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Biomedical subjects

Y F Huang

Publications and source records attributed to Y F Huang.

At least 37 records · Page 2Linked to original sources
PubMed2000

Tc99m sulfur colloid scintigraphy for detection of intrathoracic extramedullary hematopoiesis in patient with beta-thalassemia major--a case report.

Extramedullary hematopoiesis (EMH) refers to the production of blood cells outside the bone marrow and is a compensatory mechanism for bone marrow dysfunction. A 34 year-old female patient with beta thalassemia major was found to have multiple large, well-circumscribed radiopaque paravertibral mass lesions in chest radiography. Magnetic resonance imaging (MRI) of the thorax disclosed a right upper apical and two lower thoracic paraspinal mass lesions with heterogeneous isointensity on T1-weighted images and hypointensity on T2-weighted images. Because intrathoracic EMH is suspected in our case, which had obvious bone marrow dysfunction, radionuclide bone marrow scintigraphy is helpful in supporting the diagnosis. Tc99m sulfur colloid scintigraphy demonstrated three intense radioactive thoracic paraspinal mass lesions corresponding to the lesions seen on MRI. We believe whole body bone marrow scintigraphy with Tc99m sulfur colloid is the best convenient noninvasive method for supporting the diagnosis of EMH.

Adult↗
PubMed1999

Synthesis of Tc-D,D-HMPAO and Tc-L,L-HMPAO and their comparison of chemical and biological properties.

Tc-D,D- and TC-L,L-HMPAO were synthesized. The stability of Tc-D,D- and TC-L,L-HMPAO in vitro is similar to that of d,l-isomers by the spectrophotometric and three strips methods. Cerebral uptake (%D in brain) for the L,L-isomer is higer than the D,D- and d,l-isomer in rats. Delayed studies shows that T-L,L-HMPAO reveals less washout and reflects a higher cerebral deposition properties than the D,D- and d,l-isomer.

Animals↗
PubMed1999

In situ measurements of skeletal muscle power output using new capacitive strain gauge.

Experiments are described in which a fatigue index is determined for the latissimus dorsi muscle of sheep in situ, using capacitive strain gauges. Parallel experiments for invasive and non-invasive measurements are conducted, measuring global contraction and relaxation rates and shortening duration for paced muscle. The results show that, above one pulse per burst (5 V, 100 microseconds pulsewidth), contraction rates (62 +/- 11 mm s-1) and relaxation rates (50 +/- 7 mm s-1) are constant for unloaded muscle. For one animal, fatigue testing with a 2.5 kg load at six pulses per burst shows shortening rates increasing to a maximum (80 mm s-1) after 30 s and reducing to 5 mm s-1 after 150 s. The decrease in shortening amplitude is used as a fatigue index, log displacement against time. Power output is load dependent, measuring 4.7 W kg-1 with a 2.5 kg load. There is good agreement between the invasive and non-invasive measurements, thus providing a method for monitoring changes in muscle parameters non-invasively during future pacing transformation.

Animals↗
PubMed1999

Mitochondrial genetic variation in Chinese pigs and wild boars.

The mitochondrial DNAs (mtDNAs) from 30 pig breeds (29 Chinese native breeds and 1 European breed) and wild boars were investigated for restriction fragment length polymorphisms (RFLPs) to determine the phylogenetic relationships and genetic diversity among pig breeds and wild boars. Of the 24 enzymes used, 8 (AvaI, BclI, BglII, EcoRI, EcoRV, ScaI, StuI, and XbaI) detected polymorphisms. By combining the cleavage patterns for each enzyme, 108 individuals were sorted into eight mtDNA mitotypes. There are two haplotype lineages in domestic pigs, i.e., Chinese and European lineages. The pairwise nucleotide sequence divergence was calculated to be 0.56% between Chinese pigs and European pigs, suggesting that they might have diverged from a common ancestor approximately 280,000 years ago. The wild boars showed more extensive genetic variation, four mitotypes were detected in six wild boars. In addition, one of the Zhejiang wild boars was found to share the same mitotype with Chinese native pigs. A UPGMA tree based on genetic distance among mitotypes indicated that mtDNAs of Chinese pigs and European pigs are clearly divided into two clusters, and Chinese wild boars are more closely related to the Chinese pigs. Our results provide molecular evidence to support the previous hypothesis that pigs may be derived from two maternal origins, Asian and European wild boars. Chinese native pig breeds may have a single origin.

Animals↗
PubMed1999

Parathyroid hormone regulates the expression of fibroblast growth factor-2 mRNA and fibroblast growth factor receptor mRNA in osteoblastic cells.

We examined the effect of parathyroid hormone (PTH) on basic fibroblast growth factor-2 (FGF-2) and FGF receptor (FGFR) expression in osteoblastic MC3T3-E1 cells and in neonatal mouse calvariae. Treatment of MC3T3-E1 cells with PTH(1-34) (10-8M) or forskolin (FSK; 10-5M) transiently increased a 7 kb FGF-2 transcript with a peak at 2 h. The PTH increase in FGF-2 mRNA was maintained in the presence of cycloheximide. PTH also increased FGFR-1 mRNA at 2 h and transiently increased FGFR-2 mRNA at 1 h. FGFR-3 and FGFR-4 mRNA transcripts were not detected in MC3T3-E1 cells. In cells transiently transfected with an 1800-bp FGF-2 promoter-luciferase reporter, PTH and FSK increased luciferase activity at 2 h and 4 h. Immunohistochemistry showed that PTH and FSK increased FGF-2 protein labeling in the nuclei of MC3T3-E1 cells. PTH also increased FGF-2 mRNA, and FGFR-1 and FGFR-2 mRNA levels within 30 minutes in neonatal mouse calvarial organ cultures. We conclude that PTH and cAMP stimulate FGF-2 mRNA abundance in part through a transcriptional mechanism. PTH also regulated FGFR gene expression. We hypothesize that some effects of PTH on bone remodeling may be mediated by regulation of FGF-2 and FGFR expression in osteoblastic cells.

Animals↗
PubMed1999

The relationship between the myocardial kinetics of meperidine and its effect on myocardial contractility: model-independent analysis and optimal regional model.

The myocardial kinetics of meperidine and the relationship between these kinetics and the effect of meperidine on myocardial contractility (maximum positive rate of change of left ventricular pressure) were examined by analysis of previously published data collected in sheep after the i.v. injection of 100 mg of meperidine over 1 s. There was significant hysteresis between reductions in myocardial contractility and the arterial concentrations of meperidine, but not the coronary sinus blood (effluent from the heart) or calculated myocardial concentrations. The peak reduction in contractility occurred after the peak arterial concentration, at the time of the peak myocardial concentration, but before the peak coronary sinus concentration, suggesting that the site of drug action in the heart was not in equilibrium with either arterial blood or effluent blood from the heart. The most appropriate form of a dynamic model (a linear model with a threshold) was determined, without the need to assume a kinetic model, by directly fitting the observed reductions in myocardial contractility to the calculated myocardial concentrations. To determine the optimal kinetic and combined kinetic-dynamic models, a variety of one-, two-, and three-compartment models of the myocardium were fitted to the coronary sinus concentrations by using hybrid modeling. These included "tank in series" models that accounted well for drug dispersion and "peripheral compartment" models that accounted well for deep distribution. The most appropriate model was a "compilation" model, which incorporated features of both these extremes and was a better fit to the observed data than either a traditional single flow-limited compartment or a traditional membrane-limited model.

Algorithms↗
PubMed1999

Evaluation of serum CA27.29, CA15-3 and CEA in patients with breast cancer.

The Truquant BR radioimmunoassay (RIA) using monoclonal antibody BR 27.29 to recognize a peptide sequence on the MUC-1 gene product for quantification of the CA 27.29 antigen in serum was used in this report to evaluate in 145 patients with breast cancer and compared the other conventional serum markers such as CA15-3 and CEA. The upper limit of normal (25 u/ml) was determined from CA27.29 values 12.4 +/- 4.1 u/ml (mean +/- 3 S.D.) for 112 female subjects apparently free of disease. The CA15-3 levels above 25 u/ml and CEA levels above 5 ng/ml were considered positive values. Thirty-seven cases of 145 patients studied had elevated CA 27.29 levels (sensitivity: 25.5%), 35 of 145 had positive CA15-3 levels (sensitivity 24.1%) and 27 of 145 patients had positive CEA levels (sensitivity: 18.6%) (p < 0.05). One hundred and ten cases of the breast cancer patients (75.8%) did not have metastatic disease. In this group CA 27.29 sensitivity was 6.4%, while CA15-3 sensitivity was 5.5% and CEA sensitivity was 4.5% (p > 0.05). Mean values were 10.2 +/- 9.2 u/ml for CA 27.29, 14.1 +/- 5.6 u/ml for CA 15-3 and 1.7 +/- 1.5 ng/ml for CEA. Thirty-five patients (24.2%) had metastatic disease. In this group CA 27.29 sensitivity was 85.7%, CA15-3 sensitivity was 82.8% and CEA sensitivity was 62.8% (p < 0.05). Mean values for CA27.29 was 152.6 +/- 131.6 u/ml, CA15-3 was 123.1 +/- 107.6 u/ml and 21.8 +/- 36.9 ng/ml of CEA. With regard to the correlation of three tumor markers with clinical stages, patients had significantly higher levels of CA27.29 than CEA, but they were similar to CA 15-3 in metastatic breast cancer. These results suggest CA27.29 to be more sensitive and specific than CEA, but that it is similar to CA15-3 for metastatic breast cancer detection and monitoring.

Adult↗
PubMed1999

Ureaplasma urealyticum infection and apoptosis of spermatogenic cells.

AIM: To study the relationship between Ureaplasma urealyticum (UU) infection and apoptosis of human spermatogenic cells. METHODS: Spermatogenic cells were observed under light microscope with Wright-Giemsa staining and by means of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP)-biotin nick-end labeling (TUNEL) technique. RESULTS: Apoptotic rate of UU-infected males (15.5% +/- 6.8%) was significantly higher than that of controls (5.2% +/- 2.3%). CONCLUSION: Apoptosis of spermatogenic cells can be caused by UU infection, which provides further evidence for UU-induced male infertility.

Adult↗
PubMed1999

Studies on apoptosis of spermatogenic cells in normal fertile men treated with supraphysiological doses of testosterone undecanoate.

AIM: To study the anti-spermatogenic mechanism of supra-physiological doses of testosterone undecanoate (TU). METHODS: Twenty fertile adult men received four intramuscular injections of TU at monthly intervals, 1000 mg upon admission and 500 mg for the subsequent injections. The apoptotic germ cells in the semen were studied under light microscope with terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) and Wright-Giemsa staining methods. RESULTS: After treatment, the sperm density and the number of spermatogenic cells in the semen were significantly decreased (P < 0.01), while the apoptotic ratios of spermatocytes and spermatids increased significantly (P < 0.01) as compared with the pretreatment levels. Apoptosis was found to be augmented in the whole series of castoff spermatogenic cells. CONCLUSION: Besides its suppressive effect on spermatogenesis through a negative feed-back mechanism, TU enhances apoptosis of spermatogenic cells, which may be an additional mechanism of its anti-spermatogenic activity.

Apoptosis↗
PubMed1999

At the crossroad of conception and infection: initiatives for immunoglobulin-based contraceptive R & D.

Better understanding of the immunological mechanisms implying the insemination and the infertility of some men and women is needed and crucial to the development of an effective immunocontraceptive method. To provide good protection against conception or infection, and avoid any possible and unexpected complications which immunocontraceptive "vaccine" may arise of, it seems the right time for scientists to create a virtually new thinking for this extremely urgent and important issue. This conceptual article describes our original thoughts of the future development of immunocontraceptives, preferably, based on immunoglobulins rather than vaccines, against human sperm specific antigens and seminal plasma immunosuppressive factors. Its general correctness, advantages and feasibility for fertility regulation and prevention of infection are discussed.

Anti-Infective Agents↗
PubMed1999

[The relationship between fMLP induced neutrophil respiratory burst and the apoptosis of neutrophil].

The relationship between apoptosis of neutrophils and the change of their intracellular free Ca2+ concentration [Ca2+]i was studied. FMLP and A23187 were used to elevate the [Ca2+]i while BAPTA was used to deplete it. Fluorescence microscope, flow cytometry and gel electrophoresis were used to study the percentage of cell apoptosis and the change of f-actin during apoptosis. The results showed that the apoptosis was obviously inhibited by fMLP and A23187, while accelerated by BAPTA. The detection of f-actin showed that the f-actin depolymerized obviously during apoptosis. The elevation of [Ca2+]i inhibit the actin depolymerization while depletion of [Ca2+]i accelerated it. This result indicated that the apoptosis of neutrophil was obviously inhibited by [Ca2+]i elevation but accelerated by [Ca2+]i depletion.

Apoptosis↗
PubMed1999

[Anaerobes analysis in 80 cases with ora maxillofacial infections]

OBJECTIVE:To define the infection types of 80 cases of ora-maxillofacial infection and investigate its anaerobes' distribution and the role of the anaerobes' metabolic products in their identification.METHODS:We isolated and cultured anaerobes from the purulent specimen and applied the gasliquid chromatograph (GLC) technique to analyze the anaerobes' metabolic products to define their genera and species in the meantime.RESULTS:Bacteria were isolated from all of the purulent specimen.Isolation rate of bacteria was 100.00% and isolation rate of anaerobes,which distributed in 8 genera,29 species,was 95.00%. The higher detectable rate of them were respectively peptostreptococcus,petococcus,bacteroides,fusobacterium,verillonella,eubacterium. The rate of mixed infection was 80.00%. The proportion ratio of aerobes and anaerobes was 1:1.08.CONCLUSION:Oral-maxillofacial infection mostly belongs to endogenous mixed infection in which anaerobes are preponderant bacteria. GLC technique is a effective,sensitive,selective and specific method for defining anaerobes' genera and species through analyzing their metabolic products. It is a promising and recommendable rapid anaerobes' identification method comparatively at present.

Journal Article↗
PubMed1998

Quantification of Helicobacter pylori infection: Simple and rapid 13C-urea breath test in Taiwan.

The 13C-urea breath test (13C-UBT) is a non-invasive method for detecting Helicobacter pylori. This study was performed to determine the cutoff value and evaluate the sensitivity and specificity of 13C-UBT in Taiwan. 13C-Urea (100 mg of 99% 13C-labeled urea) was dissolved in 50 ml sterile water for the test. The test meal for delaying gastric emptying was 100 ml fresh milk. Patients fasted for at least 6h. A baseline breath sample was collected 5 min after they had the test meal. Two other samples were collected at 15 and 30 min after the patients ingested the 13C-urea. The test was evaluated in 352 patients after routine upper gastrointestinal endoscopy, and the urease test, culture, and histopathology were taken as the gold standards for detecting H. pylori. According to the receiver operating characteristic (ROC) curves, we chose values of 2.8 and 4.2 excess delta 13CO2 per mil as the cut-off values for 15 and 30 min, respectively, post 13C-urea. The sensitivity and specificity of 13C-UBT were 99% and 93% at 15 min, and 98% and 93% at 30 min post 13C-urea, respectively. The 13C-UBT breath test is an efficient non-invasive method of high sensitivity and high specificity for detecting H. pylori infection. We suggest that the use of fresh milk as the test meal and the detection of excess delta 13CO2 15 min after the ingestion of 13C-urea are suitable for the clinical use of 13C-UBT. This test is simple and rapid.

Adolescent↗
PubMed1998

Parathyroid hormone induces interleukin-6 heterogeneous nuclear and messenger RNA expression in murine calvarial organ cultures.

The cytokine, interleukin-6 (IL-6), is produced by osteoblasts and may in part mediate parathyroid hormone (PTH)-stimulated bone resorption. The goals of the present study were: (1) to examine PTH induction of IL-6 expression in 7-day-old mouse calvarial organ cultures; (2) to assess the role of intracellular signaling pathways in this model; and (3) to determine whether PTH regulates IL-6 expression by a transcriptional mechanism. Northern blot analysis of calvarial RNA showed that PTH(1-34) at 0.1-100 nmol/L induced IL-6 mRNA at 0.5 h with a peak at 2 h. Forskolin at 10 micromol/L and 8-bromocyclic-AMP at 3 mmol/L also induced IL-6 mRNA with a peak at 2 h. Phorbol myristate acetate induced IL-6 expression, whereas ionomycin and PTH(3-34) amide, an N-terminal-truncated PTH analog that has reduced ability to activate the cAMP-PKA pathway, were much less effective. PMA pretreatment of calvariae greatly blocked IL-6 mRNA induction by a subsequent dose of PMA and decreased induction by PTH and forskolin to a much lesser extent. A reverse-transcriptase polymerase chain reaction (RT-PCR) assay was used to measure IL-6 heterogeneous nuclear RNA (hnRNA) and mRNA. A 5' primer spanning exons 1 and 2 and a 3' primer complementary to exon 5 of the murine IL-6 gene were used to detect IL-6 mRNA as a 638 bp product. A 5' primer corresponding to intron 4 of the murine IL-6 gene and the 3' primer were used to detect IL-6 hnRNA as a 370 bp product. RT-PCR of total calvarial RNA showed that the induction of IL-6 hnRNA by PTH and other agonists was similar to their induction of IL-6 mRNA. These data support the conclusion that PTH transcriptionally induces IL-6 gene expression in murine calvarial organ cultures mainly through the cAMP-PKA signaling pathway.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1998

Tachycardia alone fails to change the myocardial pharmacokinetics and dynamics of lidocaine, thiopental, and verapamil after intravenous bolus administration in sheep.

Previous reports have suggested that tachycardia alone can increase the rate of myocardial uptake of some drugs. As part of a systematic study of the determinants of the myocardial uptake and effects of drugs in critical illness, the effect of tachycardia induced by intracardiac pacing on the myocardial disposition and effects of lidocaine, verapamil, and thiopental were studied in chronically instrumented sheep. For each drug, seven sheep received either 100 mg of lidocaine, 10 mg of verapamil, or 750 mg of thiopental over 2 min in unpaced and paced (140 beats/min) states on separate occasions and in random order. Arterial and coronary sinus (effluent from the heart) blood samples were taken at regular intervals for 30 min, and the maximum rate of change of left ventricular pressure (LV dP/dtmax) was measured as an index of myocardial contractility. There were no differences between unpaced and paced studies in the time courses of arterial and coronary sinus concentrations, or the time-courses of myocardial contractility and blood flow, after bolus iv injections of these drugs. Tachycardia alone does not appear to influence the myocardial kinetics or dynamics of lipophilic drugs that can rapidly diffuse into the heart.

Animals↗
PubMed1998

Gene expression induced by physical impedance in maize roots.

Two cDNA clones, pIIG1 and pIIG2, corresponding to mRNAs that accumulate in maize root tips subjected to 10 min of physical impedance, were isolated by differential screening of a cDNA library. The deduced proteins, based on DNA sequence analysis, have molecular masses of 13 and 23 kDa for pIIG1 and pIIG2, respectively. pIIG1 showed 97% similarity at the nucleic acid level to a maize root cortical cell delineating protein (pZRP3) and was also similar to some bimodular proteins that are developmentally or stress regulated in other plant species. In situ localization of pIIG1 showed some expression in cortical cells of control maize roots; however, after a 10 min physical impedance treatment, pIIG1 accumulation increased greatly in cortical cells and extended to include the procambial region. pIIG2 did not show sequence similarity with any identified gene of known function, but a bipartite nuclear targeting sequence occurs in its deduced amino acid sequence which indicates it may function in the nucleus. Thus, rapid accumulation of specific mRNAs occurs in maize roots in response to impedance stress, and these mRNAs may be responsible for some responses of the roots to physical impedance.

Amino Acid Sequence↗
PubMed1998

Cardiovascular and central nervous system effects of intravenous levobupivacaine and bupivacaine in sheep.

UNLABELLED: Commercially available bupivacaine is an equimolar mixture of R(+)- and S(-)-bupivacaine. S(-)-bupivacaine (i.e., levobupivacaine) is currently undergoing preclinical evaluation. Cross-over studies with i.v. levobupivacaine and bupivacaine were conducted in two groups of seven conscious sheep. Doses were chosen to avoid convulsions (smaller dose 6.25-37.5 mg/min) or to be potentially toxic (larger dose 75-200 mg/3 min). In subconvulsive doses, both drugs produced similar time- and dose-dependent depression of left ventricular systolic contractility (dP/dt(max)). Convulsions occurred consistently with > or = 75 mg of bupivacaine and > or = 100 mg of levobupivacaine, producing an abrupt reversal of dP/dt(max) depression. Subconvulsive doses produced minor cardiovascular effects on heart rate and blood pressure, whereas both were increased by convulsions. Cardiac output and myocardial blood flow were decreased with larger doses of both drugs. Doses > 75 mg of bupivacaine or > 100 mg of levobupivacaine induced QRS widening and ventricular arrhythmias, but significantly fewer and less deleterious arrhythmias were induced by levobupivacaine. Three animals died after 150, 150, and 200 mg of bupivacaine from the sudden onset of ventricular fibrillation. These doses of levobupivacaine produced nonfatal arrhythmias that automatically returned to sinus rhythm. We conclude that levobupivacaine could offer a greater margin of clinical safety than bupivacaine. IMPLICATIONS: Levobupivacaine comprises 50% of commercially available bupivacaine and is being considered for use in its own right. Local anesthetics can cause toxicity to the cardiovascular and central nervous systems. As a part of a preclinical evaluation of levobupivacaine, this study compared the toxic effects of levobupivacaine and bupivacaine in sheep.

Anesthetics, Local↗