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Biomedical subjects

J C Chang

Publications and source records attributed to J C Chang.

At least 145 records · Page 8Linked to original sources
PubMed1992

In vitro postantibiotic effect of roxithromycin and erythromycin against gram-positive cocci.

A persistent suppression of bacterial growth following a brief exposure to an antibiotic (postantibiotic effect [PAE]) has been described for a variety of antibiotics and microorganisms. Data concerning PAE have not yet been demonstrated in Taiwan. In this study, the PAEs of erythromycin (EM) and roxithromycin (RXM) against 4 strains of Staphylococcus aureus, 3 of Streptococcus pyogenes and 1 of Streptococcus pneumoniae were tested. Dilution method was used for removal of drugs. Two controls, one free of drug and one in 1/1000 of the original drug concentrations were used. The results showed that the PAE lasted longer in strains of S. aureus (RXM 1.7-2.1 h; EM 1.7-2.1 h) and S. pyogenes (RXM 1.7-3.0 h; EM 1.9-2.9 h) than those in S. pneumoniae (RXM 0.6-1.6 h; EM 0.8-1.4 h). There was no difference of PAE between RXM and EM against each bacterial strain tested.

Erythromycin↗
PubMed1992

Symptomatic rib lesions as the primary presentation of sarcoidosis. Report of two cases and review of literature.

Skeletal involvement in sarcoidosis is considered a manifestation of chronic disease. Rib lesions, while rarely reported, have been usually asymptomatic and often associated with vertebral sarcoidosis. Here, we report two patients with symptomatic rib lesions in sarcoidosis. Both patients were black males. In both cases, chest X-rays lacked characteristics of pulmonary sarcoidosis. A definite diagnosis was made on rib biopsies and confirmed by the positive Kveim test. One case was particularly interesting in that low back pain preceded the right hilar adenopathy for many years. This suggests that sarcoidosis involving the bone may occur at early stage of disease, and that low back pain in young male may be the first presentation of sarcoidosis. A literature review of osseous involvement in sarcoidosis reveals that skeletal lesions in sarcoidosis may preferentially manifest in the axial skeleton in some individuals.

Adult↗
PubMed1992

Interpleural administration of bupivacaine for postoperative analgesia after thoracotomy in patients with patent ductus arteriosus.

Interpleural analgesia for postoperative pain with bupivacaine 0.25%, 0.375% and 0.5% at dosage of 1.5 mg/kg was evaluated in three randomized groups (A, B and C) of 22 children having triple ligation for patent ductus arteriosus (PDA). Complete pain relief was obtained within 30 min irrespective of the concentration of bupivacaine. The duration of pain relief significantly varied with the concentrations of the drug used, respectively 5.02 +/- 0.4 h, 6.88 +/- 0.7 h and 8.24 +/- 1.08 h (mean +/- SD) for 0.25%, 0.375% and 0.5% bupivacaine (p less than 0.05). No side effects were observed and no other supplemented narcotics were given. We concluded that 0.5% bupivacaine at the dose of 1.5 mg/kg was effective in postoperative pain relief after thoracotomy in patients undergoing PDA ligation surgery.

Adolescent↗
PubMed1992

[Open heart surgery without homologous blood transfusion in small children of body weight less than 20 kg].

In 28 children with congenital cardiac lesions, open heart surgery was attempted without homologous blood transfusion using extreme hemodilution for cardiopulmonary bypass (CPB) and moderate to profound hypothermia. The entry criteria for this study were preoperative hemoglobin value above 10 g/dl and expected CPB time of less than 120 minutes. Acyanotic heart diseases such as ventricular or atrial septal defect were the main lesion, but some cases of tetralogy of Fallot and single ventricle were also included in this study. Intraoperative saving of autologous blood and autotransfusion using cell saver were carried out in a part of the subjects. Acceptable lowest values for hemoglobin was 4-5 g/dl and 40% for mixed venous oxygen saturation. As the results, 18 patients tolerated CPB without transfusion and eventually 16 patients were discharged without transfusion at all. The body weight for those without transfusion was 13.9 kg in average and the lowest was 6.8 kg. The significant factor affecting the needs for homologous blood transfusion was prolonged CPB time over 120 minutes. Although there was a tendency that the patients with body weight less than 15 kg received transfusion more frequently than those with body weight more than 15 kg, the body weight was not necessarily a limiting factor. Pre-CPB blood saving and intraoperative autotransfusion were the positive factors for successful non-transfusion open heart surgery.

Blood Transfusion↗
PubMed1992

[An unusual case of annular constrictive pericarditis--a "framed heart"].

We presented a 62-year-old female with constrictive pericarditis of an unusual anatomy. A calcified constrictive band, 2-3 cm wide, ran parallel to the frontal plane, coursing circularly along the anterior aspect of the great arteries, right atrium, diaphragmatic surface of the right ventricle, posterolateral aspect of the left ventricle and back to the great arteries. The course of the constrictive band was circular but completely different from that of typical annular constrictive pericarditis in which a constrictive band runs along the atrioventricular groove. Hemodynamic consequences of our patient was rather non-specific impairment of ventricular filling than functional valvular stenoses due to external compression characteristic for the typical annular constrictive pericarditis. Effective surgical relief of the constriction was accomplished under cardiopulmonary bypass and cardioplegic cardiac arrest.

Calcinosis↗
PubMed1991

Cigarette smoking and risk of adult leukemia.

A case-control study investigated the relation between cigarette smoking and histologic subtypes of adult leukemia in Missouri in 1984-1990. Among males, elevated risks associated with ever smoking were observed for acute nonlymphocytic leukemia (odds ratio (OR) = 1.5; 95% confidence interval (CI) 1.1-2.0) and acute myelocytic leukemia (OR = 1.5; 95% CI 1.1-2.1). Females also showed an increased risk of acute nonlymphocytic leukemia associated with ever smoking (OR = 1.4; 95% CI 1.0-1.9), with an increasing trend in risk by level of smoking (p less than 0.01). Attributable risk estimates of the proportion of acute nonlymphocytic leukemia caused by smoking were 33 percent in males and 29 percent in females. Elevations in risk were not apparent for chronic forms of leukemia. The findings support the hypothesis that some types of leukemia may be etiologically related to cigarette smoking.

Adult↗
PubMed1991

Cellular uptake and toxicity study of cis-bis(6-aminoquinoline) dichloroplatinum (II).

A fluorescent analog of cis-diamminedichloroplatinum(II), cis-bis(6-aminoquinoline)dichloroplatinum(II), was prepared from K2[PtCl4] and 6-aminoquinoline (AQL). HPLC of the thiourea derivative of the new complex showed that it has the cis-configuration. The Pt-AQL complex and the parent ligand AQL were evaluated for biological activity and cellular uptake, using the ciliate Tetrahymena pigmentosa. The complex was relatively nontoxic at the tested levels below 5 x 10(-4) M, but did exhibit inhibition of culture growth at 5 x 10(-4) M. Measurement of cellular uptake of the Pt-AQL complex demonstrated incorporation into the cell, with localization primarily within the vacuoles of the cells. Comparable measurement of the parent ligand AQL showed little measurable cellular uptake.

Animals↗
PubMed1991

Evaluation of a new finger-type intraoperative epicardial echocardiographic probe for infants and small children.

A new finger-type epicardial echocardiographic probe was evaluated in 26 children with complex cardiac anomalies during open heart surgery. The probe is a small 3.75 MHz phased array transducer for 2-dimensional echo and color Doppler imaging. The tip is slightly angled to facilitate the apical approach through a median sternotomy. The patients included 4 neonates and 8 infants, and the major cardiac lesions were complete atrioventricular (AV) canal, transposition of the great arteries, double outlet right ventricle, and others. The intraoperative study was possible in most of the patients facilitating various approaches for the assessment of left-sided AV valve function, left ventricular outflow obstruction, residual shunt and intraatrial anatomy. Four patients received subsequent operative procedures after the assessment. This transducer appears to be useful in the intraoperative study during surgery for complex cardiac anomalies in neonates and small infants.

Child↗
PubMed1991

Evidence for the covalent binding of aflatoxin B1-dichloride to cytosine in DNA.

In vitro studies of the effect of aflatoxin B1-dichloride (AFB1-Cl2) on the template function for RNA synthesis of several single- and double-stranded synthetic DNAs containing cytosine and/or hypoxanthine bases are reported. The results indicate: (i) AFB1-Cl2 strongly inhibits the template function of the single-stranded homopolymer polydC and has no effect on polydI, (ii) the inhibition is stronger when cytosine is in the double-stranded alternating copolymer poly[d(I-C)], and (iii) polydI directed RNA synthesis can be inhibited if it is in the double-stranded homopolymer polydI.polydC, although the template function of the polydC strand is still inhibited to a greater extent. The evidence that the selective inhibition of the DNA template function is a direct reflection of the binding specificities of AFB1-Cl2 is provided by the binding studies of [3H]AFB1-Cl2 to these DNAs. The binding of AFB1-Cl2 to polydC is substantiated by the dose-response template inhibition and by the dose-response template binding studies. Additionally, these results show that AFB1 per se has neither inhibitory nor binding activity. Auto radiography of [alpha-32P]GTP labeled RNAs suggests that the mechanism of inhibition of polydC template function by AFB1-Cl2 is mainly due to the inhibition of the elongation of RNA synthesis. Spectrum measurement of the products of enzyme digestion of the AFB1-Cl2 modified polydC reveals that the deoxycytidine fraction gives a typical cytosine absorption peak at 275 nm followed by a broad peak between 300 and 400 nm with a maximum at 390 nm. High performance liquid chromatography confirms the existence of a cytosine-AFB1 adduct which absorbs strongly in the regions between 250 and 400 nm with peaks identifiable at 260, 350 and 390 nm. These results strongly suggest that AFB1 in the activated form of AFB1-Cl2 is able to covalently bind to cytosine in DNA.

Aflatoxin B1↗
PubMed1991

Physical activity on the job and cancer in Missouri.

We conducted a series of case-control studies to investigate the risks of 16 cancer types in relation to occupational physical activity. These studies were based on Missouri Cancer Registry data for 17,147 White male cancer patients registered between 1984 and 1989. Colon cancer risk was increased for both the moderate (odds ratio (OR) = 1.1; 95% confidence interval (CI) = 1.0, 1.3) and low (OR = 1.2; 95% CI = 1.0, 1.5) activity levels. Similar elevations were observed for prostate cancer at the moderate (OR = 1.1; 95% CI = 1.0, 1.3) and low (OR = 1.5; 95% CI = 1.2, 1.8) levels of activity, and for cancer of the testis at the low activity level (OR = 2.2; 95% CI = 1.3, 3.7). An opposite trend (p less than 0.01) was noted for lung cancer, which showed decreased risk at the moderate (OR = 0.9; 95% CI = 0.8, 1.0) and low (OR = 0.8; 95% CI = 0.6, 0.9) activity levels. These associations suggest that further study of the relationship between physical activity and site-specific cancer risk is warranted.

Case-Control Studies↗
PubMed1991

Epidural tramadol for postoperative pain relief.

Forty-two surgical patients were given epidural tramadol for control of postoperative pain. They were randomly assigned to three groups: group 1 (n = 15), in which 25 mg of tramadol were given; group 2 (n = 13), in which 50 mg of tramadol were given; and group 3 (n = 14), in which 75 mg of tramadol were given. When the patients complained of wound pain, epidural tramadol was given. Heart rate, blood pressure, respiratory rate, oxygen saturation (SpO2), sedation scale, motor blockade, verbal rating scale, subjective grading, and visual analogue pain scale (VAPS) were measured and recorded before the tramadol administration, at 5 and 15 min, and at 1, 2, 4, and 8 h after the tramadol administration. Only 26.6% of the patients in group 1 had significant relief of pain. The rest of them needed at least one incremental dose of 25 mg of tramadol. The baseline VAPS of the patients in group 2 was 8.9 +/- 2.0. It became 5.46 +/- 3.0 (p greater than 0.05) 15 min after tramadol was given, and dropped further to 1.9 +/- 1.8 (p greater than 0.05) 2 h later. The average duration of pain relief was 12.0 +/- 5.9 h. In group 3, the initial VAPS was 8.14 +/- 1.9. It decreased to 4.28 +/- 1.8 (p greater than 0.05) 15 min, and further dropped to 1.7 +/- 0.9 (p greater than 0.05) 2 h following tramadol administration. The average duration of pain relief was 11.3 +/- 4.8 h. The common side effects of tramadol such as dizziness, nausea, and dry mouth, were most frequently found in group 3.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[A case report on a double chambered right ventricle (DCRV)--pre- and postoperative responses of the right ventricle to atrial pacing and the isoproterenol tolerance test].

To evaluate the development of an anomalous muscle bandle of the right ventricle (RV) and results of surgical intervention, responses of the RV to atrial pacing and the isoproterenol tests were examined in both the pre- and postoperative periods. Although cardiac output did not increase in proportion to the rate of atrial pacing or the dose of isoproterenol, the pressure gradient through the RV increased abnormally from 38 mmHg to 59 mmHg (atrial pacing) and 116 mmHg (isoproterenol). On the other hand, postoperative evaluation showed normal RV responses in these tests. Since the response of the right ventricle to these tolerance tests in patients with DCRV in pre- and postoperative periods has not been well elucidated, a precise evaluation is reported in this paper.

Cardiac Output↗
PubMed1991

Simultaneous ectopic pregnancy with intrauterine gestation after in vitro fertilization and embryo transfer.

A case of combined intrauterine and tubal ectopic pregnancy is described following in vitro fertilization and the transfer of two four-cell and one two-cell embryos. This phenomenon is known to be related to ovarian stimulation by gonadotropin therapy, and there is an increased risk with tubal disease. Techniques applied at the time of embryo transfer, the use of culture medium with 50% fetal cord serum to convey the embryos to the uterus, the catheterization method, and the position of the patient during transfer are presented. The risk of multiple pregnancies and combined intrauterine and ectopic gestations increases with increasing numbers of transfers and large volume of transfer medium. We would therefore recommend that after IVF-ET treatment in women with tubal disease, intensive care should be taken in the early follow-up period to rule out the possibility of ectopic pregnancy. In this case, a viable ongoing intrauterine pregnancy was confirmed after surgery for right ampullary ectopic pregnancy. And a 2925gm male in excellent condition was delivered by cesarean section without complications.

Adult↗
PubMed1991

Effect of glucose concentration, agar, and amount of inoculum on the 6.5% sodium chloride tolerance test for presumptive identification of enterococci.

The 6.5% NaCl tolerance test is simple and commonly used for presumptive identification of enterococci; however, it is not strictly standardized. The effect of glucose concentration, types of media and the size of inocula on the growth of enterococci have been evaluated. The results showed that broth was superior to agar media for enterococcal growth at any amount of inoculum. The media containing 1.0% glucose also showed superiority to media containing 0.1% glucose. It is suggested that broth containing 1.0% glucose be the medium of choice for 6.5% NaCl tolerance test.

Agar↗
PubMed1991

[Anticoagulation therapy and circulatory management with left ventricular catheter under left ventricular bypass using centrifugal pump--an experience in a case with mitral valve replacement].

A 53-year-old woman who had severe mitral regurgitation associated with moderate tricuspid regurgitation and mild aortic regurgitation underwent mitral valve replacement with a 27 mm Björk-Shiley mechanical valve, left atrial plication and tricuspid annuloplasty. She fell into low output syndrome on the first postoperative day because of persistent intractable ventricular arrhythmia and eventually required open cardiac massage. The left ventricular (LV) bypass using a centrifugal pump was initiated with cannulation to ascending aorta and left atrium. Echocardiography showed LV wall motion extremely poor with the prosthetic valve being in closed posture. For prevention from thrombus formation on the prosthetic valve and in the LV, a catheter was inserted into LV through RV to give heparin and monitor the LV pressure. As the result, activated clotting time of LV was higher (range from 280-388 sec) than that of systemic blood (range from 182-258 sec). Also, the change of LV pressure was monitored through this LV catheter. Under this monitor, IABP was smoothly applied in the presence of aortic regurgitation, and she was weaned from LV-bypass successfully after 157 hrs support. She was discharge on the 77th postoperative day without thromboembolic complication.

Cardiac Catheterization↗
PubMed1990

Heterogeneity in direct cytotoxic function of L3T4 T cells. TH1 clones express higher cytotoxic activity to antigen-presenting cells than TH2 clones.

In the process of generating culture supernatant from T cell clones, with anti-CD3 antibodies and the B lymphoma A20 as APC, a striking difference in the stimulation of TH1 and TH2 clones was observed, i.e., TH2 clones produced higher levels of lymphokines than TH1 clones. This prompted us to test the hypothesis that differential killing of APC (thus the removal of stimuli) by T cells led to differential T cell activation. By studying a panel of five TH1 and seven TH2 clones, it was demonstrated that TH1 clones mediated significantly higher levels of cytotoxicity toward A20 cells in the presence of soluble anti-CD3 antibody (as opposed to immobilized anti-CD3). Although T cell clones could, when activated with immobilized anti-CD3, produce lymphokines cytotoxic to A20 cells, experiments in which lymphokine production was blocked indicated that T cell clones, in the presence of soluble anti-CD3, mediated killing of A20 through direct cytotoxicity. A higher level of cytotoxicity, by TH1 compared with TH2 clones, was not restricted to anti-CD3 or a particular target cell type, because it also occurred with Con A- or Ag-dependent killing (a monocyte-macrophage cell line), and LPS blasts. Furthermore, the higher cytotoxic activity of TH1 clones compared with TH2 clones was independent of the stage of T cell activation and was unlikely a result of the length of in vitro culture. High levels of killing of APC led to low levels of T cell activation, the significance of which may be as a negative feedback mechanism in the immune response. Other biologic relevancies of higher cytotoxic activity in TH1 vs TH2 cells were also discussed.

Animals↗