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Biomedical subjects

C M Huang

Publications and source records attributed to C M Huang.

At least 19 recordsLinked to original sources
PubMed1998

Measuring parallel fiber length in the rat cerebellum.

A new approach was devised to obtain the mean length of parallel fibers in Golgi sections of the rat cerebellum. This method was based on the principle that within a given region of the cerebellum the mean length of parallel fibers should be inversely proportional to the likelihood of spotting the ends of parallel fibers. An experimental protocol was designed based on the statistical relationship between the mean fiber length and the number of the ends of parallel fibers for a given total length of parallel fibers examined. Our methodology was simple and could have advantages over other existing methods.

Animals↗
PubMed1998

Unilateral sacroiliitis as an unusual complication of acupuncture.

Septic sacroiliitis is an uncommon disease and is rarely reported as a complication of acupuncture. We present a case of unilateral septic sarcoiliitis, which developed as a complication of acupuncture because of failure to sterilise the skin properly before treatment. Bone scan and computed tomography were positive for sacroiliitis. After a course of antibiotics with oxacillin for 6 weeks, the condition was completely improved. This case report stresses the importance of sterilisation procedures before acupuncture therapy.

Acupuncture Therapy↗
PubMed1998

Ultrasound-guided fine needle aspiration biopsy in the diagnosis of pulmonary cryptococcosis.

The purpose of this study was to assess the safety and reliability of ultrasound-guided fine needle aspiration biopsy (US-guided FNAB) combined with modified Papanicolaou's staining in the diagnosis of pulmonary cryptococcosis. The study included 10 patients (9 men, 1 woman, 28-70 yr). Percutaneous US-guided FNAB was performed through a puncture probe with central channel guidance (n = 8) or in a 'free-hand' manner (2), depending on the size of the lesion and the experience of the operator. Sonography disclosed homogeneously hypoechoic lesions with air bronchograms over the peripheral or central portion in nine patients, and occasional heterogeneous echogenicity with necrotic tissue without air bronchogram in one. Thirteen lesions were found on the chest radiographs of the 10 patients; these could be divided into three patterns: infiltrates (2), nodules or masses (7), and consolidation (4). Using US-guided FNAB and immediate modified Papanicolaou's stain, a diagnosis of pulmonary cryptococcosis was confirmed in nine of the 10 patients. The remaining case was proven by surgical resection. No major complications developed after US-guided FNAB. We conclude that this technique, combined with modified Papanicolaou's staining, provides a safe, rapid, and reliable method for diagnosing pulmonary cryptococcosis.

Adult↗
PubMed1997

The enhanced tumorigenic activity of a mutant epidermal growth factor receptor common in human cancers is mediated by threshold levels of constitutive tyrosine phosphorylation and unattenuated signaling.

Deregulation of signaling by the epidermal growth factor receptor (EGFR) is common in human malignancy progression. One mutant EGFR (variously named DeltaEGFR, de2-7 EGFR, or EGFRvIII), which occurs frequently in human cancers, lacks a portion of the extracellular ligand-binding domain due to genomic deletions that eliminate exons 2 to 7 and confers a dramatic enhancement of brain tumor cell tumorigenicity in vivo. In order to dissect the molecular mechanisms of this activity, we analyzed location, autophosphorylation, and attenuation of the mutant receptors. The mutant receptors were expressed on the cell surface and constitutively autophosphorylated at a significantly decreased level compared with wild-type EGFR activated by ligand treatment. Unlike wild-type EGFR, the constitutively active DeltaEGFR were not down-regulated, suggesting that the altered conformation of the mutant did not result in exposure of receptor sequence motifs required for endocytosis and lysosomal sorting. Mutational analysis showed that the enhanced tumorigenicity was dependent on intrinsic tyrosine kinase activity and was mediated through the carboxyl terminus. In contrast with wild-type receptor, mutation of any major tyrosine autophosphorylation site abolished these activities suggesting that the biological functions of DeltaEGFR are due to low constitutive activation with mitogenic effects amplified by failure to attenuate signaling by receptor down-regulation.

Amino Acid Sequence↗
PubMed1997

Hyperprolactinemia in systemic lupus erythematosus.

BACKGROUND: Recent evidence demonstrates that hyperprolactinemia was found in active systemic lupus erythematosus (SLE). This indicates prolactin (PRL) is an important immunoregulator and may play a role in the pathogenesis of SLE. However, study of the prevalence and the clinical significance of hyperprolactinemia in SLE and other rheumatic disease has rarely been carried out. METHODS: From January 1995 to January 1996, 79 individuals were enrolled in this study. PRL levels of 30 cases of SLE were compared with those in 29 rheumatoid arthritis (RA) and 20 normal healthy volunteers. Moreover, a correlation between levels of PRL and SLE disease activity index (SLEDAI) in SLE patients was studied. RESULTS: The mean value of serum PRL level in SLE patients (19.35 +/- 11.33 ng/dl) was significantly higher than in RA patients (12.33 +/- 8.30 nd/dl, p < 0.05). The difference was more pronounced between SLE patients and healthy individuals (12.01 +/- 7.53 ng/dl, p < 0.01). However, patients with RA had no significant difference from the control group. Analysis made between SLEDAI and PRL levels in SLE patients revealed no significant correlation (r = 0.537, p = 0.07). Furthermore, no significant correlation was found between antinuclear antibody (ANA), C3, C4, anti-DNA and hyperprolactinemia. CONCLUSIONS: This study has shown that hyperprolactinemia is prevalent in random SLE patients, but not in RA patients. The elevated PRL levels seem not to be associated with disease activity and ANA positivity.

Adolescent↗
PubMed1997

Importance of sputum differential cell counting in the diagnosis of airway diseases.

We examined the sputum of 114 subjects by noninvasive methods (voluntary coughing or induced cough with hypertonic saline) to determine whether sputum examination could be used to separate patients with episodic wheezing, dyspnea or cough of unknown origin into different diagnostic categories. An increased percentage of sputum eosinophils was seen in 92% (48/52) of asthmatics, 36% (9/25) of patients with chronic obstructive pulmonary disease (COPD) and 28% (7/25) of chronic coughers, but not in any of the 12 patients with congestive heart failure (CHF). Eight patients with combined symptoms of COPD and asthma (mixed COPD subgroup) showed above average diurnal peak expiratory flow variation (10.3 +/- 2.1% vs 2.5 +/- 1.4%, p < 0.05) and an above average percentage of sputum eosinophils (19.8 +/- 9.1 vs 2.1 +/- 3.2, p < 0.01) than those in the pure COPD group. After therapeutic corticosteroid trial, all of the mixed COPD patients and six of the 17 pure COPD patients were steroid responders. Seven of the 25 chronic coughers had sputum eosinophilia, but no asthmatic symptoms. The cough symptoms subsided in five of these seven patients after steroid treatment but not in the other 18 chronic coughers. Further study is indicated to determine if simple eosinophilic bronchitis is an early stage of asthma. In conclusion, sputum differential cell counting is a useful noninvasive diagnostic tool in differentiating diseases with episodic wheezing or chronic cough.

Adolescent↗
PubMed1996

Suppression of glioblastoma angiogenicity and tumorigenicity by inhibition of endogenous expression of vascular endothelial growth factor.

The development of new capillary networks from the normal microvasculature of the host appears to be required for growth of solid tumors. Tumor cells influence this process by producing both inhibitors and positive effectors of angiogenesis. Among the latter, the vascular endothelial growth factor (VEGF) has assumed prime candidacy as a major positive physiological effector. Here, we have directly tested this hypothesis in the brain tumor, glioblastoma multiforme, one of the most highly vascularized human cancers. We introduced an antisense VEGF expression construct into glioblastoma cells and found that (i) VEGF mRNA and protein levels were markedly reduced, (ii) the modified cells did not secrete sufficient factors so as to be chemoattractive for primary human microvascular endothelial cells, (iii) the modified cells were not able to sustain tumor growth in immunodeficient animals, and (iv) the density of in vivo blood vessel formation was reduced in direct relation to the reduction of VEGF secretion and tumor formation. Moreover, revertant cells that recovered the ability to secrete VEGF regained each of these tumorigenic properties. These results suggest that VEGF plays a major angiogenic role in glioblastoma.

Animals↗
PubMed1996

Characterization of human leucocytes bearing the IL-3 receptor.

Human leucocytes from peripheral blood and tonsil were examined for the presence of the IL-3 receptor using monoclonal antibodies directed to epitopes of the alpha and beta chains of the receptor. We found that the beta chain, common to IL-3, IL-5, and GM-CSF, was either present at low levels or not detected on the majority of peripheral blood and tonsil B lymphocytes, while the alpha chain showed a distinct but restricted distribution. In peripheral blood the IL-3R alpha chain was limited to a subpopulation of peripheral B lymphocytes and a population of cells which lack lineage-specific markers. Dimly staining cells were identified as B lymphocytes as they coexpressed CD19, CD20, CD22, CD24, and HLA-DR. A brightly staining population lacks T and B lymphocyte, NK specific, and macrophage lineage markers but expresses CD9, CD45RO, CD26, and, in a proportion of cells, CD36 and CD60. This population remains unclassified. In tonsil tissue IL-3R alpha chain expression was strongest on B lymphocytes present in the T cell rich areas of tonsillar tissue. The IL-3R alpha bearing B tonsil cells included cells in both CD23 and IgD positive and negative populations. The phenotype of the IL-3R alpha positive B cells defines them as a population of B lymphocytes distinct from previously characterized cells in the lymphoid architecture. Lymphoblastoid cell lines with a corresponding phenotype were also identified.

Antigens, CD↗
PubMed1996

Isolation and characterization of bacteriocin-producing lactic acid bacteria from ready-to-eat food products.

Lactic acid bacteria isolated from a range of foods sold in ready-to-eat form were screened for bacteriocin production. Twenty-two bacteriocin-producing cultures were isolated from 14 of the 41 foods sampled. Bacteriocin-producing isolates from meat, fish and dairy products were Lactobacillus and Leuconostoc species typically found associated with these products. Most of these isolates gave only a narrow inhibitory spectrum although two showed activity against Listeria monocytogenes. Fruit and vegetable products gave a broader range of organisms but most of the bacteriocin-producing cultures were found to be strains of Lactococcus. Several lactococci produced a nisin-like activity, and showed a broad inhibitory spectrum against the indicator strains tested. The ease with which bacteriocin-producing strains could be isolated implies that they are already being safely consumed in food, and highlights the potential for using bacteriocin-producing cultures for biopreservation, especially in association with minimally processed products.

Bacteriocins↗
PubMed1996

Nerve growth factor, epidermal growth factor, and insulin differentially potentiate ATP-induced [Ca2+]i rise and dopamine secretion in PC12 cells.

To study how growth factors affect stimulus-secretion coupling pathways, we examined the effects of nerve growth factor (NGF), epidermal growth factor (EGF), and insulin on ATP-induced [Ca2+]i rise and dopamine secretion in PC12 cells. After a 4-day incubation of cells, all three factors increased ATP-induced dopamine secretion significantly. We then examined which step of ATP-induced secretion was affected by the growth factors. Cellular levels of dopamine-beta-hydroxylase and catecholamines were increased by NGF treatment but were not affected by EGF or insulin. The ATP-induced [Ca2+]i rise was also enhanced after growth factor treatment. The EC50 of ATP for inducing [Ca2+]i rise and dopamine secretion was increased by NGF treatment but not by treatment with EGF or insulin. Accordingly, the dependence on [Ca2+]i of dopamine secretion was increased significantly only in NGF-treated cells. Our results suggest that for EGF- and insulin-treated PC12 cells, the increase in secretion is mainly due to increased potency of ATP in inducing [Ca2+]i rise. NGF treatment not only increased the potency of ATP but also decreased the Ca2+ sensitivity of the secretory pathway, which as a result becomes more tightly regulated by changes in [Ca2+]i.

Adenosine Triphosphate↗
PubMed1996

Role of Ca2+ in differentiation mediated by nerve growth factor and dibutyryl cyclic AMP in PC12 cells.

Nerve growth factor (NGF) and dibutyryl cyclic AMP (dbcAMP) have synergistic effects on the neurite outgrowth of rat pheochromocytoma PC12 cells. The sites of interaction between NGF and dbcAMP have been studied extensively; however, the role of Ca2+ in differentiation induced by the two agents remains unclear. To understand whether intracellular Ca2+ is involved in the differentiation induced by the two agents, PC12 cells were treated with NGF, dbcAMP, or NGF plus dbcAMP for 2 days, and then effects on neurite outgrowth, ATP-induced Ca2+ influx, and Ca2+ mobilization from intracellular Ca2+ pools were examined. NGF or dbcAMP alone enhanced neurite outgrowth and Ca2+ accumulation by nonmitochondrial Ca2+ pools or the thapsigargin (TG)-sensitive Ca2+ pool. The dbcAMP acted synergistically with NGF to increase neurite outgrowth and to enlarge the TG-sensitive Ca2+ pool. The synergistic effect occurred within the first hour of treatment with dbcAMP plus NGF. On the other hand, dbcAMP abolished NGF's ability to enhance ATP-induced influx of extracellular Ca2+ . Therefore, NGF and dbcAMP induced different effects on Ca2+ signaling pathways through two different but interacting pathways. In PC12 cells pretreated with TG to deplete the TG-sensitive Ca2+ pool, the dbcAMP- or dbcAMP plus NGF-mediated neurite outgrowth was significantly inhibited, whereas NGF-mediated neurite outgrowth was not affected by TG pretreatment. Our results suggest that the intracellular nonmitochondrial Ca2+ pools were changed in the differentiation process and were necessary for the synergistic effect of NGF and dbcAMP.

Adenosine Triphosphate↗
PubMed1996

Changing epidemiology of triplet pregnancy: etiology and outcome over twelve years.

Neonates of 34 triplet pregnancies were admitted to our neonatal unit over a twelve-year period (1983 to 1995), with an incidence of 1 out of 812 deliveries. Thirty (88%) of the pregnancies were the result of ovulation induction and artificial fertilization: artificial insemination from husband (n = 3), in vitro fertilization (n = 9), and gamete intra-fallopian transfer (n = 6). All except one had antenatal sonographic diagnosis, 79% in the first trimester. The most common pregnancy-related complication was preterm labor (56%). Twenty-seven (79%) were delivered by cesarean section. There were 101 live births (one stillborn). Mean gestation age was 33.6 +/- 2.94 weeks, mean birthweight 1809 +/- 485 g, with 7 extremely low birthweight (< 1000 g [6.8%]). Neonatal complications included respiratory distress syndrome (12%), intraventricular hemorrhage (8.8%), retinopathy of prematurity (8%), sepsis (3%), severe asphyxia (3%), and omphalopagus conjoined twins (1%). The perinatal and neonatal mortality was 49 per 1000 and 59 per 1000, respectively. The introduction of advanced artificial fertilization techniques and ovulation induction agents resulted in a major increase in multifetal gestations. Early prenatal diagnosis, judicious prolongation of gestation, and planned delivery by cesarean section combined with major improvement in neonatal care by experienced neonatologists has improved survival of triplet neonates.

Adult↗
PubMed1996

Effect of Ozonation on the biodegradability of atrazine in GAC columns.

The biodegradation of atrazine as influenced by preozonation was studied in biological GAC columns. Metabolism of isopropyl-14C atrazine produced more 14CO2 than ring-UL-14C atrazine, indicating dealkylation was more rapid than ring cleavage. Preozonation increased mineralization of ring-UL-14C atrazine and, consequently, enhanced the performance of GAC columns. Sixty-two percent of the influent atrazine was converted to 14CO2 in columns that received ozonated atrazine and ozonated surface water, while 50% of the influent atrazine was converted to 14CO2 in columns that received untreated atrazine and ozonated surface water, and only 38% of the influent atrazine was converted to 14CO2 in columns with untreated influent.

Absorption↗
PubMed1996

Ultrasound-guided fine needle aspiration biopsy of small pulmonary nodules abutting to the chest wall.

BACKGROUND: Ultrasound (US)-guided needle biopsies in peripheral pulmonary lesions are widely applied. Most pulmonary lesions had a large size. We report our results in evaluating the availability of US-guided fine needle aspiration biopsy (US-guided FNAB) in diagnosing small pulmonary nodules abutting to the chest wall. METHODS: Forty patients, whose chest radiographs showed peripheral pulmonary nodules of diameter smaller than 3.0cm, received chest sonographic examination and US-guided FNAB. Of those, six patients had no definite diagnoses; the remaining 34 patients with pulmonary nodules, we divided into three groups. There were four tiny nodules of diameters smaller than 1.0cm, 11 nodules between 1.1 and 2.0cm, and 19 nodules between 2.1 and 3.0cm. We evaluated the diagnostic yields and rates of complication in relation to the size or nature of the nodule. RESULTS: In the enrolled 40 patients, six were lost to surveillance and had indeterminate diagnoses. Of the remaining 34 patients with proven pathological diagnoses and compatible clinical conditions, the diagnostic yields of US-guided FNAB achieved 88% (30/34) which include 96% (26/27) in malignancies and 57% (4/7) in benign nodules. According to the nodular size, the diagnostic rate achieved 100% (4/4) in tiny nodules, 91% (10/11) in nodules between 1.1 and 2.0cm, and 84% (16/19) in nodules between 2.1 and 3.0cm. Only one patient with a 2.5-cm nodule developed pneumothorax after the US-guided FNAB procedure. CONCLUSIONS: US-guided FNAB is a useful and safe diagnostic tool for small pulmonary nodules abutting to the chest wall. The nodular nature, but not size, affects the diagnostic yields and rates of complication.

Adult↗
PubMed1995

Translocation of ferritin and biomineralization of goethite in the radula of the limpet Cellana toreuma reeve.

The radula of the limpet, Cellana toreuma, consists of a continuous series of teeth in various stages of iron biomineralization. The major iron-binding protein of the limpet's iron-containing granule (siderosome) has been purified and identified as ferritin. Limpet ferritin has a M(r) of 575 kDa and can be resolved into two bands by SDS-PAGE analysis, with respective M(r)s of 26 and 21 kDa. The partial N-terminal amino acid sequences of these two subunits were confirmed, and antisera against them were respectively generated. The specifity of these two antisera shows no difference between them. By using transmission electron microscopy and immunogold staining techniques the following two events were revealed: (1) in the superior epithelial cell of the radula, ferritin was disassembled through autophagy or heterophagy before exocytosis; (2) of the limpet ferritin, at least the 26-kDa subunit was found to pass through the microvilli, resulting in the accumulation of iron in the extracellular tooth chamber and the formation of goethite needles. Intracellular ferritin being translocated to the extracellular environment is discussed in the text.

Amino Acid Sequence↗
PubMed1995

Differentiation of dextran-producing Leuconostoc strains from fermented rice cake (puto) using pulsed-field gel electrophoresis.

Lactic acid bacteria were isolated from puto, a fermented rice cake consumed as a breakfast and snack food in the Philippines. The microflora was dominated by dextran-producing leuconostocs, and these were differentiated into four groups using pulsed-field gel electrophoresis of restriction enzyme digested chromosomal DNA, in conjunction with taxonomic tests. The four groups corresponded to the species Leuconostoc mesenteroides subsp. mesenteroides, Leuconostoc pseudomesenteroides, Leuconostoc citreum and Leuconostoc fallax. Several strains showed an unusual clumping phenotype, and two of these were capable of inhibiting other strains of lactic acid bacteria.

Bacteriocins↗
PubMed1995

Localization, interaction, and RNA binding properties of the V(D)J recombination-activating proteins RAG1 and RAG2.

The RAG1 and RAG2 gene products are indispensable for activating somatic rearrangement of antigen receptor gene segments. The two proteins form a stable complex in primary thymocytes as well as when expressed in adherent cells. In both cell types, most cells localize RAG proteins at the periphery of the nucleus. However, when overexpressed in fibroblast cells, RAG1 is found largely in the nucleolus. Nucleolar localization of RAG1 is mediated by several domains containing stretches of basic amino acids, indicating that RAG1 has affinity for RNA or ssDNA. The RAG1 interacting proteins SRP1 and Rch1 directly bind to the nuclear localization signals of RAG1, which mediate the nuclear and nucleolar translocation of the protein. RAG1 appears to have a binary structure, each half containing multiple regions that can act as NLSs, binding sites for the SRP1/Rch1 family, and RNA binding domains.

3T3 Cells↗