Air in the bone? Diagnosis and treatment of a pneumatocyst of the ilium. Apropos of a case

We present a case of symptomatic pneumatocyst of the ilium observed in a professional scuba diver exposed to pressure variations. Pneumatocysts are rare and except for one case reported in a clavicular localization, are always found in subchondral bone of the iliac or sacral side of the sacroiliac joint. Undoubtedly, air fills an intraosseous node. We report here the first case of efficient treatment achieved by filling the cyst via percutaneous access under scopic control.     

Systemic retinoids. What''s new?

Drug-induced pleural disease in the form of pleural fibrosis or pleural effusions is a common but frequently overlooked toxic or allergic manifestation of usage of a particular class of drugs. A detailed history of drug intake will often unveil the cause for the pleural pathology. Discontinuation of the drug with or without the addition of steroid therapy may be helpful.     

Incremental value of myocardial perfusion scintigraphy in prognosis and outcomes of patients with coronary artery disease

The concept of incremental value in prognosis and outcome of patients with coronary artery disease is important to the field of noninvasive imaging. Because these tests are expensive, they should be held to the standard of demonstrating a statistical improvement over the information provided by clinical assessment and treadmill testing. Responding to the demand for cost-effective applications of myocardial perfusion scintigraphy, a large amount of research has recently been devoted to defining specific patient subsets in which incremental value exists for scintigraphy. Subsets thus far demonstrated to benefit incrementally include those men and women referred for possible coronary artery disease, with known coronary artery disease, and after percutaneous transluminal coronary angioplasty, coronary artery bypass grafting, unstable angina, or recent infarction. Incremental cost savings also apply to these subsets except for patients with normal ECGs at rest and less than 15% likelihood for significant coronary artery disease.     

Cytosolic enzymes with a mitochondrial ancestry from the anaerobic chytrid Piromyces sp. E2

The anaerobic chytrid Piromyces sp. E2 lacks mitochondria, but contains hydrogen-producing organelles, the hydrogenosomes. We are interested in how the adaptation to anaerobiosis influenced enzyme compartmentalization in this organism. Random sequencing of a cDNA library from Piromyces sp. E2 resulted in the isolation of cDNAs encoding malate dehydrogenase, aconitase and acetohydroxyacid reductoisomerase. Phylogenetic analysis of the deduced amino acid sequences revealed that they are closely related to their mitochondrial homologues from aerobic eukaryotes. However, the deduced sequences lack N-terminal extensions, which function as mitochondrial leader sequences in the corresponding mitochondrial enzymes from aerobic eukaryotes. Subcellular fractionation and enzyme assays confirmed that the corresponding enzymes are located in the cytosol. As anaerobic chytrids evolved from aerobic, mitochondria-bearing ancestors, we suggest that, in the course of the adaptation from an aerobic to an anaerobic lifestyle, mitochondrial enzymes were retargeted to the cytosol with the concomitant loss of their N-terminal leader sequences.     

Comparison of the plasma pharmacokinetics and renal clearance of didanosine during once and twice daily dosing in HIV-1 infected individuals

OBJECTIVE: To compare the plasma pharmacokinetics of didanosine during once daily (qd) and twice daily (bid) dosing. DESIGN: Open-label, randomized, cross-over study. METHODS: HIV-1 infected patients who used didanosine were randomized to either a qd or a bid dosing regimen of didanosine. The total daily dose of didanosine was identical in both regimens. Seven days after the start of the study, the pharmacokinetic profile of didanosine in plasma and urine was assessed during an 8-h period. The next day, the patient was switched to the opposite dosing regimen, and after another 7 days, the study was concluded by again assessing the plasma and urine pharmacokinetics of didanosine during 8 h. RESULTS: A total of 19 patients completed the study. The pharmacokinetics of didanosine in plasma (with maximum plasma concentration adjusted for dose) and urine were not significantly different in the qd and bid dosing regimen (P > 0.28 for all parameters). CONCLUSION: We conclude that qd dosing of didanosine leads to a similar exposure in plasma as bid dosing (using the same total daily dose). Since qd dosing may lead to improved compliance of patients to regimens containing didanosine, these results provide a rationale for prescribing didanosine in a qd regimen, and is reassuring when we realize that the drug is being administered in a qd dosing regimen on a large scale in clinical practice.     

Germ-cell mutagenesis in lambda lacZ transgenic mice treated with ethylating and methylating agents: comparison with specific-locus test

Germ-cell mutagenesis has been studied in male lambda lacZ transgenic mice in such a way that the data can be compared with literature data for germ-cell mutagenesis obtained with the specific-locus test (SLT). Mutagenesis induced by ethylnitrosourea (ENU), ethylmethanesulphonate (EMS), methylnitrosourea (MNU) and methylmethanesulphonate (MMS), has been studied in mature spermatozoa isolated from the epididymis and vas deferens. In order to investigate mutagenesis in different phases of spermatogenesis, animals were sacrificed at various time points after treatment. ENU at 150 mg/kg body weight significantly induced mutations in stem cells (analysis at 100 days post-treatment), but not in post-stem cells (7 days post-treatment). EMS (250 mg/kg) and MMS (60 mg/kg) induced mutations only in post-stem cells (7 days), but not in stem cells (100 days). MNU (70 mg/kg) resulted in an increase of mutations in both post-stem cells (14 and 37 days) and stem cells (100 days), although the latter, due to a limited number of data, was not statistically significant. All these data are in accordance with published SLT data. These results indicate that lambda lacZ transgenic mice are a suitable model to study gene mutations in different phases of spermatogenesis.