[Progress in the study of rheumatic diseases in China].
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Biomedical subjects
Publications and source records attributed to G Shi.
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OBJECTIVE: The functional anatomy of Golgi-phobic dendrites (GBD) of spinal motoneurons (Mn) in rats was studied from their postnatal development. METHODS: Cholera toxin B subunit conjugated with horseradish peroxidase (CB-HRP) retrograde labelling method was mainly used. RESULTS: In the extensor digitorum longus Mn pool (EDL-Mn) GBD gradually decrease during development and are only a few in adults. The related value of the surface density of the white matter dendrites, most of them are GBD, of the soleus Mn pool (SOL-Mn) is nearly double than that of EDL-Mn. CONCLUSIONS: GBD of motoneurons might be related to their action patterns, especially the tonic action of slow muscle, such as the soleus. The hypotheis of dual circuits in motor control, the paralateral circuit on GBD regulates control of tonic action and the core circuit on Golgi-philic dendrites (GLD) and somata regulates phasic action, such as on EDL-Mn, has been further enhanced.
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FHIT (Fragile Histidine Triad), a putative tumor suppressor gene, was cloned from fetal brain and colon cDNA libraries. Portions of this gene are deleted in esophageal, colon, lung and breast tumors, but this gene has not been found altered in sporadic renal cell carcinomas. We report here an alternatively spliced form of this gene cloned from a kidney cDNA library. This cDNA is 1189 bp in length, and contains an additional 94 bp exon, designated exon 2a (E2a). This novel sequence is located between exon 2 and exon 3 of the FHIT gene's untranslated region and exon 2a is present in all normal kidney tissues and cell lines. Analyses performed on sporadic renal cell carcinoma (RCC) tissues and cell lines, show consistent loss of exon 8 of the FHIT cDNA in almost 60% of the cases. Interestingly, in a familial, as well as, in a metastatic RCC, derived from a patient with the sporadic form, exon 2a and exon 3 are also deleted. Northern analyses with the exon 2a of the familial and the metastatic RCC demonstrates concurrent loss of expression of a 4.4 kb transcript with the loss of the E2a sequence, suggesting that exon 2a of the FHIT gene may play an important role in the oncogenesis of renal cell carcinoma.
We have identified ten patients with acute myeloid leukemia (AML) and one patient with chronic myeloid leukemia with megakaryocytic crisis who displayed an inv(3)(q21q26). Seven of them had an additional monosomy 7. Most of them had a myelodysplastic syndrome (MDS) preceding AML, normal or increased platelet counts, increased number of megakaryocyte, megakaryocytic dysplasia, and erythroid dysplasia. There was a high incidence of resistance to induction chemotherapy, short remission time, and early relapse. Seven patients were immunologically analyzed. The main immunophenotypes were as follow: CD7+, CD34+, HLA-DR+, CD38+, CD13+, CD33+, CDw65+, CD2-, CD3-, CD4-, CD8-, CD19+, CD20-, CD11b-. Our results suggest that the leukemia with inv(3)(q21q26) represents a new cytogenetic-clinicopathologic subtype, characterized by 1) abnormal megakaryopoiesis and multiple hematopoietic lineage involvement; 2) an antecedent MDS; 3) poor response to conventional chemotherapy; and 4) expression of CD7, CD34, CD38, HLA-DR, CD13, and CD33 antigens. We propose that the malignant transformation in patients with inv(3)(q21q26) occurs in an early stem cell prior to lineage commitment.
In this study, we have performed fluorescence in situ hybridization (FISH) with chromosome-specific DNA painting probes 1, 2, 3, 4, 6, 8, and 12 and centromere-specific DNA probes 7,10,12,17,18, and X after G-banding on the same metaphase spreads from four patients with malignant hematological disorders to more precisely interpret their complex karyotypes. The findings demonstrated that the application of combined G-banding and FISH can more accurately explain complex karyotypes of hematological malignancies. FISH can detect not only the origin of marker chromosomes, but also the complex rearrangements that cannot be identified by routine banding techniques. This approach is very important to complement the cytogenetic analysis of malignant disorders and to evaluate the role of chromosome change in the development, progression, and prognosis of tumors.
Two new bioactive Annonaceous acetogenins, rollitacin (1) and rollinacin (2), along with one known acetogenin, javoricin, were isolated from the ethanolic extract of the leaves of Rollinia mucosa. Compounds 1 and 2 exhibited selective inhibitory effects among six human solid tumour cell lines. The structural elucidations of 1 and 2 were achieved by various spectroscopic analyses and chemical derivatizations.
Trilobalicin (1), a new nonadjacent bis-THF ring annonaceous acetogenin, 2,4-cis- (2) and 2,4-trans-trilobacinone (3), the ketolactones of trilobacin, an adjacent bis-THF ring acetogenin, were isolated from the stem bark of Asimina triloba (L.) Dunal (Annonaceae). Their structures were established based on chemical and spectral evidence. The relative stereochemistry of 1 was determined as trans/threo/threo/trans/erythro from C-10 to C-22 by comparisons of NMR data with those of model compounds. Compound 1 is the first example of a nonadjacent bis-THF acetogenin being isolated from the title species and represents a new type of these compounds. Bioactivities of these new structures against brine shrimp larvae and six human solid tumor cell lines were determined, and cytotoxic selectivities were shown for the lung (A-549) and breast (MCF-7) cell lines with up to a million times the potency of adriamycin.
Reversed-phase high-performance liquid chromatography (RP-HPLC) fractionation, monitored by liquid chromatography/electrospray mass spectrometry (LC/ESI-MS), led to the isolation of two new bioactive annonaceous acetogenins, rollidecin C (1) and rollidecin D (2), from the bioactive aqueous methanol fraction of the leaves of Rollinia mucosa (Annonaceae). The structures were confirmed by analyses of the 1H and 13C NMR data. In addition, a known adjacent bis-tetrahydrofuran (THF) acetogenin, desacetyluvaricin (3), was isolated from this plant for the first time utilizing the LC/ESI-MS monitoring approach. Compound 1 exhibited selective cytotoxicity toward the colon tumor cell line (HT-29), while 2 showed only borderline cytotoxicity in a panel of six human tumor cell lines.
The Annonaceous acetogenins are amenable to analysis by liquid chromatography/mass spectrometry (LC/MS) using the electrospray positive-ion mode. Under conditions of atmospheric pressure in-source collision-induced dissociation (APICID), the acetogenins reproducibly provided characteristic ion patterns and fragment ions. Accordingly, the presence of these biologically interesting acetogenins and other derivatives in plant extracts and chromatographic fractions can be readily detected by analyzing selected ion chromatograms. LC/MS screening of a bioactive crude methanol-soluble fraction of Rollinia mucosa detected the presence of some 40 known acetogenins in this plant extract, in addition to four new acetogenins of diverse structure. This rapid and relatively uncomplicated selected ionization procedure should also prove suitable for the screening of many other structural families of natural products.
Two new sesquiterpenes, 10 alpha-hydroxyamorphan-4-en-3-one (1) and 4 alpha-methylcadinane-4 alpha-methyl-1 alpha,2 alpha,10 alpha-triol (2), together with four known compounds, sesquiterpenes 10 alpha-hydroxycadinan-4-en-3-one (3) and alpha-cadinol (4), diterpene ferruginol and lignan helioxanthin, were isolated from the whole plant of Taiwania cryptomerioides under bioassay-guided fractionations. The structures of 1 and 2 were elucidated mainly by the NMR spectroscopic analyses. Bioactivities of the isolated compounds against brine shrimp, yellow fever mosquito larvae, and human tumor cells are reported; compound 4 was the most bioactive, showing selectivity for the human colon tumor cell line (HT-29).
Three sesquiterpenes, konishiol (1), cadalenol (2), 3-cedranol (3), one diterpene, manool (4), and one lignan, (+)-tsugacetal (5), have been isolated, for the first time, from the whole plant of Cunninghamia konishii by using bioactivity-directed fractionation. Compound 1 is new to the literature, and its chemical structure was determined by various spectroscopic analyses including EIMS, HREIMS, NOE, NOESY, and by preparing its di-acetyl derivative (1a). Compounds 2-5 showed moderate to weak bioactivities in brine shrimp (BST) and mosquito larvae (YFM) bioassays as well as cytotoxicities against three human solid tumor cell lines.
The voltage-gated delayed-rectifier-type K+ channel Kv2.1 is expressed in high-density clusters on the soma and proximal dendrites of mammalian central neurons; thus, dynamic regulation of Kv2.1 would be predicted to have an impact on dendritic excitability. Rat brain Kv2.1 polypeptides are phosphorylated extensively, leading to a dramatically increased molecular mass on sodium dodecyl sulfate gels. Phosphoamino acid analysis of Kv2.1 expressed in transfected cells and labeled in vivo with 32P shows that phosphorylation was restricted to serine residues and that a truncation mutant, DeltaC318, which lacks the last 318 amino acids in the cytoplasmic carboxyl terminus, was phosphorylated to a much lesser degree than was wild-type Kv2.1. Whole-cell patch-clamp studies showed that the voltage-dependence of activation of DeltaC318 was shifted to more negative membrane potentials than Kv2.1 without differences in macroscopic kinetics; however, the differences in the voltage-dependence of activation between Kv2.1 and DeltaC318 were eliminated by in vivo intracellular application of alkaline phosphatase, suggesting that these differences were due to differential phosphorylation. Similar analyses of other truncation and point mutants indicated that the phosphorylation sites responsible for the observed differences in voltage-dependent activation lie between amino acids 667 and 853 near the distal end of the Kv2.1 carboxyl terminus. Together, these parallel biochemical and electrophysiological results provide direct evidence that the voltage-dependent activation of the delayed-rectifier K+ channel Kv2. 1 can be modulated by direct phosphorylation of the channel protein; such modulation of Kv2.1 could dynamically regulate dendritic excitability.
BACKGROUND: Recent studies indicate that gastric emptying may be influenced by patterns of previous nutrient intake. Endogenous cholecystokinin (CCK), whose synthesis and release can be affected by dietary intake, has a major role in the regulation of gastric emptying. AIMS: To evaluate the influence of diets with differing protein content on gastric emptying of differing liquid test meals and plasma CCK levels in the rat and to check whether the inhibitory effect of exogenous CCK on gastric emptying is modified after long term intake of diets with differing protein content. METHODS: Rats were fed for three weeks with high protein, medium protein (regular), or low protein diet. On day 22 gastric emptying of a peptone meal was studied. In addition, basal and postprandial CCK levels after the different dietary regimens were measured by bioassay. The time course of dietary adaptation was studied and its specificity assessed through the use of different (peptone, glucose, and methylcellulose) test meals. The effect of exogenous CCK-8 on gastric emptying was studied at the end of the adaptation period (three weeks). RESULTS: Feeding the animals with a high protein diet for three weeks resulted in a significant (p < 0.05) acceleration (by 21.2 (8.2)%) of gastric emptying while feeding with a low protein diet was followed by a significant (p < 0.05) delay (by 24.0 (6.2)%) in the emptying rate. When the time course of the effect of dietary adaptation on gastric emptying was studied, it appeared that at least two weeks are required for dietary protein to be effective. The regulatory effect of dietary protein on gastric emptying proved to be dependent on meal composition. Only the emptying rate of a protein containing meal (40% peptone) was significantly modified by previous dietary intake. No significant (p > 0.05) changes were observed with glucose and methylcellulose meals whose emptying rates were similar in rats receiving a high protein or low protein diet. A peptone meal strongly and significantly (p < 0.05) increased plasma CCK levels in rats fed a medium protein (regular) diet. Results were similar in rats receiving a low protein diet (p < 0.05) but not in rats on a high protein diet (p > 0.05). As a consequence, postprandial plasma levels of CCK in rats fed with a medium or low protein diet were significantly (p < 0.05) higher than those in rats receiving a high protein diet. In rats on high and low protein diets, dose response curves to CCK-8 were virtually identical, suggesting that dietary protein intake has no influence on the effect of exogenous CCK. CONCLUSIONS: These results clearly show that gastric emptying of a protein containing meal can be modified by previous dietary protein intake. This effect, which is time dependent and meal specific, may be related to changes in endogenous CCK release which will affect emptying rate. While the exact mechanisms underlying this adaptive response need to be studied and clarified further, these results emphasise the importance of dietary history in the evaluation and interpretation of gastric emptying data.
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We analysed the associations of DR and DQ alleles with rheumatoid arthritis (RA) in Han nationality of China. PCR-RFLP technique was used to determine DRB1, DQA1 and DQB1 alleles in 35 unrelated patients with RA and 100 healthy controls from the Hans. The frequency of DR4 was 51.4% in RA patients and 24.0% in the healthy controls (P < 0.01, RR = 3.30). Subtyping of DR4 revealed no differences in the relative distributions of the DR4 alleles between the RA group and the controls, which both were predominated by DRB1 * 0405 allele, but there was a significant increase in the absolute frequency of DRB1 * 0405 in RA patients compared with the healthy controls (31.4% vs 12.0%, P < 0.01). DQ4 (DQB1 * 04) was also increased both in the RA patients compared with the healthy controls (37.1% vs 10.0%, P < 0.001) and in DR4+ RA patients compared with DR4+ healthy ones (72.2% vs 41.6%, P = 0.0376). Further analysis showed that the haplotype DR4-DQ4 was associated with RA (RR = 5.17, P < 0.001), and that the DR4(+)-DQ4+ patients had more severe disease than the DR4- patients. These results suggest that DR4, mainly the DRB1 * 0405, is associated with RA in Han nationality, and DQ4 may play a role in DR4 conferring susceptibility to RA. The DR4-DQ4 haplotype could be taken as a predictive marker for disease severity.
OBJECTIVE: To approach the characteristics of magnetic resonance imaging (MRI) and CT in detection and localization of intraocular foreign bodies. METHODS: Detection and localization of 28 cases (42 foreign bodies) of non-magnetic intraocular foreign body were compared in MRI and CT with criteria of operative results. RESULTS: The positive rates of MRI and CT in detection of 42 non-magnetic intraocular foreign bodies were respectively 90.5% and 95.2% (chi 2 test: P > 0.5). The positive rates of MRI and CT in localization were respectively 89.5% and 60.0% (chi 2 test: P < 0.05). CONCLUSION: MRI could be used in detection and localization of non-magnetic intraocular foreign bodies with high positive rates in detection and superior to CT in demonstrating non-magnetic intraocular foreign bodies with low density and the relationship between foreign bodies and intraocular tissues. MRI was not as believable as CT in detection of foreign bodies in eye wall and not an appropriate modality in examinations of magnetic intraocular foreign body.