Springer Science and Business Media LLC

In der Arbeit wird die Anwendung flüssiger Emulsionen in Gel-Form bei der Herstellung von Autoradiogrammen zum Nachweis H3-markierter Substanzen beschrieben. Die Vor- und Nachteile von Emulsionen unterschiedlicher Empfindlichkeit und verschiedenen Silberkorndurchmessers werden besprochen. An Hand von Abbildungen kann gezeigt werden, daß mit flüssigen Emulsionen bei leichterer Anwendbarkeit und zeitsparender Technik die gleichen Ergebnisse erhalten werden können wie mit der Stripping-Film-Technik.

 The protooncogene protein, Bcl-2, protects cells from apoptosis and ensures their survival in vitro by inhibiting the action of the apoptosis-inducer, Bax. Its expression in proliferative and long-lived cells in vivo also indicates that it protects against cell death. The chondrocytes of the epiphyseal plate cartilage undergo a series of maturation steps and deposit mineral in the cartilage matrix before dying. The possibility that Bcl-2 helps protect chondrocytes until mineral deposition is completed was investigated by determining the distribution of Bcl-2 immunoreactivity in the epiphyseal plate cartilage of growing rats and its subcellular localization, using a specific antibody. The involvement of Bax in the triggering of chondrocyte death was checked by immunocytochemistry. Bcl-2 expression in the osteoblasts and the final result of their evolution, the osteocytes, was also examined in trabecular bone. Bcl-2 immunoreactivity was non-uniformly distributed throughout the epiphyseal cartilage. It was maximal in proliferative chondrocytes, decreased in mature chondrocytes, and low in hypertrophic chondrocytes, whereas there was Bax immunoreactivity in all chondrocytes examined. Immunolabeling was intense in osteoblasts but considerably lower in fully differentiated osteocytes. Bcl-2 immunoreactivity was mainly in the cytoplasm of chondrocytes, osteoblasts, and early osteocytes; the nuclei appeared clear. The subcellular distribution of Bcl-2 immunolabeling in chondrocytes, revealed by gold particles in the electron microscope, showed that gold particles were frequently concentrated in the mitochondria in all the cartilage zones and lay mainly within the organelles, not at their periphery. The endoplasmic reticulum contained moderate immunoreactivity and there were few gold particles in the cytoplasm and nuclei. The number of gold particles decreased in all the subcellular compartments from proliferative to hypertrophic chondrocytes. In contrast, Bax immunoreactivity changed little during chondrocyte terminal evolution, and its subcellular distribution mirrored that of Bcl-2. These immunocytochemical data indicate that Bcl-2 helps maintain chondrocytes and osteoblasts until their terminal maturation.

To demonstrate the presence and localization of Fc receptors, rat liver cryostat sections were incubated with heterologous and autologous immune complexes (ICx) and immunoglobulin (Ig) aggregates. Binding was demonstrated using the immunoperoxidase technique. Autologous and heterologous ICx as well as aggregates from human and rat Ig appeared to bind to the sinusoidal wall. ICx bind in preference to aggregates. Monomeric Ig and aggregated Ig from swine and rabbit did not bind. The results demonstrated that ICx and rat and human Ig aggregates were bound via an Fc receptor. This Fc receptor was still intact in livers from carbontetra chloride and galactosamine treated rats. The receptor could also be demonstrated on spleen macrophages and on kidney interstitial cells. This method turned out to be an useful functional histochemical method to localize Fc receptors and to demonstrate their affinity and species specificity in tissues.

d-Amino acid oxidase (DAO), which catalyzes oxidative deamination ofd-amino acids, is known to be highly expressed in the kidney. This study was designed to examine the localization of DAO mRNA in the mouse kidney using in situ hybridization histochemistry (ISH). For comparison, ISH for mRNA of ornithine decarboxylase (ODC), which is also highly expressed in the mouse kidney, was simultaneously performed. Adult, male mice which received 1 mg of testosterone propionate or vehicle injection, were sacrificed 14 h after injection and their kidneys were removed and processed for ISH. Hybridization signals for both mRNAs were exclusively located over the epithelial cells of the proximal tubule in the vehicle-treated animals. Signals for the DAO mRNA were observed at nearly the same hybridization intensity throughout the proximal tubule, whereas hybridization signals for the ODC mRNA were observed exclusively in the pars convoluta. Following testosterone treatment, ODC mRNA in the pars convoluta was expressed with a stronger intensity than that in the vehicle-injected animals. ODC mRNA was also expressed in the pars recta with a weaker intensity than in the pars convoluta. On the other hand, DAO mRNA expression was little affected by testosterone treatment. These results indicate that, although both genes are possibly expressed in the same cells, the expression of these genes is regulated by different mechanisms.

Histochemically demonstrable Golgi-associated TDP-ase activity in liver cells from cat, chicken, rat and frog has been investigated. This activity is highly substrate-specific, insensitive to aldehyde fixation, ethanol, acetate, lead and most enzyme inhibitors. It is stimulated by divalent manganese, calcium, magnesium and cobalt and optimum pH is at pH 6 to 7. The characteristics are identical for all four species but significant differences exist at a comparison with bile canalicular activity, Golgi-associated activity in other cells and biochemical findings.

The orderly organization in a number of discrete classes of weight persists in the hepatocytes during acute and chronic poisoning with thioacetamide and during a prolonged treatment with hydrocortisone, though many striking cytological and structural changes occur in the liver. The number of hepatocyte classes decreases under hydrocortisone treatment and during acute and chronic thioacetamide poisoning, and increases during recovery after acute thioacetamide poisoning and during the late phases of chronic thioacetamide poisoning. This is due to decrements and increments in dry mass of the hepatocytes, which occur by steps, through repeated losses and additions of a constant amount of solids substantially corresponding to the class period. Such a mechanism is similar to that acting in the hepatocyte atrophy due to starvation and in the hepatocyte enlargement occurring during postnatal development. Therefore, the increment and the decrement in dry mass by defined steps takes place in the hepatocytes in both physiological and pathological conditions.

Các phản ứng miễn dịch thường đi kèm với việc trình diện kháng nguyên và sự tăng sinh cũng như biệt hóa của các lymphocyte đặc hiệu kháng nguyên (sự tăng sinh miễn dịch), nhưng việc phân tích những sự kiện này tại chỗ trên các mảnh mô là rất khó khăn. Chúng tôi đã phát triển một phương pháp nhuộm miễn dịch huỳnh quang đa màu đồng thời mới cho miễn dịch mô học và phân tích dòng tế bào, sử dụng một dẫn xuất thymidine, 5-ethynyl-2′-deoxyuridine (EdU). Do kích thước nhỏ của thuốc nhuộm azide sử dụng hóa học click và loại bỏ các bước biến tính DNA, nhuộm EdU cho phép nhuộm huỳnh quang với ít nhất bốn màu bao gồm hai dấu hiệu khác nhau trên bề mặt tế bào đơn lẻ, điều này là không thể thực hiện với phương pháp 5-bromo-2′-deoxyuridine tiêu chuẩn. Bằng cách sử dụng hai mô hình chuột, các tham số được phát hiện thành công là các kháng nguyên cụm phân biệt bao gồm các dấu hiệu hình thái và chức năng của các tế bào miễn dịch khác nhau, các kháng nguyên phức hợp histocompatibility, và thậm chí một số yếu tố phiên mã hạt nhân. Các tế bào đang tăng sinh có thể được phân loại thêm và sử dụng cho phân tích RT-PCR. Phương pháp này do đó cho phép phân tích động học chức năng tại chỗ về các phản ứng miễn dịch tăng sinh trong một miền cụ thể của các cơ quan lympho, điều này được xác nhận định lượng bởi phân tích dòng tế bào.

Intracytoplasmic fibrillar inclusions, generally referred to as nucleolus-like bodies (NLBs) were studied by means of ultrastructural cytochemistry. The structure of these bodies was visualized by several different staining procedures: conventional electron microscopy and preferential staining methods for localization of various proteins including ribonucleoproteins, basic proteins, glycoproteins and phosphorylated proteins. The results of the cytochemical tests indicate that NLBs have an essentially proteinaceous nature. They consist of ribonucleoproteins, basic proteins and glycoproteins but do not contain phosphorylated proteins. These findings suggest that NLBs are, at least partially, of the same nature as nucleoli and coiled bodies. The origin of NLBs and their possible functional role is briefly discussed.