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Biomedical subjects

K P Chen

Publications and source records attributed to K P Chen.

At least 19 recordsLinked to original sources
PubMed1999

Activation of indices of cell-mediated immunity in bipolar mania.

BACKGROUND: Evidence supports that macrophages as well as lymphocytes and their products may be involved in the pathophysiology of psychiatric disorders. Whether patients with bipolar disorder have activation or reduction of immunity during a manic episode remains unclear. METHODS: The purpose of this case-control study was to investigate the lymphocyte proliferation to phytohemagglutinin (PHA), concanavalin A, and pokeweed mitogen, and plasma levels of soluble interleukin-2 receptor (sIL-2R) and sIL-6R in patients with bipolar mania (DSM-III-R). The subjects were 23 physically healthy patients with Young Mania Rating Scale (YMRS) scores > or = 26 as well as aged < or = 45 years and 23 age- and gender-matched normal control subjects. The above immune variables were measured in acute mania and consequent remission (YMRS scores < or = 12) among bipolar patients. RESULTS: The lymphocyte proliferation to PHA and the plasma sIL-2R levels, but not sIL-6R, of bipolar patients were significantly higher in acute mania than in consequent remission. These elevations were not due to differences in medication status. Only in acute mania were the plasma sIL-2R levels of patients significantly higher than control subjects. A positive correlation between the changes of manic severity and plasma sIL-2R levels was observed. Remitted bipolar patients and normal control subjects did not differ in any of these measures. CONCLUSIONS: Cell-mediated immunity activation in bipolar mania was demonstrated and may be through a specifically state-dependent immune response.

Acute Disease↗
PubMed1998

Antiapoptotic but not antiviral function of human bcl-2 assists establishment of Japanese encephalitis virus persistence in cultured cells.

Upon infection of Japanese encephalitis virus (JEV), baby hamster kidney (BHK-21) and Chinese hamster ovary (CHO) cells were killed by a mechanism involved in apoptosis. While readily established in a variety of cell lines, JEV persistence has never been successfully instituted in BHK-21 and CHO cells. Since stable expression of human bcl-2 in BHK-21 cells has been shown to delay JEV-induced apoptosis, in this study we investigated whether JEV persistence could be established in such cells. When constitutively expressing bcl-2, but not its closest homolog, bcl-XL, following a primary lytic infection, approximately 5 to 10% of BHK-21 and CHO cells became persistently JEV infected during a long-term culture. From the persistent bulks, several independent clones were selected and expanded to form stable cell lines that continuously produced infectious virus without marked cytopathic effects (CPE). Among these stable cell lines, the truncated nonstructural protein 1 (NS1) was also detected and was indistinguishable from the NS1 truncations previously observed in JEV-persistent murine neuroblastoma N18 cells. However, the stable expression of NS1 alone, regardless of whether it was truncated or full length, failed to render the engineered cells persistently infected by JEV, implying that aberrant NS1 proteins were likely a consequence of, rather than a cause for, the viral persistence. Enforced bcl-2 expression, which did not affect virus replication and spread during the early phase of cytolytic infection, appeared to attain JEV persistence by restriction of virus-induced CPE. Our results suggest that it is the antiapoptotic, rather than the antiviral, effect of cellular bcl-2 which plays a role in the establishment of JEV persistence.

Amino Acid Sequence↗
PubMed1996

[Clinical experience of laryngeal mask airway combined with continuous intravenous propofol infusion during general anesthesia].

BACKGROUND: Propofol's greatest attributes are its pharmacokinetic properties which result in a rapid, clear emergency and lack of cumulative effects even after prolonged administration. It is a drug of popular choice for the maintenance of general anesthesia. The laryngeal mask airway (LMA), originally described by Dr. Brain is now a good alternative as the airway management technique. Because of its high success rate in securing a clinically acceptable airway in anesthetized patients, LMA has been proposed as a practical airway and conveyer for general anesthesia. This study was designed to observe and evaluate the feasibility of propofol infusion combined with N2O for maintenance of anesthesia, with a LMA as airway and conveyer during general anesthesia. METHODS: Sixty patients, ASA class I-II, aged 15-59 years, were selected for this study. They were scheduled for upper-limb orthopedic surgeries in supine position. No patient was premedicated. Intraoperative monitoring included electrocardiography, pulse oximetry, end-tidal carbon dioxide and automatic non-invasive blood pressure. The agents for induction of anesthesia included atropine 0.01 mg/kg, atracurium 5 mg, fentanyl 2-3 micrograms/kg, 2% lidocaine 1.5-2 mg/kg, propofol 2 mg/kg, and succinylcholine 1-1.5 mg/kg, all of which were given intravenously in sequence. After that laryngeal mask airway (LMA) was inserted. The position of LMA was confirmed by even undulation of chest wall and breathing sound. Anesthesia was then maintained with nitrous oxide in 40% oxygen and continuous propofol infusion. The pumping rate was set to start at 6 mg/kg/h. Muscle relaxation was achieved by intravenous tracrium given intermittently. All patients were mechanically ventilated with a ventilator incorporated to the anesthesia machine. The ventilator was set to give a tidal volume of 8 ml/kg at a rate of 12-14/min. At the end of the operation, the propofol infusion and nitrous oxide were simultaneously discontinued. The effect of muscle relaxant was antagonized by atropine 1.0 mg and neostigmine 2.5 mg intravenously. The LMA was removed while the patient was awake and able to open mouth at request. They were followed 24 h postoperatively for inquiring intraoperative awareness and other complaints. RESULTS: No patient was noted to experience awareness during the intraoperative period. Regarding LMA insertion, success in the first attempt was seen in 55 patients (90.2%). Success in the second attempt was seen in 5 patients (8.2%). Failure was encountered in one patient (1.6%). The average time of emergence was 92 +/- 3.4 min. The average rate of speed of propofol infusion was 6.29 +/- 0.97 mg/kg/h. CONCLUSIONS: The combination of propofol infusion and N2O with laryngeal mask as airway and recovery was a good alternative in administration of general anesthesia.

Adolescent↗
PubMed1995

Foley catheter used as bronchial blocker for one lung ventilation in a patient with tracheostomy--a case report.

Anesthesia with one-lung ventilation is a good anesthetic technique for patients receiving thoracotomy in various underlying diseases. One lung ventilation can be achieved successfully by the application of a double-lumen endotracheal tube through the oral route. However, there are several situations such as low body weight, young age, difficult intubation, anatomic anomaly, and tamponading endobronchial bleeding in some adult patients, etc., in which lung separation by a double-lumen endotracheal tube may be relatively contraindicated because insertion is either difficult or dangerous. Bronchial blocker with a Fogarty embolectomy catheter has been used successfully for such situations. Here, we reported the clinical experience in using the Foley catheter as the bronchial blocker in a patient with tracheostomy.

Adult↗
PubMed1993

Lumbar extradural morphine and caudal extradural morphine for postoperative analgesia and their adverse effects.

The efficacy of morphine by either lumbar extradural route or caudal extradural route and their adverse effects for postoperative analgesia were studied by comparing with the control group without morphine administration. 105 patients, 79 males and 26 females, aged 18 to 70 years, scheduled for hemorrhoidectomy surgery were selected. They were randomly assigned into three groups, i.e group I: without morphine use as control group (n = 35), group II: lumbar extradural morphine group (n = 35) and group III: caudal extradural morphine group (n = 35). Patients in group I received general anesthesia by face mask after induction by intravenous anesthetics and maintained with potent halogenated inhalation agents (isoflurane) through face mask. Patients in group II received lumbar extradural blockade through the L4-L5 intervertebral space, and those in group III received caudal extradural blockade through the sacrococcygeal junction (sacral hiatus) for intraoperative anesthesia and analgesia. Drugs included 0.5% bupivacaine 10ml + 2% xylocaine 10ml + 2mg morphine HCl + 0.1mg epinephrine were given either into the lumbar extradural space or into the caudal extradural space. No more narcotic has been given throughout the whole intraoperative course. All of these patients were followed up 24 hours later after the end of anesthesia. There were 11 patients (31.4%) in the control group, 26 patients (74.3%) in the lumbar extradural morphine group, and 25 patients (71.4%) in the caudal extradural morphine group who did not need additional narcotic for pain relief for more than 24 hours postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

The depth to the epidural space.

Two hundred and ten patients, 145 males and 65 females, aged 20 to 72 years old, ready to receive extracorporeal shock wave lithotripsy under epidural anesthesia were studied to evaluate if any correlation existed between body weight, body surface area, body mass index and body height and the depth to the epidural space. The mean value for the depth to the epidural space was 4.77 +/- 0.55 cm for males, 4.25 +/- 0.55 cm for females and the overall average was 4.61 +/- 0.60 cm. The range of the depth to the epidural space was 3.0-7.0 cm. Linear regression analysis revealed significant correlation between body weight, body surface area, body mass index, body height an the depth to the epidural space, in the order of BW greater than BSA greater than BMI greater than BH. It is concluded that body weight, body surface area, body mass index and body height affect the depth to the epidural space and play an important role in predicting the depth to the epidural space.

Adult↗
PubMed1989

Combined epidural lidocaine-fentanyl-epinephrine for cesarean section.

The combined use of fentanyl-epinephrine-lidocaine in epidural analgesia was investigated in 60 mothers who underwent elective Cesarean section. They were randomly classified into 4 groups of 15 each. Group A received 20 mL of 2% lidocaine 3 mL normal saline. Group B received 20 mL of 2% lidocaine with freshly added 1:200000 epinephrine and 5 mL normal saline. Group C received 20 mL of 2% lidocaine and 2 mL of fentanyl in 3 mL normal saline. Group D received 20 mL of 2% lidocaine and 5 mL normal saline. The duration of action was nearly doubled in the groups with epinephrine added. The quality of the analgesia was assessed by the degree of intraoperative analgesia; 93% of the patients in group A were classified as "Excellent"; while only 67% in group B were classified as "Excellent". The difference in patient's acceptance was statistically significant. 93% vs 27% in Group A and Group C; 67% vs 6.7% in Group B and Group D rated "Excellent". The results suggest that both fentanyl and epinephrine improve intraoperative analgesia. Epinephrine offers a greater analgesic effect than fentanyl.

Adult↗
PubMed1984

Determination of calcium gluconate by selective oxidation with periodate.

A modified analytical method was developed which can accurately quantitate calcium gluconate and its pharmaceutical preparations in the presence of other calcium compounds or other cations able to complex with EDTA. The proposed method was based on the principle of the Malaprade reaction, according to which gluconic acid is selectively and quantitatively oxidized by sodium periodate. The content of calcium gluconate was calculated from the amount of gluconic acid found. The selective oxidation proceeded at 50 degrees C for 10 min, yielding approximately 100% recovery of calcium gluconate. The proposed method was accurate, precise, and superior to the compendia EDTA- complexometric method in terms of specificity.

Calcium Gluconate↗
PubMed1983

Incidence of hepatitis A virus infection in children in Taipei, Taiwan.

To understand the prevalence and incidence of hepatitis A virus (HAV) infection in Chinese children in Taiwan, we determined the age-specific prevalence of hepatitis A antibodies (anti-HAV) in 823 children, ranging from birth (cord blood) to 19 years of age. The frequency of anti-HAV rose with increasing age with three different slopes, probably reflecting different age-specific incidences: lowest under 4 years of age, intermediate between 4 and 10 years, and highest above 10 years. We obtained follow-up specimens on 618 of the preschool children under 6 years of age. 11 (1.9%) of the 573 without antibodies had seroconversions after an average of 1.9 years of follow-up. The annual incidence was 1.0% and increased with advancing age of the children after infancy. None of the 11 seroconversions had clinical hepatitis. Among the 28 children 1-24 months of age who had antibodies, only 1 was positive on follow-up, reflecting loss of passively acquired maternal antibody in most children.

Adolescent↗
PubMed1982

Incidence of hepatitis B virus infections in preschool children in Taiwan.

To determine the incidence of infections with hepatitis B virus (HBV) among Chinese preschool children, 1,510 children (mean age, 29 months) were tested for HBV markers; 15.9% were infected with HBV (7.8% positive for hepatitis B surface antigen [HBsAg] and 8.1% positive for antibody to HBsAg) and 84.1% were susceptible when the children were enrolled in the study. The average length of follow-up was 2.1 years among 1,110 children. Among the 924 susceptible children who were followed up, 10.6% had seroconversions for HBV markers, none of which was associated with clinical illness; the annual incidence of HBV infections was 5.0%. Among the 98 children who experienced HBV infections during the study, 23% became HBsAg carriers, and HBsAg persistence was age-related, with most carriers being among the youngest children infected. In contrast, among the children with HBV markers at the time of enrollment, 118 (49.2%) were HBsAg-positive and 86% were still positive on follow-up. The incidence of HBV infections was significantly associated with the frequency of previous injections.

Age Factors↗