Hydroxylapatite-coated total prosthesis of the hip

Since 1987, 80 hydroxyapatite-coated (HA) cementless total hip prostheses have been implanted. Thirty patients were examined 21 months postoperatively and the results compared with data for uncoated prosthesis. Earlier mobilization and freedom from pain, together with evidence of bone ingrowth without connective tissue membrane formation, confirmed the benefits of HA-coated prostheses.     

Uptake of Adriamycin in tumour and surrounding brain tissue in patients with malignant gliomas

Summary Eight patients with malignant gliomas verified on CT scan, received an intravenous injection of 50 mg of Adriamycin R, 24 hours prior to surgical removal of the tumour. Peroperatively, both tumour and surrounding tissue specimens were obtained for determination of the tissue concentrations of Adriamycin and its reduced metabolite Adriamycinol. It was found that Adriamycin could be detected in tumour tissue from all patients. The concentration varied between 0,9 and 4,6 nmol/g tissue. In contrast, Adriamycin could only be detected in surrounding brain tissue from one patient.In anin vitro study a human malignant glioma cell line (U-251 MG) was exposed to various concentrations of Adriamycin for 24 hours. It was found that an intracellular drug concentration above 30 nmol/g cells caused a concentration dependent inhibition of cell growth. Thus, it is likely that the poor effect of Adriamycin on patients with malignant gliomas is due to an ineffective drug accumulation in the tumour tissue.     

New stand magnifiers do not meet rated levels of performance

A new range of stand magnifiers has been released by the COIL company in the United Kingdom. Examination of these magnifiers reveals that they fail to deliver the rated magnifications labelled prominently on the appliances, as a result of the manufacturer's conformance with the requirements of the German DIN standard and the use of back vertex power (F'_v) rather than equivalent dioptric power (F_m) of the magnifier. In this study we provide information on the optometric parameters of these new stand magnifiers that will assist the more accurate specification of improvements in vision expected from their use.     

Bilateral congenital pseudarthrosis of the clavicle

Summary A case of bilateral congenital pseudarthrosis of the clavicle in a baby boy is described. The patient is fully asymptomatic, and no functional impairment is present. This is probably only the seventh case described of this rare congenital anomaly.     

Hypertension in Jordanian children: a retrospective analysis of 70 cases

Seventy patients, aged 1–20 years, were seen at Jordan University Hospital with high blood pressure (BP) over a 3-year period. BP values ranged from 140 to 230 mmHg for systolic pressure and from 90 to 130 mmHg for diastolic pressure. Essential hypertension was seen in only 6 patients (8.6%); secondary hypertension (n=64 or 91.4%) was due to renal parenchymal diseases (RPD) in 46 patients (65.7%), reno-vascular lesions in 8 (11.4%), renal transplantation in 5 (7.2%), teenage pregnancy in 4 (5.7%), and phaeochromocytoma in 1 patient (1.4%). The aetiologies of RPD were as follows: end-stage renal disease requiring dialysis in 14 patients, acute glomerulonephritis in 14, idiopathic nephrotic syndrome in 10, chronic renal insufficiency in 5, and polycystic kidney in 3 patients. Surgical cure of hypertension was achieved in 5 of the children with reno-vascular lesions and in the patient with phaeochromocytoma.     

Preoperative staging of gastrointestinal tumors by endosonography

Summary Intracavitary application of ultrasound was first performed for diagnostic purposes in 1967; since that time, it has been more and more widely used. As far as the gastrointestinal tract is concerned, endoscopically controlled ultrasonic probes provide visualization of the various layers of the intestinal wall. It is therefore possible to describe lesions of the esophagus, stomach, and the rectum with regard to their nature and depth of infiltration. Furthermore, periesophageal and perigastric organs can be visualized. It has become evident that endosonography is particularly important for pretherapeutic staging of tumors of the esophagus, stomach, and rectum. Here prospective comparative studies confirm the superiority of this new diagnostic procedure when compared to the methods available to date.     

Uncertainty in Fitted Estimates of Apparent in Vivo Metabolic Constants for Chloroform

It has become common practice to rely on fitted estimates ofapparent in vivo metabolic constants (e.g., V_max and K_M) inparameterization of PBPK models. Yet, quantitative estimatesof precision in these fitted parameters are not routinely reported.Such information is needed to assess the reliability of modelpredictions. The purpose of this study was to assess the precisionin estimates of V_max and K_M for chloroform, accounting for boththe statistical uncertainties in parameter estimates from individualdata sets and any additional uncertainty due to differencesin the parameter estimates derived from various experiments.Joint confidence regions for V_max and K_M from each experiment,generated using maximum likelihood techniques, were used toevaluate these questions. Three previously published data setswere considered. Estimates of V_max and K_M obtained from thesedata sets differed more than could be explained as a consequenceof a limited number of observations, measurement error, or stochasticerror. Issues associated with the use of maximum likelihoodtechniques to estimate joint confidence regions, the estimationof metabolic constants from individual experiments within agas uptake study versus the full data set, the degree of overlapin the joint confidence regions for metabolic constants obtainedfrom separate data sets, and the implications for risk assessmentare discussed.