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Biomedical subjects

S Xiao

Publications and source records attributed to S Xiao.

At least 145 records · Page 8Linked to original sources
PubMed1995

[Field studies on preventive effect of artemether against infection with Schistosoma japonicum].

From August to October 1994, a field trial of preventive treatment with artemether (Art) was carried out in Minglang District of Yiyang City, Hunan Province, an islet with embankment type endemic area nearby southern Donting Lake region. The residents who frequently contacted with the infested water were selected for study and allocated to the Art group and the control group in reference to paired methods of randomization table. About one month before administration of Art, all residents under study were examined by stool hatching technique after nylon-bag concentration to determine the infection rate of each group, and then treated with praziquantel at a single dose of 40 mg/kg in stool egg-negative residents and 50 mg/kg in stool egg-positive ones. In Art group, the first dose of 6 mg/kg was given in late August, followed by repeated dosing every 15 days for 3 times. Placebo (starch) was given to the study residents in the control group at the same time as in Art group. The efficacy was evaluated by stool examination 25-32 days after the last medication. The results showed that after the preventive administration of Art, 20 out of 365 study residents in Art group revealed stool positive with an infection rate of 5.5%, while in the control group 51 out of 376 study residents showed stool positive with an infection rate of 13.6%. The difference between the two groups was statistically significant. Meantime, two cases of acute schistosomiasis were seen in the control group, but none was observed in Art group. The egg per gram of feces (EPG) determined with the Kato-Katz method was 122 +/- 79 (range 12-192) in Art group and 681 +/- 909 (range 12-2,760) in the control group. No apparent adverse side effect was seen during the treatment with Art, and no abnormal change in liver and renal function was detected after the last medication. The preliminary study indicates that application of the preventive administration of Art in the endemic area during the transmission season may effectively reduce both the infection rate and intensity of schistosomiasis.

Adolescent↗
PubMed1995

Effect of antihydatid drugs on carbohydrate metabolism of metacestode of echinococcus granulosus.

A biochemical some enzymes of glycolysis and a partial reversed tricarboxylic acid cycle together with hydrolytic enzymes in the cyst wall of Echinococcus granulosus was carried out. Lactate dehydrogenase (LDH), pyruvate kinase (PK), phosphoenolpyruvate carboxykinase (PEPCK), and adenosine triphosphatase (ATPase) showed their high level of activity, suggesting that the proliferation of E. granulosus cyst wall is an energy-dependent process and the major pathways for glucose metabolism is glycolysis. Treatment of E. granulosus-infected mice with mebendazole and albendazole resulted in marked inhibition of PK, PEPCK and ATPase of E. granulosus cyst wall, whereas praziquantel had no effect, indicating that PK, PEPCK, and ATPase might be chemotherapeutic targets and the differences in the inhibitory effects might account for the efficacy of the three antihydatid drugs.

Adenosine Triphosphatases↗
PubMed1995

[Experimental studies on the preventive effect of artemether against schistosomal infection].

In order to study the preventive effect of artemether (Art) against schistosomal infection, mice, rabbits and dogs infected with Schistosoma japonicum cercariae were treated intragastrically (ig) with Art on various days after infection. The preventive effect was assessed by total and female worm reduction rate, the number of the animals without female worm, measurement of some parameters relevant to the acute schistosomiasis, and histopathological observation on the liver. The results showed that in mice a promising effect was obtained when an initial dose of Art 300 mg/kg was given ig on d7 after infection with cercariae, followed by repeated dosing every wk for 4 times. In rabbits and dogs treated ig with Art according to above-mentioned appropriate regimen on d7 after infection at a dosage of 10 or 15 mg/kg given every 1 or 2 wk for 2-4 times, the total and female worm reduction rates were 96.8%-100%, and part of the animals were free from female worm. After preventive treatment of the rabbits with Art, the body temperature and eosinophil count were normal and no schistosome egg was found in the feces. When rabbits infected with 48-52 schistosome cercariae once every other day for 5 times were initially treated ig with Art 15 mg/kg on d7 after the first infection, and the same dosing was given repeatedly every 1 or 2 wk for 2-4 times, the total and female worm reduction rates were 97.6%-98.4%. Histopathological observation showed that the above-mentioned infected dogs and rabbits received preventive treatment with Art exhibited a promising protective effect on their livers. The protective effect of Art given every 1 wk on the liver was similar to that of the drug given every 2 wk. The results indicate that Art possesses an effect for prevention of schistosomiasis which could be helpful for reducing infection rate and intensity of infection, and controlling acute schistosomiasis.

Animals↗
PubMed1994

Syp (SH-PTP2) is a positive mediator of growth factor-stimulated mitogenic signal transduction.

Syp (SH-PTP2) was recently identified as a phosphotyrosine phosphatase containing two SH2 domains within its primary structure. In response to appropriate growth factor stimulation, Syp becomes phosphorylated on tyrosine residues and associates with insulin receptor substrate 1 (IRS-1) and/or the corresponding growth factor receptor via its SH2 domains, leading to increased Syp activity. To assess the importance of Syp in mitogenic signaling, we microinjected mammalian fibroblasts with several reagents designed to interfere with Syp SH2/phosphotyrosine interaction in vivo. Insulin-, insulin-like growth factor-1-, and epidermal growth factor-stimulated DNA synthesis, indicated by bromodeoxyuridine (BrdUrd) incorporation, was dramatically decreased following microinjection of a Syp antibody (Ab) (65-85%) or a Syp GST-SH2 fusion protein (approximately 90%) in comparison with cells microinjected with control IgG or glutathione S-transferase (GST), respectively. In addition, microinjection of an IRS-1-derived phosphonopeptide, which inhibits in vitro binding of Syp-SH2 to IRS-1 with an ED50 value of approximately 23 microM, also decreased BrdUrd incorporation in vivo by approximately 50-75%. Microinjection of the Syp Ab, Syp GST-SH2 fusion protein, or the phosphonopeptide had no effect on serum-stimulated BrdUrd incorporation. In conclusion, disruption of Syp function in living cells inhibited cell cycle progression in response to growth factor stimulation, indicating that Syp is a critical positive regulator of mitogenic signal transduction.

Amino Acid Sequence↗
PubMed1994

Early treatment with artemether and praziquantel in rabbits repeatedly infected with Schistosoma japonicum cercariae.

When rabbits infected with 48-52 Schistosoma japonicum cercariae once every wk for 6 times or every other day for 5 times were treated ig with artemether (Art) 10 or 15 mg.kg-1 on d7 after the first infection, followed by the repeated administration of the same dose once every 1-2 wk, a promising effect was seen in the groups treated with Art at higher dose. In another group of rabbits with the same drug administration regimens of praziquantel (Pra) were also used in early treatment, but the initial dose was given on d21 after the first infection. The results showed that Pra given at 40 mg.kg-1 in each administration was more promising than the lower dose of 30 mg.kg-1 especially in group treated at 2 wk intervals. Further study indicated that the presence of adult schistosomes in rabbits increased the effect of Pra not only on 21-day-old schistosomule, but also on 14-day-old schistosomules. The results suggest that Art and Pra could be used in field trial for controlling acute schistosomiasis and decreasing the intensity of schistosomal infection.

Animals↗
PubMed1994

[Effect of artemether on glycogen, protein, alkaline phosphatase and acid phosphatase of Schistosoma japonicum].

When mice infected with Schistosoma japonicum for 32-35 d were treated ig with artemether (Art) at a single dose of 300 mg.kg-1 for 24 h, the glycogen content of female and male schistosomes decreased significantly with reduction rates of about 50%. 72 h after medication, the glycogen reduction rates were 64.1-77.9%. Meantime, the protein content of female and male worms was also decreased, the reduction rates being 68.1% and 49.3%, respectively. In infected mice treated ig with Art at the same dosage for 24 h, the inhibition rates of alkaline phosphatase (AKP) activity in female and male worms were 30% and 25%, respectively. 72 h later, the AKP activity of female worm was further inhibited to 62.3% as compared with the control. Besides, the inhibitory effect of Art on acid phosphatase (ACP) activity of female worm was also more apparent than that of male worm. 72 h after medication, the respective inhibition rates of ACP activity in female and male worms were 75.7% and 47.6%. The results indicated that Art might exert its effect on both carbohydrate and protein metabolism of schistosomes.

Acid Phosphatase↗
PubMed1994

Effect of albendazole on the larvae and eggs of Necator americanus in golden hamster.

When golden hamsters infected with adult Necator americanus were treated ig with albendazole(Alb) 75 or 150 mg/kg, the efficacy rates were 83.8% and 100%, respectively. Three days before treatment, the mean numbers of larvae recorded from the incubation of feces from 2 treated groups were 29,716 +/- 3,299 and 28,256 +/- 118 per gram of feces, while in the control group, it was 8,828 +/- 2,659. Within 3 days after treatment, no larva was detected in the 2 treated groups, but in the control group the mean larva number was 9,066 +/- 7,416. Furthermore, in 2 treated groups none or only a few degenerated eggs could be found using saturated saline solution method. when infected golden hamsters were treated ig with Alb at a single dose of 150 or 300 mg/kg on day 3, 7 or 14 after infection with the third stage larvae, the egg positive rates in the feces were 0-9.1%, while the worm reduction rates were 96.8-100%.

Albendazole↗
PubMed1994

Effect of albendazole on Ancylostoma caninum larvae migrating in the muscles of mice.

When mice inoculated with 1,000 third-stage larvae of Ancylostoma caninum for 1 week were treated intragastrically (ig) with albendazole (Alb) 75, 150 or 300 mg/kg.d for 3 days, the mean larva numbers collected from the muscles of each group were 2.7 +/- 1.7, 2.0 +/- 1.5 and 1.0 +/- 1.0, respectively, being much less than that 205 +/- 68 of the control group. In mice treated ig with Alb 150 mg/kg.d for 3 days, the concentrations of Alb and its effective metabolite, albendazole sulfoxide (AlbSO), were determined in plasma and the muscles at different intervals after the last medication using high performance liquid chromatography. The results showed that only low concentrations of Alb were detected in both plasma and the muscles. However, higher concentrations of AlbSO were found not only in the plasma (5.4-10.5 micrograms/ml), but also in the muscles (2.2-4.6 micrograms/g). The higher contents of AlbSO in the muscles would be helpful for killing the Ancylostoma larvae migrating in the muscles of mice.

Albendazole↗
PubMed1994

[Synthesis of new fluorescent reagent and its application in solution fluorescence analysis].

In our laboratory we have designed and synthesized a new fluorescent CGE(N), which has a fluo-rigen and can react with active hydrogen in chemical compounds. We have studied its application in solution fluorescence, thin-layer fluorescence and solid fluorescence analysis. The results have indicated that CGE (N) is a good reagent in analysis. And the example of its application in solution fluorescence analysis is given in this paper.

Colchicine↗
PubMed1993

Direct chromosome analysis of 50 primary breast carcinomas.

Direct chromosome analyses were performed in 50 cases of primary breast carcinoma. Thirty-six cases had modal chromosome counts in the diploid range; the other 14 cases were polyploid. Of the 22 cases with detailed G-banding analyses, the most frequent structural changes involved chromosome 1 (15 of 22), 3 (13 of 22), and 6 (13 of 22). Deletion of chromosome 1p was noted in nine cases, and both 3p- and 6q- were noted in 10 cases.

Breast Neoplasms↗
PubMed1993

Analysis of lectin receptors in normal nasal mucosa, nasal polyp, inverted papilloma and papillary adenocarcinoma.

In order to investigate the changes in glycoprotein structure in the process of cellular differentiation of the nasal mucosa, formalin-fixed, paraffin-embedded biopsy specimens of normal nasal mucosae, nasal polyps, inverted papillomas and papillary adenocarcinomas were analysed by the Avidin Biotin-Peroxidase Complex technique for the demonstration of peanut agglutinin (PNA) receptors, concanavalin ensifomis agglutinin (ConA) receptors, ulex europeaus agglutinin (UEA-I) receptors, wheat germ agglutinin (WGA) receptors, carcino-embryonic antigen (CEA) and keratin. The quantity and distribution of PNA receptors, ConA receptors, UEA-I receptors and CEA were different, in relation to the varying pathological changes. The results suggest that the glycoprotein structure in the cells of the nasal mucosa will change following their differentiation and malignant transformation, which may be helpful in establishing the diagnosis.

Adenocarcinoma, Papillary↗
PubMed1993

5' distal and proximal cis-acting regulator elements are required for developmental control of a rice seed storage protein glutelin gene.

Using a homologous transgenic rice system it is demonstrated that 5' distal and proximal cis-acting transcriptional regulatory elements are required for developmental control of a rice seed storage protein glutelin gene. Analyses of gene expression of nine progressively truncated 5' promoter sequences in developing endosperm indicated the existence of at least one major positive element located from the -5.1 to -1.8 kb region. The functional importance of proximal elements in the context of 1.8 kb promoter was demonstrated by single substitution mutations in the TATA box (-28/-23), AACA motif (-73/-61), and protein-binding boxes I (-103/-86), II (-124/-110), III (-175/-158) and IV (-200/-217). A simultaneous mutation of five protein-binding sites (-410/-86) essentially eliminated the activity of the 1.8 kb promoter. Although temporal control of the Gt1 gene during endosperm development was retained in plants of constructs from -5.1 kb to -155 bp, spatial control of the glutelin gene was altered when the 5.1 kb promoter was deleted to -507 bp or -154 bp as the reporter gene activities of these constructs were detected in phloem of leaves, and in stems, sheaths and roots of plants.

Base Sequence↗
PubMed1993

Interspecific somatic hybrid of Ichang papeda with Valencia orange.

Protoplasts from the leaf of Ichang papeda (Citrus ichangensis Swingle) were fused with the protoplasts of embryogenic suspension culture of Valencia orange (Citrus sinensis Osbeck) in vitro by polyethylene glycol (PEG)-induced fusion. The regenerated embryoids were malformed and were transferred onto shoot induction medium. The shoots were then grafted on 15-day-old seedlings of trifoliate orange in vitro. Chromosome counts of the young leaves showed that the parents were diploids, 2n = 2x = 18, and the regenerated plants were tetraploids, 2n = 4x = 36. Peroxidase and glutamate oxaloacetate transaminase isozyme analysis confirmed that these tetraploids were somatic hybrids. They have the bands of both parents. The hybrid plants grew vigorously after transplanted into soil. Leaf morphology of the hybrid was similar to that of sweet orange.

Cells, Cultured↗
PubMed1992

Direct chromosome analysis of seven primary colorectal carcinomas.

Chromosome studies were performed on direct preparations of seven cases of primary colorectal carcinomas. Two cases had relatively simple chromosome changes: 48,XY,+8,+21/51, XY,+8,+9,+10,+i(17q),+21, and 47,der(X)t(X;14)(q11;q11)-Y,t(6;18)(p22;q24)+7,+8,der(19)t (19;?)(q13;?). The five others had complicated deletions and translocations; 1p- was noted in five cases, and i(17q) was noted in three cases.

Adenocarcinoma↗
PubMed1992

Cytogenetic studies of eight primary gastric cancers.

Cytogenetic analysis was performed on eight primary gastric cancers. Three of them had simple chromosome changes: 47,XX,+X/48,XX,+X,+X; 48,XX,+8,+19,t(3;5) (q21;q31) and 47,XY,+del(7)(q22). The five others had complicated chromosome changes; both 3p- and 7q- were noted in four cases and i(5p) was noted in two cases.

Adenocarcinoma↗
PubMed1992

Cytogenetic abnormalities in a squamous cell carcinoma of the penis.

Cytogenetic findings in a squamous cell carcinoma (SCC) of the penis in a 60-year-old patient was observed for the first time. The stemline karyotype of the tumor was 46,XY,del(2) (q33q36),der(4)t(4;?)(p16;?),der(5;15)(q10;q10),der(8)t(8;?13)(p21 ;?),-13,- 13,-15,+3mar.

Carcinoma, Squamous Cell↗
PubMed1992

Effects of activin and follicle-stimulating hormone (FSH)-suppressing protein/follistatin on FSH receptors and differentiation of cultured rat granulosa cells.

The aim of this study was to investigate the actions of both activin and FSH-suppressing protein (FSP)/follistatin either alone or in combination on FSH receptor number and on the responsiveness of granulosa cells to FSH and LH. Granulosa cells were harvested from diethylstilbestrol-treated immature Sprague-Dawley rats and cultured 48 h in serum-free medium with or without treatment. Activin treatment alone (3-100 ng/ml) resulted in a 4-fold increase in FSH receptor number with no change in binding affinity. This effect of activin was inhibited 31% by FSP (100 ng/ml) treatment which alone had no effect on FSH receptor number. Treatment with activin (100 ng/ml) prevented FSH-induced down-regulation of FSH receptor number, whereas at lower concentrations (3-30 ng/ml) activin enhanced down-regulation of FSH receptor number by 20% (P less than 0.05). In contrast, FSP alone prevented FSH-induced down-regulation by increasing FSH receptor number up to 40-50%. Pretreatment of granulosa cells with activin, but not FSP, for 24 h increased the responsiveness of cells to FSH (20 ng/ml) and LH (40 ng/ml) shown by increases in aromatase activity, progesterone, and immunoreactive inhibin production over and above control in a manner which depended upon activin doses. We conclude that 1) activin enhancement of FSH action on rat granulosa cells may be mediated in part via regulation of FSH receptor number, and 2) the effects of FSP on granulosa cells are likely to be due to its activin binding properties.

Activins↗