[Changes in coagulation and fibrinolysis system in lung infection].
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Aged↗
Biomedical subjects
Yi Xu
Publications and source records attributed to Yi Xu.
[Psychological status and its influencing factors on patients undergoing electrophysiology studies and radiofrequency catheter ablation].
OBJECTIVE: To study the psychological status and its influencing factors in patients before and after electrophysiology studies and radiofrequency catheter ablation (RFCA). METHODS: 125 inpatients (71 men, 54 women, mean age 42.91 years +/- 16.1 years) who underwent a scheduled electrophysiology studies and RFCA for the first time and fulfilled entry criteria, were enrolled. They were randomly assigned to receiving either a consent which did not detail specific risk (group B) regarding the procedure or one that detailed the risks (group A). All patients were examined by the Chinese version of Symptom Check List-90 (SCL-90) within 24 hours before the procedure (after the consent) and on the third day after. RESULTS: (1) Before the electrophysiology studies and RFCA, scores of anxiety and phobic anxiety constructs were higher than the norm. After the procedure, no specific construct score became higher. (2) After the procedure, patients showed a significantly decrease in the scores of obsessive-compulsive, depression, anxiety, hostility, phobic anxiety, paranoid ideation, psychotism constructs, global severity index, total positive symptoms and positive symptom severity index. (3) Women scored higher on somatization, depression, anxiety, phobic anxiety constructs, global severity index and positive symptom total before the procedure. (4) Detail informed consent was not associated with increased mental symptoms when compared with consent that did not detail specific risks. CONCLUSIONS: In this study, patients showed slightly anxiety and phobic anxiety before electrophysiology studies and RFCA with women having more mental symptoms before the procedure that called for special attention. Detail information including the course and specific risk regarding the procedure was not associated with increased psychological symptoms. It was suggested that the patients should receive detail information before electrophysiology studies and RFCA.
Adolescent↗
[Treatment of posterior-communicating wide-necked aneurysms with endovascular stent and Guglielmi detachable coils].
OBJECTIVE: To summarize our clinical experience in treating posterior-communicating wide-necked aneurysms using endovascular stent and Guglielmi detachable coils (GDCs). METHODS: The coronary stents were implanted across the neck of 32 posterior-communication wide-necked aneurysms. Microcatheters were introduced into the aneurysm sac through stent mesh, GDCs were used to embolize aneurysms. RESULTS: All operations were successful. Total occlusion was achieved in 26 patients, over 90% in 4, 60 - 70% in 2. The patients were perfectly recovered with patency of the parent arteries. CONCLUSION: Endovascular therapy combined with stent implatation and GDC placement is a valid approach to the treatment of posterior-communication wide-necked aneurysms.
Adult↗
Protection of human lung cells against hyperoxia using the DNA base excision repair genes hOgg1 and Fpg.
Hyperoxia causes pulmonary toxicity in part by injuring alveolar epithelial cells. Previous studies have shown that toxic oxygen-derived species damage DNA and this damage is recognized and repaired by either human enzyme 8-oxoguanine DNA glycosylase (hOgg1) or Escherichia coli enzyme formamidopyrimidine DNA glycosylase (Fpg). To determine whether these DNA repair proteins can reduce O(2)-mediated DNA damage in lung cells, A549 lung epithelial cells were transduced with either hOgg1 or Fpg using a retroviral vector containing enhanced green fluorescent protein. Expression of each gene in the transduced cells was confirmed by fluorescent microscopy, Northern blotting, Western blotting, and an enzymatic oligonucleotide cleavage assay. A549 cells expressing either hOgg1 or Fpg were protected from hyperoxia as evidenced by a decrease in DNA damage and a corresponding increase in cell survival. Further, we determined that overexpression of hOgg1 or Fpg partially mitigated the toxic effects of hydrogen peroxide in lung cells. Our data suggest that increased expression of DNA base excision repair genes might represent a new approach for protecting critical lung cells from the toxic effects of hyperoxia.
Cell Survival↗
Mutations in the rho transcription termination factor that affect RNA tracking.
Model studies have identified 16 conserved positively charged amino acids that form a positive strip pointing toward the center hole of Rho. Fourteen residues were individually changed to either an alanine or a glycine and one to a glutamate. Residues Arg(269), Arg(272), Lys(283), Arg(296), Lys(298), and Arg(299) form a subdomain (locus) located N-terminal to (above) the ATP hydrolysis domain (P-loop) and mutations in these residues led to either inactive Rho or to proteins displaying decreased k(cat) for poly(C)-dependent ATP hydrolysis, increased K(m) for ribo(C)(10) activation, and decreased transcription termination efficiencies (57-77%) compared with wild-type Rho. Residues Arg(347), Lys(348), Lys(352), and Arg(353) form a subdomain (locus) C-terminal to (below) the ATP hydrolysis domain, and mutations in these residues also show a decreased k(cat) for poly(C)-dependent ATP hydrolysis, an increased K(m) for ribo(C)(10) activation, and a 50-70% decrease in transcription termination, compared with wild-type Rho. Residues Arg(212) and Lys(336) surround the ATP hydrolysis domain, and mutations in these residues also altered the kinetic properties of Rho. We conclude that the secondary RNA-tracking site consists of amino acids whose putative orientation faces the central hole in Rho and in part reside in two clusters of positively charged residues located above and below the ATP hydrolysis domain.
Adenosine Triphosphate↗
Crystallization and preliminary X-ray crystallographic analysis of Ace: a collagen-binding MSCRAMM from Enterococcus faecalis.
Ace is a collagen-binding bacterial cell surface adhesin from Enterococcus faecalis. The collagen-binding domain of Ace (termed Ace40) and its truncated form Ace19 have been crystallized by the vapor-diffusion hanging-drop method. Ace19 was crystallized in two different crystal forms. A complete 1.65 A data set has been collected on the orthorhombic crystal form with unit cell parameters a=38.43 b=48.91 and c=83.73 A. Ace40 was crystallized in the trigonal space group P3(1)21 or P3(2)21 with unit cell parameters a=b=80.24, c=105.91 A; alpha=beta=90 and gamma=120 degrees. A full set of X-ray diffraction data was collected to 2.5 A. Three heavy atom derivative data sets have been successfully obtained for Ace19 crystals and structural analysis is in progress.
Adhesins, Bacterial↗
Streptococcal Scl1 and Scl2 proteins form collagen-like triple helices.
The collagens are a family of animal proteins containing segments of repeated Gly-Xaa-Yaa (GXY) motifs that form a characteristic triple-helical structure. Genes encoding proteins with repeated GXY motifs have also been reported in bacteria and phages; however, it is unclear whether these prokaryotic proteins can form a collagen-like triple-helical structure. Here we used two recently identified streptococcal proteins, Scl1 and Scl2, containing extended GXY sequence repeats as model proteins. First we observed that prior to heat denaturation recombinant Scl proteins migrated as homotrimers in gel electrophoresis with and without SDS. We next showed that the collagen-like domain of Scl is resistant to proteolysis by trypsin. We further showed that circular dichroism spectra of the Scl proteins contained features characteristic of collagen triple helices, including a positive maximum of ellipticity at 220 nm. Furthermore the triple helices of Scl1 and Scl2 showed a temperature-dependent unfolding with melting temperatures of 36.4 and 37.6 degrees C, respectively, which resembles those seen for collagens. We finally demonstrated by electron microscopy that the Scl proteins are organized into "lollipop-like" structures, similar to those seen in human proteins with collagenous domains. This implies that the repeated GXY tripeptide motif is a structural indicator of collagen-like triple helices in proteins from such phylogenetically distant sources as bacteria and humans.
Alleles↗
Perceived pitch of synthesized voice with alternate cycles.
Both in normal speech voice and in some types of pathological voice, adjacent vocal cycles may alternate in amplitude or period, or both. When this occurs, the determination of voice fundamental frequency (defined as number of vocal cycles per second) becomes difficult. The present study attempts to address this issue by investigating how human listeners perceive the pitch of alternate cycles. As stimuli, vowels /a/ and /i/ were synthesized with fundamental frequencies at 140 Hz and 220 Hz, and the effect of alternate cycles was simulated with both amplitude- and frequency-modulation of the glottal volume velocity waveform. Subjects were asked to judge the pitch of the modulated vowels in reference to vowels without modulation. The results showed that (a) perceived pitch became lower as the amount of modulation increased, and the effect seems to be more dramatic than would be predicted by existing hypotheses, (b) perceived pitch differed across vowels, fundamental frequencies, and modulation types, that is, amplitude versus frequency modulation, and (c) the prediction of perceived pitch was best made in the frequency domain in terms of subharmonic-to-harmonic ratio. These findings provide useful information on how we should assess the pitch of alternate cycles. They may also be helpful in developing more robust pitch determination algorithms.
Adolescent↗
A complete sequence of the T. tengcongensis genome.
Thermoanaerobacter tengcongensis is a rod-shaped, gram-negative, anaerobic eubacterium that was isolated from a freshwater hot spring in Tengchong, China. Using a whole-genome-shotgun method, we sequenced its 2,689,445-bp genome from an isolate, MB4(T) (Genbank accession no. AE008691). The genome encodes 2588 predicted coding sequences (CDS). Among them, 1764 (68.2%) are classified according to homology to other documented proteins, and the rest, 824 CDS (31.8%), are functionally unknown. One of the interesting features of the T. tengcongensis genome is that 86.7% of its genes are encoded on the leading strand of DNA replication. Based on protein sequence similarity, the T. tengcongensis genome is most similar to that of Bacillus halodurans, a mesophilic eubacterium, among all fully sequenced prokaryotic genomes up to date. Computational analysis on genes involved in basic metabolic pathways supports the experimental discovery that T. tengcongensis metabolizes sugars as principal energy and carbon source and utilizes thiosulfate and element sulfur, but not sulfate, as electron acceptors. T. tengcongensis, as a gram-negative rod by empirical definitions (such as staining), shares many genes that are characteristics of gram-positive bacteria whereas it is missing molecular components unique to gram-negative bacteria. A strong correlation between the G + C content of tDNA and rDNA genes and the optimal growth temperature is found among the sequenced thermophiles. It is concluded that thermophiles are a biologically and phylogenetically divergent group of prokaryotes that have converged to sustain extreme environmental conditions over evolutionary timescale.
Bacillaceae↗
Maximum speed of pitch change and how it may relate to speech.
How fast speakers can change pitch voluntarily is potentially an important articulatory constraint for speech production. Previous attempts at assessing the maximum speed of pitch change have helped improve understanding of certain aspects of pitch production in speech. However, since only "response time"--time needed to complete the middle 75% of a pitch shift--was measured in previous studies, direct comparisons with speech data have been difficult. In the present study, a new experimental paradigm was adopted in which subjects produced rapid successions of pitch shifts by imitating synthesized model pitch undulation patterns. This permitted the measurement of the duration of entire pitch shifts. Native speakers of English and Mandarin participated as subjects. The speed of pitch change was measured both in terms of response time and excursion time-time needed to complete the entire pitch shift. Results show that excursion time is nearly twice as long as response time. This suggests that physiological limitation on the speed of pitch movement is greater than has been recognized. Also, it is found that the maximum speed of pitch change varies quite linearly with excursion size, and that it is different for pitch rises and falls. Comparisons of present data with data on speed of pitch change from studies of real speech found them to be largely comparable. This suggests that the maximum speed of pitch change is often approached in speech, and that the role of physiological constraints in determining the shape and alignment of F0 contours in speech is probably greater than has been appreciated.
Adolescent↗
AT(1) and AT(2) receptor expression and blockade after acute ischemia-reperfusion in isolated working rat hearts.
We assessed ANG II type 1 (AT(1)) and type 2 (AT(2)) receptor (R) expression and functional recovery after ischemia-reperfusion with or without AT(1)R/AT(2)R blockade in isolated working rat hearts. Groups of six hearts were subjected to global ischemia (30 min) followed by reperfusion (30 min) and exposed to no drug and no ischemia-reperfusion (control), ischemia-reperfusion and no drug, and ischemia-reperfusion with losartan (an AT(1)R antagonist; 1 micromol/l), PD-123319 (an AT(2)R antagonist; 0.3 micromol/l), N(6)-cyclohexyladenosine (CHA, a cardioprotective adenosine A(1) receptor agonist; 0.5 micromol/l as positive control), enalaprilat (an ANG-converting enzyme inhibitor; 1 micromol/l), PD-123319 + losartan, ANG II (1 nmol/l), or ANG II + losartan. Compared with controls, ischemia-reperfusion decreased AT(2)R protein (Western immunoblots) and mRNA (Northern immunoblots, RT-PCR) and impaired functional recovery. PD-123319 increased AT(2)R protein and mRNA and improved functional recovery. Losartan increased AT(1)R mRNA (but not AT(1)R/AT(2)R protein) and impaired recovery. Other groups (except CHA) did not improve recovery. The results suggest that, in isolated working hearts, AT(2)R plays a significant role in ischemia-reperfusion and AT(2)R blockade induces increased AT(2)R protein and cardioprotection.
Adenosine↗
Escherichia coli FPG and human OGG1 reduce DNA damage and cytotoxicity by BCNU in human lung cells.
The pulmonary complications of 1,3-N,N'-bis(2-chloroethyl)-N-nitrosourea (BCNU) are among the most important dose-limiting factors of BCNU-containing cancer chemotherapeutic regimens. BCNU damages DNA of both cancer cells and normal cells. To increase the resistance of lung cells to BCNU, we employed gene transfer of Escherichia coli formamidopyrimidine-DNA glycosylase (FPG) and human 8-oxoguanine-DNA glycosylase (hOGG1) to A549 cells, a lung epithelial cell line, using a bicistronic retroviral vector, pSF91-RE, that encoded both FPG/hOGG1 and an enhanced green fluorescent protein. The transduced epithelial cells were sorted by flow cytometry, and expression of FPG/hOGG1 protein was determined by the level of FPG/hOGG1 RNA and enzyme activity. The single-cell gel electrophoresis (comet assay) measured DNA damage induced by BCNU. FPG/hOGG1-expressing A549 cells incubated with 40-500 microg/ml BCNU exhibited significantly less DNA damage than vector-transduced cells. In addition, FPG- and/or hOGG1-expressing cells incubated with 10-40 microg/ml BCNU showed at least a 25% increase in cell survival. Gene transfer of FPG/hOGG1 reduced BCNU-induced DNA damage and cytotoxicity of cultured lung cells and may suggest a new mechanism to reduce BCNU pulmonary toxicity.
Antineoplastic Agents, Alkylating↗
[Application of tissue flaps in repair of limbs injuries].
OBJECTIVE: To summarize and analyze the main point on the reconstruction of traumatic tissue defects of limbs with vascularized skin and multi-tissue flaps. METHODS: Sixty-seven cases of traumatic tissue defects of limbs were reconstructed with 14 kinds of skin or multi-tissue flaps. The operative methods included local transposition, cross-transposition with vessel pedicles and vessel anastomosed free transplantation. RESULTS: Forty cases with vessel anastomosed free transplantation and 26 cases with local or cross-transposition of vessel pedicled flaps were survived. In the followed up cases, 53 cases were satisfied with the outward appearance of the skin flaps. All the cases with bone flap or skin-bone flap resulted in union. And the cases with motor nerve anastomosed myocutaneous flap transplantation had recovered to 2-3 grade muscle contraction ability. CONCLUSION: It is important that the appropriate flaps and operative methods should be chosen according to the size, location, depth and structure of the tissue defects. To raise the success rate and to gain better operation effect, the correct manipulation in operation and the rational postoperative treatment are necessary.
Adolescent↗
Increased AT2R protein expression but not increased apoptosis during cardioprotection induced by AT1R blockade.
BACKGROUND: The angiotensin II type 2 receptor (AT2R) is considered to be antigrowth and to mediate apoptosis in several cell types. Whether AT2R upregulation, associated with angiotensin II type 1 receptor (AT1R) blockade and cardioprotection after ischemia-reperfusion (IR), might not result in increased cardiomyocyte (CM) apoptosis has not been documented. OBJECTIVES: To determine whether increased AT2R protein expression, during AT1R blockade after acute IR, is associated with no increase in CM apoptosis. MATERIALS AND METHODS: The recovery of left ventricular (LV) mechanical function after acute IR (30 min of ischemia, 40 min of reperfusion) was measured in isolated Langendorff rat hearts following pretreatment with the AT1R antagonist candesartan (CN) (CN 10 nmol/L) for 40 min before ischemia. The authors established with an initial dose-response curve using escalating concentrations of CN that 10 nmol/L abrogated vasoconstriction induced by angiotensin II (0.1 mmol/L). AT1R and AT2R protein expression (Western immunoblot), CM apoptosis (terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick end-labelling assay and nuclear morphology) and apoptotic markers (Bax, Bcl-2, caspase-3, p53) were assessed in LV tissue. RESULTS: Compared with IR controls, CN improved peak systolic pressure, LV developed pressure and positive dp/dt, and increased AT2R (not AT1R) protein, but did not change the level of apoptosis or the expression of Bax, Bcl-2, caspase-3 or p53. CN also increased AT2R protein after ischemia alone but did not change CM apoptosis or expression of the markers. CONCLUSIONS: Increased AT2R protein expression during AT1R blockade after IR in the isolated Langendorff rat heart is associated with cardioprotection but no increase in CM apoptosis.
Angiotensin Receptor Antagonists↗
Increased AT(2)R protein expression but not increased apoptosis during cardioprotection induced by AT(1)R blockade.
BACKGROUND: The angiotensin II type 2 receptor (AT2R) is considered to be antigrowth and to mediate apoptosis in several cell types. Whether AT2R upregulation, associated with angiotensin II type 1 receptor (AT1R) blockade and cardioprotection after ischemia-reperfusion (IR), might not result in increased cardiomyocyte (CM) apoptosis has not been documented. OBJECTIVES: To determine whether increased AT2R protein expression, during AT1R blockade after acute IR, is associated with no increase in CM apoptosis. MATERIALS AND METHODS: The recovery of left ventricular (LV) mechanical function after acute IR (30 min of ischemia, 40 min of reperfusion) was measured in isolated Langendorff rat hearts following pretreatment with the AT1R antagonist candesartan (CN) (CN 10 nmol/L) for 40 min before ischemia. The authors established with an initial dose-response curve using escalating concentrations of CN that 10 nmol/L abrogated vasoconstriction induced by angiotensin II (0.1 mol/L). AT1R and AT2R protein expression (Western immunoblot), CM apoptosis (terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick end-labelling assay and nuclear morphology) and apoptotic markers (Bax, Bcl-2, caspase-3, p53) were assessed in LV tissue. RESULTS: Compared with IR controls, CN improved peak systolic pressure, LV developed pressure and positive dp/dt, and increased AT2R (not AT1R) protein, but did not change the level of apoptosis or the expression of Bax, Bcl-2, caspase-3 or p53. CN also increased AT2R protein after ischemia alone but did not change CM apoptosis or expression of the markers. CONCLUSIONS: Increased AT2R protein expression during AT1R blockade after IR in the isolated Langendorff rat heart is associated with cardioprotection but no increase in CM apoptosis.
Analysis of Variance↗
[Expression of p27 protein and cyclinD1 in laryngeal carcinoma].
OBJECTIVE: To find out whether the expression of p27 and cyclin D1 is different in laryngeal squamous cell carcinoma and the edge tissues, and to study the relationship between the expression of p27 and cyclin D1 with the clinic character in patients with laryngeal squamous cell carcinoma. METHOD: An immunohistochemistry method was used to study the expression of p27 protein and cyclinD1 in 38 laryngeal squamous cell carcinoma and the edge tissues. RESULT: The expression of p27 protein and cyclin D1 was significantly different between the laryngeal carcinoma and the edge tissue. Low expression of p27 and over expression of cyclinD1 was associated with the liability of lymph node metastasis and the poor prognosis for patient with laryngeal squamous cell carcinoma. An interesting observation was that the inverse expression between p27 and cyclinD1 might play an important role in laryngeal squamous cell carcinoma. CONCLUSION: p27 protein and cyclinD1 in laryngeal carcinoma is apparently a significance predictor of survival.
Aged↗
Prosodic and lexical-syntactic aspects of the therapeutic register.
The current study examined features of speech addressed to younger versus older and impaired versus normal listeners and explored factors that might motivate speech modification in the therapeutic register. Ten speech-language clinicians in training were engaged in a simulated storytelling task and produced narrations to four imaginary listener groups. Results revealed that clinicians modified their speech at multiple levels according to both the age and the diagnostic status of their listeners. As a group, the clinicians demonstrated decreased speaking rate, elongation of pauses, and use of shorter and less complex sentences when speaking to young children and individuals with language impairments. Despite these group trends there was notable individual variability between clinicians. Findings from this constrained experimental context may be extended to real life clinician-client interactions and have implications for therapeutic success.
Acoustics↗