[Chemical components of Seseli yunnanense Franch].
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Coumarins↗
Biomedical subjects
D Liu
Publications and source records attributed to D Liu.
[Sensitivity of Plasmodium falciparum to seven antimalarials in China-Laos border].
The sensitivity of P. falciparum to chloroquine (CHL), piperaquine (PIP), artesunate (ATS), dihydroartemisinine (DAT), artemether (ATM), arteether (ATE) and pyronaridine (PRN) were assayed by in vitro microtechnique in China-Laos border in 1992. The resistance rates of isolates from the south of Yunnan of China in the border were 97.0%, 96.4%, 12.5%, 16.0%, 6.3% and 34.5%, respectively; ID50 were 119.0, 320.0, 7.2, 5.4, 295.0, 74.4 and 31.9 nmol/L, ID95 were 625.0, 2426.0, 42.2, 36.6, 767.0, 371.1 and 325.2 nmol/L. The resistance rates of isolates from the north border of Laos were in order 9/10, 8/10, 1/5 to CHL, PIP, PRN, ID50 were 114.0, 166.9, 16.4 nmol/L, ID95 were 570.0, 631.1 and 107.7 nmol/L. All the isolates from Laos were sensitive to ATS, DAT, ATM and ATE. ID50 were 5.0, 4.4, 91.6 and 56.7 nmol/L, ID95 were 23.4, 11.1, 3276.1 and 223.9 nmol/L, respectively. The results indicate that P. falciparum in the border was highly resistant to CHL and PIP, while most of the isolates were susceptible to the other 5 of the above-mentioned drugs. A comparison between the isolates from China and Laos showed that there was no significant difference in resistance degree to CHL but the sensitivity of isolates from China to other 6 drugs was lower than those from Laos.
Animals↗
Demonstration of in vitro cultured exoerythrocytic schizonts and hypnozoites of Plasmodium vivax (southern China isolate) by an immunoperoxidase antibody technique.
By indirect immunoperoxidase staining, different forms of exoerythrocytic (EE) stage of Plasmodium vivax (Southern China isolates) are revealed in d8 cultured material. The mature schizonts are elongated in shape measuring 42-48 microns in diameter, immature schizonts 14-28 microns and hypnozoites 4-7 microns. EE schizonts are stained dark-brown only after conjugated by monoclonal antibody (McAb) 4B2 specific against erythrocytic stages of P. vivax while hypnozoites are only stained after conjugated by McAb 2F2 against sporozoite. These results show that the antigenic components of these two forms of EE plasmodia are quite different. The ratio of EE schizont and hypnozoite found within hepatoma cells (HepG2-A16) is 1.5 to 1. Referred to the clinical manifestations of the isolate, among 5 volunteers not radically cured, two had long incubation period (283 d and 304 d, respectively) and three relapsed 235, 260 and 365 days after the primary attack. These data are unanimous with the comparatively large ratio of hypnozoites in the cultured material.
Animals↗
Molecular cloning of a cDNA encoding filarial common antigen.
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Amino Acid Sequence↗
[Chemical components of Pleurospermum rivulorum (Diels)].
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Coumarins↗
[Reduction mammaplasty and mastopexy with a circumareolar incision].
Since 1990, we have done reduction mammaplasty and mastopexy on 22 patients using the circumareolar incision method. The advantages of the operation are as follows: simple design, less operative trauma, the possibility of performance under local anaesthesia, lactation preserved, good appearance with inconspicuous scar.
Adult↗
[Effects of manganese on learning abilities in school children].
Manganese in drinking water of Wu Village, Qingchu County, Taiyuan, Shanxi Province persisted in an excessive level all the year round, hair and blood manganese contents in its primary school pupils, averaged 1.242 micrograms/g and 617 nmol/L (3.39 micrograms/dl), respectively, were higher than those in normal children, and the school records of the former were poorer than those of the latter. Levels of serum 5-hydroxytryptamine (5-HT), dopamine, norepinephrine and acetylcholine esterase of those 92 school children were determined to study their relationship with poor learning abilities. Results showed levels of four neurotransmitter in them all were lower than those in control children. School records for Chinese language and mathematics correlated positively to the levels of most neurotransmitter. Multiple linear regression analysis showed the order of the effects of neurotransmitter on school records of Chinese language was 5-HT, norepinephrine, acetylcholine esterase and dopamine, and those on mathematics was norepinephrine, 5-HT, acetylcholine esterase and dopamine.
Adolescent↗
[Chronic sphenoid sinusitis].
Sphenoid sinusitis is often ignored by doctors, for the sphenoid sinuses are the most neglected paranasal sinuses and sphenoid sinusitis lacks specific symptoms. 58 cases of sphenoid sinusitis were reported in this article. The specific clinical symptoms remain to be deficient. At present, computerized tomography, MRI and telescope help to make accurate evaluation of sphenoid sinus diseases. The endoscopic intranasal surgery for sphenoid sinusitis enables the complicated surgical procedures simple. In our series, most cases (53) are sphenoethmoid sinusitis. The isolated sphenoid sinusitis is rare in clinical practice.
Adult↗
[Steady-state characteristics and optimal dosage regimens for Michaelis-Menten elimination drugs].
In this paper, for the nonlinear process of the Michaelis-Menten elimination drugs, we first workout an analytical expression of the drug concentration after n times of intravenous injection. Then we study the steady-state characteristics of multiple intravenous dosing and give the analytical expressions to the steady-state drug concentration, the maximum, the minimum, the average drug concentration at steady state, the fraction reaching plateau concentration and the accumulation coefficient. Their application to the formation of the optimal dosage regimen is also discussed.
Humans↗
A gene encoding chinook salmon (Oncorhynchus tschawytscha) gonadotropin alpha subunit: gene structure and promoter analysis in primary pituitary cells.
The cDNA clones coding for the chinook salmon gonadotropin alpha (sGTH alpha) subunit were isolated from a salmon pituitary cDNA library. The full-sized cDNA clone, sGTH alpha-C2, was 678 bp in size and encoded a precursor polypeptide of 114 amino acids, including a signal peptide of 22 amino acids. The deduced mature sGTH alpha subunit polypeptide is identical with the major alpha subunit of chum salmon gonadotropin. Genomic clones coding for the sGTH alpha subunit were isolated from a partial BamHI genomic library in lambda EMBL3 using the cDNA as a probe. Seven positive clones were identified from 1 x 10(6) plaques. Restriction mapping of positive clones suggested that there were two copies of the GTH alpha subunit gene in the salmon genome. The 2 kb of 5'-flanking region and the 1.1 kb of the entire sGTH alpha subunit coding region were sequenced from the genomic clone, sGTH alpha-G1. The sGTH alpha subunit gene contains four exons and three introns. However, its introns are smaller than those in the mammalian hormones. Inspection of the sGTH alpha subunit promoter region revealed several potential cis-acting elements, including the gonadotrope-specific element (GSE), Ap-1, AP-2, and others. Functional analysis of the sGTH alpha subunit promoter by the transient transfection of several sGTH alpha/CAT chimeric plasmids into rainbow trout pituitary cells suggests that its pituitary-specific expression is GSE-dependent. The activity of the chimeric plasmids can be stimulated by 8-bromo-cAMP. These experiments indicate that pituitary primary cells can be used to dissect various cis-acting elements important for salmon GTH alpha subunit gene expression.
Amino Acid Sequence↗
[Research on the factors influencing the sporogonic multiplication of Plasmodium vivax in the mosquito vector].
Volunteers with no previous malaria history infected with northern Guangdong isolate of Plasmodium vivax and mosquito vector, Anopheles stephensi, were the objects and materials used in the research. Totally there were 16 volunteers, half of them were infected by mosquito-bite and another half by blood-inoculation. Blood was drawn when parasitemia reached a certain level and the erythrocytic forms developed into large trophozoites. Mosquitoes fed on infected blood from 5 and 4 donors of the two groups gave high gland infection rate and high gland indices respectively, but the highest gland indices were got from volunteers infected by mosquito-bite. The time of blood-feeding is important, only those blood samples taken from the people 3 to 8 days after the first onset gave good sporozoite harvest and the gland infection was greatly reduced on the 9th day. During this period (d3-8), the density of gametocyte had obvious influence on the intensity of mosquito infection. When the sex ratio of gametocyte (female:male) was 4:1 or less, the result would be good. For the purpose of reflecting more perfectly the circumstance of the sporogonic multiplication of plasmodium in the mosquito vector, we suggest the concept of gut/gland infection intensity which equals the product of the infection rate and the index of oocyst/positive gland.
Adult↗
[A clinicopathological study of eighteen autopsy cases with acquired toxoplasmosis].
Eighteen autopsy cases of acquired toxoplasmosis in New York City were studied. Seventeen cases were with acquired immunodeficiency syndrome (AIDS) and one patient with Hodgkin's disease. All 18 cases involved the brain and nine of them disseminated to the heart (8 cases), lung (4 cases), pancreas (3 cases), alimentary tract (2 cases) and urogenital organs (3 cases). The authors divided the acquired toxoplasmosis into (1) immunocompetent, (2) immunocompromised and (3) immunodeficient types. The autopsy findings showed that the brain, heart and lung were the most susceptible organs. Pseudocysts were also found in lungs and alimentary tract, suggesting an autoinfection by swallowing sputum containing Toxoplasma. Toxoplasma in the urogenital organs might become a source for sexual transmitted toxoplasmosis.
Acquired Immunodeficiency Syndrome↗
Concomitant sensitivity to orientation, direction, and color of cells in layers 2, 3, and 4 of monkey striate cortex.
The receptive field properties of cells in layers 2, 3, and 4 of area 17 (V1) of the monkey were studied quantitatively using colored and broad-band gratings, bars, and spots. Many cells in all regions studied responded selectively to stimulus orientation, direction, and color. Nearly all cells (95%) in layers 2 and 3 exhibited statistically significant orientation preferences (biases), most exhibited at least some color sensitivity, and many were direction sensitive. The degree of selectivity of cells in layers 2 and 3 varied continuously among cells; we did not find discrete regions containing cells sensitive to orientation and direction but not color, and vice versa. There was no relationship between the degree of orientation sensitivity of the cells studied and their degree of color sensitivity. There was also no obvious relationship between the receptive field properties studied and the cells' location relative to cytochrome oxidase-rich regions. Our findings are difficult to reconcile with the hypothesis that there is a strict segregation of cells sensitive to orientation, direction, and color in layers 2 and 3. In fact, the present results suggest the opposite since most cells in these layers are selective for a number of stimulus attributes.
Animals↗
[Effect of environmental temperature, cryopreservation and aging on Plasmodium vivax sporozoites developing into exoerythrocytic stages].
After Anopheles stephensi mosquitoes with salivary infection of Plasmodium vivax were put in environments with temperatures of 30 +/- 1 degrees C, 26 +/- 1 degrees C or 13 +/- 1 degrees C for 5 d, their glands were aseptically dissected and sporozoites were collected and inoculated into HepG2-A16 cell monolayers. Seven days post-inoculation the cultured materials were harvested and the exoerythrocytic schizonts and hypnozoites were observed under the microscope by using immunoperoxidase staining technique. The results showed that the sporozoite developing rate of 30 +/- 1 degrees C group and 13 +/- 1 degrees C group was significantly lower than that of 26 +/- 1 degrees C group (0.33%, 0.35% and 0.75% respectively). The proportion of hypnozoites in the total number of EE forms was the highest in the low temperature group (62.5%) compared with 26 +/- 1 degrees C and 30 +/- 1 degrees C group (40.1% and 42.7% respectively). Suggesting that the low environmental temperature first affected the viability of tachysporozoites or the phenotype of sporozoites and thus resulted in heightened hypnozoite rate. This is parallel to the epidemiological data that in the regions of high latitute vivax malaria with long incubation period was more frequently observed. When the sporozoites within the body of mosquito were cryopreserved at -70 degrees C or in liquid nitrogen for 24 h or 5 d respectively, the proportion of hypnozoite increased 87.4% and 82.4%, respectively. However, cryopreservation did not inactivate all of the tachysporozoites, indicating that the resistance to ultralow temperature in bradysporozoite was much greater than that in tachysporozoites. Aging of sporozoites decreased their developing rate and the exoerythrocytic (EE) schizonts were found to grow sluggishly and asynchronously, indicating that the size of EE schizont and the age of sporozoites are in negative correlation. Meantime, proportion of the hyponozoite decreased significantly.
Aging↗
[Observation on hypnozoite of different isolates of Plasmodium vivax in cultured materials].
The hypnozoites of different isolates of P. vivax from Shenzhen and Shixin, Guangdong Province, Changsha, Hunan Province and Yincheng, Hubei Province of China in cultured materials were observed employing immunoperoxidase staining method. The percentages of hypnozoites among exoerythrocytic stages were 40.1, 43.5, 50.6 and 57.1%, respectively, indicating that the percentage of hypnozoites and the latitude are in positive correlation. The equation is y = -6.68 + 2.05x. When the difference in latitude of Plasmodium vivax isolate source was more than 5 degrees, a significant difference in the percentage of hypnozoites in various geographic isolates was found. However, the average diameters of hypnozoites and schizonts among various geographic isolates showed no significant difference. The results showed that in the regions north to the Yangtze River, the proportion of hypnozoite in the liver stage of P. vivax was larger than those in the southern China, being consistent with the clinical manifestations.
Animals↗
Protoplast culture and plant regeneration from the suspension cells of Gynostemma pentaphyllum (Thumb) Mak.
From the suspension cultures of Gynostemma pentaphyllum (Thumb) Mak. protoplasts were isolated and cultured in a different medium with liquid and nurse culture method. Cell division was observed within 4 days and microcalli were formed within 4 weeks. On an MS solid medium with 1 mg/L of KT and 0.5 mg/L of IAA, protoplast-derived calli differentiated into embryos. Stems and leaves were formed on the MS medium with 1 mg/L of 6-BA and 0.5 mg/L of IAA. Finally, complete plantlets were obtained on a hormone-free MS solid medium.
Cells, Cultured↗
[Effect of erythroid enhancer on the expression of beta-globin gene in mice erythroleukemia (MEL) cells].
Our previous works have verified that the beta-globin gene carrying large fragments of erythroid enhancer transferred by retrovirus vector caused the unstable provirus integration and low virus titer in infected cells, but the 36bp enhancer had not this negative effect. In order to circumvent this problem, we inserted the intact beta-globin gene (beta) or partially IVS II deleted beta-globin gene (delta beta) and truncated erythroid enhancer (36bp, 292bp and 341bp) into the N2A retrovirus vector. Recombinants were transfected into psi-2 ecotropic pachaging cells first, then the produced virus were used to infect PA317 amphotropic packaging cells. Virus supernatent from PA317 clonies with high virus titer and intact provirus integration was used to infect MEL cells. RNase protection assay was used to detect the expression of beta-globin gene. Results showed that not only the stable provirus integration and high virus titer of the transferred genes, but also the high levels expression of beta-globin gene carrying 292bp or 341bp erythroid enhancer were got.
Animals↗
[Surveillance of levels of neutralizing antibodies against poliovirus among children aged 0-3 in rural areas of Anhui Province].
Levels of neutralizing antibodies against poliovirus (PV) in 1,755 children aged 0-3 sampled randomly from 18 counties in Anhui Province were determined in September, 1993. Results showed the positive rates and geometric mean titer (GMT) of neutralizing antibodies against PV type 1, 2 and 3 were 96.98%, 96.01% and 96.18%, and 524.80, 323.59 and 436.50, respectively. Immune level of children was considerable high in each county sampled. No significant difference was found among different age groups and between boys and girls in positive rates and GMT of polioantibodies, but there was significant difference in them between children administered varied doses of oral polio vaccine (OPV). Children investigated took four doses of OPV in average, and their GMT was in proportion to the dose they took. Positive rate of PV antibodies was more than 95% in children who finished the full course of OPV immunization. There were very few townships or villages with a low coverage of OPV immunization in children. It indicated polio immune status was in a higher level in the Province.
Antibodies, Viral↗