Use of E mu-PIM-1 transgenic mice short-term in vivo carcinogenicity testing: lymphoma induction by benzo[a]pyrene, but not by TPA

E mu-pim-1 transgenic mice are predisposed to develop lymphomas. Due to their low spontaneous tumour incidence and their increased sensitivity towards the lymphomagen ethylnitrosourea these mice may present an interesting model for short-term carcinogenicity testing. Here, we report on the further exploration of this transgenic mouse model with two additional carcinogens known to have, among others, the lymphohaematopoietic system as target, i.e. benzo[a]pyrene (B[a]P) and 12-O-tetradecanoylphorbol-13-acetate (TPA). B[a]P, given three times a week (by gavage) for 13 weeks at 4.3, 13 or 39 mg/kg body weight, resulted in a dose-related increase in lymphomas up to a 90% incidence in E(mu)-pim-1 mice during the observation period of 40 weeks. B[a]P also induced tumours of the forestomach within this observation period, though at a lower incidence and apparently equally effective in wildtype and transgenic mice. TPA, on the other hand, was unable to induce lymphomas (or tumours in any other organ) in either transgenic or wildtype animals within the observation period of 44 weeks, when applied dermally at the maximum tolerated dose of 3 microg/mouse, twice a week for 35 weeks. Molecular analysis showed that B[a]P-induced lymphomas in transgenic mice were of T-cell origin, 80% of which had elevated levels of c-myc expression. None of the lymphomas had increased N-myc expression and mutation analysis of the ras-gene family revealed a K-ras mutation in only one out of eight tumours investigated. Also, none of the lymphomas showed aberrant expression of p53 as determined by immunohistochemistry. It is concluded that the E mu-pim-1 mouse model will not be very suitable for short-term carcinogenicity testing in general: only genotoxic chemicals that have the lymphohaematopoietic system as target for carcinogenesis in wild- type mice, appear to be efficiently identified.      

Localized muscular mucormycosis in a child with acute leukemia

Mucormycosis is a rare fungal infection of childhood, occurring mainly in patients with chronic illnesses such as diabetes and malignancies. The fungus seldom grows in culture and confirmation of the diagnosis depends on histologic examination of infected tissues. To date, the reported natural history of the disease has been rapid progression and a fatal outcome. Therefore, the importance of early diagnosis by tissue biopsy and early treatment with surgical debridement and systemic antifungal therapy cannot be overemphasized. The pulmonary system is the most common site for mucormycosis in patients with leukemia. We report what we believe to be the first successfully treated case of isolated muscular mucormycosis occurring in a child with biphenotypic acute leukemia. The diagnosis was made promptly by tissue examination at the time of surgical debridement. The patient was also given systemic amphotericin-B therapy.      

Standards for total body fat and fat-free mass in infants

Data on body composition in conjunction with reference centiles are helpful in identifying the severity of growth and nutritional disorders in infancy and for evaluating the adequacy of treatment given during this important period of rapid growth. Total body fat (TBF) and fat-free mass (FFM) were estimated from total body electrical conductivity (TBEC) measurements in 423 healthy term Caucasian infants, aged 14-379 days. Cross sectional age, weight, and length related centile standards are presented for TBF and FFM. Centiles were calculated using Altman's method, based on polynomial regression and modelling of the residual variation. The TBF percentage steeply increased during the first half year of life, and slowly declined beyond this age. Various simple TBEC derived anthropometric prediction equations for TBF and FFM are available to be used in conjunction with these standards. Regression equations for the P50 and the residual SD, depending on age, weight, or length, are provided for constructing centile charts and calculating standard deviation scores.     

Pharmacokinetics of azithromycin in pediatric patients with acute otitis media.

The objective of our study was to characterize the pharmacokinetics of azithromycin after the oral administration of multiple doses in suspension to children with acute otitis media. Thirteen children (ranging in age from 7.5 months to 5 years) received a single oral dose of 10 mg of azithromycin per kg of body weight on day 1 followed by single daily doses of 5 mg/kg on days 2 to 5. Each child fasted overnight before receiving the final dose on day 5. Multiple blood samples were collected after the last dose. Concentrations of azithromycin in serum were measured by a specific high-performance liquid chromatography-mass spectrometry method. The means and standard deviations for the maximum concentration of azithromycin in serum, the time to maximum concentration of azithromycin in serum, the area under the concentration-time curve (from 0 to 24 h), and the elimination half-life were 224 +/- 120 ng/ml, 1.8 +/- 0.4 h, 1,841 +/- 651 ng.h/ml, and 31.6 +/- 6.6 h, respectively. Concentrations in serum (means +/- standard deviations) at 0 h (predose) and at 24, 48, and 72 h after the final dose were 51 +/- 26, 47 +/- 21, 27 +/- 17, and 17 +/- 13 ng/ml, respectively. Thus, the once-daily administration of azithromycin resulted in sustained systemic exposure to the drug. The drug dosage regimen used in this study should lead to tissue drug concentrations exceeding the MICs for common pathogens.     

Quality assessment and assurance in diagnostic imaging. Theoretical and practical considerations and a quality audit of the excretory urogram

Concepts necessary to an understanding of the basics of quality assurance audits are presented. Included are specific examples that bridged theory and practice by applying the protocol to a real-life diagnostic imaging situation. This method meets the present requirements of the Joint Commission of the Accrediation of Hospitals.     

The permeability of the posterior blood ocular barrier after xenon photocoagulation: a study using fluorescein labelled dextrans.

Xenon photocoagulation burns in the rabbit fundus were studied angiographically with fluorescein labelled dextrans of molecular weights in the range 3000 to 150 000. Recent photocoagulation burns showed dye leakage to all molecular weights used. Angiograms 2 days after burns had been produced showed leakage of dextrans of molecular weights up to and including 70 000 but no leakage of dextran of 150 000 molecular weight. At 7 days after photocoagulation healed burns remained permeable to dextrans of molecular weight 3000 or 20 000, but in the majority of eyes such burns did not leak dextrans of over 40 000 molecular weight. The clinical significance of the selective nature of photocoagulative damage to the posterior blood ocular barrier is discussed.     

Colon perforation following percutaneous nephrostomy and renal calculus removal

Two patients had colonic perforation as a result of percutaneous nephrostomy placement followed by track dilatation and renal calculus removal. We present the technical aspects of nephrostomy placement and stone removal, as well as the clinical diagnosis and management of these cases. Both patients recovered well with conservative therapy and required no surgical intervention. This report reviews the anatomic considerations for percutaneous nephrostomy in patients undergoing renal stone removal.     

A case series of nicotine nasal spray in the treatment of tobacco dependence among patients with schizophrenia

A retrospective case series of 12 smokers with schizophrenia or schizoaffective disorder who had not successfully quit smoking with previous treatments for tobacco dependence were treated with nicotine nasal spray. All but one patient (92 percent) tolerated the nasal spray well, and nine (75 percent) used it at maximal doses for prolonged periods. After treatment five patients (42 percent) were abstinent from smoking for more than 90 days, and four patients (33 percent) substantially reduced the amount that they smoked. Ten patients (83 percent) used the spray in combination with other medications, and all received psychosocial support. Nicotine nasal spray was found to be well tolerated.