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Biomedical subjects

K Arnold

Publications and source records attributed to K Arnold.

At least 217 records · Page 12Linked to original sources
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↗
PubMed1981

[Parenteral and enteral feeding of neurologic patients in crisis from the viewpoint of long-term intensive therapy].

32 patients in a neurological intensive-care unit with severe disturbances of conscious or impaired function of the swallowing muscles had to receive artificial nutrition on an average of 164 days. They were nourished either parenterally, with the nutrient defined diet Biosorb in combination with parenteral nutrition, or exclusively via a feeding tube. Enteral nutrition was given preference over parenteral nutrition if justified under the clinical circumstances. A multivariable study was intended to investigate to what extent the respective type of nutrition and its individual components met the actual clinical requirements during such a long period. Moreover, the study was intended to demonstrate to what degree adverse factors influenced the different nutritional regimens and necessitated--in addition to infusion programs and dietetics--supplementary steps which might also be of use under completely optimized circumstances.

Adolescent↗
PubMed1978

Calorimetric, 13C NMR, and 31P NMR studies on the interaction of some phenothiazine derivatives with dipalmitoyl phosphatidylcholine model membranes.

1. The dipalmitoyl phosphatidylcholine/water system was employed to study the interaction of phenothiazines with model membranes. In particular the effects of the drugs upon the lipid phase transition were examined using differential scanning calorimetry and NMR spectroscopy. The studied phenothiazines have peripheral (diethazine) or central (chlorpromazine) properties. 2. Both drugs were observed to lower the phase transition temperature of dipalmitoyl phosphatidylcholine. The molar activity of chlorpromazine is somewhat higher than of diethazine. At low concentrations the drugs affect the dipalmitoyl phosphatidylcholine pretransition endotherm. 3. In the 13C NMR spectra of the drug-containing samples the signal of the trimethylammonium group of dipalmitoyl phosphatidylcholine is broadened, whereas a narrowing of the signal of the fatty-acid chain methylene groups is observed. Further, addition of the phenothiazines causes higher values of the effective chemical shift anisotropy of the 31P in the phosphate group, in comparison to the pure dipalmitoyl phosphatidylcholine sample. 4. The results obtained by three different techniques indicate a higher fluidity in the fatty-acid chain region and a mobility reduction of the polar headgroup of the dipalmitoyl phosphatidylcholine molecules in the presence of the phenothiazines. These phenomena can be well accounted for by a model for the incorporation of the phenothiazines in the dipalmitoyl phosphatidyl-choline bilayer, in which the dialkylaminoalkyl chains are located near the polar headgroups and the ring system does not penetrate far beyond the glycerol backbone into the hydrocarbon phase.

Calorimetry, Differential Scanning↗
PubMed1978

Typhoid fever. Studies of blood coagulation, bacteremia, and endotoxemia.

Patients with typhoid fever were studied to determine whether disseminated intravascular coagulation (DIC), circulating bacteria, and endotoxemia were responsible for the signs and symptoms of their illnesses. Coagulation tests in 28 patients detected thrombocytopenia in 17, hypofibrinogenemia in nine, and elevated titers of fibrinogen-related antigens in 20. Repeated testing during convalescence showed a return toward normal values. Intestinal bleeding, however, did not correlate with abnormalities of coagulation tests. Thus, DIC occurred commonly but appeared to be a subclinical event in these patients. In 25 patients with positive blood cultures for Salmonella typhi, quantitative cultures detected from less than 10 to 9 x 10(2) bacteria/ml. Limulus tests for endotoxin in plasma were negative in all 21 patients tested. These results indicated that the concentrations of circulating bacteria and endotoxin in typhoid fever are lower than in other Gram-negative bacterial infections and suggested that circulating bacteria and endotoxin do not play a major role in the pathogenesis of typhoid fever.

Antigens↗