Topical antimicrobial prophylaxis of nosocomial pneumonia in mechanically ventilated patients. Microbiological observations

Generally, reduction of colonization and infection with potentially pathogenic microorganisms in intensive care units (ICU) is attempted by a combination of antimicrobial agents administered topically in the digestive tract and systematically. We tested the efficacy of topical antimicrobial prophylaxis of the oropharynx and stomach administered in combination with sucralfate without systemic prophylaxis in 25 mechanically ventilated ICU patients. The regimen successfully reduced colonization with potentially pathogenic microorganisms in the oropharynx and trachea without modifying the intestinal flora. However, colonization and infections with gram-positive cocci and gram-negative rods other than Enterobacteriaceae and Pseudomonadaceae and resistant to one or both the antimicrobial agents used were observed.     

Radioimmunoconjugates in the detection of infection and inflammation

Various nuclear medicine techniques are widely used to image foci of infection and inflammation. Among the relatively new radiopharmaceuticals for this purpose are radioimmunoconjugates such as labeled murine monoclonal antigranulocyte antibodies and labeled human polyclonal nonspecific immunoglobulin G. This article reviews some background information, mechanism of action, side effects, biodistribution, kinetics, results of clinical studies, and dosimetry of several radioimmunoconjugates both of murine monoclonal and human polyclonal origin. The efficacy of these agents has been demonstrated in a variety of clinical conditions. Radiolabeled immunoconjugates may emerge as convenient alternatives to the present technique of choice: in vitro blood cell labeling techniques with their inherent problems and risks.     

Tensile strength and histological changes of abdominal aorta of malnourished rats

The resistance of the abdominal aorta of rats after 6, 7 and 8 weeks of malnutrition, compared with control animals, was evaluated by longitudinal tensiometry. Weakness of this vessel in malnourished rats was demonstrated; microscopic examination of the aorta stained by Masson, Calleja and hematoxylin-eosin methods showed a decrease in amorphous ground substance and an increase in the width of elastic laminae. There was no visible alteration either in the endothelial lining layer or in the smooth muscle fibers. Such alterations of the aorta are, to the authors' knowledge, the first reported modifications in the peripheral vasculature after malnutrition.     

Prevalence and structure of dental benefit schemes in Hong Kong

Before the impact of employer-provided dental benefit schemes on the dental care delivery system can be evaluated in Hong Kong, the prevalence of these schemes and their structures must be established. A mailed questionnaire survey was conducted of a representative group of companies with more than 100 employees (n = 495). Response rate to the mail survey was 38 per cent (n = 186). Non-respondents were stratified according to their nature of business and one third was randomly selected for a follow-up by telephone to which 84 per cent responded (n = 81). After adjustment, 16 per cent of companies of that size were found to be providing dental benefit schemes to their staff. The prevalence was related to the nature of business of the companies. Among companies providing dental benefits, administrators from selected companies were interviewed. It was found that dental benefit schemes could be broadly divided into two types: One characterised by cash-benefit and the other by service-benefit. Treatment items covered by the schemes were mostly simple services such as diagnostic items, simple restorations and simple extractions. The influence of these dental benefit schemes on the dental care-seeking behaviour of the beneficiaries is under investigation.     

A new dominant selectable marker for genetic transformation; Hsp70-opd

New P element plasmids containing the organophosphate-degrading gene opd as a dominant selectable marker were tested as transformation vectors in Drosophila melanogaster. One of these vectors was modified by the addition of the D. melanogaster mini-white gene as a comarker. When transformed individuals were identified using paraoxon selection for opd alone, results were similar to those obtained with mini-white. No false positives were recovered, however one strain contained the mini-white gene but inadequate resistance to survive our screening regimen due to a defective Hsp70-opd gene. Results suggest that Hsp70-opd is similar to mini-white for distinguishing transformed individuals but does not require time-consuming individual examination. Due to the mode of action of organophosphorus nerve agents, Hsp70-opd has potential as a selectable marker in numerous animals beside fruit flies.     

Cocaine-sensitive sigma-receptor and its interaction with steroid hormones in the human placental syncytiotrophoblast and in choriocarcinoma cells

The expression and ligand binding characteristics of sigma-receptors in human placental syncytiotrophoblast and choriocarcinoma cells were investigated using haloperidol as a ligand. Haloperidol bound to purified placental brush border membranes with high affinity; the apparent dissociation constant for the process was about 3 nM. These binding sites were not related to dopamine (D2) and serotonin (5-HT2) receptors nor to serotonin and norepinephrine transporters. The ligands of sigma-receptors [3.g. (+)-3-(3-hydroxyphenyl)N-(1-propyl)piperidine, 1,3-di-(2-tolyl)guanidine, clorgyline, rimcazole, and dexromethorphan] were very potent in competing with haloperidol for the binding sites. The binding sites were detected not only in the brush border membrane, but also in intracellular membranes. The rank order of potency of various sigma-receptor ligands to inhibit haloperidol binding indicated that placental sigma-receptors belong to the sigma 1 subtype. Cocaine and its analog RTI-55 [2 beta-carbomethoxy-3 beta-(4-iodophenyl-) tropane] inhibited the binding of haloperidol to placental membranes with appreciable potency. The steroid hormones, progesterone and testosterone, were also potent inhibitors, and the inhibition constant for progesterone was 0.3 microM, a concentration much smaller than that found in plasma during pregnancy. The inhibition was competitive. beta-Estradiol and a number of other steroids were relatively much weaker inhibitors than progesterone and testosterone. Phenytoin and neuropeptide-Y did not interact with sigma-receptors in placenta. The choriocarcinoma cell line JAR was also found to express sigma-receptors in the plasma membrane as well as in intracellular membranes. The characteristics of the receptors in this cell were qualitatively similar to those of the receptors in normal placenta, including subtype identity and interaction with cocaine and progesterone. Interestingly, however, all sigma-receptor ligands interacted with the receptors in the JAR cell with much higher affinity than with the receptors in normal placenta. It is concluded that the placental syncytiotrophoblast and choriocarcinoma cells express cocaine-sensitive sigma-receptors and that progesterone is most likely an endogenous ligand for these receptors.     

Continuous murmur following Mustard operation for transposition of the great arteries. A sign of pulmonary venous obstruction

Three patients developed severe pulmonary venous obstruction following Mustard operation for transposition of the great arteries. Each patient had a soft continuous murmur with distinct diastolic accentuation at the low left sternal border or xiphoid area. Simultaneous recording of intracardiac sound and pressure in one patient showed that the murmur originated at the site of obstruction in the surgically-constructed pulmonary venous atrium. Selective cineangiograms demonstrated the baffle to be the cause of the obstruction. A continuous murmur in a patient following Mustard operation may suggest significant pulmonary venous obstruction.     

Pneumonectomy: review of 351 cases

Among 351 patients undergoing pneumonectomy, the mortality was 6%, and when the operation was performed for malignant disease, the mortality was 8.5%. Much of the risk of the operation is associated with the age, physiologic state, and associated diseases which are prevalent in patients who require pneumonectomy. The conduct of the operative procedure itself is of paramount importance since complications clearly increase the mortality. Operative mishaps predispose to postoperative complications, and the addition of postoperative problems to the operative complications combine to bring the mortality to 24%. Careful hemostasis, meticulous technique, fluid and blood replacement, as well as careful preoperative and postoperative management combine to produce an acceptable mortality in this serious procedure.