[A large scale gene scanning method of human frontal cortex cDNA library: isolation of specifically functional genes in adult brain and fetal brain].
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Adult↗
Biomedical subjects
N Zhao
Publications and source records attributed to N Zhao.
Identification of a serine/threonine-specific protein phosphatase from the archaebacterium Sulfolobus solfataricus.
We have observed that soluble extracts from the extreme acidothermophilic archaebacterium Sulfolobus solfataricus contained protein phosphatase activity that was greatly stimulated by the divalent metal ions Mn2+, Mg2+, Ni2+, or Co2+. This activity apparently arose from a single enzyme since (a) stimulation by these divalent metal ions was not additive and (b) protein phosphatase activity eluted as a single peak from both a DE52 ion-exchange column and a Sephadex G-100 gel filtration column. Its apparent molecular mass was approximately 28,000 daltons. The enzyme dephosphorylated a variety of phosphoserine-containing substrates including casein, histone H2a, phosphorylase kinase, or glycogen phosphorylase. The enzyme would not dephosphorylate either histone H1 or a number of phosphotyrosine-containing compounds. It removed only half the phosphate bound to histone H2b, which is phosphorylated at two sites by the cAMP-dependent protein kinase. Protein phosphatase activity was inhibited by EDTA, Cu2+, Zn2+, NaF, inorganic phosphate, or pyrophosphate; but was unaffected by other potential activators and inhibitors such as microcystin, okadaic acid, vanadate, polyamines, or sulfhydryl modifying reagents. This enzyme represents the first protein phosphatase to be identified in any member of the third and oldest phylogenetic kingdom in nature, the archaebacteria.
Enzyme Activation↗
[Meta-analysis of smoking and lung cancer in China: combined analysis of fifteen case-control studies].
In the present paper, 15 case-control studies on the relation between smoking and lung cancer in China were analyzed by means of Meta-analysis method. The cumulative cases and controls were 5703 and 5669, respectively. Peto's model and Der Simonian and Nan Laird model were applied to process data. The pooled OR (smoking vs no smoking) was 3.01 (95% CI: 2.63-3.46) in males and 2.32 (95% CI: 2.02-2.66) in females. The PAR was 56.84% in males and 33.10% in females. There was significant dose-response relation between the amount of smoking, the years of smoking, the age at start of smoking and the OR for developing lung cancer. The pooled OR of squamous carcinoma was 4.79 (95% CI: 4.02-5.70), PAR was 65.44%. The pooled OR of adenocarcinoma was 1.02 (95% CI: 0.87-1.20), PAR was 0.99%.
Adenocarcinoma↗
[Allergic granulomatous angiitis].
Allergic granulomatous angiitis (AGA) is a rare disease, which varies in clinical manifestation. The clinical course includes three stages. In the first stage most of the patients show symptoms of respiratory disease, 82 per cent of the patients has asthma and 88 per cent chronic rhinitis. In the second stage there is blood eosinophilia and in the last stage involvement of multiple organs. The etiology is not yet clear. Since 1982 four cases of AGA have been encountered in PUMC Hospital, but they were all diagnosed after 1988. All were male and aged 36-54 years. Two of them had asthma history and three enlargement of liver and proteinuria, ECG showed heart block in two, all four had neuromuscular and cutaneous involvement and elevated blood eosinophil with absolute number ranging from 1254 to 8104/mm3. Biopsy from different sites showed panangiitis associated with eosinophil infiltration and/or granulomatosis formation. All were sensitive to prednisone therapy with or without CTX after treatment the absolute eosinophil count in the four patients was less than 1000/mm3 and the symptoms alleviated.
Adult↗
[A case-control study of risk factors of colorectal cancer in Shanxi Province].
A case-control study of risk factors of colorectal cancer was conducted in 202 cases and 404 controls. The results of conditional logistic regression analysis showed that the history of intestinal diseases, psychic trauma, eating of more protein and fat, unhealthy eating habit, deficiency of fruits were risk factors of colorectal cancer; and the odds ratio were 2.86, 8.67, 1.64, 2.70, 1.48 respectively. Blood selenium levels were determined by fluorometric method. Significantly lower selenium values were observed in blood from colorectal cancer patients than from normal individuals (0.1349 ppm vs. 0.1502 ppm. P less than 0.01).
Adolescent↗
[Electron microscopic observations on Pseudomonas cocovenenans].
A strain of food-poisoning bacterium has been isolated by Jin Jiexiang (1963) in China from the fermented cornflour that has gone bad. These pathogenic microorganism has been identified and named Pseudomonas by Zhao Naixin in 1988, which is the same species as P. cocovenenans. The characteristics of them were conformed to these of the species P. cepacia of section 2 of the genus Pseudomonas. In view of the fact that the fine structures of the above mentioned three strains of Pseudomonas have not been described yet, we decided to observe them with electron microscope. Results indicate there are many things in common among the three strains, such as: appearing short rods, 0.6-0.8 microns in diameter by 1.5-2.0 microns in length, one polar multiflagella; non-pili, non-capsules, non-endospores; containing intranuclear inclusions (electron-dense bodies or concentric laminae bodies), accumulating intracytoplasmic PHB granules; forming filaments, minicells and bizarrecells; producing extracellular cellulose-like materials by the three strains have not been reported previously.
Microscopy, Electron↗
Chemical evolution of interstellar dust, comets and the origins of life.
It now appears that the chemical evolution of the pre-solar system interstellar dust ensures that a major fraction of comets is in the form of complex organic molecules at least partially of a prebiotic nature and that the submicron interstellar dust preserves its chemical integrity as result of forming a very tenuous low density comet structure whose solid matter occupies approximately 1/5 of the total volume. This low density micro structure further provides a physical basis for comets bringing a significant fraction of the original interstellar organic molecules to the earth unmodified by the impact event. Finally, the evidence for a large number of comet collisions with the early earth ensured that the major organic molecular budget on the earth's surface was "continuously" supplied along with water well before 3.8 billion years ago which is the earliest date for life. The chemistry and morphological structure of a comet nucleus as an aggregate of interstellar dust is used to provide comparisons with a variety of comet Halley results: the density of the nucleus and of the dust; the dust cloud model and its consequences on the production of C+ and CN in the coma by small organic grains; the surface albedo and the low nucleus heat conductivity and high surface temperature; the appearance of 10(-14) g and 10(-17) g dust particles along with higher masses; the mass spectra of dust and infrared spectroscopy as evidence for complex organic grain mantles and of very small (approximately 0.01 micrometer) carbonaceous and silicate grains; the appearance of small grains resulting from breakup of larger grains. The cosmic ray dosage of a comet nucleus during its 4.5 billion years in the Oort cloud appears to be many orders of magnitude less than the dosage of the preaggregated interstellar dust by ultraviolet photons except perhaps in the outer few meters of the nucleus of a new comet. The heat conductivity calculated for aggregated dust is certainly less than 10(-4) that of crystalline ice. This, in combination with the interstellar dust microstructure, provide a basis for showing that solar heating of the interior of a nucleus is lower than previously estimated.
Carbon↗