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Biomedical subjects

C C Liu

Publications and source records attributed to C C Liu.

At least 91 records · Page 5Linked to original sources
PubMed1998

Successful resection of sigmoid colon cancer in a patient with factor XI deficiency.

A 42-year-old-women with sigmoid colon adenocarcinoma was found to have isolated prolonged activated partial thromboplastin time (aPTT 102.5 s, normal range 24-36 s) preoperatively. Her medical history included an episode of prolonged postdelivery uterine bleeding 16 years previously. A mixed aPTT test showed immediate correction of the prolonged aPTT, indicating a coagulation factor deficiency in the intrinsic pathway. Factor assays showed factor XI was below 1% of average normal value whereas factor VIII, IX and XII activities were normal. Family screening revealed one sister among the three siblings also had isolated prolonged aPTT. The patient was transfused with four units (5mL/kg) of fresh frozen plasma the day before surgery, then with two units during surgery. The operation was uneventful with no bleeding problems. The patient recovered smoothly and is currently undergoing adjuvant chemotherapy. This is the first formal report of a patient with factor XI deficiency undergoing major surgery in Taiwan. Careful monitoring of aPTT, with fresh frozen plasma transfusion, when needed, may safely overcome bleeding problems during surgery.

Adenocarcinoma↗
PubMed1998

Role of mitogen-activated protein kinase in taxol-induced apoptosis in human leukemic U937 cells.

The induction of apoptosis by Taxol was investigated in human leukemic U937 cells. Treatment of U937 cells with 20 nM Taxol for 24 h induced apoptosis in 30-40% of cells, which resulted in an 80% growth inhibition 3 days after treatment. Synchronous cells at different cell cycle stages exhibited different sensitivities toward Taxol, and their reversion by certain protein kinase inhibitors was also phase specific. Kinetic studies of cell cycle progress reveal that Taxol accelerates the progression of the cell cycle, which facilitates the process of apoptosis, especially for cells initially in the G1 phase. This acceleration may result from transient activation of p42/ 44 mitogen-activated protein (MAP) kinase, because inhibition of upstream MAP/extracellular signal-regulated kinase kinase (MEK1/2) by PD98059 reversed this effect. However, the delayed S-G2-M-phase progression by PD98059 was insignificant. The results suggest that MAP kinase may not only mediate cell cycle progress but may also participate in the apoptosis pathway for cells originally in S phase.

Antineoplastic Agents, Phytogenic↗
PubMed1998

p53 gene alternation in squamous cell carcinoma of the esophagus detected by PCR-cold SSCP analysis.

Mutations of the p53 tumor suppressor gene play an important role in the development of common human malignancies. Previous reports revealed that the frequencies of p53 alternations in esophageal carcinoma varied from 26% to 87%. The clinical significance of p53 alternations is still disputed. In the present study, we used polymerase chain reaction--"cold" single-strand conformation polymorphism (PCR-"cold" SSCP)--to investigate p53 genetic alternations in 63 surgical specimens of esophageal squamous cell carcinoma (ESC). Our experiments showed that the optimum buffer temperature for "cold" SSCP analysis was 14 degrees C while the PCR products were around 200-300 bp in size. Among 63 tumorous samples, p53 alternations was detected in 47 tumors, or an incidence rate of 74.6%. For nontumorous mucosal samples, the incidence of p53 alternations was 55.5% (35/63 samples). Additionally, p53 alternations occurred most frequently at exon 6 (50.8%), followed by exon 7 (33.3%), exon 8 (17.5%) and exon 5 (12.7%). Multiple genetic alternations (> or = 2 exons) between p53 exons 5-8 in the same examined samples were found in 21 (33.3%) of 63 tumors, and in 8 (12.7%) of 63 nontumorous mucosal specimens. Our results further showed that p53 alternations did not correlate with age, depth of tumor invasion, lymph node metastasis, tumor stage, cell differentiation or lymphovascular invasion in ESC (P > 0.05). Moreover, the survival rate in patients with p53 alternations was similar to that in patients without p53 alternations (P > 0.05). In conclusion, PCR-"cold" SSCP is a rapid and sensitive method for identifying p53 genetic alternations. p53 genetic alternations occur with a relatively high incidence for ESC, but p53 abnormality has no impact on prognosis.

Age Factors↗
PubMed1998

Effects of ondansetron on postoperative emesis in Chinese children.

BACKGROUND: Postoperative nausea together with vomiting (PONV) is a common adverse effect of general anesthesia. Ondansetron, a new serotonin (5-hydroxytryptamine) receptor antagonist of the subtype 3 is shown to be effective and safe in the prophylaxis and treatment of PONV. However, the clinical experiences of using ondansetron for prevention of PONV is lacking in Taiwan. The purpose of this study is to evaluate the efficacy and safety of ondansetron for prevention of PONV in Chinese children. METHODS: Eighty pediatric patients aged from 2 to 12 years undergoing herinorrhaphy were prospectively randomized to receive either ondansetron 0.1 mg/kg or saline placebo. All patients received general anesthesia with tracheal intubation. The parents of patients were educated how to record the episodes of postoperative emesis and other complications and answer questions in the form of questionnaire. The observation period lasted for 24 h postoperatively. RESULTS: The incidence of postoperative emesis was 55% and 10% in placebo and ondansetron group respectively. As to the severity of emetic symptoms it was milder in the ondansetron group. There was no difference in the incidence of other complications between the two groups. CONCLUSIONS: The intravenous administration of ondansetron 0.1 mg/kg is safe and effective in reducing postoperative emesis in Chinese children undergoing herinorrhaphy surgery.

Antiemetics↗
PubMed1998

Epidural anesthesia combined with propofol sedation for abdominal hysterectomy in a patient with amyotrophic lateral sclerosis--a case report.

Amyotrophic lateral sclerosis (ALS) is a disease characterized by progressive degeneration of the lower motor neurons, motor nuclei of the brain stem, and the descending pathway of the upper motor neurons. As the disease progresses, atrophy and weakness involve most of the skeletal muscles, including those of the tongue, pharynx larynx and chest. Impairment of respiration, altered response to muscle relaxants, and predisposition of aspiration affect a safe anesthetic management. General anesthesia with tracheal intubation might ensure intraoperative ventilatory management, but it could also increase the risk of aspiration with its entailing airway obstruction and demand the need of postoperative artificial ventilatory support. In this report, we described the use of epidural analgesia with 2% lidocaine combined with continuous infusion of low dose propofol for sedation for a ALS patient undergoing abdominal hysterectomy. The anesthetic management of this patient was smooth and successful. Besides, epidural morphine could provide excellent postoperative pain relief without respiratory complications.

Amyotrophic Lateral Sclerosis↗
PubMed1998

Treatment results of 17 patients with diffuse pleural mesothelioma.

Treatment for diffuse pleural mesothelioma is very difficult. A retrospective study is established for analyzing the experiences in management of such a rare but fatal disease. From May 1960 to August 1996, 17 patients underwent treatment for pathologically confirmed malignant pleural mesothelioma at Veteran General Hospital-Taipei. The chart records were carefully reviewed and surgical specimens were reconfirmed by the pathologist. Single or combined treatment protocols with surgery, chemotherapy, and radiotherapy had been used according to the clinical situation. Pathological staging was recorded according to the Butchart staging system. Gender, smoking, asbestos exposure, histology, and survival were analyzed. There were 17 patients in total, including 15 males and 2 females with a mean age of 62 years. The most common symptoms were chest pain, cough, dyspnea and weight loss. For getting definite pathological diagnosis, the most sensitive procedures were video-assisted thoracic biopsy and open lung biopsy. In spite of trying multiple different treatment protocols, disease staging ( p = 0.0186) and the epithelial pathological type ( p = 0.0353) were the significant prognostic factors in our series. Prognosis of diffuse pleural mesothelioma is very poor. It was predominant in nen and no definite relationship with smoking or asbestos exposure was noted in our series, but it was relatively better in patients with early-stage and epithelial-type disease. Further efforts to improve the survival should be delivered on more aggressive cytoreductive surgery with early postoperative concurrent chemo-radiotherapy.

Adolescent↗
PubMed1997

Channel formation and [Ca2+]i accumulation induced by perforin N-terminus peptides: comparison with purified perforin and whole lytic granules.

Cytotoxic T lymphocytes (CTL) and natural killer (NK) cells express the pore forming protein perforin, which contributes to lymphocytotoxicity. The hallmark of perforin action is opening high-conductance transmembrane channels that enable massive influx of Ca2+ ions (deleterious to many cell types), as well as granzymes, which may trigger the apoptotic pathway. To explore the functional domains in the perforin molecule, we investigated in PN71 lymphocytes, the ability of perforin N-terminus synthetic peptides (compared to purified perforin and perforin-containing lytic granules), to cause intracellular Ca2+ ([Ca2+]i) accumulation and open transmembrane channels. To this end, we used the whole cell recording technique and Indo 1 fluorescence to measure membrane currents and [Ca2+]i, respectively. We have demonstrated that the N-terminus peptide Hu-34 (amino acids 1-34) closely resembled perforin action, reflected by [Ca2+]i accumulation and channel activity, while shorter peptides (e.g., Hu-16) generated mostly short-lived channels but no [Ca2+]i elevation. Hence, the first 34 amino acids of the perforin N-terminus sequence are sufficient for the perforin action.

Amino Acid Sequence↗
PubMed1997

Cloning and sequence analysis of the gene (eprA1) encoding an extracellular protease from Aeromonas hydrophila.

A gene (eprA1) encoding the extracellular protease of Aeromonas hydrophila AH1 has been cloned and sequenced. Nucleotide sequence analysis of eprA1 predicted a single open reading frame (ORF) of 1038 bp encoding a 346 amino acid (aa) polypeptide, with a potential 21-aa signal peptide. When the eprA1 gene was expressed in minicells, one major band of approx. 37 kDa was identified, while protease activity staining experiments identified a caseinolytic band of approx. 29 kDa determined by SDS-PAGE analysis of the minicells. The deduced C-terminal aa region (Arg-290 to Gly-313) showed sequence homology to partial C-terminal sequences of other zinc metalloproteases including Penicillium citrinum metalloprotease (PlnC), Aspergillus oryzae metalloprotease (NpII), Aspergillus flavus metalloprotease (MepA), and Aspergillus fumigatus metalloprotease (Mep20), particularly with respect to zinc-binding residues.

Aeromonas hydrophila↗
PubMed1997

Tumor necrosis factor alpha plays a central role in immune-mediated clearance of adenoviral vectors.

Adenovirus (Ad) gene transfer vectors are rapidly cleared from infected hepatocytes in mice. To determine which effector mechanisms are responsible for elimination of the Ad vectors, we infected mice that were genetically compromised in immune effector pathways [perforin, Fas, or tumor necrosis factor alpha (TNF-alpha)] with the Ad vector, Ad5-chloramphenicol acetyl transferase (CAT). Mice were sacrificed at 7-60 days postinfection, and the levels of CAT expression in the liver determined by a quantitative enzymatic assay. When the livers of infected mice were harvested 28 days postinfection, the levels of CAT expression revealed that the effectors most important for the elimination of the Ad vector were TNF-alpha > Fas > perforin. TNF-alpha did not have a curative effect on infected hepatocytes, as the administration of TNF-alpha to infected severe combined immunodeficient mice or to infected cultures in vitro had no specific effect on virus persistence. However, TNF-alpha-deficient mice demonstrated a striking reduction in the leukocytic infiltration early on in the infection, suggesting that TNF-alpha deficiency resulted in impaired recruitment of inflammatory cells to the site of inflammation. In addition, the TNF-deficient mice had a significantly reduced humoral immune response to virus infection. These results demonstrate a dominant role of TNF-alpha in elimination of Ad gene transfer vectors. This result is particularly important because viral proteins that disable TNF-alpha function have been removed from most Ad vectors, rendering them highly susceptible to TNF-alpha-mediated elimination.

Adenoviridae↗
PubMed1997

Antibodies against dengue virus E protein peptide bind to human plasminogen and inhibit plasmin activity.

Both mice and rabbits immunized with dengue virus E protein peptide spanning amino acids 100-119 (D4E) produced antibodies that reacted not only with the D4E peptide itself but also with human plasminogen, as shown by ELISA and Western blot. Sera from dengue virus-hyperimmunized mice and dengue patients also contained antibodies against D4E and plasminogen. Furthermore, such sera all contained plasmin inhibitory activity. Using affinity-purified anti-D4E antibodies and free D4E peptide for competitive inhibition, we demonstrated that the inhibition of plasmin activity was due to anti-D4E antibodies rather than other substances in the sera. Taken together, these results suggest dengue virus E protein amino acids 100-119 are a cross-reactive immunogenic region, and antibodies against this region may interfere with human fibrinolysis.

Animals↗
PubMed1997

Augmentation of protein kinase C activity and liver cell proliferation in lead nitrate-treated rats.

It is shown that lead alters calcium mediated cellular processes in several biological systems. Calcium enhances the activity of protein kinase C (PKC) which takes part in eliciting cell mitosis. In this study, the effects of lead nitrate on the activity of PKC enzyme were investigated in rat liver. The PKC activity was determined at 12, 24, 48, 72, 120, 168 hours after treatment with a single dose of lead nitrate in male Wistar rats. The results showed that the specific PKC activity of the purified particulate fraction was increased and reached a maximum at 24 hour, and lasted for 48 hours. This augmented activity of PKC was parallel with the increase of the lead level in the purified particulate fraction, although the protein levels of PKC alpha, PKC delta and PKC zeta were unchanged. Moreover, the frequency of mitotic cells also exhibited a significant increase, and like PKC activity, reached its maximum at 24 hour with accompany signs of liver enlargement. The results suggest that the PKC activation may be involved in promoting liver cell proliferation in lead nitrate-treated rats.

Animals↗
PubMed1997

Perforin, a cytotoxic molecule which mediates cell necrosis, is not required for the early control of mycobacterial infection in mice.

Host defense against mycobacterial infection requires the participation of monocytes and T cells. Both CD4+ and CD8+ T cells have been shown to be important in resistance to mycobacterial infection in vivo. The main contribution of CD4+ T cells to the protective antituberculosis response involves the production of Th1-type cytokines, including interleukin-2 (IL-2) and gamma interferon (IFN-gamma). CD8+ T cells have been considered to be responsible primarily for cytotoxicity mediated by toxic molecules, including perforin. CD8+ T cells may also elaborate Th1-type cytokines, such as IFN-gamma, in response to the infection. To elucidate the contribution of perforin-mediated target cell death to the control of mycobacterial infection in vivo, mice with a disruption in the perforin gene (P-/-) were infected with Mycobacterium bovis BCG or M. tuberculosis Erdman for 5 and 13 weeks, respectively. At 1, 3, 5, and 13 weeks postinfection, the number of viable mycobacteria in the lungs, spleens, and livers of mice were determined by CFU assay. The infected tissues were examined histologically, and cytokine mRNA levels in the spleens of these mice were determined. Similar studies were carried out in Fas receptor-defective (CBA/lpr(cg)) mice to evaluate the contribution of this alternative cytotoxic pathway to the control of mycobacterial infection. The absence of either perforin gene function or Fas receptor gene function did not modify the course of experimental mycobacterial infection in these mice. In addition, both P-/- and Fas receptor-defective mice appeared to have a compensatory activation of cytokine genes, even in the absence of the experimental infection. P-/- mice had a mean 3.4- to 5-fold increase in mRNA levels for IL-10, IL-12p35, IL-6, and IFN-gamma. Similarly, Fas receptor-defective mice had a mean 3- to 3.6-fold increase in mRNA levels for IFN-gamma, IL-12p35, and IL-10. Our results indicate that both perforin-mediated cytotoxicity and Fas-mediated cytotoxicity do not appear to be necessary for the early control of mycobacterial infection in vivo.

Animals↗
PubMed1997

Using monoclonal antibodies to characterize a sequential epitope on the group I allergen of Bermuda grass pollen.

BACKGROUND: Cyn d 1, the group I allergen of Bermuda grass pollen, had been purified and characterized. METHODS: A sequential B cell epitope on Cyn d 1 was studied with monoclonal antibodies (MoAbs). Cyn d 1 was cleaved by Achromobacter protease I into fragments, and the resulting peptides were fractionated on reversed-phase columns before being reacted with anti-Cyn d 1 MoAbs in a radioimmunoassay. A Cyn d 1 fragment recognized by its MoAb was selected for Edman degradation. A synthetic peptide was constructed according to the determined sequence. RESULTS: The epitope on Cyn d 1 recognized by MoAb 18-53 was found to be conformation independent, since its activity was not changed after sodium periodate, guanidine or urea treatment. The enzyme-cleaved fragment containing this epitope was determined to be DVDKPPFDGMTACGNEPIF which corresponds to the N-terminal 46-64 residues of Cyn d 1. The presence of this sequence in the epitope recognized by MoAb 18-53 was demonstrated by enzyme immunoassay and further confirmed by inhibition of binding enzyme immunoassay with synthetic peptides. Some cross-reactivity with the N-terminal 45-63 residues of Lol p 1 was also found. CONCLUSIONS: The primary structure of a sequential epitope on Cyn d 1 was determined, and its activity was confirmed with peptides synthesized according to the determined sequence.

Allergens↗
PubMed1997

Laryngeal candidiasis in children.

Candidiasis of the larynx is rare and often related to immunocompromised hosts. We here report a case of laryngeal candidiasis in an immunocompetent infant. The diagnosis was obtained by direct fibre-optic laryngoscopy with specimens submitted for culture. He received anti-fungal medication and was quite well at 1-year follow up. The pertinent literature is also reviewed.

Administration, Oral↗
PubMed1997

Intravenous infusion of low dose propofol for conscious sedation in cesarean section before spinal anesthesia.

BACKGROUND: Conscious sedation, not affecting the safety of both mother and fetus, is especially favorable in anxious patients undergoing Cesarean delivery. However, when sedation is started before performing intrathecal anesthesia, the infusion time before delivery will be prolonged. In this study, the incidence of maternal and fetal complications under propofol infusion were evaluated as well as the blood concentrations of propofol during delivery at different time of sedation. METHODS: Maternal and fetal effects of pre-spinal sedation with low dose propofol infusion technique (3 mg/mg/h following 0.3 mg/kg bolus) in 37 Cesarean parturients were evaluated, compared with another 33 parturients under spinal anesthesia without any sedatives. RESULTS: The induction to delivery time was 32.6 +/- 7.7 min. Satisfactory, airway-maintaining conscious sedation was shown without increasing the incidence of post-spinal hypotension and hypoxemia compared with non-sedative group. The plasma propofol concentrations in the mean time of delivery in maternal vein and umbilical vein were 0.86 +/- 0.29 and 0.33 +/- 0.11 microgram/ml, respectively. Umbilical venous concentration neither correlated with infusion time nor exceeded the maternal venous concentration. The 1-min and 5-min Apgar scores as well as umbilical venous blood gas analyses did not differ significantly between two groups. CONCLUSIONS: Conscious sedation by low dose propofol infusion is safe for both mother and fetus in spite of longer infusion time.

Adult↗
PubMed1997

Streptococcal toxic shock syndrome complicating varicella in children.

The most common complication in children with varicella is cutaneous superimposed infection with pyogenic bacteria. Group A beta-hemolytic streptococci, which are known to cause life-threatening infections in both previously healthy children and those with underlying diseases, are the most frequently associated pathogens. A newly recognized disease, called streptococcal toxic shock syndrome, is associated with severe morbidity and mortality. We report a 3-year-old boy with a diagnosis of this syndrome who presented with increasing fever, vomiting, and lethargy 7 days after the development of a classic varicella skin lesion. In spite of aggressive fluid supply, administration of inotropic agents, and cardiopulmonary resuscitation, a rapidly deteriorating clinical course led to death 4 hours after hospitalization. This is the first report of this association in Taiwan. Pediatricians evaluating children with varicella must be mindful of the potential for Group A beta-hemolytic streptococcal infection.

Chickenpox↗
PubMed1997

Comparison of neuromuscular action of rocuronium, a new steroidal non-depolarizing agent, with vecuronium.

BACKGROUND: Rocuronium is a new nondepolarizing muscle relaxant. It features a rapid onset and lack of histamine release: It has an intermediate onset of action as vecuronium. The purpose of this study was to compare the neuromuscular action and condition of intubation after a bolus dose of rocuronium or vecuronium (2 x ED90). We also compared the duration of relaxation after intubation and maintenance doses of each drug. METHODS: Sixty male or female patients, age 18-65, scheduled for elective surgery under general anesthesia were divided randomly into two groups (rocuronium and vecuronium group). All patients were ASA class I-II and pre-operative laboratory data were normal. Anesthesia was performed with fentanyl, isoflurane and O2. Rocuronium 0.6 mg/kg (2 x ED90) or vecuronium 0.1 mg/kg (2 x ED90) was given during induction of anesthesia. The response of adductor pollicis was measured with acceleromyography. Neuromuscular block was maintained by bolus injection of rocuronium 0.15 mg/kg or vecuronium 0.025 mg/kg when T1 reached 25% of control. Onset time, duration, recovery indices, intubation condition and T4/T1 ratio to 70% were recorded. Side effects were recorded during the study. RESULTS: The onset time was significantly longer in vecuronium group than that of rocuronium group (102.8 +/- 26.9 s vs. 54.9 +/- 10.9 s, p < 0.05). The clinical durations of action were respectively 44.2 +/- 13.2 min in rocuronium group and 42.5 +/- 9.1 min in vecuronium group (T1 to 25%). The duration of the maintenance were respectively 28.8 +/- 9.5 min in rocuronium group and 26.1 +/- 6.8 min in vecuronium group (T1 to 25%). No adverse effect occurred with either drug. The intubation condition was similar in both groups. CONCLUSIONS: We conclude that rocuronium provides a more rapid onset of action than that of vecuronium. Rocuronium is an intermediate-acting muscle relaxant as vecuronium with good to excellent intubation condition. It may be an useful alternative to vecuronium for rapid tracheal intubation.

Adolescent↗