the fiber apex, small amounts of an amorphous intercellular substance and numerous vesicles were observed in SHR. In these animals, the expression of vinculin was more marked showing a regular distribution and a pattern of transverse striations along the sarcolemma. The presence of this protein in transverse bands suggests that vinculin surrounds myofibrils in the region of the Z band. Vinculin staining was also more marked in the region of the tendinous cord–papillary muscle junctions of SHR compared to control animals. Vinculin was quantified by electrophoresis and higher amounts of this protein were observed in SHR compared to control animals.     

Iota-carrageenan/casein micelles interactions: evidence at different scales

The effect of temperature on the behaviour of iota-carrageenan (CI) 0.1 wt.%/casein micelles (CM) 0–5 wt.% mixtures has been studied using three techniques: confocal laser scanning microscopy (CLSM), differential scanning calorimetry (DSC) and spectrophotometry. The microscopy clearly shows that those mixed systems separate in two phases, one being enriched in CM. It has been shown that the CM concentration seems to have an effect on the extent of the phase separation phenomenon. The DSC experiments show that addition of CM modifies the helix to coil transition temperature of carrageenan. The enthalpy of melting of helices decreases as the CM concentration increases, and the peak is shifted towards higher temperature. Local electrostatic interactions between carrageenan chains and CM have been studied by a spectrophotometric method using methylene blue (MB) properties of absorption. The absorption spectra of MB in presence of CI and CM were compared with the one of MB in presence of carrageenan alone at temperatures above and below the carrageenan coil to helix transition. The modifications of the spectrum by addition of CM are discussed in terms of interactions and rigidification of the carrageenan chains.     

Sperm morphology of Trichospilus diatraeae and Palmistichus elaeisis (Hymenoptera: Chalcidoidea: Eulophidae)

In this study, the sperm morphology of the parasitoids Trichospilus diatraeae and Palmistichus elaeisis (Eulophidae) was investigated using light and transmission electron microscopy. In the two species, the sperm are spiral along their entire length and measure about 130 μm and 195 μm in length, respectively. The head region consists of the acrosome and nucleus. The acrosome is composed of an acrosomal vesicle and, in P. elaeisis, a perforatorium. In both species, an extracellular layer in which several filaments are radiated covers the acrosome and the anterior nuclear region. The nuclei are filled with homogeneous and compact chromatin and measure about 50 μm in length in P. elaeisis and 20 μm in T. diatraeae. The flagellum consists of an axoneme with the 9 + 9 + 2 microtubule arrangement spiraled in a long helix, two mitochondrial derivatives coiling around the axoneme and, in P. elaeisis, two accessory bodies. In T. diatraeae were observed transverse striations throughout the central region of the axoneme, whereas the central pair of microtubules was rarely observed. In the final flagellar region in T. diatraeae, different from P. elaeisis, one mitochondrial derivative ends well before the other and both end before the axoneme. The sperm of these two species exhibit features that discriminate one species from each other, as well as characteristics suggest that Eulophidae is closely related to Trichogrammatidae and both of these families are more similar to Eurytomidae than Agaonidae.     

艾塞那肽对2 型糖尿病大鼠糖脂代谢和胰岛超微结构的影响

目的 研究胰高糖素样肽-1 受体激动剂艾塞那肽对2型糖尿病大鼠糖脂代谢和胰岛细胞的影响及其作用机制。方法 健康雄性SD 大鼠随机分为正常对照组（C 组6只）、正常对照+ 艾塞那肽处理组（C+E 组6 只）、糖尿病组（D 组5 只）以及糖尿病+ 艾塞那肽处理组（D+E 组5 只）,由高脂饮食加小剂量STZ 诱导成2型糖尿病后,D+E 组以及C+E 组大鼠予艾塞那肽,5μg,腹部皮下注射,1 次/d 干预;8 周后,分别测定各组大鼠体重、FBG、空腹胰岛素（FINS）、稳态模型胰岛素抵抗指数（HOMA-IR）、胰岛素敏感指数（ISI）以及血脂谱。同时行透射电子显微镜观察大鼠胰岛组织超微结构改变。结果 D+E 组大鼠FBG、FINS、TG、TC、LDL、HOMA-IR水平均明显低于未予干预的D 组大鼠（均P＜0.05）,ISI 则显著高于D 组大鼠（P＜0.05）。超微结构研究,与D 组大鼠比较,D+E 组大鼠胰岛β 细胞数量增加,形态较规则,胞质分泌颗粒增加,颗粒密度较正常;仅见少量线粒体肿胀,结构模糊。内质网结构无明显破坏。结论 艾塞那肽能显著改善2型糖尿病大鼠糖脂代谢紊乱,对其残存的胰岛细胞具有明确的保护作用。     

Ultrastructural changes to rat hippocampus in pentylenetetrazol- and kainic acid-induced status epilepticus: A study using electron microscopy

A pentylenetetrazol (PTZ)-induced status epilepticus model in rats was used in the study. The brains were studied one month after treatment. Ultrastructural observations using electron microscopy performed on the neurons, glial cells, and synapses, in the hippocampal CA1 region of epileptic brains, demonstrated the following major changes over normal control brain tissue. (i) There is ultrastructural alterations in some neurons, glial cells and synapses in the hippocampal CA1 region. (ii) The destruction of cellular organelles and peripheral, partial or even total chromatolysis in some pyramidal cells and in interneurons are observed. Several astrocytes are proliferated or activated. Presynaptic terminals with granular vesicles and degenerated presynaptic profiles are rarely observed. (iii) The alterations observed are found to be dependent on the frequency of seizure activities following the PTZ treatment. It was observed that if seizure episodes are frequent and severe, the ultrastructure of hippocampal area is significantly changed. Interestingly, the ultrastructure of CA1 area is found to be only moderately altered if seizure episodes following the status epilepticus are rare and more superficial; (iv) alterations in mitochondria and dendrites are among the most common ultrastructural changes seen, suggesting cell stress and changes to cellular metabolism. These morphological changes, observed in brain neurons in status epilepticus, are a reflection of epileptic pathophysiology. Further studies at the chemical and molecular level of neurotransmitter release, such as at the level of porosomes (secretory portals) at the presynaptic membrane, will further reveal molecular details of these changes.