IMMUNOELECTRON MICROSCOPIC STUDY ON THE LOCALIZATION OF MONOCLONAL ANTIBODIES ON GASTRIC CANCER CELLS

The localization of three monoclonal antibodies (MAb) against gastric cancer was studied on two human gastric cancer cell lines by immunoelectron microscopic technique. It has shown that the corresponding antigens of MAb 3G9 and 3H11 were distributed on the microvilli (M) and non-microvillus (NM) plasma membrane of target cells, with various M to NM ratios depending on the MAbs and target cells used. However, the corresponding antigens of MAb PD4 was only localized on the surface of round or finger-like bulges of target cells and never on the microvilli and non-microvillous plasma membrane. Since the nature and function of these tumor antigens have not been identified yet, the implication of the different distributions of these antigens remians to be clarifated.

Effect of Short-Term Exposure to Mercuric Chloride on the Air-Breathing Catfish,Heteropneustes fossilis──Ⅰ.Light Microscopic Study of the Gill

Histopathological effects of sublethal (0.1, 0.2, 0.3 ppm) and lethal (0.5, 1.0 ppm)solutions of mercuric chloride (HgCl2) have been studied on the gills of the air breathing catfish, Heteropneustes fossilis at the intervals ranging from 6h to 15 days. Thickening of the epithelium, swelling and hyperplasia of the mucous cells, fusion of secondary lamellae, formation of interlamellar bridge and deposition of mucous over the entire surface are some noteworthy features of mercury poisoning in sublethal concentrations. Acute pathological manifestations are formation of subepithelial space, sloughing of the epithelial layer, hemorrhage and hypertrophy of the mucous cells. Causes and impact of these cellular alterations affecting survival of the fish have been discussed

Glitch Crisis or Not:a Microscopic Study

The problem of glitch crisis has been a great deal of debate recently. It might challenge the standard two- component model, where glitches are thought to be triggered by the sudden unpinning of superfluid vortices in the neutron-star crust. It says that due to crustal entrainment the amount of superfluid in the crust cannot explain the changes in angular momentum required to account for the glitches. However7 the argument of this crisis is based on the assumption that the core superfluid is completely coupled to the crust when a glitch happens. The fraction of the coupled core part is actually a quite uncertain problem so far. In this work, we take three possible values for the fraction of the coupled core part and study in detail the crisis problem for a 1.4M⊙ canonical star, based on a microscopic equation of state for the neutron star＇s core using the Brueckner-Hartree-Fock approach. For this purpose, two requisite parameters are chosen as follows： the core-crust transition pressure is in the range of Pt = 0.2-0.65 MeV/fm3, and the fractional crust radius AR/R = 0.082 based on experiments. To account for the possibility of a heavier star, a larger value of AR/R = 0.15 is also chosen for comparison. Then we take the crustal entrainment into account, and evaluate the predictions for the fractional moment of inertia at various conditions. The results show that there is commonly no such glitch crisis, as long as one considers only a small fraction of the core neutron superfluid will contribute to the charged component of the star. Only if the core-crust transition pressure is determined to be a low value, the crisis problem may appear for complete core-crust coupling. This is consistent with a recent study in a phenomenological model.

Scanning Tunneling Microscopic and Scanning Tunneling Spectroscopic Studies of Nanocrystalline CdSe Thin Film

Nanocrystalline CdSe thin film prepared by chemical solution deposition was imaged in air with a scanning tunnelling microscope(STM). Scanning tunnelling current spectroscopy(STS) was taken at a fixed tip - sample separation. Tunnelling current(i) - voltage(v) curve and differential conductance spectrum show an n-type schottky rectifying behaviour and yield a direct measure of band gap energy. An increase of bandgap energy (1.8 - 2.1eV) was measured indicating energy quantization of this particular thin film.,

Gill surface architecture of mullet, Mugil soiuy (Basilewsky) : A scanning electron microscope study

Specimens of Mugil soiuy were collected from the coastal waters of Bohai Sea in Tianjin. The gillfilaments were cut with fine scissors and soaked for 24h in a fixative consisting of 2.5% glutaralde-hyde in 0.1 mol lphosporic acid buffer. After three washes in a buffer solution the tissue was fixedin a mixture of 1% osmium tetraoxide at 4℃ for 1h. The tissue was dehydrated in graded ethandethanols and dried. The tissue was examined and photographed with an SEM at an accelerating voltage

Fluid Inclusion Studies of Ore and Gangue Minerals from the Piaotang Tungsten Deposit, Southern Jiangxi Province, China

The Piaotang deposit is one of the largest vein-type W-polymetallic deposits in southern Jiangxi Province,South China.The coexistence of wolframite and cassiterite is an important feature of the deposit.Based on detailed petrographic observations,microthermometry of fluid inclusions in wolframite,cassiterite and intergrown quartz was undertaken.The inclusions in wolframite were observed by infrared microscope,while those in cassiterite and quartz were observed in visible light.The fluid inclusions in wolframite can be divided into two types:aqueous inclusions with a large vapor-phase proportion and aqueous inclusions with a small vapor-phase ratio.The homogenization temperature(Th)of inclusions in wolframite with large vapor-phase ratios ranged from 280℃ to 390℃,with salinity ranging from 3.1 to 7.2 wt%NaCl eq.In contrast,the Th values of inclusions with small vapor-phase ratios ranged from 216℃ to 264℃,with salinity values ranging from 3.5 to 9.3 wt%NaCl eq.T_(h) values of primary inclusions in cassiterite ranged from 316℃ to 380℃,with salinity ranging from 5.4 to 9.3 wt%NaCl eq.T_(h) values for primary fluid inclusions in quartz ranged from 162℃ to 309℃,with salinity values ranging from 1.2 to 6.7 wt%NaCl eq.The results show that the formation conditions of wolframite,cassiterite and intergrown quartz are not uniform.The evolutionary processes of fluids related to these three kinds of minerals are also significantly different.Intergrown quartz cannot provide the depositional conditions of wolframite and cassiterite.The fluids related to tungsten mineralization for the NaCl-H_(2)O system had a medium-to-high temperature and low salinity,while the fluids related to tin mineralization for the NaCl-H_(2)O system had a high temperature and medium-to-low salinity.The results of this study suggest that fluid cooling is the main mechanism for the precipitation of tungsten and tin.

Ultrastructure of Kupffer cells and hepatocytes in the Dubin-Johnson syndrome:A case report

Ultrastructure of Kupffer cells and hepatocytes in liver bioptate was evaluated in a 17-year-old boy with Dubin -Johnson syndrome （D.1S）. The liver tissue obtained by needle biopsy was fixed in glutaraldehyde and paraformaldehyde and routinely processed for electron microscopic analysis. The ultrastructural examinations of liver bioptate revealed the accumulation of membranebound, electron-dense lysosomal granules within the cytoplasm of hepatocytes, characteristic of D.1S. They were located mainly in the vicinity of the biliary pole, and preferentially in the centrilobular region that corresponded to the pigment deposits seen under light microscope. The presence of the granules was accompanied by dilated elements of the granular endoplasmic reticulum and paracrystalline mitochondrial inclusions as well as dilation of the bile canaliculi. The changes in hepatocytes coexisted with marked stimulation and enhanced phagocytic activity of Kupffer cells. This was manifested in the accumulation of pigment deposits within their cytoplasm that corresponded to those observed in hepatocytes. Hyperactive pericentral Kupffer cells which are involved in the response to pigmentary material originating from disintegrated hepatocytes may play an essential role in the development of DJS.

Preliminary Studies of Practicability of Laminar Plasma Surface Treatment Process

The basic remelting and cladding tests with laminar plasma technology on metals have been conducted in order to demonstrate the possibility of the technology applied in material surface modification. The experimental results show that the properties of the modified layers of the cast iron surface can be improved notably by the remelting treatment and those of the stainless steel by the cladding treatment. The related results are also verified by microscopic studies such as scanning electron microscopic （SEM） observations, energy dispersive spectra （EDS） analysis and the Vickers hardness measurements of the surface modified layers.

Pharmacognostic and phytochemical studies as an invaluable approach for correct identification of medicinal plants:The case of Artemisia vulgaris L.substituted for Artemisia annua L.in Western Uganda

Background:Different parts of Artemisia vulgaris L.(A.vulgaris)are ethno-medicinally used as an emmenagogue and for the treatment of ailments such as malaria fever,ulcers,and cancer.However,anecdotal evidence shows that the plant is often substituted for Artemisia annua L.(A.annua)by herbalists in Western Uganda due to similarities in their morphology.Misidentification of medicinal plants and mislabelling of herbal products have been incriminated in toxicity and adverse health outcomes in traditional medicine practise.Because safety continues to be a major issue with the use of herbal remedies,it becomes imperative therefore that medicinal plants should be correctly identified.Methods:This study focused on investigating the macroscopic,microscopic,physicochemical characteristics and phytochemical composition of A.vulgaris leaves compared to A.annua to ease its correct identification.Results:The results showed that there are some colour differences between the leaves of the two species,with a close arrangement of microscopic features but different leaf constants.The leaves of the two Artemisia species had similar tastes,but their shapes and colours(greenish-yellow for A.annua and dark green for A.vulgaris)can be used by the local community to distinguish between them.The artemisinin content was higher in A.vulgaris leaves(1.72%)than in A.annua(1.43%),but the reverse was observed for the total flavonoid content.Conclusion:This observation could justify the change in the use of A.vulgaris by the indigenous community in western Uganda.Further studies should consider the pharmacognostic comparison of A.annua with other species in the genus Artemisia and the use of molecular techniques such as DNA barcoding.

ELECTRON MICROSCOPIC AUTORADIOGRAPHIC STUDIES ON DYNAMICS AND LOCATION OF DNA SYNTHESIS OF DUCK PLAGUE VIRUS

Electron microscopic autoradiographic studies on the dynamics and location of DNAsynthesis by means of incorporation of ~8H-thymidine during the replication of duck plaguevirus (DPV) revealed that the duration of DNA synthesis of DPV was rather long. The repli-cation of viral DNA occurred simultaneously with the assembly procedure of nucleocapsids, thematuration and release of viruses. DNA synthesis of DPV occurred in the matrix with lowerelectron density in the nucleus. The replicated viral DNA accumulated in the viroplast With highelectron density where the assembly of nucleocapsids occurred. The viroplast with high electrondensity was not the region of viral DNA synthesis.