Structure and ultrastructure of the egg capsule of Thermobia domestica (Packard) (Insecta, Zygentoma)

Eggs of Thermobia domestica (Packard) were collected from a laboratory culture. They were prepared for analysis in light and electron microscopes (TEM, SEM). A few hours after oviposition the egg capsule starts to tarnish and changes its colour to brown. Polygonic shapes on its surface can be seen. The egg capsule consists of a thin vitelline envelope and the chorion. The chorion consists of a one-layered endochorion and a three-layered exochorion. There are minor and major mushroom-like structures placed on the surface of the chorion. Their function is proposed. One micropyle is observed on the anterior pole of the egg. The micropylar opening is formed on the process of a follicular cell

Origin of the brushborder in the differentiating midgut of Melasoma saliceti (Chrysomelidae, Coleoptera) embryos

The embryonic development of Melasoma saliceti takes eight days at room temperature. At the beginning of the 5th day the endoderm cells have already formed a unilayered epithelium of the midgut primordium. The midgut epithelium is formed by flat cells that are not connected by specialized intercellular junctions. Large vesicles can be seen in dilated intercellular spaces of the epithelium. Cytoplasmic projections, similar to microvilli, appear in the vesicles. During the 5th day of development, the vesicles grow and become enclosed by the intercellular junctions of a zonula adherens type. During the 6th day of development the cell junctions surrounding the vesicles become transformed into a septate type.On the 8th day of development the vesicles come close to the apical sides of the midgut cells and open towards the yolk. At the same time the microvilli spread over the apical surface of the midgut primordium to form the regular brushborder of the larval midgut. In the species studied the vesicles appear to preabricate the apical surfaces of the future midgut epithelium

Fine structure of the midgut epithelium of nicoletia phytophila gervais, 1844 (Zygentoma: Nicoletiidae: Nicoletiinae) with special emphasis on its degeneration

The midgut epithelium of Nicoletia phytophila is composed of columnar digestive cells and regenerative cells that form regenerative nests. The cytoplasm of midgut epithelial cells shows typical regionalization in organelle distribution. Two types of regenerative cells havebeen distinguished: cells which are able to divide intensively and cells which differentiate. Spot desmosomes have been observed between neighboring regenerative cells. The occurrence of intercellular junctions is discussed. Themidgut epitheliumdegenerates both in an apoptotic and necrotic way. Necrosis proceeds during each molting period (cyclic manner), while apoptosis occurs between each molting, when the midgut epithelium is responsible for e.g. digestion. These processes of epithelium degeneration are described at the ultrastructural level. Our studies not only add new information about fine structure of the midgut epithelium of N. phytophila, but contribute to resolving the relationships within the Zygentoma. There are no doubts about the very close sister position of Nicoletiidae and Ateluridae. The midgut epithelium characters confirm their close relationship. However we do not recommend classifying the atelurid genera only within Nicoletiidae: Nicoletiinae

The role of autophagy in the midgut epithelium of Parachela (Tardigrada)

The process of cell death has been detected in the midgut epithelium of four tardigrade species which belong to Parachela: Macrobiotus diversus, Macrobiotus polonicus, Hypsibius dujardini and Xerobiotus pseudohufelandi. They originated from different environments so they have been affected by different stressors: M. polonicus was extracted from a moss sample collected from a railway embankment; M. diversus was extracted from a moss sample collected from a petrol station; X. pseudohufelandi originated from sandy and dry soil samples collected from a pine forest; H. dujardini was obtained commercially but it lives in a freshwater or even in wet terrestrial environment. Autophagy is caused in the digestive cells of the midgut epithelium by different factors. However, a distinct crosstalk between autophagy and necrosis in tardigrades’ digestive system has been described at the ultrastructural level. Apoptosis has not been detected in the midgut epithelium of analyzed species. We also determined that necrosis is the major process that is responsible for the degeneration of the midgut epithelium of tardigrades, and “apoptosis–necrosis continuum” which is the relationship between these two processes, is disrupted

Skin care during the menopause period : noninvasive procedures of beauty studies

Ageing is a resultant of two processes, including genetically encoded changes in an organism and modifications caused by a negative external environment impact. In the histological aspect, the skin ageing, due to endogenous factors and hormonal changes shows: excessive dryness, Malpighian layer thinning, microcirculation disorders, collagenic or elastin fiber degradation and simultaneous glycation, decreased speed of sebum and perspirationsecretion. It is said that skin is a functional picture of the organism and endocrinological system. Any hormoneconcentration ups and downs may improve its appearance or significantly worsen its condition as well as it maylead to occurrence of dermatological changes. In adult women, the ageing process changes its significance step bystep. Despite the passage of time, women want to feel good inside their skins. The adult skin is more requiring andit needs special care, often using a cosmetic apparatus. For better effect and permanent revitalization of the ageingskin, it is recommended to apply properly selected home-use cosmetic preparations. A holistic approach makes itpossible to reach the skin density and thickness increase, wrinkles shallowing, humidity and resilience improvementand also recovery of the proper face oval. Key words: menopause, skin ageing, hormones, noninvasive cosmetic procedures, mature skin care at home

Morphology and ultrastructure of the midgut in Piscicola geometra (Annelida, Hirudinea)

This paper presents information on the organization of the midgut and its epithelium ultrastructure in juvenile and adult specimens of Piscicola geometra (Annelida, Hirudinea), a species which is a widespread ectoparasite found on the body and gills and in the mouth of many types of fish. The analysis of juvenile nonfeeding specimens helped in the explanation of all alterations in the midgut epithelium which are connected with digestion. The endodermal portion (midgut) of the digestive system is composed of four regions: the esophagus, the crop, the posterior crop caecum, and the intestine. Their epithelia are formed by flat, cuboidal, or columnar digestive cells; however, single small cells which do not contact the midgut lumen were also observed. The ultrastructure of all of the regions of the midgut are described and discussed with a special emphasis on their functions in the digestion of blood. In P. geometra, the part of the midgut that is devoid of microvilli is responsible for the accumulation of blood, while the epithelium of the remaining part of the midgut, which has a distinct regionalization in the distribution of organelles, plays a role in its absorption and secretion. Glycogen granules in the intestinal epithelium indicate its role in the accumulation of sugar. The comparison of the ultrastructure of midgut epithelium in juvenile and adult specimens suggests that electron-dense granules observed in the apical cytoplasm of digestive cells take part in enzyme accumulation. Numerous microorganisms were observed in the mycetome, which is composed of two large oval diverticles that connect with the esophagus via thin ducts. Similar microorganisms also occurred in the cytoplasm of the epithelium in the esophagus, the crop, the intestine, and in their lumen. Microorganisms were observed both in fed adult and unfed juvenile specimens of P. geometra, which strongly suggests that vertical transmission occurs from parent to offspring

The fine structure of the midgut epithelium in Xerobiotus pseudohufelandi (Iharos, 1966) (Tardigrada, Eutardigrada, Macrobiotidae)

The aims of our studies were to describe the ultrastructure of the midgut epithelial cells of the eutardigrade Xerobiotus pseudohufelandi and to determine if there are any differences in the ultrastructure of midgut epithelial cells between males and females. The analysis was performed with the use of the light and transmission electron microscopes. In X. pseudohufelandi the midgut epithelium is composed of digestive cells, but in the anterior portion of the midgut a group of cells with different ultrastructure has been observed. Histochemical staining showed the accumulation of reserve material in the cytoplasm of digestive cells. We suggest that some of them fulfil the role of regenerative cells (crescent-like cells, midgut stem cells), whereas others are differentiating cells which form new digestive cells. No differences in the ultrastructure of the midgut epithelium between males and females were distinguished except in the amount of multivesicular bodies

Cell death in the epithelia of the intestine and hepatopancreas in Neocaridina heteropoda (Crustacea, Malacostraca)

The endodermal region of the digestive system in the freshwater shrimp Neocaridina heteropoda (Crustacea, Malacostraca) consists of a tube-shaped intestine and large hepatopancreas, which is formed by numerous blind-ended tubules. The precise structure and ultrastructure of these regions were presented in our previous studies, while here we focused on the cell death processes and their effect on the functioning of the midgut. We used transmission electron microscopy, light and confocal microscopes to describe and detect cell death, while a quantitative assessment of cells with depolarized mitochondria helped us to establish whether there is the relationship between cell death and the inactivation of mitochondria. Three types of the cell death were observed in the intestine and hepatopancreas- apoptosis, necrosis and autophagy. No differences were observed in the course of these processes in males and females and or in the intestine and hepatopancreas of the shrimp that were examined. Our studies revealed that apoptosis, necrosis and autophagy only involves the fully developed cells of the midgut epithelium that have contact with the midgut lumen-D-cells in the intestine and B- and F-cells in hepatopancreas, while E-cells (midgut stem cells) did not die. A distinct correlation between the accumulation of Ecells and the activation of apoptosis was detected in the anterior region of the intestine, while necrosis was an accidental process. Degenerating organelles, mainly mitochondria were neutralized and eventually, the activation of cell death was prevented in the entire epithelium due to autophagy. Therefore, we state that autophagy plays a role of the survival factor

Differentiation of regenerative cells in the midgut epithelium of epilachna cf. nylanderi (Mulsant 1850) (insecta, coleoptera, coccinellidae)

Differentiation of regenerative cells in the midgut epithelium of Epilachna cf. nylanderi (Mulsant 1850) (Insecta, Coleoptera, Coccinellidae), a consumer of the Ni-hyperaccumulator Berkheya coddii (Asteracae) from South Africa, has been monitored and described. Adult specimens in various developmental phaseswere studiedwith the use of lightmicroscopy and transmission electron microscopy. All degenerated epithelial cells are replaced by newly differentiated cells. They originate from regenerative cells which act as stem cells in the midgut epithelium. Just after pupal-adult transformation, the midgut epithelium of E. nylanderi is composed of columnar epithelial cells and isolated regenerative cells distributed among them. The regenerative cells proliferate intensively and form regenerative cell groups. In each regenerative cell group the majority of cells differentiate into new epithelial cells, while some of them still act as stem cells and persist as a reservoir of cells capable for proliferation and differentiation. Because this species is an obligate monophage of plants which accumulate nickel, proliferation and differentiation

Skin care during the menopause period: noninvasive procedures of beauty studies

Ageing is a resultant of two processes, including genetically encoded changes in an organism and modifications caused by a negative external environment impact. In the histological aspect, the skin ageing, due to endogenous factors and hormonal changes shows: excessive dryness, Malpighian layer thinning, microcirculation disorders, collagenic or elastin fiber degradation and simultaneous glycation, decreased speed of sebum and perspiration secretion. It is said that skin is a functional picture of the organism and endocrinological system. Any hormone concentration ups and downs may improve its appearance or significantly worsen its condition as well as it may lead to occurrence of dermatological changes. In adult women, the ageing process changes its significance step by step. Despite the passage of time, women want to feel good inside their skins. The adult skin is more requiring and it needs special care, often using a cosmetic apparatus. For better effect and permanent revitalization of the ageing skin, it is recommended to apply properly selected home-use cosmetic preparations. A holistic approach makes it possible to reach the skin density and thickness increase, wrinkles shallowing, humidity and resilience improvement and also recovery of the proper face oval