Search PubMed⌕ Search

Biomedical subjects

S Zhou

Publications and source records attributed to S Zhou.

At least 361 records · Page 20Linked to original sources
PubMed1997

Multiprimer--PCR for screening of IgH and T-cell receptor rearranged genes in acute lymphoblastic leukemia.

OBJECTIVE: To develop a multiprimer-polymerase chain reaction (multiprimer-PCR) method for detecting immunoglobulin heavy chain (IgH) and T-cell receptor (TCR) rearranged genes in the same amplification. METHODS: Multiprimer-PCR protocol, a mixture of four different primers used in the same reaction detected IgH CDR-III and TCR V gamma I-J gamma Ligenetic rearrangements in 40 acute lymphoblastic leukemia (ALL) patients. RESULTS: Thirteen cases were found to have IgH CDR-III and TCR V gamma I-J gamma genetic rearrangements. Ten cases were found to have TCR V gamma I-J gamma genetic rearrangements. Thirteen cases were found to have IgH CDR-III genetic rearrangements. The amplification result of multiprimer-PCR was the same as separate amplification. The sensitivity of multiprimer-PCR was 10(-4)-10(-5) DNA level, which was the same as separate PCR amplification. All positive cases with IgH rearranged gene were confirmed by Southern blot. CONCLUSION: Multiprimer-PCR could screen two distinct rearranged genes in a single amplification, and is more suitable for screening of specimens collected at diagnosis.

Adolescent↗
PubMed1997

[Clinical analysis of pregnancy with overt diabetes complicated with retinopathy].

OBJECTIVE: To study the outcome of pregnancy in overt diabetes with retinopathy and the changes of retinopathy during pregnancy. METHOD: Retrospective study was made on 49 pregnancies with overt diabetes from 1981 to 1995. RESULTS: Maternal complications and perinatal morbidity were higher in pregnancies with retinopathy but there were no significant differences between those with and without retinopathy. Retinopathy progressed during pregnancy i 31.1% of the parturients. CONCLUSION: Pregnancies with overt diabetes complicated with retinopathy are not the indications for terminating pregnancy, but the changes of retinopathy should be carefully monitored during pregnancy.

Adult↗
PubMed1997

Observation of developing cercaria of Schistosoma japonicum on ultrastructural level and remarks at its morphology of mature stage.

OBJECTIVE: To study the developing cercaria of Schistosoma Japonicum (S. japonicum) on ultrastructural level by transmission electron microscope (TEM) for analyzing the morphological dynamic changes of the tegument, glands and musculature. METHODS: Artificial infected Oncomelania hupensis were dissected under dissecting microscope and the daughter sporocysts picked up for studying the germinal cells stage (S1). The other embryonic cercaria were selected according to the modified parameter of Chen and Bier (1972). The specimens were prepared by conventional procedure of the laboratory of TEM and were observed by Hitachi H600. RESULTS: Beside the germinal cell stage (S1), this is the first chronological study on the morphological development of S. japonicum cercaria from S2-S5 concerning the tegument and its elements (glycocalyx, sensory papilla, basal lamina and spine), head and acetabular gland and musculature of the body and tail. This article discusses the ultrastructural morphological differences from prior authors and emphasizes on the postacetalar gland and the pattern of tail musculature of the matured stage cercaria. CONCLUSIONS: According to the cell division and differentiation, the process of development may be divided into 5 stages: S1, the single germinal cell stage; S2, the germinal ball stages: major multiplication and minor differentiation; S3, tail budding embryonic stage, both active in multiplying and differentiating; S4, the pre-matured stage, major differentiation and minor multiplication; and S5, the fully matured stage (completing the differentiation).

Animals↗
PubMed1997

[A comparative study of laryngeal reinnervation from the ansa cervicalis].

A comparative study of four methods of laryngeal muscle reinnervation in dogs is presented. Twenty-eight cases were divided into four groups to undergo main branch and branch of ansa cervicalis nerve anastomosis, and nerves implantation an neuromuscular pedicles transfer respectively for restoration of vocal cord adduction on left sides. The results showed that the four procedures seemed to induce effective reinnervation of adductor muscles. But the main branch of ansa cervicalis nerve suture was superior to the other methods among which little difference was noted in the functional recovery, electrophysiological activity and muscle strength. It demonstrated that main branch of ansa nerve suture was the best procedure for treatment of unilateral vocal cord paralysis among the four methods.

Animals↗
PubMed1997

[Evaluation of electrophysiological diagnosis of concealed accessory pathway (CAP) during transesophageal atrial pacing (TEAP)].

CAP were diagnosed by TEAP using RPE intervals in 55 cases of paroxysmal supraventricular tachycardia (PSVT). There were no obvious CAP manifestations of ECG in those cases, the mean RPE interval during tachycardia was 140 +/- 29 ms, and the lower limit of x +/- 2 s was 82 ms. Among them, the VA intervals were measured by electrocardiophysiological examination in 21 cases. The mean value was 130 +/- 25 ms, and the lower limit of x +/- 2 s was 80 ms. The results suggest that RPE over 82 ms may be an important diagnostic threshold cut off point of atrioventricular reciprocation.

Adolescent↗
PubMed1997

[Radiofrequency catheter ablation of idiopathic ventricular tachycardia].

Thirteen consecutive patients with idiopathic ventricular tachycardia underwent radiofrequency catheter ablation. This group included 9 idopathic left ventricular tachycardia (ILVT) and 4 idiopathic right ventricular tachycardia (IRVT). Five ILVT patients with left axis deviation and one with right axis deviation were ablated successfully. By pace mapping, two IRVT patients with ventricular tachycardia originating from right ventricular out-flow tract were ablated. No complications occured. By means of follow-up of 3-22 months one case showed recurrence with successful reablation. It indicates that radiofrequency catheter ablation therapy is an effective and safe procedure in patients with idiopathic ventricular tachycardia.

Adolescent↗
PubMed1996

SREBP transcriptional activity is mediated through an interaction with the CREB-binding protein.

The sterol regulatory element binding proteins (SREBP-1 and -2) activate transcription of genes whose products are involved in the cellular uptake and synthesis of cholesterol. Although considerable effort has been exerted to define the events regulating the levels of active SREBP, little is known about the transcriptional cofactors mediating SREBP function. In an unbiased search for potential coactivators of SREBP, we isolated a protein of 265 kD from HeLa cells that directly bound SREBP-1 and SREBP-2. Peptide sequencing and Western blot analysis established that the 265-kD protein was CBP (CREB-binding protein), a recently identified transcriptional coactivator. The putative activation domain of SREBP was shown to bind specifically to amino-terminal domains of recombinant CBP and p300 (a CBP-related protein). Moreover, transfection studies demonstrated that CBP enhances the ability of SREBP to activate transcription of reporter genes in HeLa cells. Together, these data suggest that CBP mediates SREBP transcriptional activity, thus revealing a new step in the biochemical pathway regulating cholesterol metabolism.

Animals↗
PubMed1996

Human TAFII 105 is a cell type-specific TFIID subunit related to hTAFII130.

We previously characterized Drosophila and human TAF subunits that make up the core TFIID complex found in all cells. Here, we report that differentiated B cells contain a novel substoichiometric TAF of 105 kDa not found associated with TFIID isolated from other cell types. The cDNA encoding hTAFII105 reveals a highly conserved C-terminal domain shared by hTAFII130 and oTAFII110, while the N-terminal coactivator domain has diverged significantly. All cells tested express TAFII105 mRNA, but only B cells contain significant levels of protein associated with TFIID. Transient overexpression of hTAFII105 selectively squelches the transcription of some genes in B cells. These properties suggest that TAFII105 is a cell type-specific subunit of TFIID that may be responsible for mediating transcription by a subset of activators in B cells.

Amino Acid Sequence↗
PubMed1996

Post-transcriptional regulation of vascular endothelial growth factor mRNA by the product of the VHL tumor suppressor gene.

The VHL tumor suppressor gene is inactivated in patients with von Hippel-Lindau disease and in most sporadic clear cell renal carcinomas. Although VHL protein function remains unclear, VHL does interact with the elongin BC subunits in vivo and regulates RNA polymerase II elongation activity in vitro by inhibiting formation of the elongin ABC complex. Expression of wild-type VHL in renal carcinoma cells with inactivated endogenous VHL resulted in unaltered in vitro cell growth and decreased vascular endothelial growth factor (VEGF) mRNA expression and responsiveness to serum deprivation. VEGF is highly expressed in many tumors, including VHL-associated and sporadic renal carcinomas, and it stimulates neoangiogenesis in growing solid tumors. Despite 5-fold differences in VEGF mRNA levels, VHL overexpression did not affect VEGF transcription initiation or elongation as would have been suggested by VHL-elongin association. These results suggest that VHL regulates VEGF expression at a post-transcriptional level and that VHL inactivation in target cells causes a loss of VEGF suppression, leading to formation of a vascular stroma.

Animals↗
PubMed1996

Purification and biochemical heterogeneity of the mammalian SWI-SNF complex.

We have purified distinct complexes of nine to 12 proteins [referred to as BRG1-associated factors (BAFs)] from several mammalian cell lines using an antibody to the SWI2-SNF2 homolog BRG1. Microsequencing revealed that the 47 kDa BAF is identical to INI1. Previously INI1 has been shown to interact with and activate human immunodeficiency virus integrase and to be homologous to the yeast SNF5 gene. A group of BAF47-associated proteins were affinity purified with antibodies against INI1/BAF47 and were found to be identical to those co-purified with BRG1, strongly indicating that this group of proteins associates tightly and is likely to be the mammalian equivalent of the yeast SWI-SNF complex. Complexes containing BRG1 can disrupt nucleosomes and facilitate the binding of GAL4-VP16 to a nucleosomal template similar to the yeast SWI-SNF complex. Purification of the complex from several cell lines demonstrates that it is heterogeneous with respect to subunit composition. The two SWI-SNF2 homologs, BRG1 and hbrm, were found in separate complexes. Certain cell lines completely lack BRG1 and hbrm, indicating that they are not essential for cell viability and that the mammalian SWI-SNF complex may be tailored to the needs of a differentiated cell type.

Amino Acid Sequence↗
PubMed1996

Localization and activation of substance P receptors in unmyelinated axons of rat glabrous skin.

Immunohistochemical staining for the substance P (neurokinin INK1) receptor labels 32% of the unmyelinated axons in the glabrous skin of the rat hindpaw. This is the first demonstration of substance P (SP) receptors associated with the membranes of primary afferent fibers. Injection of SP into the subcutaneous tissue of the third hind toe results in behavioral changes interpreted as mechanical hyperalgesia and mechanical allodynia. These nocifensive behaviors can be blocked by the NK1 antagonist CP99,994-1. The presence of peripheral axons immunolabelled for NK1 receptors and the demonstration that exogenous peripheral SP causes nocifensive behaviors would seem to indicate that SP can have a direct effect on sensory afferents with activation of these receptors resulting in fine afferent firing and thus the pain-related behaviors. Additionally, the presence of round, clear vesicles in some of the SP receptor-labelled axons suggests the presence of autoreceptors since it is known that many primary sensory afferents contain SP.

Animals↗
PubMed1996

Diversity and specialization of mammalian SWI/SNF complexes.

The SWI/SNF complex in yeast facilitates the function of transcriptional activators by opposing chromatin-dependent repression of transcription. We demonstrate that in mammals SWI/SNF complexes are present in multiple forms made up of 9-12 proteins that we refer to as BRG1-associated factors (BAFs) ranging from 47 to 250 kD. We have isolated cDNAs for human BAF155, BAF170, and BAF60. BAF155 and BAF170 are encoded by separate genes that are both homologs of yeast SWI3. Both contain a region of similarity to the DNA binding domain of myb, but lack the basic residues known to be necessary for interaction with DNA. The two SWI3 homologs copurify on antibody columns specific for either BAF155 or BAF170, indicating that they are in the same complex. BAF60 is encoded by a novel gene family. An open reading frame from yeast, which is highly homologous, encodes the previously uncharacterized 73-kD subunit of the yeast SWI/SNF complex required for transcriptional activation by the glucocorticoid receptor (Cairns et al., this issue). BAF60a is expressed in all tissues examined, whereas BAF60b and BAF60c are expressed preferentially in muscle and pancreas, respectively. BAF60a is present within the 2000-kD BRG1 complex, whereas BAF60b is in a distinct complex that shares some but not all subunits with the BRG1 complex. The observed similarity between mammalian BAF190, BAF170, BAF155, BAF60, and BAF47 and yeast SNF2/SWI2, SWI3, SWI3, SWP73, and SNF5, respectively, underscores the similarity of the mammalian and yeast complexes. However, the complexes in mammals are more diverse than the SWI/SNF complex in yeast and are likely dedicated to developmentally distinct functions.

Amino Acid Sequence↗
PubMed1996

Isolation and characterization of TAF25, an essential yeast gene that encodes an RNA polymerase II-specific TATA-binding protein-associated factor.

We describe the cloning and analysis of TAF25, a previously uncharacterized yeast gene that encodes a yeast TATA-binding protein-associated factor or yTAF of Mr = 25,000. The gene encoding yTAF25 is a single copy essential gene, and the protein sequence deduced from TAF25 exhibits sequence similarity to a metazoan hTAFII. The results from immunological studies confirm that yTAF25 is a subunit of a large multiprotein TATA-binding protein-yeast TATA-binding protein-associated factor complex that contains a subset of the total number of the yTAFs present in yeast cell extracts. Both genetic and biochemical analyses demonstrate that yTAF25 can interact directly with itself. Transcriptional data show that the activity of the multiprotein complex containing yTAF25 is RNA polymerase II-specific, thus indicating that TAF25 encodes a bona fide yeast RNA polymerase II TAF. Hence the protein encoded by TAF25 has been termed yTAFII25.

Amino Acid Sequence↗
PubMed1996

Peripheral administration of NMDA, AMPA or KA results in pain behaviors in rats.

The present study investigated the role of N-methyl-D-aspartate (NMDA) and non-NMDA glutamate receptor subtypes in peripheral pain transmission. Activation of NMDA, alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) and kainate acid (KA) receptors in glabrous skin of the rat hindpaw resulted in mechanical allodynia and mechanical hyperalgesia. These agonist-induced pain behaviors were attenuated following peripheral injection of appropriate antagonists (MK-801 and CNQX). Thus, activation of NMDA, AMPA or KA receptors at the level of the peripheral nerve terminal can produce nociceptive behavior. These data suggest that topical application of glutamate receptor antagonists may be useful in treating pain disorders. Since all three receptor subtypes are involved in peripheral pain transmission, however, it will be necessary to antagonize multiple glutamate receptor subtypes to achieve effective pain relief.

Animals↗