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Biomedical subjects

C C Chao

Publications and source records attributed to C C Chao.

At least 181 records · Page 10Linked to original sources
PubMed1991

Altered cytokine release in peripheral blood mononuclear cell cultures from patients with the chronic fatigue syndrome.

Chronic fatigue syndrome (CFS) is an idiopathic illness associated with a variety of immunologic abnormalities. To investigate potential pathogenetic mechanisms, we evaluated serum levels and peripheral blood mononuclear cell (PBMC) production of selected cytokines and immunoglobulins. Serum bioactive transforming growth factor beta (TGF-beta) levels were higher (P less than 0.01) in patients with CFS (290 +/- 46 pg/mL) than in control subjects (104 +/- 18 pg/mL), but levels of other cytokines tested were not different. Lipopolysaccharide-stimulated release of interleukin 1 beta (IL-1 beta), IL-6, and tumor necrosis factor-alpha was increased (P less than 0.05) in PBMC cultures from patients with CFS versus control subjects; enhanced (P less than 0.01) IL-6 release to phytohemagglutinin was also observed. In contrast, TGF-beta release in response to lipopolysaccharide was depressed (P less than 0.01) in PBMC cultures derived from patients with CFS. No differences in IL-2 and IL-4 or immunoglobulin production were observed. The enhanced release of inflammatory cytokines by stimulated PBMC from patients with CFS suggests that these cells are primed for an increased response to immune stimuli. These data also suggest an association between abnormal regulation of TGF-beta production in vivo and in vitro with the immunologic consequence of CFS.

Cytokines↗
PubMed1991

Cross-resistance to UV radiation of a cisplatin-resistant human cell line: overexpression of cellular factors that recognize UV-modified DNA.

A human cell line selected for cisplatin resistance (CPR) was irradiated with UV light and showed cross-resistance to UV light. Applying a modified chloramphenicol acetyltransferase assay, we observed that CPR cells acquired enhanced host cell reactivation of a transfected plasmid carrying UV damage. Gel mobility shift analysis indicated that two nuclear factors that recognize UV-modified DNA were overexpressed in CPR cells. In addition, factors that bind UV-modified DNA were independent from the factors that bind cisplatin-modified DNA. The significance of the identified binding factors, possibly DNA repair enzymes, is discussed.

Binding, Competitive↗
PubMed1991

Mini-dose intrathecal morphine for post-cesarean section analgesia.

Dose-response relationship of mini-dose intrathecal morphine (0.025-0.125 mg) for analgesia after Cesarean section was studied. Sixty-three patients were randomly divided into six groups by the following intrathecal morphine injection: group 1 (0 mg), group 2 (0.025 mg), group 3 (0.05 mg), group 4 (0.075 mg), group 5 (0.1 mg), and group 6 (0.125 mg). The selected dose of morphine mixed with 2 ml 0.5% hyperbaric bupivacaine (10 mg) was administered intrathecally to induce spinal anesthesia. The mean analgesia duration in each group was 3.6 +/- 2.0, 10.6 +/- 7.1, 17.3 +/- 13.8, 25.6 +/- 7.5, 33.9 +/- 10.1, and 39.5 +/- 11.9 h respectively (mean +/- SD). In morphine groups, duration of analgesia was significantly longer (p less than 0.05) than control group (0 mg), and the first 24 h pain scores were also lower (p less than 0.01). Furthermore, a significant linear dose-response relationship between analgesic duration and the dose of intrathecal morphine was revealed (y = 3.28 + 295.5x, r2 = 0.64, p less than 0.05). Among morphine groups, analgesic quality was significantly better in patients in groups 4-6 than those in group 2 and 3 (p less than 0.05), so as in the proportion of effective analgesia in the first 24 h (p less than 0.01). Neonatal condition was not adversely affected by such mini-dose of intrathecal morphine. The most common maternal adverse effect observed was pruritus, and its incidence was significantly greater in groups 3-6 than in the control group (p less than 0.05). However, no significant difference was observed among all morphine groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Cocaine-mediated suppression of superoxide production by human peripheral blood mononuclear cells.

Cocaine, like opiates, modulates a variety of immune functions. In the present study, we investigated the effect of cocaine on superoxide anion (O2-) production, an index of a microbicidal activity, by cultured human peripheral blood mononuclear cells. Release of O2- was measured by superoxide dismutase-inhibitable reduction of ferricytochrome C in response to phorbol myristate acetate. Peripheral blood mononuclear cells cultured in the presence of cocaine (1 microM) for 48 hr released less (P less than .05) O2- than did nontreated control cells (95.1 +/- 10.2 vs. 57.9 +/- 6.6 nmol/10(7) cells/60 min, respectively). This suppressive effect was dose-dependent. Antibodies to transforming growth factor-beta, a cytokine inhibitory of monocyte O2- production, abrogated (P less than .01) cocaine-mediated suppression, suggesting that transforming growth factor-beta is involved in the suppression. Also, naloxone blocked (P less than .01) the suppressive effects of both cocaine and transforming growth factor-beta on O2- production, suggesting that the suppressive mechanism is naloxone-sensitive.

Adult↗
PubMed1990

Increased mdr gene expression and decreased drug accumulation in a human colonic cancer cell line resistant to hydrophobic drug.

An adriamycin-resistant human colonic cancer cell line was characterized. This clone exhibits the classical multidrug resistance (MDR) phenotype, being cross-resistant to hydrophobic drugs such as colchicine, and vinblastine. In contrast, this clone shows a normal response to DNA-damaging agents. The appearance of MDR in these cells was linked to a decreased accumulation of the drug [3H]colchicine as compared to the drug-sensitive cells. This MDR line expressed 80-100 fold increased levels of the specific 4.5-kb mdr mRNA, and a gene amplification. Our results indicate that MDR in human colonic cancer cells can result from increased expression of at least one member of the mdr gene family.

Antineoplastic Agents↗
PubMed1990

Coordinated induction of two unrelated glucose-regulated protein genes by a calcium ionophore: human BiP/GRP78 and GAPDH.

The induction of human BiP/GRP78 and GAPDH protein genes by the calcium ionophore A23187 was determined. Steady-state levels of mRNA for both the glucose starvation-responsive BiP/GRP78 gene and the glucose-responsive GAPDH gene were dramatically induced in a variety of human cells. There is a homologous palindromatic sequence GCCGTTAACGGC in the active promoter region of the two genes that is known to be required for the induction of mammalian BiP/GRP78 by A23187. The evidence confirms in general the function of this element in the regulation of calcium-associated gene activity.

Base Sequence↗
PubMed1990

Phenotypic reversion of cisplatin resistance in human cells accompanies reduced host cell reactivation of damaged plasmid.

Revertant cell lines were established from cisplatin (CP) resistant HeLa cells. Expression of CP damaged plasmid DNA carrying bacterial chloramphenicol acetyltransferase (CAT) gene after transfection into cells was measured. Revertant cells showed reduced host cell reactivation of damaged plasmid, as compared to resistant cells. Addition of aphidicolin, an inhibitor for DNA polymerase alpha, to resistant cells effectively blocked enhanced plasmid reactivation and acquired resistance. The results are consistent with the notion that cellular ability in repair CP-damaged DNA is a mechanism for CP resistance.

Aphidicolin↗
PubMed1990

Effects of immobilization stress on the pathogenesis of acute murine toxoplasmosis.

Stress modulates a variety of immune responses. We investigated the effects of immobilization stress on the pathogenesis of acute murine toxoplasmosis, an infection in which cell-mediated immunity is of major importance in host defense. Repetitive overnight immobilization beginning 3 days prior to infection enhanced (p less than 0.05) the mortality of mice infected with a virulent strain (C56) of Toxoplasma gondii (77% vs 15% mortality in restrained and control mice, respectively). Daily immobilization for 14 days prior to infection abrogated (p less than 0.05) the lethal effect of immobilization, suggesting an adaptive mechanism. To explore the effect of immobilization with a less virulent strain, the Me49 strain of T. gondii was studied. Acute infection with T. gondii Me49 resulted in anorexia and weight loss, while spleen size and respiratory burst activity of peritoneal exudate cells were enhanced (p less than 0.01). Immobilization (twice daily for 2 h) did not significantly alter survival or other clinical features of acute T. gondii infection. In addition, immobilization suppressed (p less than 0.05) phorbol myristate acetate-stimulated release of superoxide anion by peritoneal exudate cells in healthy naive mice, but not in infected mice. These findings indicate that immobilization stress can alter the pathogenesis of acute T. gondii infection in healthy mice, but the effect of this stress paradigm will be influenced, in part, by the timing of the immobilization and the virulence of the strain of T. gondii.

Animals↗
PubMed1990

Oral complications associated with endotracheal general anesthesia.

A series of 745 consecutive cases of endotracheal anesthesia were collected at the National Taiwan University Hospital. Evaluation of the oral conditions was performed before, during and after the anesthesia. Injuries to oral structures were recorded. An 18% incidence of oral injuries was noted and the frequency for dental damage was 12.1%. Maxillary incisors, especially the left ones, were accident-prone. Risk factors identified in this study included large decay or restoration, advanced periodontitis, presence of dental prosthesis, shedding deciduous tooth, class II jaw relationship and anterior crowding. More than one third of the complications occurred during the maintenance or emergence stage of the anesthesia. Recommendations for prevention and management of this problem were given.

Adolescent↗
PubMed1990

Characterization of ocular mucus extracts by crossed immunoelectrophoretic techniques.

Crossed immunoelectrophoresis (CIE) and crossed immunoelectrofocusing (CIEF) were used to characterize proteins and mucosubstance in the saline extract of human ocular mucus pooled from the normal eyes of donors. CIE resolved more components with greater specificity than previous techniques. Up to 25 components were identified. Lactoferrin, protein G, tear prealbumin, and ocular mucosubstance were found to be ocular-specific. CIE also allowed for the study of protein associations of: 1) albumin-alpha 1-antitrypsin; 2) albumin-tear prealbumin; and 3) IgA-secretory component and lactoferrin-mucosubstance. CIEF revealed that most of the proteins were in the pI range of 4.6-7.4. Up to 19 components were identified. Protein associations revealed by CIE were not evident by CIEF. These results provide a basis for future comparative analyses of tear and mucus from normal and diseased eyes, essential for a better understanding of tear and mucus function.

Adult↗
PubMed1990

Suppression of hemodynamic change before extubation--lidocaine through modified endotracheal tube.

Twenty females, aged 31 to 49 years, scheduled for abdominal total hysterectomy were randomly divided into two groups in this study. An epidural catheter was placed at T11-12 before general anesthesia. All patients receive the combination of epidural anesthesia and general anesthesia for the operation and relief of pain postoperatively. The modified endotracheal tube we used is shown in Fig. 1. For patients in group I (Lidocaine group), 2 mL 4% lidocaine solution was injected through the catheter to desensitize the tracheal mucosa around the cuff after the surgeon had removed the uterus. In group II (Control group), no special management was made. All patients were not extubated until they were considered to be awake. Systolic blood pressure at three and one minute before extubation and pulse rate recorded at one minute before extubation showed in patients of group I were statistically smoother than those recorded in group II (p less than 0.01). All patients had gag reflex just after awake extubation.

Adult↗
PubMed1990

Epidural anesthesia for spine surgery.

Over the last 2 years, the authors have had experience with epidural anesthesia for a variety of spine operations in 20 patients. It is proved to be safe, reliable, and effective. Perioperative complications were minimal and could be easily treated. No patient had a new neurologic deficit as a result of the epidural technique. Thus, epidural anesthesia should not be excluded from the anesthesiologist's consideration simply because of the presence of spine disease or neurologic deficit.

Adult↗
PubMed1990

General anesthesia with propofol (continuous intravenous infusion) supplemented with nitrous oxide: comparison with isoflurane.

Thirty adult surgical patients (ASA I-II) undergoing superficial operations of short duration (about 1h) were arbitrarily divided into two groups. In group A (n = 15), anesthesia was induced with propofol, 2 mg/kg, iv. After endotracheal intubation with the aid of succinylcholine (1 mg/kg, iv), anesthesia was maintained by continuous iv infusion of propofol (0.05-0.2 mg/kg/min) with nitrous oxide and oxygen (2:1). In group B (n = 15), induction and endotracheal intubation were accomplished using thiopental (4 mg/kg, iv) and succinylcholine (1 mg/kg). Anesthesia was maintained with isoflurane (0.5-2.0%), nitrous oxide and oxygen (2:1). Atracurium was used in both groups as muscle relaxant. Hemodynamic responses to laryngoscopy and endotracheal intubation and during operation were not significantly different between the two groups. However, recovery to verbal command and orientation was significantly more rapid in the propofol group (7.8 +/- 4.8 min and 11.2 +/- 5.1 min) than in the isoflurane group (15.6 +/- 4.9 min and 22.6 +/- 6.0 min). In conclusion, continuous propofol infusion combined with nitrous oxide and muscle relaxant is suggested as a better method compared with isoflurane for short operations because of more rapid complete recovery.

Adult↗
PubMed1990

Lethality of morphine in mice infected with Toxoplasma gondii.

Opiates modulate a variety of immune responses. We investigated the effect of morphine on the pathogenesis of an acute Toxoplasma gondii infection. Repeated s.c. injections with morphine sulfate (300 mg/kg) every 36 hr addicted mice and increased markedly the mortality of mice infected with an avirulent strain of T. gondii (86%) vs. 0% mortality in addicted and control mice, respectively, P less than .001). However, a single challenge with morphine (300 mg/kg) also markedly (P less than .001) increased mortality (94%) of infected mice when the morphine was administered at day 13 postinfection; susceptibility to the lethal effect was not observed until day 9 postinfection, a time when immune reactivity was evident (i.e., 3- to 4-fold splenic enlargement). This lethal effect was attenuated by pretreatment with naltrexone, suggesting involvement of an opiate receptor mechanism. Sulfadiazine treatment abrogated morphine-induced mortality, indicating a prerequisite of an active infectious state. These findings suggest that immune activation by T. gondii infection plays a critical role in morphine-induced mortality in this murine model.

Animals↗
PubMed1990

A new approach to suppress bucking before extubation--lidocaine through modified endotracheal tube.

The conventional endotracheal tube was modified with an epidural catheter adhered on the concave aspect of it. The opening of the catheter is at the proximal margin of the cuff. Local anesthetic can be injected into the trachea, then desensitize the tracheal mucosa nearby the cuff. Thirty-four female gynecological patients underwent abdominal total hysterectomy were studied and divided into three groups. In group 1, anesthesia was maintained without special management. In groups 2 and 3, 2 mL gentian violet stained 4% lidocaine solution was administered intratracheally by two different methods 60-120 minutes before the conclusion of the surgery. The peak cuff pressures generated by the awakening patients were 53.8 +/- 2.2 cm H2O (mean +/- SE) in group 1, 47.3 +/- 2.5 cmH2O (Group 2) and 36.4 +/- 1.6 cmH2O Group 3) respectively. Bucking before awakening was also evaluated clinically and showed 100%, 73% and 0% in each group. Intratracheal administration of lidocaine in dose of 2 mL 4% showed significant effect for the suppression of bucking during the recovery of general anesthesia in group 2 and 3 compared with the group 1. Lidocaine administered through the catheter of modified endotracheal tube also resulted in less increase in the peak cuff pressure and even no clinically observed bucking than direct administered through the endotracheal tube. Gag reflex was preserved in all patients and none had suffered from aspiration postoperatively.

Adult↗
PubMed1990

The application of pulse oximeter for supraclavicular brachial block.

The subclavian artery is the most important landmark of the supraclavicular brachial block. However, it is difficult to locate the artery by palpation in the patients with poor landmark. The present study was aimed to compare two localizing methods of the subclavian artery by a pulse oximeter or by palpation. One hundred patients were divided into three groups. Group A (Slim Group): 6 patients, Group B (Normal Weight Group): 75 and Group C (Obese Group): 19. All patients received both methods to locate the subclavian artery. The first method was by palpating the pulsation of the subclavian artery. The second was by observing the wave depression of the pulse oximeter while pressing supraclavicular area. It was found that the detection rate of the first method was 83.3% in Group A, 52.0% in Group B, 26.3% in Group C and 49.0% in overall patients. However, the detection rate of the second method was 100% in each group. It shows a significant difference between the two methods in Group B, Group C and all patients (P less than 0.001), but no difference in Group A (P = 0.68). There were 13 patients among the 100 patients undergoing surgery of the upper extremity. Seven of them whose pulsation was not clearly palpated but could be located exactly by pulse oximeter. Supraclavicular brachial block was still completed successfully in these 13 patients. No pneumothorax was found. Utilizing pulse oximeter in supraclavicular block provides a high detection rate of the pulsation of the subclavian artery and improves the reliability of the block, especially in the patients with poor landmark.

Adult↗
PubMed1990

Estimation of the length of nasopharyngeal airway in Chinese adults.

Nasopharyngeal airway should be placed to reach the tongue base without contact with the epiglottis. The correct length of the nasopharyngeal airway in Chinese adults was estimated in seventy-three surgical patients under general anesthesia (30 males and 43 females, aged 18-82 yr). Measurements were performed with a soft, uncuffed, ID 6.0 mm endotracheal tube (Portex) introduced through the nasopharyngeal passage. The proper tip placement of the tube was evaluated under direct laryngoscopy. The Nostril-epiglottis distance (N-E distance) is 15.31 +/- 1.09 cm (mean +/- SD) for all cases, 16.03 +/- 1.04 cm for male cases and 14.97 +/- 0.95 cm for female cases. There are correlation between the N-E distance and the height (p less than 0.001, r = 0.41), and between the N-E distance and the N-A distance (The distance from nose tip to mandibular angle) (p less than 0.004, r = 0.324). Linear regression analysis relating the N-E distance to the height and the N-E distance to the N-A distance were also statistically significant (p less than 0.001 and p less than 0.01, respectively).

Adolescent↗