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Biomedical subjects

T P Chen

Publications and source records attributed to T P Chen.

At least 19 recordsLinked to original sources
PubMed2001

Secondary chronic myelogenous leukemia after autologous peripheral blood stem cell transplantation for lymphoma.

A 31-year-old woman was diagnosed with intestinal lymphoma (high-grade mucosa-associated lymphoid tissue lymphoma, stage IIE) in September 1996. Eleven courses of chemotherapy were administered, but the results were poor. She received autologous peripheral blood stem cell transplantation (PBSCT) in September 1997. Leukocytosis was noted, and chronic myelogenous leukemia was diagnosed 8 months after the PBSCT, progressing to blast phase 10 months later. We report this case because secondary chronic myelogenous leukemia after stem cell transplantation is rare.

Adult↗
PubMed2001

CD34+ stem cell transplantation in malignancies: report of three cases.

Purging tumor cells from peripheral blood stem cells (PBSCs) used to treat patients with malignancy is important in the prevention of relapse. Positive selection of CD34+ stem cells using either immunomagnetic methods or an avidin-biotin conjugated CD34 monoclonal antibody binding column can reduce the number of contaminating tumor cells. We describe the management of three patients with malignancy treated using high-dose chemotherapy and enriched CD34+ cell transplantation. PBSCs were mobilized with cyclophosphamide plus recombinant granulocyte-colony stimulating factor (rG-CSF), and then leukophoresis was performed to harvest the PBSCs. The collected cells were positively selected for CD34+ cells using the Cellpro system. The CD34(+)-enriched PBSCs were then cryopreserved in the vapor phase of liquid nitrogen for future reinfusion. All three patients recovered smoothly after transplantation. The mean time to full hematologic recovery was 12 days for white blood cells (> or = 1 x 10(9)/L) and 14 days for platelets (> or = 20 x 10(9)/L), respectively. Partial remission occurred in two patients who were disease free for more than 4 years, and in one patient who died of hepatic failure with liver cirrhosis 5.5 months posttransplantation.

Adult↗
PubMed2001

A molecular genetic analysis of the Kidd blood group polymorphism in Taiwanese, Thais, and Filipinos.

In this study, we molecularly detect the Jka/Jkb polymorphism in Taiwanese, Thais, and Filipinos with PCR-restriction enzyme digestion. We designed the primers with mutagenic bases to create two restriction enzyme cutting sites (EcoN I and Xba I) simultaneously to confirm the genetic polymorphism of Jka/Jkb. One hundred and seven unrelated Taiwanese, 107 Thais foreign laborers, and 102 Filipino foreign laborers in Taiwan were analyzed. The frequency of Jka and Jkb is 0.51 and 0.49 in Taiwanese, 0.44 and 0.56 in Thais, and 0.45 and 0.55 in Filipinos, respectively. The molecular analysis of Jka/Jkb polymorphism is simple, accurate and could confirm the uncertain results obtained by serological typing. The method could be used for predicting fetal Kidd genotype from amniocyte DNA, and to avoid the hemolytic disease of newborns caused by Jk antibody.

Humans↗
PubMed2001

Autologous peripheral blood stem cells harvesting in Kaohsiung Medical University Hospital.

We report our clinical experience in autologous peripheral blood stem cells harvesting. A total of 40 patients with 112 apheresis procedures were analyzed, 88 with Cobe system and 24 with MCS3P system. Our results revealed that there was no significant difference in efficiency of CD34(+) cell harvesting between both apheresis systems, but the Cobe system had more nucleated cells collected and less red cell contaminated in the final PBSCs collections. The percentage of CD34(+) cells collected decreased significantly following the first day's harvesting (p = 0.026). There was a good correlation between the percentage of CD34(+) cells in PBSCs and colony forming units-granulocyte macrophage (CFU-GM) or burst forming unit-erythrocyte (BFU-E)(r = 0.909, p < 0.0001; r = 0.788, p < 0.0001, respectively). However, it was negatively correlated with the patient's age. The CD34(+) cells collected in patients with acute leukemias were also higher than those patients with other solid tumors. Ten cases (13%) with 15 apheresis procedures experienced side effects like numbness, nausea, fever, or headache etc. The Cobe system seemed to have higher frequency of side effects than that of MCS3P system (16% vs 4%). From our results, we concluded that both COBE and MCS3P system have similar efficiency and all patients could tolerate the apheresis procedures in peripheral blood stem cells harvesting. The CD34(+) cell can be used as a good parameter to estimate the amount of stem cells collected. The patient's age and disease pattern were significant factors influencing the CD34(+) stem cells collection in autologous peripheral blood stem cells harvesting.

Adolescent↗
PubMed2001

[Prospective study of lethal blood concentration of organophosphorous in humans].

Total cases of organophosphorous (dichlorvos, methamidophos, dimethoate) poisoning outpatients from six hospitals during four years were collected consecutively for lethal blood concentration study. Blood samples were detected with gas chromatography. The probabilities of death, coma were analyzed with Bliss method and their linear regressive equations of probit were obtained respectively, their 50% lethal concentrations (LC50) and 50% coma concentrations(CC50) were calculated by the formulas above. As the death rate was influenced by therapy, its natural death probability has been discussed and estimated their natural LC50 were between the LC50 and CC50 themselves. Combined LC50 and CC50, their natural LC50 were calculated.

Adolescent↗
PubMed2000

Mutation analysis of PTEN/MMAC1 in acute myeloid leukemia.

Recently, a putative tumor suppressor gene, PTEN/MMAC1, has been identified at chromosome 10q23.3, which encodes a 403 amino acid dual-specificity phosphatase containing a region of homology to tensin and auxillin. Somatic mutations of the PTEN/MMAC1 gene have been identified in a number of cancer cell lines and primary cancers. Mutations in PTEN/MMAC1 are most frequently found in advanced cancers. To evaluate the role of the PTEN/MMAC1 gene in leukemia, bone marrow and/or peripheral blood from 62 acute myeloid leukemia (AML) patients, 5 hemopoietic cell lines (HL60, U937, Raji, KG-1, K562), and 30 normal controls were analyzed. The results showed aberrant PTEN/MMAC1 transcripts in 15 of the 62 (24%) AML patients, 4 of the 5 cell lines (80%), and 4 of the 30 (13%) normal controls. As in our previous study of TSG101, the abnormal transcripts may result from aberrant RNA splicing as evidenced by the presence of both these aberrant transcripts and normal full length transcripts in all specimens examined. Loss of heterozygosity (LOH) analysis and PCR-SSCP of the entire coding region showed that none of the AML cases had LOH or mutation. Only one frameshift mutation at codon 130 (insertion of CCCG) with premature termination of coding sequence was observed in the U937 cell line. Our results indicate that the PTEN/MMAC1 gene may play a role in a small percentage of AML, but its significance needs to be further evaluated.

Acute Disease↗
PubMed2000

Apparatus used for small-scale volatile extraction from ethanol-supplemented low-salt miso and GC-MS characterization of the extracted flavors.

An extraction apparatus was equipped with a nitrogen-flushing vessel to purge volatiles from a 10-g miso prepared solution at 40 degrees C, a reflux condenser to recover water, a coiled cold-trap to separate ethanol in advance, and a glass-lined stainless (GLS) trap filled with Tenax TA for flavor adsorption. Volatiles in the GLS tube were released with a thermal desorption device and condensed with a Micro-cryo trap prior to connection with GC and GC-MS for characterization. After analysis, a broad volatile profile comprising 9 categories of functional group and 97 identified compounds was achieved. As affected by ethanol supplementation for miso fermentation, most volatiles except alcohols and acetals in the low-salt products fermented with 5% NaCl and 7.5% ethanol were higher than those in the control products fermented with 9% NaCl and 0% ethanol and the high-ethanol supplemented products fermented with 5% NaCl and 15% ethanol. It reveals that supplementation of ethanol in miso at an appropriate level not only enabled a low-salt miso fermentation but also enhanced flavor formation.

Ethanol↗
PubMed2000

Nonholonomic orthogonal learning algorithms for blind source separation.

Independent component analysis or blind source separation extracts independent signals from their linear mixtures without assuming prior knowledge of their mixing coefficients. It is known that the independent signals in the observed mixtures can be successfully extracted except for their order and scales. In order to resolve the indeterminacy of scales, most learning algorithms impose some constraints on the magnitudes of the recovered signals. However, when the source signals are nonstationary and their average magnitudes change rapidly, the constraints force a rapid change in the magnitude of the separating matrix. This is the case with most applications (e.g., speech sounds, electroencephalogram signals). It is known that this causes numerical instability in some cases. In order to resolve this difficulty, this article introduces new nonholonomic constraints in the learning algorithm. This is motivated by the geometrical consideration that the directions of change in the separating matrix should be orthogonal to the equivalence class of separating matrices due to the scaling indeterminacy. These constraints are proved to be nonholonomic, so that the proposed algorithm is able to adapt to rapid or intermittent changes in the magnitudes of the source signals. The proposed algorithm works well even when the number of the sources is overestimated, whereas the existent algorithms do not (assuming the sensor noise is negligibly small), because they amplify the null components not included in the sources. Computer simulations confirm this desirable property.

Algorithms↗
PubMed2000

Clinical implications of aberrant TSG101 transcripts in acute myeloblastic leukemia.

Tsg101 is a mouse tumor suppressor gene whose homozygous deletion produces transformation of NIH3T3 cells and leads to metastases in nude mice. The human homologue of the gene, TSG101, is localized in chromosome 11p15.1-p15.2. Reduced TSG101 expression may cause the defect of the cell cycle checkpoint that leads to genetic instability and consequently to the progression of neoplasia. Aberrant TSG101 transcript have been identified in many types of cancers, and the relaxation of RNA splicing fidelity may be an onco-developmental marker in cancers and could play a general role in tumorigenesis. In our previous study, smaller TSG101 transcripts were found in AML specimens, hematopoietic cell lines and normal controls. The aberrant transcripts occurred more frequently in the AML cases and cell lines. The patients with aberrant TSG101 transcripts had higher initial white cell count, lower LDH level, and lower complete remission rate after induction chemotherapy. However, further multivariate analysis of clinical data revealed that there was no relationship to the TSG101 aberrant transcripts. The clinical significance of TSG101 aberrant transcript in AML needs further evaluation.

3T3 Cells↗
PubMed1999

Allogeneic bone marrow transplantation of chronic myeloid leukemia from an HLA-matched unrelated donor with the beta-thalassemic trait.

We report a chronic myeloid leukemia patient who underwent allogeneic bone marrow transplantation from an HLA-matched unrelated donor with the beta-thalassemic trait. The donor was a heterozygote for the -28 A-->G mutation. We examined the recipient's bone marrow and peripheral blood using the polymerase chain reaction (PCR) method to detect the -28 G-->A mutation of the donor type and monitored the sustained engraftment. This case suggests that a donor with the thalassemic trait can be a candidate for matched unrelated bone marrow transplantation for hematological malignancies and that PCR based genetic examination of the thalassemic mutation is a useful tool to detect early engraftment.

Adult↗
PubMed1999

Epidemiological study of human salmonellosis during 1991-1996 in southern Taiwan.

Within a 6-year period from January 1991 to December 1996, 249 patients of salmonellosis admitted to Kaohsiung Medical College Hospital were enrolled for clinical and microbiological analysis. The number of patients increased by year from 1991 (14 patients) to 1996 (79 patients), especially in the case of nontyphoid salmonellosis. There were 57 different serotypes isolated during these period. Salmonella typhimurium was the most common clinical serotype of human origin in southern Taiwan, followed by S. choleraesuis, S. schwanzengrund, and S. derby. Fever (81.1%), diarrhea (68.9%), and anorexia (44.6%) were the most common manifestations of human salmonellosis. Relative bradycardia was a more important feature in S. typhi group (100%) than nontyphoid salmonellosis. Leukocytosis, especially lymphocytosis, was found especially in nontyphoid, but not in typhoid salmonellosis. Elevated liver function tests were found in the most severe patients, such as S. choleraesuis and S. typhi infections. Malignancy (8.8%), especially hematological malignancy (5.2%), gastrointestinal diseases (8.8%), and diabetes mellitus (6.4%) were the common underlying diseases. Case fatality rate of human salmonellosis was 8% (20/249), especially high in S. choleraesuis group. The severity of underlying diseases may be the major cause in S. choleraesuis group. There was no fatal case with typhoid fever. Very high resistance rate to commonly used antimicrobial agents in nontyphoid Salmonella was noted in southern Taiwan with overall rates of resistance to ampicillin, 67.9%, chloramphenicol, 66.7%, and TMP/SMZ, 42.2%. The emergence of ciprofloxacin-resistant and multiresistant strains was also a major therapeutic problem in this study.

Humans↗
PubMed1999

Salmonella choleraesuis bacteremia in southern Taiwan.

Within a 6-year period from January 1991 to December 1996, 19 patients with Salmonella choleraesuis bacteremia were enrolled for clinical and microbiological analysis. Young children, the elderly and patients with hematological malignancy (36.8%), liver cirrhosis (26.3%), systemic lupus erythematosus (10.5%), chronic renal impairment (10.5%), and peptic ulcer (10.5%) were at high risk of this infection. The ratio of male to female was 3:1. Three cases (15.8%) were nosocomially acquired. Fever (89.5%), chills (57.9%) and anorexia (52.6%) were the most common clinical manifestations. Seven patients (36.8%) presented no gastrointestinal manifestations. Normal white blood cell count was noted in seven patients (36.8%), and neutropenia caused by underlying diseases or severe infection was found in six cases (31.6%). Various types of metastatic focal infections were found, such as septic arthritis, cutaneous infection, spontaneous bacterial peritonitis, and pneumonia. The severe immunocompromised status of patients and the high virulence of this pathogen may contribute to the high case fatality rate (21%). Higher resistance rate to commonly used antimicrobial agents was noted in ampicillin (94.7%), chloramphenicol (89.5%), and TMP/SMZ (63.8%). All strains of S. choleraesuis were susceptible to third-generation cephalosporins and fluoroquinolones. Generally, S. choleraesuis bacteremia should be taken into account in the differential diagnosis of sepsis in immunocompromised patients, even without gastrointestinal manifestations. The third-generation cephalosporins and fluoroquinolones may be the first choice for treatment of this invasive infections.

Adolescent↗
PubMed1999

An indigenous melioidosis: a case report.

Melioidosis is a rare but potentially fatal infectious disease in Taiwan, although it has been endemic in Southeast Asia, especially northeast Thailand, and northern Australia. In this article, we report a male diabetes with fulminant pneumonia, and septicemia caused by Burkholderia pseudomallei without traveling abroad before this episode. Productive cough and intermittent chills, high fever for one week, followed by progressively deteriorating dyspnea, shock, disturbed consciousness status were the major presentations. Blood culture grew B. pseudomallei on the fifth admission day. Unfortunately, the patient died on the 9th admission day, despite intensive care and the broad-spectrum antimicrobial regimen used.

Adult↗
PubMed1998

Aberrant TSG101 transcripts in acute myeloid leukaemia.

Recently, a tumour susceptibility gene, TSG101, has been identified at chromosome 11p15. A large intragenic deletion of this gene has been demonstrated in primary breast tumours. To evaluate the role of the TSG101 gene in leukaemia, bone marrow and/or peripheral blood from 68 acute myeloid leukaemia patients, five haemopoietic cell lines (HL60, U937. Raji, KG-1, K562) and 30 normal controls were analysed by reverse transcription of the TSG101 mRNA, followed by PCR amplification and sequencing of the products. The results showed aberrant TSG101 transcripts in 24/68 (35%) acute myeloid leukaemia (AML) patients, all of the cell lines (100%) and 3/30 (10%) normal controls. Our study indicated that the abnormal transcripts may have resulted from aberrant RNA splicing as evidenced by these aberrant transcripts. Also, normal full-length transcripts were present in all specimens examined. The aberrant transcript occurred more frequently in the AML and cell lines. However, because aberrant transcripts of TSG101 were also found in the normal controls, the role of TSG101 as a tumour suppressor gene should be evaluated carefully.

Acute Disease↗
PubMed1998

Donor leukocyte infusion as salvage therapy in an adult with relapsed acute lymphoblastic leukemia after allogeneic bone marrow transplantation.

Relapse of malignancy after allogeneic bone marrow transplantation remains the major cause of treatment failure in patients with leukemia. While donor leukocyte infusion (DLI) has been used to treat such patients, its use in patients with acute lymphoblastic leukemia is seldom reported. We describe a 35-year-old woman who suffered relapse of acute lymphoblastic leukemia after allogeneic bone marrow transplantation. She received DLI twice as salvage therapy. This patient achieved complete remission following DLI and has remained in remission for more than 11 months without further chemotherapy. We suggest DLI can be used as an initial salvage therapy, without significant toxicity, for patients with relapsed acute lymphoblastic leukemia following bone marrow transplantation.

Adult↗