Search PubMed⌕ Search

Biomedical subjects

S J Huang

Publications and source records attributed to S J Huang.

At least 19 recordsLinked to original sources
PubMed2001

Pseudo-osteomyelitic crisis upon presentation of Gaucher disease.

We report on a 4-year-old boy adopted from Paraguay who presented with an acute onset of thigh pain. Initial clinical, imaging, and histopathologic findings suggested florid osteomyelitis. However, the development of pancytopenia on intravenous antibiotics prompted further investigation and the ultimate diagnosis of Gaucher disease. In retrospect, characteristic changes on conventional radiographic and MR images, as well as growth of a contaminant organism, pointed to the diagnosis of pseudo-osteomyelitis rather than osteomyelitis.

Biopsy↗
PubMed2001

Low dose fentanyl and propofol improve the speed and quality of tidal-breathing induction techniques in sevoflurane anesthesia for adults.

BACKGROUND: The objective of this study was to investigate whether low dose fentanyl, with or without low dose propofol, as pretreatment agent/s is capable of speeding up and improving the quality of laryngeal mask airway (LMA) insertion in tidal-breathing induction technique with high-concentration sevoflurane. METHODS: One hundred and twenty patients were assigned to one of the three groups: Group S, induction with 8% sevoflurane only; Group F + S, 1.0 microgram/kg fentanyl prior to induction; and Group F + P + S, 1.0 microgram/kg fentanyl and 0.5 mg/kg propofol prior to induction. RESULTS: It was demonstrated that the time from administration of drug (drugs) to loss of eyelash reflex (P < 0.05, Group F + P + S vs. F + S; P < 0.01, Group F + P + S vs. S), to jaw relaxation (P < 0.05, Group F + P + S vs. S) and time taken for LMA insertion (P < 0.01, Group F + P + S vs. S) were all shorter in Group F + P + S, with fewer complications (coughing and involuntary movement) during induction, however, the first time success rate with LMA insertion did not significantly differ among the comparing groups. According to a postoperative inquiry (by questionnaire), there were significantly more patients in the Group F + P + S (57.5%) who considered the induction as pleasant (P < 0.05), of whom 75% expressed that they would be willing to undergo an induction of the same form again in the future (P < 0.05). This more positive rating may be related to the mild sedative effects of the agents given and shorter induction time, which significantly helped reduce the rate of recall of the unpleasant gas. CONCLUSIONS: The results of this study of LMA insertion, for ASA I or II adult patients undergoing the tidal-breathing technique with 8% sevoflurane, suggest that pretreatment with 1 microgram/kg fentanyl plus 0.5 mg/kg propofol is superior in comparison with either pretreatment with 1 microgram/kg fentanyl or absence of pretreatment.

Adult↗
PubMed2001

Pneumopericardium after bronchoscopic carbon dioxide laser surgery--a case report.

A female baby sustained pneumopericardium after bronchoscopic CO2 laser surgery for tracheal stenosis. Perioperative pneumopericardium though rare is a life-threatening condition in babies. The symptoms are usually not specific such as hypotension, bradycardia, muffled heart sound, cardiovascular collapse, etc. The causes and clinical findings of pneumopericardium were reviewed, as are the radiographic features so as to differentiate the condition from pneumomediastinum. Early recognition of pneumopericardium is important, because emergent pericardiocentesis may be required if there is clinical evidence of cardiac tamponade.

Bronchoscopy↗
PubMed2001

Hemodynamic responses of thiopental and propofol in different-aged patients during endotracheal intubation.

BACKGROUND: Thiopental and propofol are 2 popularly used anesthetic induction agents that have different pharmacological and pharmacokinetic actions. It is not clear how the hemodynamic responses differ in different-aged patients using these 2 drugs for anesthetic induction. The aim of this study was to investigate the hemodynamic responses to propofol and thiopental of different-aged patients during endotracheal intubation. METHODS: Sixty patients, 20 to 83 years old, were included in this study. Patients were randomly divided into 6 groups according to age and different inductive anesthetics. Non-invasive blood pressure (NIBP) monitoring was performed every minute before anesthesia, during anesthetic induction with 5 mg.kg-1 thiopental or 2 mg.kg-1 propofol intravenously, and after intubation. RESULTS: Propofol induction produced a smaller mean arterial pressure increase immediately after intubation than did thiopental induction in adult and elderly groups (101.0 +/- 18.5 and 104.0 +/- 21.1 mmHg in the propofol groups vs. 138.3 +/- 17.1 and 138.9 +/- 16.1 mmHg in the thiopental groups at 1 minute after intubation, p < 0.001 and p = 0.001, respectively). Differences in heart rate between propofol and thiopental groups were found in young and adult groups (85.1 +/- 9.2 and 81.7 +/- 10.9 in the propofol groups vs. 94.5 +/- 9.9 and 95.0 +/- 14.0 beats per minute in the thiopental groups at 1 minute after intubation, p = 0.041 and p = 0.029, respectively). CONCLUSION: Propofol induction produced more stable hemodynamics after intubation in adult and elderly patients than did thiopental induction. Therefore, it is safer to use propofol for induction and intubation in adult and elderly patients.

Adult↗
PubMed2000

Copolymers of itaconic anhydride and methacrylate-terminated poly(lactic acid) macromonomers.

In an effort to design cyclic anhydride copolymers that have biodegradable characteristics and are derived from renewable resources, the copolymerization of itaconic anhydride and methacrylate-terminated poly-(L-lactic acid) (PLLA) was studied. Polymers with anhydride concentrations from 85 to 15 mol% have been synthesized successfully with retention of the cyclic anhydride. Molecular weights range from 9000 to 70,000 with higher molecular weights for higher concentrations of PLLA macromonomer. High conversions are observed for samples containing 50% and less itaconic anhydride with a slight tendency for the polymer to be enriched in the monomer in smaller concentration. These copolymers show glass transition temperatures between 31 and 73 degrees C, increasing with increased itaconic anhydride content. No evidence of crystallinity from the PLLA is observed for these copolymers.

Biodegradation, Environmental↗
PubMed2000

Determination of lead in fish samples by slurry sampling electrothermal atomic absorption spectrometry.

Ultrasonic slurry sampling electrothermal atomic absorption spectrometry (USS-ETAAS) was been applied to the determination of lead in several fish samples. The influences of instrument operating conditions and slurry preparation on the signal were examined. Palladium and ammonium nitrate were used as the modifier to improve the signal. Since the sensitivity to lead in various fish slurries and aqueous solutions was different, the standard additions method was used for the determination of lead in these fish samples. The method was applied to the determination of lead in dogfish muscle reference material (DORM-2) and a swordfish muscle sample purchased from the local market. The analysis results agreed with the reference value. The accuracy was better than 6%. The precision between sample replicates was better than 16% with the USS-ETAAS method. The detection limit of lead estimated from standard additions curve was about 0.053-0.058 microgram g-1 in different samples.

Animals↗
PubMed2000

Induction of CD8 T cells by vaccination with recombinant adenovirus expressing human papillomavirus type 16 E5 gene reduces tumor growth.

The potential of the E5 protein as a tumor vaccine candidate has not been explored yet. In this study, we evaluate the human papillomavirus type 16 (HPV-16) E5 protein delivered by an adenovirus vector as a tumor vaccine for cervical lesions. The results demonstrate that a single intramuscular injection of a recombinant adenovirus carrying the HPV-16 E5 gene into syngeneic animals can reduce the growth of tumors which contain E5 gene expression. Moreover, the E5 vaccine-induced tumor protection occurs through CD8 T cells but not through CD4 T cells in in vitro assays. In addition, our studies using knockout mice with distinct T-cell deficiencies confirm that cytotoxic T-lymphocyte-induced tumor protection is CD8 dependent but CD4 independent. Hence, HPV-16 E5 can be regarded as a tumor rejection antigen.

Adenoviridae↗
PubMed2000

Induction of platelet activation by cobra venom factor from Naja naja atra in rat.

AIM: To study the effects of cobra venom factor (CVF) on platelets of rat platelet rich plasma (PRP) and to elucidate its cellular mechanism. METHODS: PRP was used to measure platelet aggregation and ATP-release simultaneously; prothrombinase, intracellular free calcium, and cAMP were assayed using chromogenic substrate, fluorophor Fura-2, and RIA respectively. RESULTS: From 19.5 nmol.L-1 to 617 nmol.L-1 CVF induced platelet aggregation and ATP release concentration-dependently. The ATP release induced by CVF 195 nmol.L-1 was independent of aggregation and was much weaker than that induced by thrombin 1 U/ml. CVF 195 nmol.L-1 increased the prothrombinase activity on platelet surface in a time-dependent manner. SZ-1, SZ-21, and SZ-22, which are monoclonal antibodies against glycoproteins I b/IX, IIIa, and IIb located on platelet membranes, inhibited CVF-induced platelet aggregation. CVF 195 nmol.L-1 also elevated moderately intracellular free calcium ion from (141 +/- 46) to (240 +/- 64) nmol.L-1 in Fura-2 AM loaded platelets, and decreased intracellular cAMP. CONCLUSION: Complement activator CVF induced platelet aggregation and ATP release, and increased prothrombinase activity on platelet surface. These actions were dependent on fibrinogen receptors on the platelet surface, elevation in intracellular free calcium ion, and reduction in cAMP.

Adenosine Triphosphate↗
PubMed1999

Genetic variation in the serotonin transporter promoter region affects serotonin uptake in human blood platelets.

The human serotonin transporter (5-HTT), encoded by a single gene on chromosome 17q11.2, is expressed in brain and blood cells. 5-HTT is implicated in mood and anxiety regulation, and is where antidepressant and antianxiety drugs initially act in the brain. A 5-HTT-linked promoter region (5-HTTLPR) insertion/deletion polymorphism with long (l) and short (s) forms affects transporter expression and function. The s variant reduced 5-HTT gene transcription in a reporter gene construct and human lymphoblasts, resulting in reduced transporter levels and 5-HT uptake, acting as a dominant allele. In this study, we investigated the expression and function of 5-HTT in platelets from healthy male volunteers. The l variant was associated with more rapid initial platelet 5-HT uptake (Vmax), the index of platelet 5-HTT function most clearly heritable, while the s allele was dominant. The 5-HTTLPR genotype had no effect on platelet [3H]paroxetine binding (Bmax), affinity for [3H]5-HT or [3H]paroxetine, or 5-HT content. The 5-HT uptake findings support a functional difference in the two 5-HTTLPR variants, reinforcing their attractiveness as candidate genes in neuropsychiatric research.

Adult↗
PubMed1999

Adenovirus-mediated p21((WAF1/SDII/CIP1)) gene transfer induces apoptosis of human cervical cancer cell lines.

p21((WAF1/SDII/CIP1)) (p21) arrests cell growth by inhibiting cyclin-depend kinases. To explore the potential of using p21 for the gene therapy of cervical cancer, we infected human papillomavirus (HPV)-positive cervical cancer cells (HeLa, SiHa, and Z172) and HPV-negative cervical cancer cells (C33A) with recombinant adenovirus encoding p21 cDNA. The results revealed that effective inhibition of cell growth could be achieved by sense p21 adenovirus but not antisense p21 adenovirus infection and occurred through apoptosis as measured by DNA fragmentation and chromatin condensation. Apoptosis was also observed in xenografts of human cervical cancer cells infected with sense p21 adenovirus, as confirmed by in situ terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL). The apoptosis was not prevented by overexpression of the bcl-2 transgene. To sum up, the apoptotic effect suggests that p21 should be a tumoricidal agent instead of a tumoristatic agent in preventing cervical cancers. In addition, our report substantiates the combination of the high efficiency of adenovirus vector-mediated gene delivery and the apoptotic effect of p21.

Adenoviridae↗
PubMed1999

The selective cytotoxicity of cobra venom factor immunoconjugate on cultured human nasopharyngeal carcinoma cell line.

The selective cytotoxicity of a CVF immunoconjugate on human nasopharyngeal carcinoma cell line was reported. Cobra venom factor (CVF), a C3b-like glycoprotein, was linked to BAC5, a murine monoclonal antibody directed against a human nasopharyngeal carcinoma-associated membrane antigen, by a disulfide bond. The high affinity to cultured human nasopharyngeal cells (CNE2) and the complement activating potency retained in CVF immunoconjugate. Although the equimolar concentration of BAC5 or CVF alone was harmless to CNE2 cells, the CVF immunoconjugate in the presence of fresh human serum exhibited selective cytotoxicity on CNE2 cells in a concentration- (IC50 3.07 x 10(-7) mol/L) and time-dependent manner. No cytotoxicity occurred on either CNE1 (another human nasopharyngeal carcinoma cell line) or MGC-803 (human gastric carcinoma cell line) cells. Furthermore, direct lytic factor (DLF, cardiotoxin) separated from cobra venom, augmented CVF immunoconjugate-induced cytotoxicity significantly. These results indicate that the CVF immunoconjugate has complement-mediated selective cytotoxicity on CNE2 cells, which can be potentiated by DLF.

Animals↗
PubMed1999

Changes in hemodynamics of the carotid and middle cerebral arteries before and after endoscopic sympathectomy in patients with palmar hyperhidrosis: preliminary results.

OBJECT: The purpose of this study was to analyze the change in carotid and middle cerebral artery (MCA) hemodynamics before and after endoscopic upper thoracic sympathectomy in patients with palmar hyperhidrosis (PH). METHODS: Sixty-eight patients with PH (35 males and 33 females) for whom the average age was 24.5+/-10.7 years (+/- standard deviation) were recruited into this study. These patients all underwent routine upper T-2 sympathectomy to treat their PH. Ultrasonography studies of the carotid arteries (CAs) and MCA were obtained in each patient before and after T-2 sympathectomy. The blood flow volume, flow velocity, and resistivity index (RI) in the bilateral common CAs (CCAs), internal CAs (ICAs), and external CAs (ECAs) were evaluated using duplex ultrasonography. The systolic peak velocity, mean velocity, diastolic peak velocity, pulsatility index, and RI of the bilateral MCAs were evaluated using transcranial Doppler ultrasonography. Blood pressure and heart rate were also recorded during this study. The Student paired t-test was used to analyze the differences between studies before and after bilateral T-2 sympathectomy. There was a significant reduction in diastolic pressure after T-2 sympathectomy (p = 0.003), but not in systolic pressure or heart rate. The vessel diameter was increased after sympathectomy in the left CAs and right CCA. The T-2 sympathectomy led to significant elevation of blood flow volume and RI in the left CCA, ICA, and ECA (p < 0.05). The authors found significant increases in maximum flow velocity and RI in the left MCA (p < 0.05). CONCLUSIONS: Patients who underwent T-2 sympathectomy demonstrated a significant increase in blood flow volume and flow velocities of the CAs and MCA, especially on the left side. Asymmetry of sympathetic influence on the hemodynamics of the CAs and MCA was noted. The usefulness of sympathectomy for the treatment of ischemic cardiovascular and cerebrovascular disease deserves further investigation.

Adolescent↗
PubMed1998

The induction of apoptosis by SV40 T antigen correlates with c-jun overexpression.

Simian virus (SV40) T antigen shares many characteristics with adenovirus E1A which is known to induce apoptosis. To verify the potential of SV40 T antigen-mediated apoptosis, we stably expressed T antigen in immortalized human epithelial cells (Z172 and HaCaT). We found that SV40 T antigen could directly cause apoptosis in 22-27% of these cells under normal growth condition as measured by chromatin condensation and nucleosomal fragmentation. The apoptosis of HaCaT cells which contain mutant p53 suggests the p53-independent nature of T antigen-mediated apoptosis. T antigen-induced apoptosis was associated with increased expression of c-Jun protein. Moreover, the overexpression of c-jun alone in these cells also induced apoptosis, indicating that c-jun might play an important role in T antigen-induced apoptosis.

Adenovirus E1A Proteins↗
PubMed1998

Cyclopiazonic acid and thapsigargin induce platelet aggregation resulting from Ca2+ influx through Ca2+ store-activated Ca2+-channels.

The effects of cyclopiazonic acid and thapsigargin, selective inhibitors of the endoplasmic reticulum Ca2+-ATPase pump, on the platelet aggregation were investigated using washed rat platelets prepared by chromatography on Sepharose 2B columns. In Ca2+-free medium, cyclopiazonic acid and thapsigargin did not induce aggregation, but in the presence of 1 mM Ca2+, platelet aggregation was induced in a concentration-dependent manner. Cyclopiazonic acid- and thapsigargin-induced platelet aggregation was blocked by 1 mM Ni2+ but not by 100 microM indomethacin or 1 microM nifedipine. In aequorin-loaded platelets, cyclopiazonic acid and thapsigargin caused sustained elevation of the cytosolic Ca2+ concentration, an effect which was blocked by Ni2+, a non-selective Ca2+ channel blocker and SK&F 96365 (1-[beta-[3-(4-methoxyphenyl)propoxy]-4-methoxyphenyl]-1H-imidazole hydrochloride), a putative receptor-operated Ca2+ channel antagonist. The above results indicated that both cyclopiazonic acid and thapsigargin induced platelet aggregation and elevation of cytosolic Ca2+ concentration, that extracellular Ca2+ was essential for cyclopiazonic acid- and thapsigargin-induced platelet aggregation, and that platelet aggregation may be associated with Ca2+ influx through Ca2+ store-activated Ca2+ channels.

Animals↗
PubMed1998

Identification of immune-related protein kinases from mosquitoes (Aedes aegypti).

Protein kinases are known to be involved in signal transduction for numerous physiological events. However, little is known about the roles of protein kinases in insect immunity. A fragment around 150 bp was amplified by polymerase chain reaction using cDNA templates from bacterial inoculated mosquitoes and primers corresponding to the conserved domain of protein kinases. Based on sequence analysis, 11 groups of protein kinases were characterized including 3 nonreceptor tyrosine kinases, 3 receptor tyrosine kinases, 3 serine/threonine kinases, and 2 novel protein kinases. The most abundant kinase obtained in this study reveals a high degree of similarity to human cholinesterase-related cell division controller (CHED) protein kinase. The expression of this mosquito CHED-like kinase is not detectable in normal female mosquitoes, but induced only after bacterial inoculation and trauma. A mosquito protein kinase was demonstrated to share homology with a plant Tousled gene, but has not yet been characterized in the animal system. In addition, analysis of the sequences of several protein kinases cloned from mosquitoes suggests that they might be involved in the regulation of cellular or humoral immunity.

Aedes↗
PubMed1998

Delayed obsessive-compulsive disorder symptom exacerbation after a single dose of a serotonin antagonist in fluoxetine-treated but not untreated patients.

Enhanced serotonergic transmission may underlie therapeutic effects of serotonin reuptake inhibitors in obsessive-compulsive disorder. However, such treatment may decrease serotonin receptor responsivity. We investigated whether the serotonin antagonist metergoline would exacerbate or further improve systems in fluoxetine-responsive patients. Pilot results suggested open metergoline produced delayed symptom worsening in fluoxetine-treated patients. Fourteen patients continuing fluoxetine received metergoline and placebo (double-blind, randomized). Symptom ratings continued for 1 week afterwards. Ten unmedicated patients underwent the same procedures. Symptoms improved 4 h after both metergoline and placebo. The day after metergoline but not placebo, fluoxetine-treated patients had significantly increased anxiety, obsessions and compulsions, abating over several days. Depression was unchanged. Metergoline had no similar delayed effects in unmedicated patients. Metergoline levels were higher in fluoxetine-treated patients. These results, consistent with less conclusive earlier findings, suggest that prolonged changes in brain serotonin function underlie symptom re-emergence following administration of metergoline to fluoxetine-treated patients with obsessive-compulsive disorder.

Adult↗
PubMed1998

Activation and inactivation properties of voltage-gated calcium currents in developing cat retinal ganglion cells.

The correlated activity of developing retinal ganglion cells is essential for the reorganization and refinement of retinogeniculate projections. Previous studies have uncovered marked changes in the spiking properties of retinal ganglion cells during this period of reorganization; however, a full understanding of the changes in the underlying ionic conductances has yet to be obtained. To this end, the whole-cell configuration of the patch-clamp technique was used to record currents conducted by voltage-gated calcium channels in 83 dissociated cat retinal ganglion cells obtained from animals aged between embryonic day 34 and postnatal day 105. Calcium currents, magnified by using barium as the major charge carrier, were isolated by substituting choline for Na+ in the bathing solution and Cs+ for K+ in the electrode solution. Three voltage-gated Ca2+ conductances were identified based on their voltage dependence and kinetics of activation and inactivation: a transient low-voltage-activated conductance, a transient high-voltage-activated conductance and a sustained high-voltage-activated conductance. During the developmental period examined there were significant increases in the densities of all three conductances, as well as significant changes in some of their activation and inactivation properties. These findings, together with those reported previously for the voltage-gated Na+ and K+ conductances, are related to the generation of excitability in developing retinal ganglion cells during a period critical to the normal development of the visual system. Furthermore, while the sustained high-voltage-activated conductance was present in all of the retinal ganglion cells observed, only about 72% expressed the transient high-voltage-activated current. During the developmental period examined, there was also an increase in the proportion of cells expressing the transient low-voltage-activated conductance. This, along with our previous finding that retinal ganglion cells heterogeneously express different types of voltage-gated K+ channels, strongly suggests that the spiking patterns observed in different classes of retinal ganglion cell may be due, in part, to their intrinsic membrane properties.

Animals↗