Search PubMed⌕ Search

Biomedical subjects

Y C Liu

Publications and source records attributed to Y C Liu.

At least 55 records · Page 3Linked to original sources

Implementation of clinical guidelines through an electronic medical record: physician usage, satisfaction and assessment.

CONTEXT: We developed and evaluated the Emergency Department Expert Charting System (EDECS) to provide real-time guidance regarding the care of low back pain in adults, fever in children, and occupational exposure to blood and body fluids in health care workers, by embedding clinical guidelines within an electronic medical record. OBJECTIVE: To describe the behaviors and attitudes of physicians who used EDECS. DESIGN: Pre-post questionnaires were used to assess physician attitudes. Time studies of the intervention phase were observational, using clocks embedded in the software. PARTICIPANTS: One hundred and forty two residents and interns in emergency, pediatric, internal, and family medicine and patients with the above-mentioned complaints. MAIN OUTCOME MEASURES: Physician utilization of EDECS, time spent using EDECS, physician satisfaction and beliefs. RESULTS: Eighty four percent of the 142 eligible physicians used EDECS at least once. Five hundred and ninety one of 789 (75%) eligible cases were completed using EDECS. Median session time decreased from 12 min for session 1, to 5.5 min for sessions 16 and above. Physicians generally agreed that care with EDECS was better than standard care, particularly with respect to documentation. There was, however, considerable heterogeneity in belief among complaints. CONCLUSIONS: These data illuminate both the potentials of computer-assisted decision making and the need for context-specific approaches when attempting to implement guidelines.

Attitude of Health Personnel↗

The expression of chicken NOV, a member of the CCN gene family, in early stage development.

The nephroblastoma overexpressed gene, NOV, is a member of the CCN gene family. We investigated the NOV gene expression pattern in the chicken during early stage embryogenesis. Several embryonic structures showed a distinct expression pattern. The initial expression was detected in Hensen's node (Hamburger and Hamilton stage (HH) 5). The expression was noted in the presumptive notochord and floor plate forming cells. The expression on the left side was more elongated posteriorly, a type of left-right asymmetry. Chicken NOV gene expression in the forming notochord and floor plate was observed until HH 18. The expression was also detected in the ventral area of the mesencephalon and isthmus at HH 14-16.

Journal Article↗

Proteolysis-independent regulation of PI3K by Cbl-b-mediated ubiquitination in T cells.

Cbl-b, a ring-type E3 ubiquitin protein ligase, is implicated in setting the threshold of T lymphocyte activation. The p85 regulatory subunit of phosphatidylinositol 3 kinase (PI3K) was identified as a substrate for Cbl-b. We have shown that Cbl-b negatively regulated p85 in a proteolysis-independent manner. Cbl-b is involved in the recruitment of p85 to CD28 and T cell antigen receptor zeta through its E3 ubiquitin ligase activity. The enhanced activation of Cbl-b(-/-) T cells was suppressed by the inhibition of PI3K. The results suggest a proteolysis-independent function for Cbl-b in the modification of protein recruitment.

Adaptor Proteins, Signal Transducing↗

Effect of the long-acting tachykinin NK(1) receptor antagonist MEN 11467 on tracheal mucus secretion in allergic ferrets.

1. We investigated the effect of MEN 11467 ((1R,2S)-2-N[1(H)indol-3-yl-carbonyl]-1-N-[N(alpha)(p-tolylacetyl)-N(alpha)(methyl)-D-3-(2-naphthyl)alanyl]diaminocyclohexane) on tachykinin-induced mucus secretion in ferret trachea in vitro and determined its effect on secretion by tracheae from allergic ferrets in response to allergen challenge. 2. Repeated administration of [Sar(9),Met(O(2))(11)]-substance P ([Sar(9)]SP, 1 microM) maintained mucus output above control values for at least 1.75 h. MEN 11467 inhibited secretion in a concentration-dependent manner with maximal inhibition at 10 microM and an approximate IC(50) of 0.3 microM. Inhibition by MEN 11467 (0.1--10 microM) was maintained, to varying degree, for at least 1.75 h after washout in the continued presence of [Sar(9)]SP. 3. In electrically stimulated tracheae, tachykininergic neural secretion was virtually abolished by 1 microM MEN 11467. 4. In tracheae from ovalbumin-sensitised animals, repeated administration of ovalbumin maintained mucus output above controls for 1.5 h. MEN 11467 inhibited ovalbumin-induced secretion in a concentration-dependent manner, with complete inhibition at 1 microM. Inhibition by MEN 11467 (1 and 10 microM) was maintained, to varying degree, after drug washout for the 1.5 h of ovalbumin stimulation. 5. MEN 11467 1 microM did not affect secretion induced by either acetylcholine or histamine, whereas 10 microM MEN 11467 did inhibit agonist-induced secretion. 6. We conclude that, in ferret trachea in vitro, MEN 11467 at concentrations of 0.1--1 microM is a long acting and selective inhibitor of tachykininergic-induced mucus secretion, and may have therapeutic potential for bronchial hypersecretion associated with allergic conditions, for example in asthma.

Acetylcholine↗

Multicenter surveillance of antimicrobial resistance of major bacterial pathogens in intensive care units in 2000 in Taiwan.

A susceptibility surveillance study of 1,274 bacterial isolates recovered from various clinical specimens from patients in intensive care units (ICUs) of five major teaching hospitals was carried out from March, 2000, to June, 2000, in Taiwan. This study demonstrated a high rate (66%) of oxacillin resistance in Staphylococcus aureus (ORSA), a high rate of nonsusceptibility to penicillin (intermediate, 50% and highly resistant, 8%), and high rates of cefotaxime nonsusceptibility for S. pneumoniae (intermediate, 29% and resistant, 4%), Enterobacter cloacae (57%), Serratia marcescens (34%), and Citrobacter freundii (60%). High rate of ceftazidime nonsusceptibility for Pseudomonas aeruginosa (22%), and high rates of imipenem nonsusceptibility for P. aeruginosa (15%) and Acinetobacter baumannii (22%) were also found. The percentage (11.9%) of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli was greater than that (11.3%) for Klebsiella pneumoniae. Rates of quinupristin-dalfopristin nonsusceptibility for S. pneumoniae (42%), Enterococcus faecium (71%), and ORSA (39%) were high, but no vancomycin-resistant enterococci were found in this study. The resistance rates of some pathogen varied by institution or type of ICUs. Surveillance for antimicrobial resistance among bacterial pathogens in hospitals, particularly in ICU settings with a preexisting higher resistance burden, is mandatory in establishing and/or modifying guidelines for empirical treatment of severe infections in ICU patients caused by these antimicrobial-resistant pathogens.

Bacteria↗

Application of digital image analysis and flow cytometry to enumerate marine viruses stained with SYBR gold.

A novel nucleic acid stain, SYBR Gold, was used to stain marine viral particles in various types of samples. Viral particles stained with SYBR Gold yielded bright and stable fluorescent signals that could be detected by a cooled charge-coupled device camera or by flow cytometry. The fluorescent signal strength of SYBR Gold-stained viruses was about twice that of SYBR Green I-stained viruses. Digital images of SYBR Gold-stained viral particles were processed to enumerate the concentration of viral particles by using digital image analysis software. Estimates of viral concentration based on digitized images were 1.3 times higher than those based on direct counting by epifluorescence microscopy. Direct epifluorescence counts of SYBR Gold-stained viral particles were in turn about 1.34 times higher than those estimated by the transmission electron microscope method. Bacteriophage lysates stained with SYBR Gold formed a distinct population in flow cytometric signatures. Flow cytometric analysis revealed at least four viral subpopulations for a Lake Erie sample and two subpopulations for a Georgia coastal sample. Flow cytometry-based viral counts for various types of samples averaged 1.1 times higher than direct epifluorescence microscopic counts. The potential application of digital image analysis and flow cytometry for rapid and accurate measurement of viral abundance in aquatic environments is discussed.

Cyanobacteria↗

Cryptococcus laurentii fungemia in a premature neonate.

Cryptococcus spp. other than Cryptococcus neoformans are generally considered nonpathogenic to humans. There are only 15 case reports of disease in humans caused by Cryptococcus laurentii infection. Underlying diseases and predisposing risk factors seem to play an important role in these cases. Our patient is the first case of an extremely low birth weight infant with C. laurentii fungemia reported in the English literature. In our case, the MIC of amphotericin B for C. laurentii was 0.25 to 1 microg/ml and the patient had a good outcome following the administration of amphotericin B at 10 mg/kg combined with central venous catheter removal. There will undoubtedly be an increasing occurrence of unusual fungal infections accompanying further advances in medicine. A high degree of suspicion and improvements in the techniques for culture and identification will contribute to the earlier diagnosis and treatment of unusual fungal infections.

Adolescent↗

Vav-Rac1-mediated activation of the c-Jun N-terminal kinase/c-Jun/AP-1 pathway plays a major role in stimulation of the distal NFAT site in the interleukin-2 gene promoter.

Vav, a hematopoiesis-specific signaling protein, plays an important role in T-cell development and activation. Vav upregulates the expression of the interleukin-2 (IL-2) gene, primarily via activation of the distal NFAT site in the IL-2 gene promoter (NFAT-IL-2). However, since this site cooperatively binds NFAT and AP-1, the relative contribution of Vav to NFAT versus AP-1 activation has not been determined. Here, we studied the respective roles of the AP-1 and NFAT pathways in the T-cell receptor (TCR)-mediated, Vav-dependent activation of NFAT-IL-2. Although Vav stimulated the transcriptional activity of an NFAT-IL-2 reporter gene, it failed to stimulate the transcriptional or DNA-binding activities of an AP-1-independent NFAT site derived from the human gamma interferon gene promoter. Vav also did not stimulate detectable Ca(2+) mobilization and nuclear translocation of NFATc or NFATp. On the other hand, Vav induced the activation of Rac1 or Cdc42 and c-Jun N-terminal kinase (JNK), enhanced the transcriptional and DNA-binding activities of AP-1, and induced increased phosphorylation of c-Jun. Dominant-negative Vav and/or Rac1 mutants blocked the TCR-mediated stimulation of these events, demonstrating the physiological relevance of these effects. Vav also associated with Rac1 or Cdc42 in T cells, and anti-CD3 antibody stimulation enhanced this association. These findings indicate that a Rac1-dependent JNK/c-Jun/AP-1 pathway, rather than the Ca(2+)/NFAT pathway, plays the predominant role in NFAT-IL-2 activation by Vav.

Active Transport, Cell Nucleus↗

An outbreak of meningitis caused by Angiostrongylus cantonensis in Kaohsiung.

Eight Thai laborers developed meningitis after eating raw snails (Ampullarium canaliculatus) during the period from September 27 to October 6, 1998. The diagnosis of Angiostrongylus cantonensis infection was established in all patients by serologic studies of serum and cerebral spinal fluid (CSF). Clinical manifestations included meningitis, radiculitis and cranial nerve palsy. Symptoms included fever, headache, orbital pain, gastrointestinal upset, hyperesthesia, muscle weakness, skin rash and diplopia. Laboratory abnormalities included peripheral eosinophilia, CSF eosinophilia, transient elevation of liver enzymes and creatinine phosphokinase, elevation of IgE. No space occupying lesions were detected by magnetic resonance imaging of the brain. None of the patients developed severe sequelae during the 6-month follow-up except for occasional headache in one patient. This report also provides evidence that third stage larvae were present in the intermediate host, A. canaliculatus, which the laborers had eaten.

Adult↗

Transmission of human immunodeficiency virus through bone transplantation: a case report.

Human immunodeficiency virus (HIV) can be transmitted through tissue or organ transplantation. Since 1988, eight cases of bone transplantation-associated HIV infection have been reported. We describe a 34-year-old woman with osteoarthritis, who was hospitalized in 1996 because of painful locomotion and deformity in the right knee. An old fracture of the femur and genu varum in the right knee was repaired by open reduction and internal fixation, with allogeneic bone transplantation for defect reconstruction. Five months later, she presented at another hospital with pain and swelling of the right thigh, where screening for HIV was positive. The transmission was tracked to a 50-year-old man with no history of HIV screening, from whom the femoral head was procured when he underwent a hip replacement for left femoral neck fracture. This is the first reported case of HIV infection through bone transplantation in Taiwan, and the preventable nature of this transmission should be underscored.

Adult↗

Clinical characteristics of emphysematous pyelonephritis.

A total of 21 patients (20 women and one man) with emphysematous pyelonephritis (EPN), treated in the Kaohsiung Veterans General Hospital during the period from 1991 through 1999 were included in this study. All of the patients were diabetic. The most common symptoms or signs were fever/chills (80%) and costovertebral angle knocking pain (71%). Diagnosis was confirmed by the presence of gas in the parenchyma or paranephric space on plain X-ray of the abdomen or computed tomography. The left kidney (11 cases, 52%) was more frequently affected than the right one (nine cases, 43%), and both kidneys were involved in one case. Obstruction of the corresponding renoureteral unit was found in 19% of the patients, and renal or ureteral stone was found in 23% of the patients. One third of the patients had type I EPN, and two-thirds had type II EPN. Escherichia coli was the most commonly isolated organism, accounting for 61%, 76%, and 47% of isolates from blood, urine, and aspirated pus culture respectively. Prompt control of blood sugar was begun and intravenous antibiotics were given. Drainage was performed in 71% of the patients, and two persons required nephrectomy because of poor control of the infection or complications. Overall survival was 72%. Emphysematous pyelonephritis is a rare, life-threatening, suppurative infection of the renal parenchyma and perirenaL tissues. For successful management of EPN, appropriate medical treatment should be initiated, and immediate nephrectomy or drainage should not be delayed.

Adult↗

Comparative study of the efficacy and safety of valaciclovir versus acyclovir in the treatment of herpes zoster.

Acyclovir, a specific and selective inhibitor of the replication of Herpesviridae family, has well-documented efficacy and tolerability in the treatment of herpes zoster. Its limited oral bioavailability and short half-life, however, necessitates frequent dosing. Valaciclovir, the l-valyl ester of acyclovir, could be rapidly converted to acyclovir after oral administration, resulting in a three- to five-fold increase in acyclovir bioavailability compared with oral acyclovir in humans. Valaciclovir allows less frequent dosing and maintains the safety profiles of the parent drug. During the period from October 1996 through May 1998, a randomized, prospective study was performed in the Kaohsiung Veterans General Hospital to compare the safety and efficacy of valaciclovir with acyclovir in the treatment of herpes zoster in Taiwanese patients. Patients presenting with herpes zoster within 72 h after the onset of rash were enrolled and randomized to receive one of the following treatments: 1000 mg valaciclovir three times daily for 7 days or acyclovir 800 mg five times daily for 7 days. Patients were followed up for 29 days beginning with the start of therapy. A total of 57 patients were enrolled and randomized to receive valaciclovir (n = 32) or acyclovir (n = 25). Five patients in the valaciclovir group and three in the acyclovir group did not complete the study. The intent-to-treat analysis (57 patients) showed that valaciclovir significantly accelerated the resolution of herpes zoster-associated pain compared with acyclovir; on day 29, the valaciclovir group was 23% superior to the acyclovir group. There was no clinically significant difference in the nature, frequency or severity of adverse events between these two groups, although one and three adverse events were reported in the acyclovir and valaciclovir group, respectively. Thus, we conclude that in the management of herpes zoster, valaciclovir accelerates the resolution of pain and offers a simpler dosing, and maintains the favorable safety profile of acyclovir.

Acyclovir↗

Comparison of the BACTEC MGIT 960 and BACTEC 460TB systems for detection of mycobacteria in clinical specimens.

The reliability of the Mycobacteria Growth Indicator Tube (MGIT) 960 system for rapid detection of mycobacteria in clinical specimens was evaluated and compared to the radiometric method (BACTEC 460TB) and to mycobacterial culture on Lowenstein-Jensen (LJ) medium. Clinical specimens (n = 590) were tested without selection. A total of 121 (20.5%) isolates of mycobacteria were recovered; 98 (81.0%) of them were recovered with the BACTEC 460TB system, 86 (71.1%) were recovered with the BACTEC MGIT 960 system, and 55 (45.5%) were recovered with LJ medium (MGIT 960 versus BACTEC 640TB, p >0.05; MGIT 960 or BACTEC 460TB versus LJ, p <0.001). The mean time to detection (TTD) was 18 da for BACTEC 460 TB, and 13 da for BACTEC MGIT 960. The mean time to detection in each system, based upon data where both systems were culture positive, was significantly different (16.6 da for BACTEC 460TB and 13 da for BACTEC MGIT 960, p<0.001). The contamination rate of the BACTEC MGIT 960 system was 13.2%, which was intermediate between the BACTEC 460TB system (11.7%) and the LJ medium (14.7%). These data indicate that the fully automated MGIT 960 system is an accurate, non-radiometric alternative to the BACTEC 460TB method for rapid detection of mycobacteria in a clinical setting.

Bacteriological Techniques↗

Legionnaires' disease in an immunocompetent young adult.

Infection with Legionella pneumophila (LP) is a rare cause of pneumonia in previously healthy young adults. Pleural effusion is relatively common in Legionnaires' disease but is usually clinically insignificant. Herein we describe an immunocompetent, 19-year-old female with LP respiratory infection that presented with pleural effusion and mild interstitial infiltrates in the lower lungs. She received 3 weeks' treatment with erythromycin and rifampin and recovered completely. Diagnosis was based on serology testing with a four-fold rise of the antibody titer in the acute and convalescent phase. Legionnaires' disease should be considered in the differential diagnosis of culture-negative pleural effusion in immunocompetent young adults.

Adult↗

Pneumocystis carinii pneumonia in systemic lupus erythematosus: a report of two cases.

Patients with systemic lupus erythematosus (SLE) have increased susceptibility to infection by Pneumocystis carinii, but this condition has rarely been reported in Taiwan. Here, we describe two cases of patients with SLE who developed Pneumocystis carinii pneumonia (PCP). The first patient was a 39-year-old woman presenting with fever and dyspnea that had lasted 2 weeks. Chest roentgenography disclosed bilateral interstitial and alveolar infiltrates. The second patient was a 22-year-old woman presenting with a 4-day history of malaise, cough, dyspnea, and fever. She had concomitant Mycobacterium tuberculosis infection. Both patients had been treated with varying doses of corticosteroids and/or cytotoxic drugs within 4 months before presentation. Diagnosis was established based on the findings of bronchoalveolar lavage (BAL) and transbronchial lung biopsy (TBLB). Both patients received trimethoprim-sulfamethoxazole (20 mg.kg-1.d-1 trimethoprim), but finally died of nosocomial septicemia (Acinetobacter baumanni and Pseudomonas aeruginosa bacteremia in one, P. aeruginosa bacteremia in the other). These two cases demonstrate that PCP should be included in the differential diagnosis of patients with SLE presenting with pneumonic processes. In addition, a second opportunistic pathogen should be suspected. Bronchoscopic examination should be performed if the diagnosis is not clear and should include TBLB and BAL.

Adult↗

Differential gene expression of livers from ApoE deficient mice.

A genomic survey for differentially expressed genes was performed to livers of ApoE deficient mice using human cDNA microarray containing approximately 9,000 human cDNA clones. Due to the homology between mouse and human, hybridization was performed at lower stringency condition, 10 degrees below the regular hybridizing temperature. Gene expression profiles of livers corresponding to high levels of blood cholesterol were generated at genomic scale. Thirty-seven genes were randomly selected from a pool of differentially expressed genes and subjected to semi-quantitative RT-PCR, further confirmed the result from microarray hybridization. These included genes associated with atherosclerosis, and novel genes that implied novel pathways correlated to high levels of blood cholesterol. It is promising using human cDNA microarray, the most complete collection among all species, to study other mammalian systems with satisfying speed and accuracy.

Animals↗

Cbl-b, a RING-type E3 ubiquitin ligase, targets phosphatidylinositol 3-kinase for ubiquitination in T cells.

Cbl-b is implicated in setting the threshold of T lymphocyte activation. In Cbl-b-deficient T cells, the activation of Vav, a guanine nucleotide exchange factor, is significantly enhanced. The molecular mechanism underlying Cbl-b-regulated Vav activation was unclear. Here it is shown that Cbl-b interacts with and induces ubiquitin conjugation to the p85 regulatory subunit of phosphatidylinositol 3-kinase, an upstream regulator of Vav. A functional RING finger of Cbl-b was essential for p85 ubiquitination. However, a loss of function mutation at the well-conserved amino-terminal variant src homology (SH) 2 domain of Cbl-b did not affect its ligase activity. A distal carboxyl-terminal proline-rich region in Cbl-b was mapped to contain the primary binding sequences for the SH3 domain of p85. Deletion of either the distal proline-rich region in Cbl-b or the SH3 domain of p85 severely reduced ubiquitin conjugation to p85. The data suggest a molecular link for Cbl-b-mediated negative regulation of Vav, with phosphatidylinositol 3-kinase as a direct target for Cbl-b E3 ubiquitin ligase.

Adaptor Proteins, Signal Transducing↗

Recognition and ubiquitination of Notch by Itch, a hect-type E3 ubiquitin ligase.

Genetic studies identified Itch, which is a homologous to the E6-associated protein carboxyl terminus (Hect) domain-containing E3 ubiquitin-protein ligase that is disrupted in non-agouti lethal mice or Itchy mice. Itch-deficiency results in abnormal immune responses and constant itching in the skin. Here, Itch was shown to associate with Notch, a protein involved in cell fate decision in many mammalian cell types, including cells in the immune system. Itch binds to the N-terminal portion of the Notch intracellular domain via its WW domains and promotes ubiquitination of Notch through its Hect ubiquitin ligase domain. Thus, Itch may participate in the regulation of immune responses by modifying Notch-mediated signaling.

Animals↗