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K Deng

Publications and source records attributed to K Deng.

31 records · Page 2Linked to original sources
PubMed1999

[Cloning and sequencing analysis of rice stripe virus genome segment 4 of Chinese isolate Y].

The cDNA fragment covering full-length sequence of RStV RNA4 of Yunnan isolate in China was obtained by RT-PCR. The PCR-derived fragment was then cloned into vector pCRII. The cloned cDNA was sequenced. Comparison of the nucleotide and deduced amino acid sequences with those of the Japanese isolate T was made. The results showed that at the nucleotides level, vORF, vcORF and the intergenic region had 94.9%, 94.1% and 86.1% identity respectively, the 5'-untranslational region was exactly the same as that of Japanese isolate T, while the 3'-terminal sequence had 96.1% identity, differing by two nucleotides; at the amino acid level, vORF and vcORF had 99.4% and 98.3% identity respectively. Therefore, as well as being exactly the same size for the two isolates, the amino acid sequences of the coding regions and the 5'- and 3'-terminal sequences were well conserved. Our results indicated that the Chinese isolate is closely related to the Japanese isolate T.

Amino Acid Sequence↗
PubMed1998

Activation of a matrix processing peptidase from the crystalline cytochrome bc1 complex of bovine heart mitochondria.

No mitochondrial processing peptidase (MPP) activity is detected in crystalline bovine heart mitochondrial cytochrome bc1 complex, which possesses full electron transfer activity. However, when the complex is treated with increasing concentrations of Triton X-100 at 37 degreesC, the electron transfer activity decreases, whereas peptidase activity increases. Maximum MPP activity is obtained when the electron transfer activity in the complex is completely inactivated with 1.5 mM of Triton X-100. This result supports our suggestion that the lack of MPP activity in the mammalian cytochrome bc1 complex is because of binding of an inhibitor polypeptide to the active site of MPP located at the interface of core subunits I and II. This suggestion is based on the three-dimensional structural information for the bc1 complex and the sequence homology between subunits of MPP and the core subunits of the beef complex. Triton X-100, at concentrations that disrupt the structural integrity of the bc1 complex as indicated by the loss of its electron transfer activity, weakens the binding of inhibitor polypeptide to the active site of MPP in core subunits, thus activating MPP. The Triton X-100-activated MPP is pH-, buffer system-, ionic strength-, and temperature-dependent. Maximum activity is observed with an assay mixture containing 15 mM Tris-HCl buffer at neutral pH (6.5-8.5) and at 37 degreesC. Activated MPP is completely inhibited by metal ion chelators such as EDTA and o-phenanthroline and partially inhibited by myxothiazol (58%), ferricyanide (28%), and dithiothreitol (81%). The metal ion chelator-inhibited activity can be partially restored by the addition of divalent cations such as Zn2+ (68%), Mg2+ (44%), Mn2+ (54%), Co2+ (62%), and Fe2+ (92%), indicating that metal ion is required for MPP activity. The cleavage site specificity of activated MPP depends more on the length of amino acid sequence from the mature protein portion and less on the presequence portion, when a synthetic peptide composed of NH2-terminal residues of a mature protein and the COOH-terminal residues of its presequence is used as a substrate.

Amino Acid Sequence↗
PubMed1996

The gene encoding bone morphogenetic protein 8B is required for the initiation and maintenance of spermatogenesis in the mouse.

Bone morphogenetic protein 8B (BMP8B) is a member of the TGFbeta superfamily of growth factors. In the mouse, Bmp8b is expressed in male germ cells of the testis and trophoblast cells of the placenta, suggesting that it has a role in spermatogenesis and reproduction. To investigate these possibilities, we have generated mice with a targeted mutation in Bmp8b. Here, we show that homozygous Bmp8b(tm1blh) mutant males exhibit variable degrees of germ-cell deficiency and infertility. Detailed analysis reveals two separable defects in the homozygous mutant testes. First, during early puberty (2 weeks old or younger) the germ cells of all homozygous mutants either fail to proliferate or show a marked reduction in proliferation and a delayed differentiation. Second, in adults, there is a significant increase in programmed cell death (apoptosis) of spermatocytes, leading to germ-cell depletion and sterility. Sertoli cells and Leydig cells appear relatively unaffected in mutants. This study therefore provides the first genetic evidence that a murine germ cell-produced factor, BMP8B, is required for the resumption of male germ-cell proliferation in early puberty, and for germ-cell survival and fertility in the adult.

Animals↗
PubMed1996

[Water soluble contents of Chinese drug beimu, the bulbs of Fritillaria plants].

Based on platelet aggregation induced by platelet activating factor (PAF), the active fraction with inhibiting effect was screened from four species of Chinese drung Beimu, the bulbs of Fritillaria przewalskii, F. ussurienis, F. anhuiensis and F. thunbergii. According to the experimental results, the active water soluble fraction of F. ussuriensis was further studied. Two nucleosides, thymidine and adenosine were isolated. Platelet aggregation assay shows that adenosine is the chief aggregation inhibitor with 1% = 42 at 5 microns. It is suggested that nucleosides may be the other type of active constituent besides alkaloids in the Fritillaria plants.

Adenosine↗
PubMed1995

Cloning, gene sequencing, and expression of the small molecular mass ubiquinone-binding protein of mitochondrial ubiquinol-cytochrome c reductase.

The cDNA encoding QPc-9.5 kDa (subunit VII) of bovine heart mitochondrial ubiquinol-cytochrome c reductase was cloned and sequenced. This cDNA is 665 base pairs long with an open reading frame of 246 base pairs that encodes an 81-amino acid mature QPc-9.5 kDa. The insert contains 395 base pairs of a 3'-noncoding sequence with a poly(A) tail. The amino acid sequence of QPc-9.5 kDa deduced from this nucleotide sequence is the same as that obtained by protein sequencing except that residue 61 is tryptophan instead of cysteine. The QPc-9.5 kDa was overexpressed in Escherichia coli JM109 cells as a glutathione S-transferase fusion protein (GST-QPc) using the expression vector, pGEX/QPc. The yield of soluble active recombinant GST-QPc fusion protein depends on the induction growth time, temperature, and medium. Maximum yield of recombinant fusion protein was obtained from cells harvested 3 h postinduction of growth at 27 degrees C on LB medium containing betaine and sorbitol. QPc-9.5 kDa was released from the fusion protein by proteolytic cleavage with thrombin. Isolated recombinant QPc-9.5 kDa showed one protein band in SDS-polyacrylamide gel electrophroesis corresponding to subunit VII of mitochondrial ubiquinol-cytochrome c reductase. Although the isolated recombinant QPc-9.5 kDa is soluble in aqueous solution, it is in a highly aggregated form, with an apparent molecular mass of over 1 million. Addition of detergent deaggreates the isolated protein to the monomeric state, suggesting that the recombinant protein exists as a hydrophobic aggregation in aqueous solution. The recombinant QPc-9.5 kDa binds ubiquinone and shows a spectral blue shift. Upon titration of the recombinant protein with ubiquinone, a saturation behavior is observed, suggesting that the binding is specific and that the recombinant protein may be in the functionally active state.

Amino Acid Sequence↗
PubMed1994

[CT analysis on correlation of parasagittal sinus and parafalx meningiomas with sagittal sinus and falx].

The computed tomographic characteristics of 59 cases of parasagittal sinus and parafalx meningiomas which were verified in operation and pathology are analysed. They were found as follows: (1) the striding sign of the tumor for the superior sagittal sinus and/or falx; (2) the smooth sign of the interior edge of the tumor; (3) the turning sign of the falx for one side of the tumor; and (4) the thickness and density increasing sign of the falx and/or sagittal. Based on the operation findings, the pathologic bases and clinical values are also discussed.

Adult↗
PubMed1994

[CT diagnosis of primary cerebral lymphoma--report of 2 cases].

CT findings of 2 patients with primary cerebral lymphoma were presented with a literature review of the CT manifestations of primary cerebral lymphoma. On the plain CT scan, most of lymphomas were either hyper- or isodense, well demarcated, and had variable surrounding edema. The tumors were mostly situated in the deep structures of brain: the basal ganglia, corpus callosum, periventricular white matter and vermis of cerebellum. On the postcontrast CT scan, cerebral lymphomas showed a homogeneous contrast enhancement. Ring enhancement, occasionally gyral enhancement also may be seen. On the CT scan, primary cerebral lymphomas were usually misdiagnosed as glioma, meningioma, metastases and abscess. The difference between lymphoma and the above lesions was discussed.

Adult↗
PubMed1994

[The causes responsible for recurrence of pituitary adenomas and an evaluation of reoperation effects].

Four hundred and twenty one cases of transfrontal removal of pituitary adenomas were presented. Of these 23 had recurrence of tumor which was confirmed by reoperation and histopathological examination. The rate of recurrence decreased while the patients' age increased. Incomplete removal of the tumor tissue was one of the most important causes of recurrence. Invasiveness was another important cause. Most of the tumors in this series were large and had pathologically proven invasiveness. At the reoperations, there were evidences of worse invasiveness, especially the infiltration of adenomas into the capsules and adjacent structures. There was a case of Nelson's syndrome, suggesting the endocrine causes of recurrence. Apparent adhesion and topographic disorders were found during reoperation, improvement of visual impairment decreased obviously, and the mortality rate increased; therefore, the reoperations should be decided with great deliberation.

Adenoma, Chromophobe↗
PubMed1993

[Computed tomography in the diagnosis of intracranial trigeminal neuroma].

CT scans of 12 cases of intracranial trigeminal neuroma were presented. Three of the neuromas were located in petrous apex-middle cranial fossa, two in posterior cranial fossa, and 7 in both the middle and posterior cranial fossae. The tumors appeared hypo- and isodense on the plain CT scan. After contrast infusion, all tumors were well circumscribed with marked enhancement, which was homogeneous, inhomogeneous or circular. None of the trigeminal neuroma had surrounding brain edema. Of 12 cases, 10 showed change of cranial bones, which included dilatation of Meckle's cave and destructions of petrous apex, clivus and the bottom of middle cranial fossa. The tumor in one case extended to paranasopharyngeal space from the bottom of middle cranial fossa, Various features of trigeminal neuroma on CT were reviewed. Also presented were the author's experiences in differentiating intracranial trigeminal neuroma from meningiom, from pituitary adenoma spreading to parasella and glioma adjacent to cranial bottom in middle cranial fossa, and from acoustic neuroma, meningioma, cholesteatoma in cerebellopontine angle.

Adult↗
PubMed1990

[Diagnosis value of lateral pharyngeal roentgenography in snoring disease].

In this paper, X-ray findings of the lateral pharynx before uvulopalatopharyngoplasty in 14 cases of snoring disease were studied. The results are as follows. There is less than 5 mm in anterior-posterior airway of pharyngeal cavity (13 cases), and 8 mm (1 case), in diameter. Minimum 2 mm, average 4.4 mm. There is less than 25 mm length of uvula (7 cases), 28-35 mm (7 cases). Minimum 22 mm, average length is 27.9 mm. Shape of uvula is thick and long (12 cases), thick and short 1 case, thin and long 1 case. The etiology, abnormal X-ray finding and X-ray examination of the lateral pharynx, etc. in snoring disease have been discussed.

Adult↗
PubMed1989

[Effects of ipratropium bromide (IPB) and its combination with salbutamol sulfate (SAS) in acute asthmatic attack].

34 patients with acute asthmatic attack were studied in double-blind, randomized and crossover manner. Each of them was treated with following two protocols during two sequential days: 0.5 mg of ipratropium bromide (IPB), followed by 5 mg of salbutamol sulfate (SAS) 75 minutes later; or 5 mg of SAS, followed by another dose 35 minutes late. The drugs were delivered via a jet nebulizer. The effects and side-effects of the treatment were evaluated immediately before the first inhalation and at peak of bronchodilatation (60-75 minutes after IPB or 20-35 minutes after SAS). Compared with inhaled SAS, IPB produced considerable improvement in central airway parameters such as forced expiratory volume in one second (FEV1) peak expiratory flow (PEF) and respiratory resistance (Rrs) (P greater than 0.05), but less improvement in peripheral airway parameters such as forced vital capacity (FVC) and maximal mid-expiratory flow (MMEF) (P less than 0.01). The sequential inhaled SAS after IPB improved all five parameters (P less than 0.01), but the repeated dose of SAS increased only MMEF (P less than 0.01). Compared with double-dose SAS, the sequential treatment with IPB and SAS 1 ed to considerable improvement in FVC and MMEF (P greater than 0.05), but greater improvement in FEV1, PEF and Rrs (P less than 0.01). Heart (rate and tremor scores after two doses of SAS increased significantly (P less than 0.01). It is concluded that IPB alone is less effective than beta-adrenoceptor agonist, but its combination with SAS would be an effective and safe treatment in acute asthmatic attack.

Adult↗
PubMed1989

[Pneumococcal pneumonia: a report of 100 cases].

This paper reports 100 cases of etiologically proved pneumococcal pneumonia. It is shown that Gram's stain smear and culture of sputum are still useful in the diagnosis of the disease but are easily influenced by antibiotics. Whereas coagglutination, a newly developed procedure in detecting pneumococcal capsular antigens, is relatively independent to antibiotic therapy. Moreover, it is rapid, convenient and sensitive. Both Gram's stain smear and coagglutination may confirm early diagnosis and are valuable in the initial treatment of the disease. If unhospitalized patients with acute pneumonia are checked routinely with these methods and samples are collected before administration of antibiotics, etiological diagnosis of pneumococcal pneumonia will be confirmed in more cases. The data from 100 cases of pneumococcal pneumonia demonstrates that pneumococcal pneumonia remains the most common type of community-acquired pneumonias in this country. Its clinical manifestations have not changed greatly since 1950s but the age of the afflicted tents to be greater especially in those with underlying diseases. There are two common types of roentgenographic manifestations, i.e., lobar consolidation and bronchopneumonia, the former is still overwhelming in those under sixty and the later is more frequently seen in those over sixty. Penicillin G showed good clinical effects in treating pneumococcal pneumonia and all the 57 strains tested were sensitive in vitro. Therefore, penicillin G is still the drug of first choice in treating pneumococcal pneumonia.

Adolescent↗