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Biomedical subjects

C L Chang

Publications and source records attributed to C L Chang.

At least 163 records · Page 9Linked to original sources
PubMed1989

Impotence evaluated by the use of prostaglandin E1.

We screened 80 patients at our hospital for the differential diagnosis of impotence using intracavernous injection of prostaglandin E1 (20 micrograms). The rate of positive response was 78.8 per cent (63 patients). Neither systemic reactions nor priapism occurred. However, a considerable incidence (23.8 per cent, 19 of 80 patients) of tolerable injection pain was encountered. The 133xenon penile washout study was conducted routinely in impotent men for hemodynamic evaluation of penile vascularity. In 80 patients a positive correlation between the response of intracavernous prostaglandin E1 injection and the result of the washout study was found (r equals 0.381, p less than 0.0002). We selected 14 subjects randomly to receive additional intravenous infusions of prostaglandin E1 (6 ampules, 120 micrograms total) for 3 days, after which another 133xenon washout study was done. The washout studies before and after intravenous prostaglandin E1 infusion were compared, and 10 patients (71.4 per cent) appeared to obtain improvement in half-time clearance and penile blood flow. However, only 3 patients noticed improvement subjectively. We suggest that prostaglandin E1 could be a desirable alternative for the diagnosis and treatment of impotence.

Adult↗
PubMed1989

Growth in atopic eczema: a controlled study by questionnaire.

The parents of 128 children with atopic eczema and 117 healthy control children responded to a questionnaire that included measurement of their own and their children's heights at home after standardised instructions. When cases and controls were compared there was no significant difference in parental height but the children with eczema were significantly shorter than the healthy control group. This difference remained significant when children with associated asthma were excluded from the analysis.

Adolescent↗
PubMed1989

[pH-adjusted lidocaine HCl with or without epinephrine for epidural anesthesia].

Preparations of local anesthetics are prepared as acidic solutions of the salts to promote solubility and stability. In solution, these salts exist as both nonionized and ionized forms. The ratio depends on the pH of the solution, and it is only the non-ionized form that permeates the nerve membrane and sheath. This study of epidural analgesia was undertaken to determine the effect of increasing the pH of the lidocaine HCl by the addition of sodium bicarbonate. Parameters studied included the time of onset of analgesia (time between the completion of injection and the loss of scratch sensation at the left L1 dermatome), the spread of sensory blockade, the degree of motor block, and the blood pressure and heart rate. Eighty seven adult patients undergoing epidural anesthesia were divided into four groups. Group 1 patients were given 2% lidocaine HCl solution plus 1.5 mL normal saline per 10 mL of lidocaine (pH 5.55). Group 2 patients were given 2% lidocaine HCl solution plus 1.5 mL 7% sodium bicarbonate per 10 mL of lidocaine (pH 7.04). Group 3 received 2% lidocaine HCl solution with 1:200000 epinephrine plus 1.5 mL normal saline per 10 mL of lidocaine (pH 5.68). Group 4 received 2% lidocaine HCl solution with 1:200000 epinephrine plus 1.5 mL 7% sodium bicarbonate per 10 mL of lidocaine (pH 7.11). The time of onset of analgesia and the spread of sensory blockade were more rapid in groups 2 and 4. The degree of motor block was more pronounced in these two groups, as were the changes in blood pressure and heart rate.

Adult↗
PubMed1989

Study of plasma neuropeptide Y and catecholamine levels during high dose fentanyl anesthesia.

Ten ASA physical status I-II patients were studied after obtaining institutional approval and informed consent. All patients were free from endocrine and metabolic disease undergoing elective low risk operation. They were premedicated with pethidine 1.0 mg/kg intramuscularly and diazepam 0.1 mg/kg orally one hour before anesthesia. Anesthesia was induced with thiopental 4 mg/kg and succinylcholine 1.5 mg/kg for tracheal intubation. Anesthesia was maintained with intermittent intravenous injection of fentanyl (50-100 micrograms/kg) and inhalation of N2O-O2 (50%). Ventilation was controlled during surgery. Atracurium (0.4 mg/kg iv) was given for muscle relaxation when needed. Blood samples were obtained from the radial artery 15 min before induction of anesthesia and 5 min after intubation, 15 min, 30 min, 60 min, 120 min during operation and 30 min after operation. Neuropeptide Y (NPY) was determined by radioimmunoassay, catecholamines were determined by radioenzymatic method using CAT-A-KIT (Amersham). Statistical analysis was performed using Student's t-test for paired and unpaired samples. P values less than 0.05 were considered significant. Naloxone 0.4 mg was given by iv at the end of operation in all of the patients to establish adequate spontaneous respiration. The results showed that the plasma NPY was significantly decreased under high dose fentanyl as well as catecholamines.

Adolescent↗
PubMed1989

Effects of pH of cerebrospinal fluid and local anesthetic on the success rate of spinal anesthesia.

Forty-three ASA physical status I-II adult patients, receiving spinal anesthesia for lower abdominal or lower limb surgery, were allocated randomly to two groups. Group 1 patients (n = 21) were given heavy bupivacaine 12 mg and group 2 patients (n = 22) were given tetracaine 12 mg in 2.5 mL of 10% dextrose. Spinal anesthesia was performed in the lateral decubitus position the at L 3-4 interspace with a 25-G spinal needle. Radial artery blood samples were collected before and after spinal anesthesia fpr pH measurement using a NOVA Biomedical machine; CSF samples were collected before and after injection of local anesthetic, and local anesthetic was also collected at the same time, for pH measurement using a Radio pH meter. The time from injection to maximal cephalad spread of analgesia and level of spinal analgesia were measured by the pin-prick method. The result was regarded as a failure if pain sensation still existed at the level of the operation site after spinal anesthesia. There were 1 failure case in the bupivacaine group and 2 failures in tetracaine group. The pH of CSF and local anesthetic in these failures were compared with those in effective cases, and the results showed that there was no significant relationship between the pH value of CSF and the local anesthetic drug.

Adolescent↗
PubMed1989

Comparison of penile vascular effect induced by intracavernous injection of papaverine and prostaglandin E1.

An intracavernous injection with papaverine or prostaglandin E1 (PGE1) combined with duplex ultrasonography is an objective technique to conduct a penile blood flow study (PBFS). Three hundred patients with impotence underwent papaverine (9-60 mg) induced PBFS at the University of California School of Medicine, San Francisco (UCSF), U.S.A. and another 80 patients with impotence received PGE1-induced (20 micrograms) PBFS at Veterans General Hospital-Taichung (VGH-TC), R.O.C. Preliminary evaluation of age, duration of disease and pre-injection diameter of cavernous arteries disclosed no significant difference in these 2 series. It was interesting to find that almost all parameters of vascular response to pavaverine vs PGE1 differed significantly, such as onset of response (6.5 +/- 6.5 vs 11.7 +/- 6.4 min, slower in the PGE1 group, p less than 0.001); post-injection diameter of cavernous arteries (right: 0.73 +/- 0.20 vs 0.79 +/- 0.18 mm, p = 0.03; left: 0.74 +/- 0.20 vs 0.82 +/- 0.21 mm, p = 0.005); diametral increment of cavernous arteries (right: 0.23 +/- 0.17 vs 0.33 +/- 0.17 mm, p less than 0.001; left: 0.24 +/- 0.17 vs 0.36 +/- 0.19 mm, p less than 0.001) and peak velocity (right: 27.5 +/- 16.1 vs 42.0 +/- 20.1 cm/sec, p less than 0.001; left: 28.9 +/- 15.9 vs 39.7 +/- 17.9 cm/sec, p less than 0.001). The side effects, primarily injection pain (23.8%, 19/80) in the PGE1 group and dizziness (3.0%, 9/300) in the papaverine group, were minor in these 2 series. Prolonged erection was not encountered in either series; however, immediate treatment was performed if a papaverine-induced erection lasted over 60 minutes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Transrectal sonography of the prostate and seminal vesicles on patients with hemospermia.

Morphological change of the seminal tract of patients with hemospermia was determined by means of transrectal sonography on 38 patients. Twenty-seven (71%) had positive sonographic findings, including 20 prostatitis and/or seminal vesiculitis, three benigh prostatic hypertrophy, three prostate calculi and one seminal vesicle stone. Simultaneous bacteriologic study revealed positive cultures on 11 patients; 9 of whom (81%) had morphologic appearance on transrectal sonography suggesting inflammatory origin. Our experience indicates that transrectal sonography is capable of surveying the histopathologic change of the prostate and seminal vesicles, and is therefore effective in studying patients with organic hemospermia.

Adult↗
PubMed1989

[Spinal anesthesia with bupivacaine for transurethral resection of prostate: effects of specific gravity, volume and dose].

The investigation was carried out in 80 patients scheduled for transurethral resection of prostate (TUR-P). All patients were ASA I or II, and received no premedication. Before anesthesia, elastic bandages were applied to both lower extremities and 6 mL/kg of G/S (5% Glucose in 0.9% saline solution) was administered by intravenous infusion. The patient was placed in the lateral position and dural puncture was performed at the L3-4 interspace using a standard midline approach with a 23 gauge spinal needle. The patients were allocated randomly to four groups, each group consisting of 20 patients. Three mL of 0.5% Bupivacaine was administered in group A; 3 mL of 0.5% Bupivacaine with 1 mL 10% G/W (Glucose water) in group B; 2 mL of 0.5% Bupivacaine with 1 mL 10% G/W in group C and 3 mL of 0.5% Bupivacaine in 8% glucose in group D. Assessment of the sensory and motor blockade and measurement of arterial pressure and heart rate were performed after injection. All data were analyzed by ANOVA. A p value of less than 0.05 was considered statistically significant. The results showed that the duration of analgesia with plain Bupivacaine was shorter than with hyperbaric Bupivacaine (2.59 +/- 0.81 h vs 3.12 +/- 0.72 h, P less than 0.05). The maximum cephalad spread of analgesia was lower with plain Bupivacaine (T 9 +/- 2 vs T 7 +/- 2, P less than 0.05). Patients receiving either 3 mL or 4 mL of hyperbaric bupivacaine were similar in regard to duration and maximum cephalad spread of analgesia, but the effect on the cardiovascular system was more severe in the group receiving 4 mL.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

Hepatic uptake of asialoglycoprotein is different among mammalian species due to different receptor distribution.

Isolated hepatocytes of rat, rabbit and guinea pig were found to take up and degrade 125I-labelled asialoorosomucoid at different rates with the rank order: rabbit greater than rat greater than guinea pig. Measurement of 125I-asialoorosomucoid binding at 4 degrees C to these hepatocytes revealed that all these cells had two classes of receptors with a major difference occurring in the number of high-affinity binding sites. The average binding affinity constants (K) and receptor concentration (N) calculated from a least-square analysis of the Scatchard plots were K1 = 1.15.10(9) M-1, K2 = 0.93.10(7) M-1, N1 = 0.049 pmol/mg cell protein and N2 = 0.27 pmol/mg cell protein for the rat; K2 = 3.16.10(7) M-1, N1 = 0.027 pmol/mg cell protein and N2 = 0.13 pmol/mg cell protein for the guinea pig and K1 = 0.74.10(9) M-1, K2 = 3.85.10(7) M-1, N1 = 0.205 pmol/mg cell protein and N2 = 0.37 pmol/mg cell protein for the rabbit hepatocytes, respectively. Measurement of the total number of cellular receptors after solubilization with Triton X-100 also revealed the same receptor concentration rank order of rabbit (5.8 pmol/mg cell protein) greater than rat (0.55 pmol/mg cell protein) greater than guinea pig (0.18 pmol/mg cell protein). Intravenous injection of 125I-asialoorosomucoid into anesthetized animals of matched body weight also indicated that the rate of plasma clearance and the rate of appearance of the degraded product of the tracer were different among these species with the same rank order as that observed with isolated hepatocytes. Thus there is a fundamental difference in the number of asialoglycoprotein receptors both on the cell surface and inside hepatocytes of these mammalian species.

Animals↗
PubMed1988

Depressant effects of isoflurane and halothane on isolated human atrial fibers.

The present experiments were designed to study the cellular mechanism responsible for the depressant effects of halothane and isoflurane on human atrial tissues obtained at cardiac surgery. The fibers were superfused in Tyrode's solution, and transmembrane potentials were recorded with a microelectrode technique. In atrial fibers showing fast response action potential (maximum velocity of depolarization [Vmax] greater than 100 V/s), halothane (0.75 vol%, 0.44 mM) and isoflurane (1.25 vol%, 0.53 mM) decreased slightly the upstroke velocity but depressed the plateau and twitch force significantly. In atrial fibers showing slow rate of phase-0 depolarization or when atrial fibers were depolarized in high [K]0, both halothane and isoflurane decreased the upstroke of slow response and the force. The depressant effects of anesthetics partially mimicked the actions of 1 microM tetrodotoxin and diltiazem and could be reversed by epinephrine or high [Ca]0. The delayed afterdepolarizations or aftercontractions and contracture induced by epinephrine or strophanthidin were also inhibited by both anesthetics. Halothane and isoflurane may depress normal electromechanical activity and arrhythmogenic triggered activity through a reduction of cation fluxes across the cell membrane.

Action Potentials↗
PubMed1988

Characterization of nifH mutations of Klebsiella pneumoniae.

Nucleotide changes in the nifH gene of Klebsiella pneumoniae were identified by DNA cloning and sequencing of six selected mutant strains. The strains were UN60, C-640-GC----TGC; UN116, C-67-TC----TTC; UN117, G-688-AG----AAG; UN1041, CG-302-C----CAC; UN1678, GC-713-C----GTC; and UN1795, G-439-AG----AAG. Their corresponding amino acid substitutions were UN60, Arg-214----Cys; UN116, Leu-23----Phe; UN117, Glu-230----Lys; UN1041, Arg-101----His; UN1678, Ala-238----Val; and UN1795, Glu-147----Lys. Results from Western and Northern blots of the mutant strains showed significant reductions in both steady-state levels of the accumulated Fe protein and nifH mRNA during derepression in the presence of serine. The relative specific activities of the nitrogenases in strains UN60, UN1041, and UN1795 were less than 2% of the wild type, whereas those in UN116, UN117, and UN1678 were between 28 and 40% of the wild type during enhanced derepression with serine. The residues of Arg-101 (UN1041), Glu-147 (UN1795), and Arg-214 (UN60) were invariant in sequences of a dozen diazotrophs that have been examined thus far. In UN1041, in which Arg-101 of the Fe protein was replaced by His, the Fe protein had a larger apparent molecular weight than that of the other strains on sodium dodecyl sulfate-gel electrophoresis, as detected with rabbit antiserum raised against the C-terminal peptide of the wild-type Fe protein. The reduced levels of nifH mRNA in point mutant strains suggests that nifH (the gene or gene product) may be involved in self-regulation. mRNA transcripts of different sizes were detected when a nifH-specific probe, CCKp2003, was used in the Northern blot hybridization.

DNA, Bacterial↗
PubMed1988

Effects of midazolam (a benzodiazepine) on cerebral perfusion and oxygenation in dogs.

Midazolam is a water-soluble benzodiazepine used for anesthetic induction. Its effects on the cerebral circulation are still controversial. We evaluated the effects of midazolam on the cerebral blood flow (CBF), cerebral vascular resistance (CVR), and cerebral oxygen consumption (CMRO2) in dogs (n = 6) using the cerebral venous outflow method. CVR was calculated as the quotient of mean arterial pressure (MAP) and CBF, CMRO2 was obtained from the measurements of CBF and arterio-venous O2 difference (A-V dO2). Midazolam was administered in sequential i.v. doses of 0.5, 1.0, and 2.0 mg/kg by bolus injection with an interval of 20 min. This agent significantly reduced the MAP, CBF and CMRO2, but did not affect the CVR. The maximal decreases in MAP, CBF, and CMRO2 from the control levels averaged 14.8%, 12.2%, and 9.3%, respectively, by 0.5 mg/kg; 18.9% 18.6% and 12.1% by 1.0 mg/kg; and 23.6%, 18.7% and 16.1% by 2.0 mg/kg. Although the increments in doses further depressed that MAP, CBF and CMRO2, the dose-dependent effects were slight. Only the values of reduction in CMRO2 were significantly different between the doses of 0.5 and 2.0 mg/kg. Therefore, a dose of 0.5 mg/kg produced nearly the maximal effects. The results indicate that midazolam causes a mild reduction (10-25%) in arterial pressure, brain perfusion and cerebral oxygenation. Cerebral vascular resistance is not significantly changed.

Animals↗