Influence of ion-pair formation on the pharmacokinetic properties of drugs. Pharmacokinetic interactions of bretylium and hexylsalicylic acid in rabbits.

The simultaneous i.v. administration of equimolar doses of bretylium and hexylsalicylic acid results in an increase in plasma area under the curve value of both substances in comparison with their separate administration. The higher plasma levels of both compounds were associated with a reduced renal excretion and an increased biliary elimination. However, the increase in biliary excretion did not compensate for the reduced elimination of bretylium and hexylsalicylic acid via the kidney. The results presented in this paper give further evidence that ion-pairing in-vivo may result in altered pharmacokinetics of drugs particularly due to changes in biliary or renal excretion.     

Panoramic screening for dental anomalies assessed by professionals with identical and different backgrounds

Abstract – The aim of the present study was to evaluate how dental professionals with identical and different backgrounds assess dental anomalies viewed on panoramic radiographs. 101 panoramic radiographs performed of 9-to-10-yr-old children were examined independently by three orthodontists and two radiologists. All observers agreed on the recording of number and identification of congenitally missing permanent teeth. The observers' assessments of malpositioned teeth, teeth in infraocclusion, and primary teeth with atypical/non root resorption varied, however, to a great extent. Two of the orthodontists seemed to report only major deviations from normality (in 38 and 51 of the children respectively) while one reported several more findings (in 85 children). The radiologists reported abnormal findings in 80 and 88 children respectively. In only three children were no dental anomalies reported by any observer. The inconsistent reporting of the majority of dental anomalies (except for agenesis) in children, even among members of subgroups with a similar educational background (e.g. orthodontists), substantiates the need for an evaluation of the expedience of panoramic screening.     

Oral radiographic screening in Danish children

Abstract – The aim of the present study was to ascertain frequency and type of radiographic screening in the Danish Dental Service for children. A 5-item questionnaire was sent to each department of public dentistry in the 275 communities of Denmark. A total of 269 questionnaires were returned, four unanswered. Radiographic screening examinations were done on 162 respondents. Of these, 25% had bitewing screening and 25% panoramic screening. Two types of routine radiographic examinations were performed on more than one third of the respondents. The most frequent combination for screening radiography was bitewing and panorama. Even though the risks included in the use of ionizing radiation for dental screening purposes may be considered negligible, it is still ethically correct to avoid unnecessary exposure by a careful selection of patients prior to radiography. As economic support for dental health care had been cut, the radiographic screening procedure must prove itself to be cost/effective to be kept unchanged.     

INTERMITTENT CLAUDICATION: A DOUBLE–BLIND CROSSOVER TRIAL OF PENTOXIFYLLINE

Abstract: The influence of the xanthine derivative pentoxifylline ('Trental' or BL191; Hoechst–Roussel) on exercise tolerance was measured in 38 subjects with stable, severe to moderately severe, intermittent claudication who completed a randomised, double–blind, placebo controlled, cross–over clinical trial. Patients received placebo tablets or 400 mg slow–release pentoxifylline tablets ('Trental 400') twice a day for one week, followed by three times daily for seven weeks, and then crossed over to receive the alternate preparation for another eight weeks.
Claudication distance and walking distance were measured on a treadmill before starting treatment and again at four–week intervals during the trial. At the same times, red blood cell filterability, plasma fibrinogen concentration and blood viscosity, resting and post–ischemic calf muscle blood flow, and the resting and post–exercise ankle/brachial systolic pressure ratio were also measured.
In this study, the observed effects of pentoxifylline treatment were no greater than those of placebo, even though serum levels of pentoxifylline and its hydroxy–metabolite were within the anticipated range. This was shown by a 'therapeutic effect ratio' of 0.98 for treadmill claudication distance and 0.96 for treadmill walking distance after within–patient analysis at the end of the cross–over (where a ratio of 1.0 means the test drug and placebo effects are identical). These ratios have 95% confidence limits of 0.72–1.34 and 0.74–1.25, respectively.     

Effect of image enhancement for detectability of bone lesions in digitized intraoral radiographs

Abstract — Digital image enhancement is concerned with the computer-controlled manipulation of image information. The aim of this study was to evaluate whether diagnostic accuracy would improve in digitally enhanced images of radiographs with impaired density. Each of 83 dry mandibles was divided into four regions. By random assignment it was decided for each region whether or not a hole should be drilled. Three intraoral radiographs (3x4 cm) were performed of each region. at different exposure times: 2.0 s, 0.60 s, and 0.16 s and interpreted. The radiographs were thereafter recorded by a video camera connected to an IBM-PC. The personal computer held a hardware digitization card defined at a 512x5I2x8 matrix resolution on the basis of which a software program with image enhancement facilities was developed. The light and dark radiographs were digitally enhanced by the use of contrast stretching and smoothing filters. The light (0.16 s) original radiographs were less accurate than the ones with optimal density (0.60 s) while no significant differences were found between dark (2.0 s) and optimal density original radiographs. No significant differences were found between original and digitized radiographs of optimal density and digitally enhanced images of light or dark radiographs. The diagnostic accuracy obtained from optimal density radiographs can thus be maintained in digitized dark radiographs and in light radiographs with a four-times dose reduction after digital image enhancement,     

Bone Marrow Biopsy Changes in the Iliac Bone Mimicking Multiple Colonic Polypi

Many different entities simulating colonic polyps on barium enema examination have been described. Of the extraluminal mimics, round bony structures such as vertebral pedicles are perhaps best known. We describe the cause of a previously undescribed artifact: bone marrow biopsy of the ilium.     

The appearance of basal cells in the developing murine epididymis and their temporal expression of macrophage antigens

This work demonstrates similarities between epididymal basal cells and macrophages in the mouse. Light microscopic studies of the postnatal development of the murine epididymis showed that basal cells were not present before days 12, 14 and 16 in the cauda, caput and corpus epididymis, respectively. An increase in cell number per unit length of tubule perimeter was demonstrated in all segments between days 20 and 27, when testicular fluid and spermatozoa start entering the epididymis. In the adult, there were more basal cells per unit perimeter in the cauda than caput or corpus epididymis. Conspicuous and consistent expression by basal cells of antigens detected by antibodies against tissue-fixed macrophages (F4/80) and mature macrophages (Mac-1) occurred only after they became established within the epithelium. Basal cells in the cauda epididymis did not display either antigen in the adult, although they persisted in the caput region. Such developmental patterns are compatible with the hypothesis that basal cells play a role in immune defence against sperm autoantigens.