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Biomedical subjects

J Ling

Publications and source records attributed to J Ling.

122 records · Page 7Linked to original sources
PubMed1983

Penicillinase-producing Neisseria gonorrhoeae isolates from different localities in south east Asia. Susceptibility to 15 antibiotics.

Sixty four penicillinase-producing Neisseria gonorrhoeae (PPNG) and 24 non-penicillinase-producing (non-PPNG) strains isolated from six different south east Asian localities were tested by the agar dilution method against 15 antibiotics. All isolates were susceptible to spectinomycin and sulphamethoxazole-trimethoprim (19:1 ratio). A large proportion of both PPNG and non-PPNG strains showed, however, a decreased susceptibility to tetracycline, kanamycin, and erythromycin: 49% with minimum inhibitory concentrations (MICs) of tetracycline greater than or equal to 2 micrograms/ml, 34% with MICs of kanamycin greater than or equal to 32 micrograms/ml, and 80% with MICs of erythromycin greater than or equal to 2 micrograms/ml. These MIC cut-off values were chosen since they are close to the highest concentrations of these antibiotics attainable in serum after drug administration. Resistance to these antibiotics was not related to penicillinase production and does not appear to be confined to gonococci isolated from one particular locality. Strains showing resistance concurrently to two or three of these drugs were often isolated from different south east Asian countries. All eight cephalosporins tested were effective against both PPNG and non-PPNG strains. On a weight to weight basis the new cephalosporins--namely, moxalactam, cefoperazone, cefotaxime, and ceftriaxone--were the most effective. In contrast to those of cefoxitin, cefuroxime, moxalactam, and cefoperazone the MICs of cefamandole, cefotaxime, and ceftriaxone were significantly affected when the inoculum size was increased from 10(3) to 10(6) colony forming units (cfu).

Anti-Bacterial Agents↗
PubMed1982

Genetic instability of R plasmids in relation to the shift of drug resistance patterns in Salmonella johannesburg.

Observation of the resistance of Salmonella johannesburg to the six drugs ampicillin (A), streptomycin (S), tetracycline (T), chloramphenicol (C), kanamycin(K) and sulphadiazine (Su) was made over the 7 years from 1973 to 1979. Strains with ASTCKSu- and ASCKSu- resistance patterns predominated in the years 1973-1975 and 1976-1979, respectively. These resistances were found to be mediated by autotransferring plasmids belonging to the incompatibility group FIme. The ASTCKSu-resistance plasmids were unstable, giving rise to deletion variants at a much higher frequency than ASCKSu-resistance plasmids either of natural origin or derived in vitro from the ASTCKSu-resistance plasmids. Thus, the ASCKSu-resistance plasmid might be a deletion variant of the ASTCKSu-resistance plasmid. This is supported by the extensive similarity of their cleavage patterns produced by specific restriction endonucleases.

Ampicillin↗
PubMed1981

In vitro susceptibility of Salmonella to various antimicrobial agents, including a new cephalosporin, Ro 13-9904.

The in vitro susceptibility of 363 strains of Salmonella isolated in Honk Kong to various antimicrobial drugs was tested, and the minimum inhibitory concentrations of ampicillin, mecillinam, and six cephalosporins (cephalexin, cephradine, cefamandole, cefoxitin, cefuroxime, and Ro 13-9904) for these strains were determined by an agar dilution method. Although strains of the typhoid and paratyphoid group remained susceptible to most antibiotics tested, many strains of the gastroenteric group of salmonellae were found to be resistant to multiple antibiotics, including ampicillin, chloramphenicol, and, occasionally, trimethoprim. Mecillinam and cefamandole, although active against most of the Salmonella strains tested, were shown to be less active against ampicillin-resistant strains. By contrast, Ro 13-9904 exhibited remarkably uniform and high activity against all the Salmonella strains tested, irrespective of their ampicillin resistance.

Anti-Bacterial Agents↗
PubMedDate not supplied

Evaluation of the stability of the proton chemical shifts of some metabolites other than water during thermal cycling of normal human muscle tissue.

MR temperature measurements made by the chemical-shift-of-water technique in peripheral muscle of volunteers have produced larger-than-expected coefficients of change and shown significant hysteresis effects as the temperature was cycled, although these effects were not reproduced in the present study. Previous work has suggested that susceptibility effects could be a contributor to the behavior of the chemical shift data. Here, we use proton spectroscopy of muscle in conjunction with temperature cycling to evaluate the relative shifts of the water peak and those of creatine, choline, and lipids. These latter are considered not to have significant temperature coefficients of chemical shift. The results show that these lines remain very stable as the temperature is cycled, suggesting that susceptibility effects are not present in this study. The method offers the possibility that the lines can be used as frequency references if there are any questions about the stability of other moieties.

Body Temperature↗
PubMedDate not supplied

Intravenous digital subtraction angiography in patients with aorto-arteritis (Takayasu's).

Aorto-arteritis is one of the commonest vascular diseases in China as well as in Japan and other parts of Asia. The results of digital subtraction angiography (DSA) in 50 patients with aorto-arteritis are reported, and the merits and demerits of intravenous (IV) DSA in the diagnosis of this entity are evaluated. Among the 51 studies performed on 50 patients, IV DSA was used in 48, intraarterial (IA) DSA in 3, and good-to-excellent visualization was obtained in 96% of patients. Aorto-arteritis of varying severity and involving the thoraco-abdominal aorta, the iliac arteries, and other major branches was clearly demonstrated by IV DSA. IV DSA, as compared to our previous experience with conventional arteriography in this entity, may be substituted for conventional arteriography in most patients. A large dose of contrast media needed for a complete study is a major deficiency of IV DSA, and it also has limitations for showing the intrarenal arterial branches.

Adolescent↗
PubMedDate not supplied

BASIC programs to analyse minimal inhibitory concentration (MIC) antimicrobial susceptibility results.

BASIC programs have been written to analyse minimal inhibitory concentration (MIC) antimicrobial susceptibility results for large numbers of organisms and a wide variety of antimicrobials. The output of the programs lists the numbers, percentages, cumulative numbers and cumulative percentages of organisms inhibited at different concentrations. The distribution of MICs are additionally printed as a histogram. The range, MIC for 50% and 90% of organisms (MIC50 and MIC90 respectively), and the geometric mean MIC of each drug are also calculated.

Electronic Data Processing↗
PubMedDate not supplied

Lispro insulin: adsorption and stability in selected intravenous devices.

PURPOSE: The adsorption characteristics and stability profile of an insulin analog, lispro insulin, were evaluated against a recombinant human regular insulin using intravenous infusion sets and syringes. METHODS: Studies were performed using either 0.9% NaCl or 5% dextrose intravenous injection solution. Effects of container type, infusion rate, product concentration, presence-absence of an in-line filter, and storage condition on release profiles of lispro and human regular insulin infusion solutions were determined. RESULTS: Lispro insulin and m-cresol were chemically stable. Release rates of insulin (both types) were steady after an initial lag time. The lag time was much longer with intravenous bag infusion than with intravenous syringe infusion. A higher product concentration, faster flow rate, and prewash of the infusion tubing were shown to substantially decrease the lag time. CONCLUSIONS: The adsorption profile of lispro insulin was the same as that of human regular insulin in both syringes and bags. Use of a load-and-sit prewash scheme may shorten or nearly eliminate the lag time, which in turn may be used to make a more accurate calculation of a patient's dose.

Adsorption↗
PubMedDate not supplied

Lithium and anti-viral drug toxicity: II. Further studies on the ability of lithium to modulate the hematopoietic toxicity associated with the anti-viral drug zidovudine (AZT).

Lithium is an agent capable of influencing many aspects of blood cell production, in particular, the formation of granulocytes. Because of this property, lithium has been demonstrated to be an effective agent whenever granulocyte production is either faulty or inadequate. The anti-viral drug zidovudine (AZT) has used been extensively in the treatment of acquired immune deficiency syndrome (AIDS). However, its effectiveness is limited because of the myelosuppression and bone marrow toxicity associated with its use. We have previously demonstrated that lithium, when combined with AZT in vitro with normal bone marrow cells or when administered in vivo to mice receiving dose-escalation AZT, reduced the myelosuppression and marrow toxicity of AZT significantly. We report here further studies designed to evaluate the extent of lithium's capacity to modulate AZT toxicity by investigating the ability of lithium to influence blood cell production when administered to normal mice during an initial exposure to AZT. C57BL6 were administered dose-escalation AZT (1.0 mg/ml and 2.5 mg/ml) for a period of 4-weeks in the presence or absence of lithium carbonate (1 mM). This was followed by an additional 4-week period during which mice received only AZT. Animals were analyzed on a weekly basis for their peripheral blood indices. Animals receiving dose-escalation AZT demonstrated anemia, thrombocytopenia, and neutropenia which was dose-related. During the period when animals received combination lithium/AZT, there was significantly less anemia, thrombocytopenia, and neutropenia as compared to the AZT controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Pulmonary artery involvement in aortoarteritis: an angiographic study.

Angiographic findings of 47 patients with pulmonary artery involvement (PAI) in aortoarteritis are described together with the diagnostic evaluation of PAI and its clinical implications. Pulmonary arteriography was obtained by intravenous digital subtraction angiography in 133 patients with aortoarteritis; 45 (33.8%) were found to have PAI. Two patients with PAI, studied by conventional arteriography, are also included. Stenosis and/or occlusion of segmental and/or lobar pulmonary arteries, and subsegmental branches, were the basic angiographic findings in PAI. Pulmonary artery branches in the upper lobes were more commonly affected than those in the lower and middle (lingula) lobes. Bilateral lesions were more common than unilateral ones. Single lobar and segmental lesions were quite rare. Dilatation was uncommon. No main pulmonary artery involvement was detected. Pulmonary artery hypertension, a late complication of patients with PAI, was revealed in 9 of the 46 patients of the present series. If it occurs, PAI becomes a factor effecting the patient's clinical course and prognosis.

Adolescent↗
PubMedDate not supplied

Immunohistochemical study of a chondroitin-6-sulfate in growth plates of broiler chickens with high and low genetic predispositions to tibial dyschondroplasia.

The distribution of a chondroitin-6-sulfate (C6S) epitope, which is a biochemical marker of chondrocyte hypertrophy, was studied in the growth plates of two lines of 3-week-old broiler chickens with low and high genetic predispositions to tibial dyschondroplasia (TD). Ultrathin sections of growth plates from both groups were subjected to immunolocalization with monoclonal antibody 3-B-3(-), the epitope of which is increased on proteoglycans made by hypertrophic chondrocytes. Bound antibody was localized with colloidal gold-labeled protein A for observation with an electron microscope. The 3-B-3(-) epitope was localized in pericellular and interterritorial matrix of growth plates of both lines. In the low-TD-incidence birds, the concentration of 3-B-3(-) bound to C6S progressively increased from the proliferative zone to the hypertrophic zone. However, in the high-TD-incidence line, the epitope expression remained at a low level in all zones. The increase of the 3-B-3(-) epitope produced by maturing growth-plate chondrocytes is indicative of changes in the glycosaminoglycan chains of proteoglycans that may be important in the process of matrical calcification. Thus, failure of chondrocytes of the high-TD-incidence line to produce this change in post-translational modification of their proteoglycans could be important in the pathological process.

Animals↗