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Biomedical subjects

S Xie

Publications and source records attributed to S Xie.

At least 91 records · Page 5Linked to original sources
PubMed1996

[Comparative research on the constituents of the volatile oil in the rhizome of Cibotium barometz (L.) J. Sm. and its processed products].

Volatile oil was extracted from the rhizome of Cibotium barometz for the first time. Its content was determined to be 83.3 micrograms/g, decreasing significantly after the drug was processed. Twelve constituents from the volatile oil were identified by method of GC-MS. The main constituents were organic acids. The contents of palmitic acid and linoleic acid were the highest. After Cibotium barometz was processed, some constituents were found decreasing and some increasing.

Drugs, Chinese Herbal↗
PubMed1996

[Intellectual status of patents cerebral cysticercosis].

OBJECTIVE: To study the intellectual status of patients with cerebral cysticercosis with dementia evaluation scale. METHODS: The intellectual status of 112 patients with cerebral cysticercosis was studied with Hasagawa dementia evaluation scale and that of 30 patients with event related potential of P 300. RESULTS: In the patientsl, 50.9% suffered from mental dysfunction. Among them 11.6% had severe abnormality, 13.4% moderate, and 25.9% mild. Hypertension, epileptic attack and improper medication may cause intellectual dysfunction. CONCLUSIONS: Protection of mental function should be considered when chosing the treatment for better recovery of the patients. Hypertension, epileptic attack and improper medication may cause intellectual dysfunction.

Brain Diseases↗
PubMed1996

[Level and significance of the soluble interleukin-2 receptor expression in serum of patients with bladder cancer].

The results of a dynamic study of the soluble interleukin-2 receptor (SIL-2R) expression, interleukin-2 (IL-2) production and natural killer cell factor (NKCF) activity before and after operation in 24 bladder carcinoma patients were reported. The SIL-2R expression level in the patients was significantly higher, the IL-2 production and NKCF activity were remarkably lower than those of controls. Furthermore, the higher the stage of the tumor, the higher the level of the SIL-2R. There was a period of immune suppression after operation. The results suggest that the changes of the SIL-2R expression level, IL-2 production and NKCF activity are closely related to the prognosis of patients with bladder carcinoma.

Aged↗
PubMed1996

[Soluble interleukin-2 receptor in patients with urinary bladder cancer].

Soluble interleukin-2 receptor (sIL-2R) levels in the serum and the effect of the sIL-2R on the natural killer cell factor (NKCF) activity were studied in 31 patients with transitional cell cancer of the urinary bladder. The results showed that serum levels of sIL-2R in the patients were significantly higher than those of controls. sIL-2R level correlated with the stage of the disease. Furthermore, sIL-2R was able to suppress NKCF activity. The results suggest that the sIL-2R may reflect the status of anti-tumor immunity.

Aged↗
PubMed1996

[Analysis of cinnamic acid in storax and its original plant by HPLC].

The contents of free and hydrolytic cinnamic acid in storax and its original plant (Liquidambar orientalis) were determined by high performance liquid chromatography, and the chromatographic behaviors were studied. In styrax gummi, the contents of free and hydrolytic cinnamic acid were 7.03% and 25.26% respectively; and in its original plant, they were 0.3% evenly.

Chromatography, High Pressure Liquid↗
PubMed1995

Abnormalities in the CDKN2 (p16INK4/MTS-1) gene in human melanoma cells: relevance to tumor growth and metastasis.

The inhibitor of cyclin-dependent kinase 4, CDKN2 (also known as p16INK4 or MTS-1, multiple tumor suppressor gene 1), has been mapped to 9p21. The gene has been shown to be deleted or mutated in high frequency in human melanoma cell lines and familial melanoma patients, suggesting that it could be a melanoma suppressor gene. How these observations are related to tumorigenicity and metastasis of human melanoma is not clear however. To test the role of CDKN2 in human melanoma metastasis, 14 human melanoma cell lines with different metastatic abilities in nude mice were analysed for possible abnormalities in the CDKN2 gene. Homozygous deletions that resulted in a lack of gene expression were found in six of 14 cell lines tested. SSCP-direct sequencing revealed point mutations in three other cell lines. One cell line displayed CC to TT transitions which constitute a hallmark of ultraviolet-induced DNA damage. Overall, abnormalities in the CDKN2 gene were found in nine of 14 (64%) cell lines tested. Homozygous deletion and lack of gene expression were found in several low tumorigenic and nonmetastatic melanoma lines, whereas other metastatic cells did not exhibit abnormalities in the CDKN2 gene. These data suggest that the absence of normal CDKN2 does not confer growth advantage to melanoma cells in vivo and that the production of metastasis by human melanoma cells can occur in the absence of CDKN2 gene abnormalities.

Animals↗
PubMed1995

A prospective follow-up study of brain morphology and cognition in first-episode schizophrenic patients: preliminary findings.

Brain morphological abnormalities have been reported in several independent investigations of chronic schizophrenic patients. The present study is a prospective 4-year follow-up of first-episode schizophrenic patients to determine whether some of these abnormalities may be a consequence of regional brain structural change over time after the onset of a first psychotic episode. Whole hemisphere, temporal lobes, superior temporal gyrus, hippocampus, caudate, corpus callosum, and lateral ventricles were measured in a series of MRI scans taken over a 4-year period in 20 patients and five controls. Total volume reduction was noted in both hemispheres to a greater degree in patients than controls. When adjusted for total brain size, left ventricular enlargement occurred in patients, but not controls, over time. These preliminary data suggest that subtle cortical atrophy may be occurring over time after the onset of illness.

Adult↗
PubMed1995

The gene encoding bovine pregnancy-associated glycoprotein-1, an inactive member of the aspartic proteinase family.

Bovine pregnancy-associated glycoprotein 1 (bPAG1) is a member of the aspartic proteinase family. It becomes detectable in maternal serum soon after implantation and is produced specifically in the invasive binucleate cells of the placenta. As a result of a key mutation within its catalytic center, bPAG1 appears to be proteolytically inactive. Its gene consists of nine exons (size range 99-281 bp) and eight introns (87-1800 bp) organized in a manner very similar to those of proteolytically active mammalian aspartic proteinases. The transcription start point (tsp) is located 53 or 54 bp upstream from the start codon (ATG) and 19 bp downstream from a 5'-TATATAA sequence. Southern blot analyses have indicated the presence of two bPAG1 genes. By screening with an antiserum raised against bPAG1, a less common cDNA with 91% sequence identity to the bPAG1 transcript has been isolated from a placental cDNA library and presumably represents the second gene. At least eight other genes with sequences that hybridize relatively weakly to the bPAG1 probe are present in the bovine genome. Despite the similarities in the transcribed portion of the genes encoding PAG1, pepsinogen and other mammalian aspartic proteinases, the sequences upstream from the tsp of bPAG1 are unique.

Amino Acid Sequence↗
PubMed1995

Glycoproteins of the aspartyl proteinase gene family secreted by the developing placenta.

Pregnancy in cattle and sheep can be diagnosed by the presence of placentally-derived antigens (pregnancy-associated glycoproteins or PAG-1) in maternal serum soon after implantation begins at about Day 20 following conception. Molecular cloning of their cDNA has revealed that PAG-1 belong to the aspartic proteinase gene family and have about 50% amino acid sequence identity to pepsin. However, critical amino acid substitutions at the active site regions suggest that both bovine and ovine PAG-1 are enzymatically inactive. PAG-1 expression has been shown by in situ hybridization and immunocytochemistry to be localized to the trophoblast binucleate cells, which invade maternal uterine endometrium during implantation. The glycoproteins are concentrated in dense cytoplasmic granules that are discharged after the binucleate cells have migrated to the maternal side of the placental barrier. We suggest, therefore, that the PAG-1 might have an endocrine function either as carriers of other bioactive peptides or by acting as hormones themselves. Recently screening of placental libraries with nucleic acid probes has identified additional cDNA that are very abundant and code for polypeptides (PAG-2 and PAG-3) related to, but antigenically and structurally distinct from PAG-1 described above. These molecules have sequences of amino acids at their catalytic centers that are consistent with their being potentially functional proteinases but their role during pregnancy, like that of PAG-1, is unclear.

Amino Acid Sequence↗
PubMed1995

Porcine pregnancy-associated glycoproteins: new members of the aspartic proteinase gene family expressed in trophectoderm.

Pregnancy-associated glycoproteins (PAG) are members of the aspartyl proteinase gene family that were initially identified in cattle (bPAG) and sheep (oPAG) as placenta-specific antigens in maternal blood. The objective of this study was to determine whether PAG are expressed in pig trophoblast. A porcine conceptus cDNA library was screened with 32P-labeled ovine and bovine PAG cDNA. Of the approximately 10(4) plaques that were initially screened, a very high number (approximately 5.3%) were positive. Two distinct types were identified, and full-length clones representing each type (1371 bp, pPAG1; 1378 bp, pPAG2) were fully sequenced in both directions. Their open reading frames coded polypeptides of 389 and 387 amino acids, respectively, including 15 amino acid signal peptides. Each had several potentials sites for N-glycosylation. Both were members of the aspartic proteinase gene family, with approximately 50% amino acid sequence identity to porcine pepsinogen and 64% to each other. They were only distantly related to PAG of ruminant species (53% and 49% identify in amino acid sequence to oPAG1 and bPAG1, respectively). Interestingly, pPAG1 had amino acid substitutions within its catalytic center (Gly-->Ala81, domain 1; Thr-->Ser263, Thr-->Ser265, Ser-->Ala266, domain 2) that together were likely to render it enzymatically inactive, whereas pPAG2 retained sequences identical to pepsin in these regions. Western blotting of secretory products of porcine trophoblast with anti-oPAG1 and anti-bPAG1 antisera indicated that pPAG, like PAG from ruminants, had an unexpectedly high M(r)(approximately 70,000).(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1995

Selective reduction of radiotracer trapping by deuterium substitution: comparison of carbon-11-L-deprenyl and carbon-11-deprenyl-D2 for MAO B mapping.

UNLABELLED: Recent human PET studies with the monoamine oxidase B (MAO B) tracer [11C]L-deprenyl show that the rapid rate of radiotracer trapping relative to transport reduces the sensitivity of the tracer in regions of high MAO B concentration. This study investigates the use of deuterium substituted L-deprenyl ([11C]L-deprenyl-D2) to reduce the rate of trapping in tissue and to improve sensitivity. METHODS: Five normal subjects (43-64 yr) were studied with [11C]L-deprenyl and [11C]L-deprenyl-D2 on the same day. Time-activity data from different brain regions and the arterial plasma were analyzed using a three-compartment model as well as graphical analysis for irreversible systems. RESULTS: For both tracers, maximum radioactivity accumulation occurred at about 5 min. For [11C]L-deprenyl, 11C concentration peaked at 5 min and remained constant throughout the study. With [11C]L-deprenyl-D2, peak 11C concentration also occurred at about 5 min but was followed by an initial washout. Carbon-11 concentration generally plateaued from 30 to 60 min. The plateau for [11C]L-deprenyl was higher than the plateau for [11C]L-deprenyl-D2. Data analysis by a three-compartment model and by graphical analysis showed that deuterium substitution: (a) does not affect plasma to tissue transport (K1); (b) reduces the rate of trapping of 11C in all brain regions; (c) facilitates the separation of model terms related to radiotracer delivery from radiotracer trapping in tissue; and (d) improves tracer sensitivity. CONCLUSION: This study demonstrates that deuterium substitution causes a significant reduction in the rate of trapping of labeled deprenyl, providing a direct link between radiotracer uptake and MAO B in the human brain and enhancing tracer sensitivity to changes in MAO B concentration.

Adult↗
PubMed1995

[Survival rates in patients with systemic lupus erythematosus].

To assess the impact of demographic and clinical factors on prognosis in patients with systemic lupus erythematosus (SLE), we examined the survival rate by lifetable analysis in 566 patients. All patients were Shanghai citizens who were diagnosed as having SLE in Huashan Hospital between 1959 and 1992. According to American Rheumatism Association's preliminary criteria. The survival rate from the time of SLE onset was 93% at 1 year, 73% at 5 years and 60% at 10 years. On univariate analysis, we found that the following factors worsened the probability of survival; male, neuropsychiatric manifestation, pleurisy-pericarditis, anemia, thrombocytopenia, lymphocytopenia, proteinuria, hematuria, urinary cast, azotemia, decreased endogenous creatinine clearance, increased cholesterol in serum, hypocomplementemia, abnormal electrocardiograph and high corticosteroid dose of treatment. On multivariate analysis, we found the four independent risk factors were male, azotemia, hypocomplementemia and high corticosteroid dose of treatment.

Adolescent↗
PubMed1994

Abundance of nuclear DNA topoisomerase II is correlated with proliferation in Arabidopsis thaliana.

Topoisomerase II (TOPII) is an important enzyme involved in DNA replication and chromosome condensation. The level of TOPII expression has been correlated with the proliferative state of eukaryotic cells. Here we report the cloning and characterization of a cDNA clone AtTopII encoding the first reported TOPII from higher plants. AtTopII is 4603 base pairs (bp) in length and encodes an open reading frame of 1473 amino acid residues. One interesting feature of AtTopII is the presence of a 110 bp direct repeat in the last one-third of the cDNA. Analysis of the genomic sequence within this region by PCR revealed that this duplication includes a small intron of 89 bp. Conservation of sequences within this repeated intron suggests that this in-frame duplication may be a relatively recent event. The deduced amino acid sequence of AtTopII shows strong homologies to TOPII sequences reported from other eukaryotes, particularly in the regions that are highly conserved among different species. Southern blot analysis with Arabidopsis DNA indicates that AtTopII is a single-copy gene while Northern blots detected a 5.0 kb transcript, the level of which is substantially higher in young seedlings than in mature plants. Using a polyclonal antiserum raised against the C-terminal one-third of AtTOPII, we found that the protein is localized in the nucleus and its level is correlated with the proliferative state of the particular tissue.

Amino Acid Sequence↗
PubMed1994

A novel glycoprotein of the aspartic proteinase gene family expressed in bovine placental trophectoderm.

The pregnancy associated glycoproteins (PAG 1) that appear in the maternal serum of cattle and sheep soon after implantation are apparently inactive members of the aspartic proteinase family. Here we describe the isolation of a highly abundant cDNA (PAG 2 cDNA) that represents a second member of this gene family which is structurally related to bovine PAG 1, ovine PAG 1, and pepsin (58%, 58%, and 51% amino acid sequence identity, respectively). The bovine PAG 2 cDNA was identified in two ways. First, the bovine placental library was screened under relatively nonstringent conditions with an ovine PAG 1 cDNA. The second fortuitous approach employed immunoscreening with an antiserum raised against a partially purified factor that competed with bovine LH for binding to the LH receptor on the CL of the ovary. The full-length cDNA (1258 bp) codes for a polypeptide of 376 amino acids. Bovine PAG 2, unlike bovine PAG 1, has a catalytic center with a consensus sequence of amino acids. Its mRNA is expressed in fetal placenta but not in other fetal organs, and is localized to both the mononucleate and binucleate cells of the trophectoderm, whereas PAG 1 is expressed only in binucleate cells. PAG 2 is synthesized by placental explants as a 70-kDa glycoprotein that is processed to several smaller molecules. Western blot analysis of culture media developed with epitope-selected antibodies to PAG 2 reveals several bands ranging in apparent M(r) from 31,000-70,000, which correspond in size to the polypeptides present in the preparation used for immunization.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1993

Test of chiral recognition in the Salmonella typhimurium (TA100) mutagenicity of mucochloric acid-cysteine adducts.

A difference in biological response to enantiomers is not an uncommon observation and is, therefore, to be expected in various manifestations of genotoxicity. The bacterial mutagen mucochloric acid (2,3-dichloro-5-hydroxy-2(5H)-furanone) has one chiral center, at C-5, but this mutagen exists in racemic form because of the facile stereoisomerization occurring by the mechanism of ring-chain tautomerism. Two readily synthesized enantiomeric analogs of mucochloric acid, as well as the racemic form of the two, were prepared from mucochloric acid and (R)-(+)-, (S)-(-)-, and (R,S)-(+/-)-cysteine. Using Salmonella typhimurium (TA100), the enantiomeric compounds were assayed together in four dose/response assays along with mucochloric acid, the reference mutagen. In three of the same four assays, the racemic form was also assayed. Neither statistically significant differences in mutagenicity, as determined in slope responses, nor distinctions from the plotted curves were observed among the two enantiomers and their racemic form. Therefore, no enantiospecific interaction between enantiomers and chiral DNA or enzymes involved in repair or replication could be concluded.

Analysis of Variance↗
PubMed1993

Embryo-uterine interactions in pigs during week 2 of pregnancy.

The second week of pregnancy is a particularly critical period for embryonic survival in pigs. Within that time, conceptus oestrogen synthesis is initiated, spacing and final placement of conceptuses is completed, and the signal for extending the functional lifespan of the corpora lutea is received by the mother. There is also a marked increase in blood flow to the uterus and the uterine endometrium produces and secretes nutrient histotrophe. Conceptus-derived oestrogen has been implicated in many of these events. It is also during this period that the trophoblast elongates dramatically and the inner cell mass starts to differentiate into the embryo proper. Here, we critically review the evidence that oestrogen is the sole factor initiating long-term corpus luteum maintenance in pigs. We also review the functions and general properties of the major secretory proteins in histotrophe and the role of oestrogen in controlling their expression. It is now generally accepted that asynchrony within a litter underlies much of the losses of conceptuses that are otherwise genetically normal, but which are lagging in their development; however, the underlying mechanisms remain unclear. Here we hypothesize that oestrogenic compounds derived from more advanced conceptuses or provided prematurely, either by injection or in the diet, trigger a massive increase in uterine expression and secretion of retinol-binding protein laden with retinol. We propose that less developed, smaller conceptuses are least able to contend with the sudden exposure to this potential teratogen at a time when they are particularly susceptible to imbalance in retinol supply. Hence, even though their growth proceeds for a few days, their developmental potential is irrevocably compromised.

Animals↗