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Biomedical subjects

C H Wang

Publications and source records attributed to C H Wang.

At least 19 recordsLinked to original sources
PubMed1992

Hodgkin's disease and non-Hodgkin's lymphoma containing Reed-Sternberg-like giant cells in Taiwan. A clinicopathologic analysis of 50 cases.

Hodgkin's disease (HD) is uncommon in Taiwan. In reviewing the clinicopathologic features of 50 cases, the authors found that the diagnosis of HD was complicated with non-Hodgkin's lymphoma (NHL). Fourteen cases were reclassified as NHL containing Reed-Sternberg (RS) giant cells, mostly peripheral T-cell lymphoma (PTL), and 34 cases as classic HD, which included 8 cases of lymphocyte predominance, 10 of nodular sclerosis, 12 of mixed cellularity, and 4 of lymphocyte depletion. For cases of HD, there was a bimodal age-incidence distribution with peaks at the third and fifth decades; 61.8% manifested Stage B symptoms and 80.6% had Stage III/IV disease. The group of patients with NHL, compared with those with classic HD, was found to be older (mean age, 41.4 years versus 33.1 years; P less than 0.05), to have more extranodal disease (35.7% versus 8.8%, P less than 0.05), less complete remission rate (25% versus 67.9%, P less than 0.05), and shorter median survival (29 months versus 90 months). Most of the NHL patients originally were diagnosed as having atypical or unclassified HD. Thus, the authors conclude that the previous observation of a predominance of mixed cellularity HD in Asian regions may be attributable to the inclusion of PTL, which may mimic HD in histology. Because there is a marked difference in clinical behavior and prognosis, it is important to distinguish between HD and NHL containing RS giant cells in an area with a high incidence of PTL.

Adult↗
PubMed1992

Nucleotide sequence comparison of the 3'-terminal regions of severe, mild, and non-papaya infecting strains of papaya ringspot virus.

The 3'-terminal 2,561 nucleotide residues of the severe HA strain of papaya ringspot virus (PRSV) was determined. Comparison with the published sequence of the mild strain PRSV HA 5-1 showed that they shared a 99.4% identity in their 3'-terminal 2,235 residues. There were ten residues different at the NIb gene, resulting in five amino acid changes, and two residues different in the coat protein gene, resulting in two amino acid changes. The 3'-untranslated regions were identical, but HA contained two more nucleotides (AG) at the 3' extreme. Comparison with the published non-papaya infecting type W strain PRSV-W revealed that they shared a 97.9% identity in their 3'-terminal 2,235 residues. There were 40 nucleotides different in the coding region, which resulted in four amino acid changes in the NIb gene and six in the CP gene, and seven nucleotides different in the 3'-untranslated region.

Amino Acid Sequence↗
PubMed1992

Cytogenetic study of acute lymphoblastic leukemia and its correlation with immunophenotype and genotype.

Among 72 Chinese patients with acute lymphoblastic leukemia (ALL), 50 had clonal chromosomal abnormalities. Structural abnormalities were detected in 42 patients: these included t(9;22) in 9, t(1;19) in 6, t(4;11) in 5, del(11)(q23) in 4, and del(6q) in 4. Adults had a higher incidence of t(9;22) and t(1;19) but a lower incidence of t(4;11) and hyperdiploid greater than 50 karyotype than children. A significant difference was also noted in white blood cell (WBC) count among various karyotypic groups. Patients with chromosomal abnormalities t(9;22), t(1;19), t(4;11) and del(11) (q23) had a shorter complete remission duration as compared with patients free of these abnormalities. Immunophenotyping was performed on 69 patients. All patients with t(9;22), t(1;19), and t(4;11) had B-lineage ALL restricted to certain stages of maturation: groups III and IV, groups IV and V, and group II, respectively (according to the classification of Foon and Tood). Among patients with t(9;22), t(4;11), and del(11)(q23), which have been considered to be associated with acute mixed-lineage leukemia, one each, respectively, showed myeloid antigen expression on the leukemic blasts (My+ ALL). No cross-lineage rearrangements of immunoglobulin (Ig) or T-cell receptor (TCR) genes were detected in these karyotypic subgroups of patients who underwent gene analysis.

Adolescent↗
PubMed1992

Fine-mapping of the spinal muscular atrophy locus to a region flanked by MAP1B and D5S6.

The microtubule-associated protein 1B (MAP1B) locus has been mapped in close proximity to spinal muscular atrophy (SMA) on chromosome 5q13. We have identified a second microsatellite within a MAP1B intron, which increases the heterozygosity of this locus to 94%. Two unambiguous recombination events establish MAP1B as a closely linked, distal flanking marker for the disease locus, while a third recombinant establishes D5S6 as the proximal flanking marker. The combination of key recombinants and linkage analysis place the SMA gene in an approximately 2-cM interval between loci D5S6 and MAP1B. Physical mapping and cloning locate MAP1B within 250 kb of locus D5S112. The identification and characterization of a highly polymorphic gene locus tightly linked to SMA will facilitate isolation of the disease gene, evaluation of heterogeneity, and development of a prenatal test for SMA.

Base Sequence↗
PubMed1992

Characterization of Philadelphia-chromosome-positive acute leukemia by clinical, immunocytochemical, and gene analysis.

Philadelphia chromosome (Ph') was detected at presentation in 10 out of 110 patients with acute lymphoblastic leukemia (ALL) and five of 168 patients with acute myelogenous leukemia (AML). Two other ALL patients who had studies at relapse were also included in the analyses. One of the 12 Ph'-positive (Ph+) ALL patients had simultaneous expression of myeloid-associated antigen on the leukemic blasts, while all the five AML patients coexpressed markers of lymphoid cells. Double labeling of the cells with myeloperoxidase and CD10 on three Ph+ AML cases showed that most leukemic blasts expressed either myeloperoxidase activity or CD10 but not both. Cross-lineage gene rearrangements of T-cell receptor (TCR) beta-chain gene were detected in three of the eight Ph+ ALL patients tested. All the four Ph+ AML cases studied showed immunoglobulin heavy chain gene rearrangements, and three of them also had simultaneous rearrangements of TCR beta-chain gene. The results revealed that Ph+ acute leukemia in this study belonged either to ALL or mixed lineage leukemia, and none was pure AML. This finding is contrary to that of acute blast crisis of chronic myelogenous leukemia in which the majority of patients had myeloid transformation. Rearrangements of bcr were detected in four of the 10 Ph+ ALL and three of the four Ph+ AML patients tested. No significant difference was noted in the clinical or hematologic manifestations among Ph+ leukemia with or without bcr rearrangements.

Adult↗
PubMed1992

Meningeal carcinomatosis from solid tumors: clinical analysis of 42 cases.

From January 1984 to June 1990, we observed 42 patients with meningeal carcinomatosis, 20 men and 22 women, aged 21 to 80 years (median age, 53 years). The two most common primary malignancies were lung cancer (50%) and breast cancer (31%). Sixty-four per cent was adenocarcinoma. On the first lumbar puncture, 86% had malignant cells in the cerebrospinal fluid. The findings of brain computed tomography were hydrocephalus (62%), contrast enhancement in the cerebral sulci or basal cisterns (31%), concomitant parenchymal metastases (15%) and normal scan (18%). In five out of seven cases, myelography showed irregular filling defects over the spinal cord or cauda equina. Treatment results were evaluated in 24 patients. Eight received radiation therapy (RT) alone, and 16 had combined therapy with RT plus intrathecal methotrexate (IT MTX). Of the patients who received RT alone, only one patient with lung carcinoma was stabilized clinically. Of the cases receiving combined therapy, seven improved clinically. Six of these were patients with breast carcinoma who received IT MTX via Ommaya reservoir. The latter had a median survival of 23 weeks. The follow-up period of the entire group of patients ranged from one day to 50 weeks. The median survival was four weeks. Based on this study, combined therapy with RT and IT MTX is indicated for breast carcinoma with meningeal carcinomatosis, but the therapeutic effects are uncertain for lung carcinoma and other malignancies.

Adult↗
PubMed1992

Prognosis of thymic carcinoma: analysis of 16 cases.

Primary thymic carcinoma is a rare malignant neoplasm which arises from the thymic epithelium. Between May 1982 and September 1990, 16 patients with thymic carcinomas, diagnosed at Chang Gung Memorial Hospital, were reviewed. Their ages ranged from 19 to 75 years, with a median of 40 years. Males predominated (male to female ratio was 11:5). The most common presenting symptoms were chest pain, cough, body weight loss and dyspnea. No paraneoplastic syndromes were seen. Chest roentgenograms of 15 patients revealed a mediastinal mass, but a definitive diagnosis could not be made until surgery. Adjacent mediastinal tissues were invaded, or adhered to, by all the tumors. Six distinct histologic types were found, squamous cell carcinoma being the most common (seven cases). The primary treatment of surgical resection was attempted in 14 patients, but only in five cases could the tumors be completely resected; two had a biopsy only. Radiotherapy, with or without chemotherapy, given postoperatively, achieved additional local control in seven of the nine partially resected patients (77%). Distant metastasis occurred in nine of 16 patients (56%). Lymph nodes, bone and lung were the most common metastatic sites. Chemotherapy with cisplatin and/or adriamycin-based regimens was given to patients who had distant metastasis, but the responses were unsatisfactory. The overall survival at one, three and five years was 88%, 51% and 31%, respectively. The median survival was 30 months. The median survival of patients with pure squamous cell carcinoma (> 49 months) was superior to that of patients with other histologic types (18 months; p < 0.01).

Adult↗
PubMed1992

Cloning and expression of a high affinity taurine transporter from rat brain.

A cDNA clone (designated rB16a) encoding a taurine transporter has been isolated from rat brain, and its functional properties have been examined in mammalian cells. The nucleotide sequence of the clone predicts a 621-amino acid protein with significant homology to other neurotransmitter transporters. Hydropathy analysis reveals stretches of hydrophobic amino acids indicative of 12 transmembrane domains, similar to those proposed for other cloned neurotransmitter transporters. The transporter displays high affinity for taurine (Km approximately 40 microM) and is dependent on external sodium and chloride for transport activity. Specific transport is sensitive to inhibition by beta-alanine and gamma-aminobutyric acid, similar to taurine transporters in vivo. Localization studies demonstrate that the transporter mRNA is located in both the brain and peripheral tissues. The structural similarity of the taurine transporter to neurotransmitter transporters is consistent with a neuromodulatory role for taurine in the nervous system.

Amino Acid Sequence↗
PubMed1992

[The stress distribution of prefabricated screw posts. Part III: Techniques].

Some commonly used endodontic screw posts were analysed for various techniques of post insertion by photoelastic stress distribution. These endodontic dowels were installed in assumed clinical conditions. These conditions included: (1) no backing off during post installation, (2) the channelling of the post without cleaning, (3) a smaller drill was used prepare the post channel, and (4) an axis deviated contrangle was used to prepare the post channel. According to this photoelastic analysis, the techniques of post insertion may affect the stress distribution. Suggestions for post insertion are as follows: 1. The stress can be reduced by counterrotating the dowel one-fourth turn after resistance to installation has been detected. 2. The channel should be cleaned thoroughly before post insertion. 3. Because accurate post fit is important to maximize both retention and support, the screw post should be used with the matched post/reamer system; and accurate contrangle drilling should be maintained.

Humans↗
PubMed1992

Characterization of cellular and molecular immune effectors against Trichinella spiralis newborn larvae in vivo.

The cellular and molecular immune effectors that participated in host immunity against Trichinella spiralis newborn larvae were characterized in vivo using AO rats. Donor rats were immunized with 2,000 muscle larvae orally or 11,400 newborn larvae i.v. Immune serum and cells from spleen, peripheral lymph nodes, mesenteric lymph node, thoracic duct lymph and the peritoneal cavity were obtained from donor rats 10-21 days after infection and transferred into normal recipient rats. The control recipients received either no cells and serum or normal cells and normal serum obtained from normal donors. Newborn larvae (20,000-50,000) were injected either i.v. or ip into these recipients and immunity against newborn larvae was measured either by muscle larvae burden of the recipients three weeks later or by direct recovery of newborn larvae from the peritoneal cavity of the recipients. The experiments demonstrated that immune lymphocytes conferred no protection in the recipients but that immune serum and immune peritoneal cells were protective and these effects were synergistic. Cell adherence to the cuticle and killing of newborn larvae were observed in the peritoneal cavity of immune rats. Positive fluorescence was observed on newborn larvae incubated with fractionated IgM and IgG(E) antibody isotypes. Massive deposition of antibody molecules on newborn larvae was demonstrated by scanning electron microscopy. Studies using transmission electron microscopy revealed that the larval adherent cells were stimulated macrophages, neutrophils and eosinophils.

Animals↗
PubMed1991

13-cis-retinoic acid induces cellular differentiation and durable remission in refractory cutaneous Ki-1 lymphoma.

A 35-year-old man with refractory cutaneous Ki-1 lymphoma was salvaged successfully with oral 13-cis-retinoic acid (1 mg/kg/day). He had a complete remission lasting for 20 months before a single nodule recurred on his skin. Excisional biopsy of the recurrent tumor revealed a distinct morphologic change, suggesting cellular differentiation toward a more benign phenotype. No significant side effects were noted except mild xerostomia, bone pain, and hyperlipidemia. The authors believe that 13-cis-retinoic acid should be considered in the treatment of cutaneous Ki-1 lymphoma.

Adult↗
PubMed1991

A role for IgE in intestinal immunity. Expression of rapid expulsion of Trichinella spiralis in rats transfused with IgE and thoracic duct lymphocytes.

In these experiments we characterize the protective antibodies in immune serum that interact synergistically with immune thoracic duct lymphocytes (TDL) to induce rapid expulsion (RE) of Trichinella spiralis in adult rats. Antibodies with both reaginic and nonreaginic activity mediated RE upon passive transfer to adult rats that had been adoptively transfused with immune TDL 7 days earlier. In serum collected 28 days after a primary infection, the most important antibody was homocytotropic IgE. Native IgE produced by active infection was isolated from 28-day immune serum by salt precipitation and/or by sequential affinity chromatography. The murine mAb A2 and B5 (anti-rat IgE) were conjugated separately to Sepharose 4B affinity columns for affinity separations. IgE was shown to be pure by gel electrophoresis and Western blots and its m.w. was estimated at approximately 190,000. As little as 183 micrograms of purified IgE could induce RE after passive transfer to adult rats. The IgE was shown to be functional by PCA activity, Ag-binding on Western blots, and skin sensitization; the latter could be blocked by pretreatment with 1R162, a rat myeloma IgE. Monoclonal IgG of any isotype transferred in amounts up to 35 mg/rat could not transfer RE to rats previously transfused with TDL cells. Immune serum collected 3 mo after the primary infection contained insufficient IgE to transfer RE, but complex non-IgE fractions were protective. The data thus demonstrate that IgE is a functional Ig in the rat capable of mediating the rejection of challenge nematode infections of the gut in the absence of other specific Ig. Secondly, other Ig may also play a role, in particular, several weeks after the primary infection when specific IgE levels in serum have declined.

Animals↗
PubMed1991

Age differences in the proliferative response of cultured arterial smooth muscle cells induced by sera of hypothalamically-stimulated rats.

In an earlier report, it was shown that arterial smooth muscle cells (ASMC) cultured from normal rat aorta, proliferated in response to homologous sera from young rats which had received hypothalamic stimulation (HS), in contrast to the effect of sera from non-stimulated age-matched controls (sham-operated). In the present study, this proliferative response was compared in young and old rats. Isolated target cells were subcultured from primary explants of aortic tissue obtained from young, male, Fischer 344 rats, which were electrode-implanted in the hypothalamus but not stimulated. After an initial quiescence period (growth arrest), target cells were exposed to plasma derived serum (PDS) from 4 experimental groups: young stimulated rats; young sham-operated controls; aged stimulated rats and aged sham-operated controls, at PDS concentrations of 2.5% and 5.0% and counted at days 2 and 5. Proliferative responses of ASMC were found to be influenced by concentration of the PDS, age of the donor animal contributing the serum and the presence of HS. The greatest responses were observed in relation to sera derived from aged stimulated rats, especially at the higher concentration, suggesting an interaction of HS with advanced age. These results are discussed in reference to their possible bearing on the pathogenesis of atherosclerosis.

Aging↗
PubMed1991

Growth retardation in senescent arterial smooth muscle cells and its reversal following brain stimulation: implications for atherogenesis.

Advancing age and psychosocial stress are each associated with a rising incidence of atherosclerosis. In this investigation we attempted to answer the question of whether they are independent of each other or not. Since a key feature of atherosclerosis is the proliferation of arterial smooth muscle cells (ASMC), we transplanted aortic tissue from aged rats, half of which had received hypothalamic stimulation, as a model for stress, to growth supporting medium, immediately after stimulation and observed their growth behavior for a period of 4 months. Similar observations were carried out on young animals for comparison. Although there was little difference in outgrowth frequency of explants from young animals between stimulated and non-stimulated subjects, in the case of the older rats, explants from animals which were not stimulated were considerably retarded in their growth, whereas those from subjects which had received HS, grew as well as those of the younger ones. These results show that HS can reverse the growth decline in aortic tissues explanted from senescent rats. They also suggest that age per se is not atherogenic in terms of proliferative behavior of ASMC, whereas when interacted with a stressful condition, this may be the case. Since in the elderly there is a decreased tolerance to stress, the 'atherogenic' effects of age in these individuals may be mediated through the stress response.

Aging↗