An integrated stage-tip-based glycomic and glycoproteomic approach for simple and rapid N-glycosylation profiling of glycoproteins.

Glycosylation is a post-translational modification that plays an active role in many cellular events. It also regulates many functions of proteins. Monoclonal antibody-derived drugs are used to treat many diseases, and glycosylation affects the activity of such drugs developed. On the other hand, N-glycans may change in certain diseases. Therefore, rapid and efficient bioanalytical methods are needed for N-glycosylation profiling. The study aimed to develop an integrated stage-tip application for the simple and rapid N-glycosylation profiling of glycoproteins. A fast and inexpensive N-glycosylation profiling was achieved by integrating all glycoproteomic and glycomic sample preparation steps into a stage-tip. The glycomic approach of the integrated stage-tip reduces the N-glycan profiling time from 2 days to approximately 2.5 hours. It also allows the profiling of immunoglobulin G (IgG) N-glycopeptides directly from human plasma. In addition, N-glycosylation profiling can be done in the developed method without sorbents, C18 or others, such as strong-cation exchange, at the glycopeptide level.

Synthesis and characterization of 8-hydroxyquinolin-1-ium 2,2,2-trifluoroacetate and 8-hydroxyquinolin-1-ium 2,2,2-trichloroacetate by z-scan technique.

The 8-hydroxyquinolin-1-ium 2,2,2-trifluoroacetate and 8-hydroxyquinolin-1-ium 2,2,2-trichloroacetate (8-HQ) salts have been synthesized and characterized by FTIR, NMR and UV-Vis absorption spectroscopic methods. The third order nonlinear optical properties (NLO) of the two 8-HQ salts have been investigated by z-scan technique. The recorded experimental data led to calculate the nonlinear optical absorption coefficient (ß), the nonlinear refractive index (n2), the excited-state absorption cross section (σex) and the ground-state absorption cross section (σg) of the studied compounds. The two 8-HQ salts have been found to exhibit large optical nonlinearity. These types of materials may be considering new photonic applications.

Single-Readout High-Density Memristor Crossbar.

High-density memristor-crossbar architecture is a very promising technology for future computing systems. The simplicity of the gateless-crossbar structure is both its principal advantage and the source of undesired sneak-paths of current. This parasitic current could consume an enormous amount of energy and ruin the readout process. We introduce new adaptive-threshold readout techniques that utilize the locality and hierarchy properties of the computer-memory system to address the sneak-paths problem. The proposed methods require a single memory access per pixel for an array readout. Besides, the memristive crossbar consumes an order of magnitude less power than state-of-the-art readout techniques.

Histology and ultrastructure of the lymph nodes of the buffalo (Bos bubalus).

Pre-scapular, femoral and mesenteric lymph nodes from five buffalo calves and five buffalo bulls were studied using light and transmission electron microscopy. The nodes were surrounded with a thin capsule of dense connective tissue and smooth muscles. Subcapsular and trabecular lymphatic sinuses were lined with endothelial cells resting on a basement membrane. The cortex was formed by lymphoid follicles and inter-follicular lymphocytes. Primary and secondary follicles were observed. The medulla was made up of medullary cords of lymphocytes separated by lymphatic sinuses. These sinuses were lined with a discontinuous epithelium and interestingly crossed by reticular fibres. High endothelial venules were found in the paracortical area. Several lymphocytes were observed infiltrating the wall of these venules. The lymph nodes of the Egyptian water buffalo showed a typical structure compared with the majority of mammals, with no age-related structural variation.

Histological, histochemical and immunohistochemical study of the haemal nodes of the dromedary camel.

Haemal nodes are lymphoid organs found in various mammals and some birds. The structure of haemal nodes has been described in a number of species but not yet in the camel. Therefore, haemal nodes from 10 camels were studied histologically and tested for CD3, CD22, major histocompatibility complex (MHC) class II/DR, alpha-smooth muscle actin and for the demonstration of acid and alkaline phosphatases. The haemal nodes were of spherical or kidney shape with one or two hili and had a capsule and trabeculae of connective tissue and smooth muscles. The main parenchyma was composed of a cortex and a medulla. The cortex was formed from lymphoid follicles and diffuse interfollicular lymphocytes. The medulla consisted of lymphoid cords separated by medullary sinuses. The interfollicular lymphocytes and those in the medullary cord were CD3-positive. The lymphoid follicles showed CD22-positive cells. MHC class II/DR was expressed by most cells of the parenchyma. There were also subcapsular, peritrabecular and medullary blood sinuses. Afferent and efferent lymphatics and lymphatic sinuses were also found. Acid phosphatase-positive cells were localized mainly in the marginal, the interfollicular zone and in the medullary cord. Alkaline phosphatase positivity was observed in the endothelium of the sinuses and in the lymphoid follicles. The morphology of these organs in the camel allows a classification as haemolymph nodes and suggests involvement in blood and lymph filtration.

Lymphocyte proliferation in lymphoid organs of the dromedary camel using the monoclonal antibody MIB-5 against the proliferation-associated nuclear epitope Ki-67.

Detection of proliferating lymphocytes is useful for studying immune reactions and for the prognosis of tumours of lymphocyte origin. Markers detecting proliferating cells are lacking in the dromedary camel. This study deals with the immunohistochemical detection of the Ki-67 proliferation-associated nuclear epitope using MIB-5 in frozen sections from spleens, different lymph nodes and haemal nodes of eight camels (0.5-12 years old). Frozen sections from rat spleens were labelled in parallel with camel tissue as a positive control. Large numbers of cells expressing the Ki-67 epitope were localized in germinal centres of all lymphoid organs tested. A few cells were found in the periarterial lymphoid sheath and the red pulp of the spleen, also in the lymphatic cords of the lymph nodes and the haemal nodes. There were no obvious differences in respect to the age of the animals. The Ki-67 epitope is well expressed by proliferating cells in camel lymphoid organs. MIB-5 can be applied to identify this epitope and will be a useful marker for cell production in immune reactions.

Megakaryocytes and platelets in the spleen of the dromedary camel (Camelus dromedarius).

This study was carried out on spleens of clinically healthy camels (n = 35) of both sexes (0.5-15 years) by routine histology, electron microscopy and immunohistochemistry using 12 anti-bovine platelet antibodies. Megakaryocytes were observed in the red pulp. Their number decreased with age: they were found in the spleens of all camels under 8 years old but only in 57% of camels over 8 years old. Only two antibodies (IVA37 and IVA38) cross-reacted with camel platelets. A large number of platelets were found in the splenic cords and the marginal zone. Ultrastructurally, the platelets were oval in shape surrounded by a plasma membrane, and their cytoplasm was rich in glycogen and contained less dense granules. Microtubules and microfilaments were found at their periphery. Several platelets were observed in the red pulp. There are similarities in some surface antigens of bovine and camel platelets. The presence of megakaryocytes in the camel spleen indicates a thrombopoietic function of the spleen until adulthood but that this decreases with age thereafter.

The spleen of the one humped camel (Camelus dromedarius) has a unique histological structure.

The histology and structure of 38 spleens of the dromedary (aged 0.5-15 y) were studied in relation to age. The spleen was found to have a thick capsule (292+/-106 mm) divided into an outer layer (113+/-39 mm) composed mainly of connective tissue and an inner layer (180+/-81 mm) consisting mainly of smooth muscle cells. Vascular and avascular trabeculae extend from the capsule, the former containing arteries and nerves but no trabecular veins, the latter being divided structurally into primary and secondary trabeculae. Subcapsular and peritrabecular blood sinuses around primary and vascular trabeculae are unique to the camel spleen. The central artery emerges from the periarterial lymphatic sheath and branches into up to 4 penicilli which extend as sheathed arterioles (42+/-8 microm). These are found near or surrounded by blood sinusoids of the red pulp. A wide marginal zone surrounds the white pulp and contains sheathed arteries but no marginal sinuses. The red pulp is characteristically divided into cords by secondary trabeculae and contains venous sinusoids of different sizes. The camel spleen is of a sinusal type that can store blood. The thick muscular capsule and trabeculae pump the stored blood according to the body's need. Both closed and open circulations are found. The venous return is unique as the blood flow is from the venous sinusoids of the red pulp to the peritrabecular sinuses to the subcapsular sinuses to the splenic vein. No significant structural differences related to age were found.

Immunohistology of the splenic compartments of the one humped camel (Camelus dromedarius).

The cellular composition of the different splenic compartments is well characterized in several species, but the spleen of the camel has not been studied due to the lack of specific antibodies detecting its leukocyte subsets. Therefore, 5microm frozen sections from 15 camel spleens (0.5-15 years) were studied for acid and alkaline phosphatases and for cross-reaction with antibodies specific for bovine (n=181), swine (n=14) and human (n=6) leukocyte determinants. Fifteen antibodies cross-reacted with camel spleen cells. These included 13 anti-bovine, two anti-human, but no anti-swine antibodies. The lymph follicles mainly consisted of B cells. The germinal centers showed a strong alkaline phosphatase activity. The periarterial lymphatic sheath harbored T lymphocytes. The marginal zone contained gammadelta T cells, CD45R0+, MHC class II DR+, CD44+, IL-A 24+ cells and few macrophages. The red pulp contained B, T, MHC class II DR+, IL-A24+ and gammadelta T cells and few macrophages. The periarterial macrophage sheaths contained many more macrophages than the marginal zone, so they may play a central role in the phagocytosis of the blood born particles. The alkaline phosphatase probably labeled activated B cells, but in contrast to other species no positive cells were found in the marginal zone. In general, lymphocyte compartmentalization in the camel spleen is similar to that in other species except for lower numbers of macrophages and the absence of alkaline phosphatase positive cells in the marginal zone. No age related differences were observed in the splenic compartments.

Differences in lymphocyte subsets in the wall of high endothelial venules and the lymphatics of human palatine tonsils.

Lymphocyte trafficking plays a critical role in disseminating specifically primed lymphocytes all over the body. Most concepts on the interaction of adhesion molecules on lymphocyte subsets and specialized endothelia such as those in high endothelial venules (HEV) are based on animal experiments as kinetic studies cannot be performed in humans. We therefore characterized lymphocyte subsets in the wall of HEV and in the lumen of lymphatics of 18 human palatine tonsils by immunohistology. All subsets studied were found in the wall of HEV (% of lymphocytes): 32% CD20+, 50% CD3+, 14% CD4+, 32% CD8+ and also 21% CD45RA+ and 39% CD45RO+. In the lymphatics, used to indicate lymphocytes emigrating from the tonsils, a different composition was found; e.g. many more T cells and three times more CD45RA+ than RO+ lymphocytes. Thus, HEV are not a selective entry site nor lymphatics an exit for specific lymphocyte subsets only, at least in these tonsils with chronic stimulation.

The gas-phase on-line production of vanadium oxytrihalides, VOX3 and their identification by infrared spectroscopy.

A new route has been devised, leading to the production of VOX3 molecules where X=F, Br and I by an on-line process using vanadium oxytrichloride, VOCl3 as a starting compound passed over the following heated salts NaF, KBr and KI at 375, 700 and 550 degrees C, respectively. The products have been characterized by the IR spectra of their vapors. The low resolution gas phase on-line Fourier transform infrared spectra reported for the first time show strong bands with PQR type structure, centered at 1058, 1035, 1030 and 1025 cm(-1) assigned to the v1(a1), the O=V stretching fundamental mode of VOF3, VOCl3 VOBr3 and VOI3, respectively.

Effect of NaCl on the accumulation of glycerol by three Aspergillus species.

The accumulation of glycerol was investigated in three Aspergillus species, A. niger, A. ochraceus and A. tamarii after being grown in media containing different NaCl concentrations. Intra-extracellular as well as total glycerol were markedly accumulated by the three organisms in response to increased salinity. However, at salinity levels of 10-14% NaCl, extracellular glycerol was somewhat lowered. In addition, it was found that the maximum accumulation of glycerol in A. niger and A. tamarii was reached within the first 10 hours after salinization. However, after desalinization, the extracellular glycerol was continuously increased within the first 6 hours at the expense of intracellular glycerol.