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Biomedical subjects

J H Liu

Publications and source records attributed to J H Liu.

At least 55 records · Page 3Linked to original sources

Complete atrio-ventricular block as a major clinical presentation of the primary cardiac lymphoma: a case report.

It is uncommon for malignant lymphomas to present primarily with cardiac invasion as the main clinical feature. What we are interested in is not only where the disease is, but also those symptoms that it may induce. Sudden onset of complete atrio-ventricular block is one of the most common clinical presentations. Cardiac tamponade is another common disease entity which, if it locates over outlets of great vessels, may also exert symptoms of obstructive vessels. Diagnosis can be made by needle aspiration under the guidance of transcutaneous or transesophageal echocardiography. Both CT scan and MRI play positive roles in the diagnosis of cardiac lymphomas, and the latter can even provide much more image information than the former. We report a 70-year-old male with primary cardiac lymphoma with initial clinical pictures of sudden onset of complete atrio-ventricular block. Chemotherapy was utilized with cyclophosphamide, vincristine and prednisolone (COP) initially for four courses and followed by adding doxorubicin (CHOP) for another three courses. The patient was still in remission status after treatment for 2 years.

Aged↗

Salvage therapy with single-agent paclitaxel by three-hour infusion in metastatic breast cancer: an experience in Taipei Veterans General Hospital.

BACKGROUND: Paclitaxel is an active agent in the treatment of breast, ovarian, lung and head and neck cancers. In previous phase I and II trials, it exerted novel cytotoxic effect on several malignancies. Various doses and regimens of paclitaxel have been assessed in metastatic breast cancer, with responses between 20 and 62%. However, combination therapy with other anti-cancer drugs leads to a high incidence of side effects. Our aim was to evaluate the efficacy of paclitaxel given by 3 h infusion as salvage chemotherapy for patients with metastatic breast cancer. METHODS: Between May 1999 and April 2000, 14 women with metastatic breast cancer were enrolled in this study and all the patients had to have measurable lesions. The median age of the patients was 48.7 years (range 39-56 years). All of them were definitely evidenced as having metastatic breast cancer and received complete courses of anthracycline-containing agents before applying paclitaxel. The protocol was single-agent paclitaxel (Anzatax, Faulding, Australia) at a moderate dosage of 175 mg/m(2) by 3 h intravenous infusion every 3 weeks. RESULTS: A total of 75 cycles were administered to these 14 patients with a median of four delivered cycles (range 3-14) and the response rate was 28.6% (95% CI: 21-40%), including four partial remission, three stable disease and seven progressive disease. The median time to progression was 3 (range 3-7) months. Hematological toxicities were minimal with no evidence of severe (grade 3 or 4) leukopenia and thrombocytopenia. Hepatic toxicities were observed in 12 cycles with five in grade 3. CONCLUSIONS: Our study indicates that utilizing single-agent paclitaxel exerts moderate activity on anthracycline-refractory metastatic breast cancer patients without excessive toxicities.

Adult↗

Pulsatile ocular blood flow in asymmetric exudative age related macular degeneration.

BACKGROUND/AIMS: Decreased perfusion or increased vascular resistance of the choroidal vessels had been proposed as the vascular pathogenesis for age related macular degeneration (AMD). This study planned to answer the question whether pulsatile ocular blood flow (POBF) was different in patients with asymmetric exudative AMD between eyes with drusen, choroidal neovascularisation (CNV), or disciform scar. METHODS: 37 patients with asymmetric exudative AMD were enrolled in this observational case series study. POBF were measured in both eyes of each subject. Eyes with high myopia, anisometropia, recent laser treatment, and glaucoma were excluded. RESULTS: After adjusting for ocular perfusion pressure, intraocular pressure, and pulse rate, multivariate regression analysis with generalised estimating equation showed POBF was significantly higher in eyes with CNV (1217 (SD 476) microl/min) than the contralateral eyes with drusen (1028 (385) microl/min) (p = 0.024). Eyes with disciform scar had lower POBF than the contralateral eyes with drusen (999 (262) microl/min and 1278 (341) microl/min, respectively, p<0.001). There was no significant correlation between the POBF and the lesion size of the CNV. CONCLUSION: The POBF in eyes with drusen was lower than their fellow eyes with CNV, but higher than their fellow eyes with disciform scar. This finding suggests that haemodynamic differences between fellow eyes in individuals are relevant to the development of CNV and the formation of disciform scar. Further studies on the follow up patients might shed light on the pathogenesis of exudative AMD.

Aged↗

Inhibition of STAT3 signaling leads to apoptosis of leukemic large granular lymphocytes and decreased Mcl-1 expression.

Large granular lymphocyte (LGL) leukemia is characterized by the expansion of antigen-activated cytotoxic T lymphocytes. These leukemic cells are resistant to Fas-mediated apoptosis despite expressing high levels of Fas. We found that leukemic LGL from 19 patients displayed high levels of activated STAT3. Treatment of leukemic LGL with the JAK-selective tyrosine kinase inhibitor AG-490 induced apoptosis with a corresponding decrease in STAT-DNA binding activity. Moreover, using an antisense oligonucleotide approach to diminish STAT3 expression, we found that Fas sensitivity was restored in leukemic LGL. AG-490-induced apoptosis in leukemic LGL was independent of Bcl-xL or Bcl-2 expression. However, we found that the Bcl-2-family protein Mcl-1 was significantly reduced by AG-490 treatment. Activated STAT3 was shown to bind an SIE-related element in the murine mcl-1 promoter. Using a luciferase reporter assay, we demonstrated that v-src overexpression in NIH3T3 induced STAT3-dependent transcriptional activity from the mcl-1 promoter and increased endogenous Mcl-1 protein levels. We conclude that STAT3 activation contributed to accumulation of the leukemic LGL clones. These findings suggest that investigation should focus on novel strategies targeting STAT3 in the treatment of LGL leukemia.

Apoptosis↗

Duration of stenting in single-stage laryngotracheal reconstruction with anterior costal cartilage grafts.

In single-stage laryngotracheal reconstruction (ss-LTR), the endotracheal tube is used as a stent. The optimal duration of stenting is not known. The stenting period requires a stay in the intensive care unit, as the patient is intubated. Sedation and, rarely, paralysis may be required. An analysis from a prospectively collected database was performed to investigate the effect of length of stenting on the outcome of ss-LTR. The outcomes used were reintubation rate and postoperative tracheostomy rate. Patients with anterior costal graft ss-LTR were selected, as they had undergone similar procedures and have similar stenosis types and grades. In 101 patients, the duration of stenting ranged from 2 to 14 days (mean, 7 days; SD, 2.6 days). No significant correlation was found between the number of days stented and the reintubation rate or the postoperative tracheostomy rate. Patients stented for longer than I week were an average of 15 months younger than those stented for less than 1 week; however, the stenosis grades for the two populations were equivalent. The differences in rates of reintubation (p = .68) and postoperative tracheostomy (p = .52) in these 2 groups were not significant. For patients undergoing ss-LTR with anterior costal cartilage grafts, no correlation was found between the number of days stented (intubated) and the reintubation rate or the postoperative tracheostomy rate.

Adolescent↗

Constraints on equifinality: goals are good explanations only for controllable outcomes.

What makes a goal or a precondition a better explanation of an action or outcome? Recent research shows that whereas goals are preferred for common actions, preconditions are preferred for actions that require substantial resources, particularly when those actions are obstructed. Two studies examined whether judgments of goals and preconditions reflect the controllability of the events, and whether previous findings apply to events generated by participants. Participants judged goals and preconditions as explanations for desirable extreme and moderate events and assessed the controllability and probability of the events. For common events, goals were better explanations than preconditions, whereas for the extreme scenarios, preconditions were judged equal or better explanations. The extreme events were seen as less controllable than the moderate events, and the controllability of the events predicted judgments of goals as explanations. The results suggest that participants see goals as better explanations only for events that the person can control, and they judge preconditions to be good explanations for events where the person has little control. These findings suggest that equifinality may apply only to those actions and outcomes where the preconditions are readily obtainable.

Achievement↗

Molecular analysis of mucosa-associated lymphoid tissue (MALT) lymphoma of ocular adnexa.

Lymphomas of mucosa-associated lymphoid tissue (MALT) are a distinct subgroup of extranodal B-cell non-Hodgkin's lymphomas. Most studies have failed to demonstrate the clonal rearrangement of BCL-1, BCL-2 or c-MYC genes for MALT lymphomas. Further, alteration of the p53 gene is rarely demonstrated in low-grade MALT lymphomas, but can be detected in high-grade disease. Lymphomas of the ocular adnexa represent approximately eight percent of all extranodal lymphomas, most of which are MALT lymphomas, but few studies had explored the alterations of BCL-1, BCL-2, c-MYC and p53 genes specifically for ocular MALT lymphomas. We investigated the changes to BCL-1, BCL-2, c-MYC and p53 genes in these lymphomas for Taiwanese patients. Clonal rearrangement for immunoglobulin heavy-chain (IgH), BCL-1, BCL-2, c-MYC and p53 genes was examined for 16 cases of ocular MALT lymphoma. Restriction-length polymorphism and polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) of the DNA, corresponding to exons 5 through 9, followed by DNA sequencing, were utilized to analyze the possible mutations of the p53 gene for these tumors. Thirteen of the cases revealed rearranged IgH genes using Southern blotting or PCR. No rearrangement of BCL-1, BCL-2, c-MYC or p53 genes was discovered, with point mutation of the p53 gene in one case. As for other types of MALT lymphomas, BCL-1, BCL-2 and c-MYC genes are not implicated in the pathogenesis of the ocular sub-group. Although alteration of the p53 gene is rare for low-grade ocular MALT lymphoma, its role in disease progression merits further research.

Adolescent↗

Non-penetrating trabeculectomy for open angle glaucoma.

BACKGROUND: Non-penetrating trabeculectomy is used as the surgical intervention for open angle glaucoma. It has advantage of creating gradual filtration through the thin trabeculo-Descemet membrane to reduce markedly the postoperative complications typical for penetrating operation. We described our experience of the non-penetrating trabeculectomy for open angle glaucoma. METHODS: This is a retrospective study of 28 eyes of 28 patients with primary open glaucoma (POAG). Non-penetrating trabeculectomy was performed by one surgeon from July 1998 to March 2000. Examinations were performed preoperatively and postoperatively in 1 and 7 days and 1, 3, 6, 12 and 21 months. RESULTS: The mean follow-up was 12.5 +/- 6.3 months (S.D.). The mean preoperative intraocular pressure (IOP) was 27.8 +/- 6.7 mmHg. The mean postoperative IOP was 11.5 +/- 6.2 mmHg in 1 day and 15.7 +/- 5.8 mmHg in 1 week, and it remained stable in the following 12 months. IOP of 71.3% (20/28) of the eyes could be controlled below or equal to 21 mmHg with no or only topical antiglaucoma medication. There were only few postoperative complications. CONCLUSIONS: Non-penetrating trabeculectomy is efficient in controlling intraocular pressure of open angle glaucoma. No entering the anterior chamber diminishes the postoperative complications typical of the penetrating trabeculectomy.

Aged↗

Design of a computerized system for the retrospective analysis by the physician of his own drug prescriptions.

The quality of drug prescription is known to be poor in many medical domains. Feedback information may help the physician to improve this component of his medical activity. The increasing use of computerized drug prescription systems makes possible the retrospective processing of prescriptions made over a given time period. This paper describes the design of a computerized system for providing feedback information to the physician about the quality of his drug prescribing activity. It is designed to be used by the physician himself. The analysis is based on two groups of quantitative indicators, simple and composite. The constraints that must be satisfied to calculate these indices automatically are given. They are related to the coding systems used for drug prescription, knowledge on drugs and patient data. The system design is based on modeling according to UML formalism. We give also a concrete view of the main functions of the system, based on a pictorial illustration with a component of the user interface. Some limitations and the possible extensions of this system for analyzing simultaneously the prescriptions made by set of physicians are discussed.

Drug Prescriptions↗

Retinopathy of prematurity: screening, incidence and risk factors analysis.

BACKGROUND: The sequela of retinopathy of prematurity (ROP) is an important cause of infant blindness. This study was designed to screen the high-risk premature infants and investigate the incidence and risk factors associated with the development of ROP. METHODS: From October 1997 to October 1998, all premature infants with birth body weight (BBW) less than 2000 gm or gestational age (GA) less than 36 weeks were enrolled and underwent ophthalmologic examination at 4 to 6 weeks of age at Taipei Veterans General Hospital. The perinatal variables were analyzed to evaluate their correlation with the development of ROP. RESULTS: In totally 108 premature infants, the incidence for development of ROP was 25% (27 in 108 patients). The threshold ROP occurred in 15 eyes (7%). The average BBW and GA (1267+/-341 gm and 29.7+/-2.7 weeks) were significantly lower in ROP group than in the non-ROP group (1703+/-368 gm and 32.3+/-2.2 weeks). The artificial ventilation for more than 5 days, chronic lung disease and periventricular leukomalacia were significant risk factors associated with highest rate of ROP. The respiratory distress syndrome, intraventricular hemorrhage, congenital heart disease and sepsis were significant risk factors accompanied by moderate rate of ROP. CONCLUSION: Low birth body weight and young gestational age are the most important risk factors in the development of ROP. The analysis of risk factors will be helpful in understanding and prediction of ROP formation in high-risk neonates. The timely clinical screening retina examination of high-risk premature infants is important to prevent the development of advanced ROP.

Female↗

[The nucleic acid analysis by DNA chip technique based on nuclease S1 protection].

OBJECTIVE: Establishing a method for quantitative analysis of nucleic acid by DNA chips. METHODS: The modified oligonucleotides with ribose at 3'-end was chemically synthesized. The 5'-end was labeled by radioisotope 32P with kinase catalyzed reactions. Such oligonucleotides were converted into di-aldehyde at 3'-end by oxidization with NaIO4, and then were spotted on glass slide with the amino group modified surface. After reduced with NaBH4, the oligonucleotides were attached strongly. The DNA chips prepared with this method were hybridized with nucleic acids existed in the solution and then digested with nuclease S1. RESULTS: When they were paired with the nucleic acids in the solution perfectly, the oligonucleotides on the chip were not cleaved by nuclease S1. Otherwise, the oligonucleotides on chip were cleaved. The protection efficiencies appeared proportional to the perfect paired nucleic acids in the solution when the content of target nucleic acids were less than the spots on the slides. CONCLUSIONS: The method was developed for both qualitative and quantitative analysis of nucleic acid. As it was not required to label the samples with radioisotope or fluorescence, it might be a practical choice for clinical tests.

DNA Probes↗

Subglottic stenosis associated with transesophageal echocardiography.

Transesophageal echocardiography (TEE) is used extensively to assess cardiac function and anatomical relationships in both adults and children. Although considered a noninvasive procedure, TEE in infants and small children may result in airway complications. A patient who developed subglottic stenosis after the use of TEE during a cardiac procedure is reported.

Echocardiography, Transesophageal↗

T-type alpha 1H Ca2+ channels are involved in Ca2+ signaling during terminal differentiation (fusion) of human myoblasts.

Mechanisms underlying Ca(2+) signaling during human myoblast terminal differentiation were studied using cell cultures. We found that T-type Ca(2+) channels (T-channels) are expressed in myoblasts just before fusion. Their inhibition by amiloride or Ni(2+) suppresses fusion and prevents an intracellular Ca(2+) concentration increase normally observed at the onset of fusion. The use of antisense oligonucleotides indicates that the functional T-channels are formed by alpha1H subunits. At hyperpolarized potentials, these channels allow a window current sufficient to increase [Ca(2+)](i). As hyperpolarization is a prerequisite to myoblast fusion, we conclude that the Ca(2+) signal required for fusion is produced when the resting potential enters the T-channel window. A similar mechanism could operate in other cell types of which differentiation implicates membrane hyperpolarization.

Calcium↗

Highly regioselective synthesis of 2,3,4-trisubstituted 1H-pyrroles: a formal total synthesis of lukianol A.

A combined use of alpha-lithiation and nucleophilic substitutions of N,N-dimethyl 3,4-bis(trimethylsilyl)-1H-pyrrole-1-sulfonamide 8c led to several 2-substituted 3, 4-bis(trimethylsilyl)-1H-pyrrole-1-sulfonamides. Utilizing the beta-effect of a trimethylsilyl group, a highly regioselective synthesis of 2,3,4-trisubstituted 1H-pyrroles 23 and 34 was accomplished. The marine natural product lukianol A (3) was prepared utilizing this strategy.

Antineoplastic Agents↗