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Biomedical subjects

E Hsu

Publications and source records attributed to E Hsu.

At least 19 recordsLinked to original sources
PubMed2005

Recycling rates of waste home appliances in Taiwan.

The objective of this study is to provide a calculation of recycling rates of waste home appliances in Taiwan, for the EPA to amend these rates in order to increase the recycling efficiency. The recycling rate is calculated by a formula according to the statistical results obtained through: (1) an estimation of domestic use of home appliances using time series analysis with multiplicative seasonal ARIMA model, (2) a further estimation of generated waste home appliances based upon the estimated domestic use and the corresponding distribution of lifetime span, and (3) a cost analysis of recycling home appliances based on a sampling survey with stratified systematic sampling conducted among collectors and a survey on five recycling plants of waste home appliances. The suggested recycling rates in this study finally used by the EPA show that all of the recycling rates have increased compared with the rates in previous years. This study also implies that amending the recycling rates may only solve some recycling problems temporarily; however, the recycling system of waste home appliances in Taiwan has to be reformed to increase the recycling efficiency for the long term.

Conservation of Natural Resources↗
PubMed2001

Improved detection of CFTR mutations in Southern California Hispanic CF patients.

Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene cause cystic fibrosis (CF), a common autosomal recessive disease in Caucasians. The broad mutation spectrum varies among different patient groups. Current molecular diagnoses are designed to detect 80-97% of CF chromosomes in Caucasians and Ashkenazi Jews but have a much lower detection rate in Hispanic CF patients. Grebe et al. [1994] reported a 58% detection rate in Hispanic patients. Since then, there has been no large-scale, complete mutational analysis of Hispanic CF patients. In this study, the mutations in 62 Hispanic patients from southern California were investigated. The entire coding and flanking intronic regions of the CFTR gene were analyzed by temporal temperature gradient gel electrophoresis (TTGE) followed by sequencing to identify the mutations. Eleven novel mutations were discovered in this patient group: 3876delA, 406-1G>A, 935delA, 663delT, 3271delGG, 2105-2117del13insAGAAA, 3199del6, Q179K, 2108delA, 3171delC, and 3500-2A>T. Among the mutations, seven were out-of-frame insertions and deletions that result in truncated proteins, two were splice-site mutations, one was an in-frame 6 bp deletion, and one was a missense mutation that involved the non-conservative change of glutamine-179 to lysine. All patients presented severe classical clinical course with pancreatic insufficiency and poor growth, consistent with the nature of truncation mutation. The results indicate that TTGE screening following the analysis of recurrent mutations will substantially improve the mutation detection rate for Hispanic CF patients from southern California.

Alleles↗
PubMed2000

X protein of hepatitis B virus inhibits Fas-mediated apoptosis and is associated with up-regulation of the SAPK/JNK pathway.

The X protein from a chronic strain of hepatitis B virus (HBx) was determined to inhibit Fas-mediated apoptosis and promote cell survival. Fas-mediated apoptosis is the major cause of hepatocyte damage during liver disease. Experiments demonstrated that cell death caused by anti-Fas antibodies was blocked by the expression of HBx in human primary hepatocytes and mouse embryo fibroblasts. This effect was also observed in mouse erythroleukemia cells that lacked p53, indicating that protection against Fas-mediated apoptosis was independent of p53. Components of the signal transduction pathways involved in this protection were studied. The SAPK/JNK pathway has previously been suggested to be a survival pathway for some cells undergoing Fas-mediated apoptosis, and kinase assays showed that SAPK activity was highly up-regulated in cells expressing the HBx protein. Normal mouse fibroblasts expressing HBx were protected from death, whereas identical fibroblasts lacking the SEK1 component from the SAPK pathway succumbed to Fas-mediated apoptosis, whether HBx was present or not. Assays showed that caspase 3 and 8 activities and the release of cytochrome c from mitochondria were inhibited, in the presence of HBx, following stimulation with anti-Fas antibodies. Coprecipitation and confocal immunofluorescence microscopy experiments demonstrated that HBx localizes with a cytoplasmic complex containing MEKK1, SEK1, SAPK, and 14-3-3 proteins. Finally, mutational analysis of HBx demonstrated that a potential binding region for 14-3-3 proteins was essential for induction of SAPK/JNK activity and protection from Fas-mediated apoptosis.

Apoptosis↗
PubMed2000

Rearrangement of immunoglobulin genes in shark germ cells.

The variable (V), (diversity [D]), and joining (J) region recombinases (recombination activating genes [RAGs]) can perform like transposases and are thought to have initiated development of the adaptive immune system in early vertebrates by splitting archaic V genes with transposable elements. In cartilaginous fishes, the immunoglobulin (Ig) light chain genes are organized as multiple VJ-constant (C) clusters; some loci are capable of rearrangement while others contain fused VJ. The latter may be key to understanding the evolutionary role of RAG. Are they relics of the archaic genes, or are they results of rearrangement in germ cells? Our data suggest that some fused VJ genes are not only recently rearranged, but also resulted from RAG-like activity involving hairpin intermediates. Expression studies show that these, like some other germline-joined Ig sequences, are expressed at significant levels only early in ontogeny. We suggest that a rejoined Ig gene may not merely be a sequence restricting antibody diversity, but is potentially a novel receptor no longer tied to somatic RAG expression and rearrangement. From the combined data, we arrived at the unexpected conclusion that, in some vertebrates, RAG is still an active force in changing the genome.

Amino Acid Sequence↗
PubMed2000

Measurement of bilirubin partition coefficients in bile salt micelle/aqueous buffer solutions by micellar electrokinetic chromatography.

The partition coefficients for the distribution of bilirubin between aqueous phosphateborate buffer and cholic, taurocholic, taurodeoxycholic, and taurochenodeoxycholic micelles have been measured by micellar electrokinetic chromatography at pH 8.5. Determination of the partition coefficients required that the critical micelle concentration and partial specific volumes be determined for each bile salt. Critical micelle concentrations were slightly higher for the trihydroxy bile salts. Partial specific volumes of the bile salt micelles differed very little from each other, and for each bile salt they were constant over the concentration range studied, which was typically from slightly above the critical micelle concentration to 35 mM. Capacity factors were corrected for the effects of applied voltage by extrapolation of the capacity factor to zero applied volts. The free solution mobility of bilirubin, determined in the absence of bile salt, was also corrected for the effects of applied voltage. Plots of extrapolated capacity factor versus phase ratio yield the partition coefficient as the slope of a linear fit to the data. Partition coefficients for bilirubin were significantly higher for dihydroxy bile salts than for trihydroxy bile salts.

Bile Acids and Salts↗
PubMed2000

A novel mutation detected by temporal temperature gradient gel electrophoresis led to the confirmative prenatal diagnosis of a Hispanic CF family.

Mutational analysis of 30 recurrent known mutations detects only about 58% of Hispanic cystic fibrosis (CF) chromosomes. The low mutation detection rate has greatly hindered prenatal diagnosis and carrier testing of Hispanic families who have multiple affected children with unidentified cystic fibrosis transmembrane conductance regulator (CFTR) mutations. We recently employed a temporal temperature gradient gel electrophoresis (TTGE) method to effectively scan unknown mutations in the entire CFTR gene. A novel mutation, 2105-2117 del13insAGAAA was identified in a Hispanic family heterozygous for delta F508. The discovery of the devastating mutation facilitated the prenatal diagnosis for this family who already had two severely affected children. The fetus was found to be a compound heterozygote of delta F508/2105-2117 del13insAGAAA. This case emphasizes the importance of whole gene mutational analysis in patients with a clinical diagnosis of CF, but without the identifiable DNA mutations by routine mutation analysis. Finding of CF mutations in the patient would allow proper genetic counselling and prenatal and carrier detection of at-risk family members.

Adolescent↗
PubMed2000

Medulloblastoma in children--the Ottawa experience.

A retrospective review of 36 children diagnosed with medulloblastoma in the Ottawa area between 1974 and 1997 was completed (mean age 7.8+/-4.2 years, range 1.2-15.3 years). Via a suboccipital approach, complete tumor resection was achieved in 75% and subtotal resection (>90%) in 25%, without any operative mortality. The tumor was located in the vermis in 39% and in the cerebellar hemisphere in 11%; it occupied both locations in 50%. In 47% of the children a ventriculoperitoneal shunt was required. Postoperatively, craniospinal radiation at 3600 cGy with a boost to the posterior fossa was administered. Chemotherapy was used in 56%. The 1-year survival rate was 92%, and survival plateaued at 54% at 5 years. Children less than 3 years of age fared worse than those over 3 years old. While the male-to-female ratio was 1.6:1, there was no gender difference in survival. Chang's classification was used to grade the tumors. T stage did not have an impact on survival, but M stage did. No statistically significant difference in survival was found between the patients who had a total resection and those who had a subtotal resection. There was no difference in survival in terms of tumor location, hydrocephalus or ventriculoperitoneal shunt. Chemotherapy showed no survival benefit. The recurrence rate was 26%, and its timing followed Collin's law. Recurrence led to death within 1-9 months. GH deficiency was diagnosed in 5 patients and hypothyroidism in 4 patients. The mean follow-up time was 4.4+/-3.7 years, with a range of 2.5 months to 16.5 years. Fourteen patients died, 5 were lost to follow-up, and 7 were transferred to adult care without persistent disease. Ten children are presently being followed up by the Neuro-oncology Clinic. Four children continue to be followed through psychology services. Our results are comparable to those in larger series, and are similar to those of the Montreal Children's Hospital.

Adolescent↗
PubMed2000

Spirit (shen), styles of knowing, and authority in contemporary Chinese medicine.

Studies on the terminology of expert knowledge tend to neglect the relevance of sociological data, in spite of general acceptance that knowledge and social practice are interdependent. This paper explores expert knowledge and practice by examining 'styles of knowing' and how they differ according to the ways in which experts establish their authority. For assessing medical authority in microsocial settings, the author takes recourse to Weber's three ideal types. The study shows that for a charismatic healer who seeks to reach mutual consensus with his clientele vagueness in terminology can be useful. When, however, medical authority depends on recognition by superiors and peers in modern bureaucratic institutions, vague terms tend to be avoided. So, the same term that a charismatic healer may refer to in a vague sense becomes more explicitly defined in the bureaucratic setting. Its sense is more clearly delimited and denotational qualities are emphasized. In institutions where traditional authority prevails, like those of the literate elite in highly stratified traditional societies, the technical terminology is not only vague, but notoriously polysemous. The article draws on ethnographic data of Chinese medicine and qigong therapy as practised in the late eighties in Kunming city, the capital of Yunnan province in the People's Republic of China, but it is meant to contribute in a more general way to an exploration of the ways in which claims to medical authority interrelate with word meaning, language use, and 'styles of knowing'. The term investigated, shen, refers to the spiritual, a domain of human experience that is widely acknowledged by traditional medical practitioners, but difficult to evaluate by sociological analysis.

Anthropology, Cultural↗
PubMed1999

Allelic exclusion in anamniotic vertebrates.

Clonal selection, a central principle in immunology, is predicated on one lymphocyte making one kind of antibody or T cell receptor. At loci encoding antigen receptors only one allele is used, and this has been shown in normal lymphocytes from frogs to humans. Fish antibody chains, however, are encoded by multiple loci, and at some of these loci the gene segments are already rearranged in the germline. The differences in germline organization and the uncoupling of rearrangement and expression raise questions as to whether some of the early vertebrates might be an exception to the clonal selection theory.

Alleles↗
PubMed1999

Junctional diversity in Xenopus immunoglobulin light chains.

Xenopus cDNA sequences encoding the homolog of mammalian kappa (kappa) light (L) chains were isolated from isogenic tadpole and adult individuals to investigate whether there existed stage-specific immunoglobulin L chain expression and somatic diversification. In the course of these studies rearrangements to a sixth J(L) gene segment and a pseudogene (J(L)psi) were found, and it is suggested that the order of these gene segments with respect to the L chain constant (C) region exon is: J(L)6-J(L)1-J(L)2-J(L)3-J(L)4-J(L)5-J(L)psi-C(L). The cDNA junctional diversity was analyzed; few N and P regions were found and almost all the CDR3 were 9 codons in length. There were restricted patterns of recombination site resolution, and this is attributed to some constraint in JL coding end processing.

Animals↗
PubMed1999

HLA-A*28 allele frequencies in the five major U.S. ethnic groups.

The frequency of each A*28 allele was determined by PCR-SSOP typing in 5 major U.S. ethnic populations: Caucasians, African Americans, Asians/Pacific Islanders, Hispanics, and Native Americans. The percent of serologically defined A28-positive individuals in the 5 populations ranged from 2.7-17.9%. Fifty-nine individuals who were previously serologically typed as A28, A68 or A69 were randomly chosen for allele-level typing from each ethnic group from a database of 82,979 consecutively typed unrelated individuals. The most common A*28 allele for Caucasians, Asians/Pacific Islanders, Hispanics, and Native Americans was A*68012, while A*6802 was found in the majority of African Americans. Only four and three A*28 alleles were seen in Caucasians and African Americans, respectively, while five to six A*28 alleles were seen in the other population groups. The A*6804 and A*6806 alleles were not observed in any of the five ethnic groups.

Alleles↗
PubMed1999

MRI diagnosis of gliomatosis cerebri.

Until recently the diagnosis of gliomatosis cerebri has been made on postmortem examination. This article reviews the use of serial magnetic resonance imaging studies to suggest premorbid diagnosis of this condition. The following is a case report of a 14-year-old female who had a subtotal cortical resection of tumor and several years later developed a progressive dementia. At postmortem examination the diagnosis of gliomatosis cerebri was made. Diffuse progressive white matter changes involving both hemispheres and brainstem, with increased thickness of the corpus callosum and without changes in cortical markings on T2-weighted magnetic resonance images, in this patient were highly suggestive of the diagnosis of gliomatosis cerebri.

Adolescent↗
PubMed1999

Brain tumors in childhood and adolescence.

Brain tumors are the second most common neoplasm in childhood and adolescence. With the recent advances in technology, changes in tumor incidence have been reported. This study examines this statement. A 19-year retrospective case review of primary brain tumors in persons younger than 18 years of age at time of diagnosis, who had permanent residence in our catchment area, was performed. Data were examined for changes in presenting symptoms and signs and incidence rates for tumors on the basis of anatomic location and histologic tumor type. An incidence rate of 2.76 per 100,000 people younger than 18 years of age was found. During the period of this study a small, but significant, trend toward increasing incidence was evident. No changes in patterns of presentation or duration of symptoms before diagnosis was observed. The incidence rate based on histologic tumor diagnosis remained fairly constant during the study period.

Adolescent↗
PubMed1998

3849 + 10 kb C --> T splicing mutation in Hispanic CF patients.

Seven patients compound heterozygous for the 3849 + 10kb C --> T mutation in the CFTR gene were found among the 152 patients attending the CHLA CF Clinic. The frequency of this mutation accounts for 2.3 and 3.9% of thetotal and Hispanic CF alleles of CHLA patients. These are significantly higher than the 0.6% of the general CF population. The average age of diagnosis of this group of Hispanics is 3.1 years, which is much younger than that reported for CF patients of other ethnicities with the same mutation. Both pancreatic sufficient and pancreatic insufficient patients were observed. It is concluded that the 3849 + 10kb C --> T mutation is associated with a variable but potentially mild type of CF.

Adult↗
PubMed1998

Bone marrow metastasis in astrocytic gliomata.

With the increasing survival time of many pediatric patients with malignancies, unexpected symptoms or signs require diligent search for rare complications or second cancers related to the disease or treatment. We recently encountered a patient with extensive glioblastoma multiforme who developed pancytopenia six months after completion of treatment with craniospinal radiation and chemotherapy with etoposide and cyclophosphamide. Bone marrow aspirate and biopsy confirmed bone marrow metastasis from the brain tumor. He showed good partial remission with chemotherapy with carmustine and cis-platinum as demonstrated by serial bone marrow aspirate for cytology and cytogenetics and enjoyed good quality of life for eight months. 14 other patients with astrocytic glioma, two of whom are children, are reported in the literature to have diffuse bone marrow metastasis. Therefore, in patients with malignant astrocytic tumor, bone marrow metastasis, though not common, should be considered when bone pain or cytopenias occur, especially when prolonged.

Adolescent↗
PubMed1998

Mutation, selection, and memory in B lymphocytes of exothermic vertebrates.

Unlike mammals, cold-blooded vertebrates produce antibodies of low heterogeneity that show little increase in binding affinity with time after immunization. In secondary responses, antibody titers and affinities are often little, if any, higher than in primary responses. That is, specificity, diversity, and memory--the hallmarks of the immune system--are rather meager in the humoral immune responses of exothermic vertebrates. As the genetic components of the immunoglobulin (Ig) gene systems in fishes, amphibians or reptiles are not deficient in number or diversity, their responses probably do not stem from restrictions in the primary antibody repertoire. Somatic hypermutation at the Ig locus, which generates diversity and higher affinity antibodies in mammals, is not lacking in the South African frog Xenopus or in the shark. However, the Ig mutants recovered are strongly biased toward alterations at GC pairs, an indication that they have not undergone effective selection. While cells resembling follicular dendritic cells are present in cold-blooded vertebrates, germinal centers do not form. It is suggested that this absence of germinal centers, the site of selection for the mutants with higher affinity receptors and of differentiation into memory B cells in mammals, may explain the principal differences between cold and warm-blooded vertebrates.

Alleles↗