Evaluation of a prototype long-lasting insecticide-treated mosquito net under field conditions in rural Burkina Faso

Insecticide measurements and standard World Health Organization bioassays on random samples of new unwashed, traditionally washed and up to 18 months field-used 'long-lasting' deltamethrin treated mosquito nets demonstrated a rapid reduction of efficacy under field conditions. The technology of 'long-lasting' insecticide-treatment needs much improvement.     

Initial and subsequent approach for the synthesis of 18FDG

2-deoxy-2-[18F] fluoro-D-glucose (18FDG) was developed in 1976 in a collaboration between scientists at the National Institutes of Health, the University of Pennsylvania, and Brookhaven National Laboratory. It was developed for the specific purpose of mapping brain glucose metabolism in living humans, thereby serving as a tool in the basic human neurosciences. With 18FDG it was possible for the first time to measure regional glucose metabolism in the living human brain. Around the same time, the use of 18FDG for studies of myocardial metabolism and as a tracer for tumor metabolism were reported. After the first synthesis of 18FDG via an electrophilic fluorination with 18F gas (produced via the 20Ne(d,alpha)18F reaction), small volume enriched water targets were developed that made it possible to produce large quantities of [18F]fluoride ion via the high-yield 18(p,n)18F reaction. This was followed by a major milestone, the development of a nucleophilic fluorination method that produced 18FDG in very high yield. These advances and the remarkable properties of 18FDG have largely overcome the limitations of the 110-minute half-life of 18F so that 18FDG is now available to most regions of the United States from a number of central production sites. This avoids the need for an on-site cyclotron and chemistry laboratory and has opened up the use of 18FDG to institutions that have a positron emission tomography (PET) scanner (or other imaging device) but no cyclotron or chemistry infrastructure. Currently, 18FDG is used by many hospitals as an off the shelf radiopharmaceutical for clinical diagnosis in heart disease, seizure disorders, and oncology, the area of most rapid growth. However, it remains an important tool in human neuroscience and in drug research and development.     

Effect of angiotensin converting enzyme inhibition on myocardial phosphoinositide metabolism visualised with 1-[1-11C]-butyryl-2-palmitoyl-rac-glycerol in myocardial infarction in the rat

We recently reported that myocardial phosphoinositide (PI) metabolism can be visualised by 1-[1-11C]-butyryl-2-palmitoyl-rac-glycerol (11C-DAG) in rats with myocardial infarction (MI). Angiotensin II, the receptors for which are expressed predominantly in infarcted areas with active fibrogenesis rather than in non-infarcted regions, is involved in the upstream signalling systems of PI metabolism and plays an important role in the process of left ventricular (LV) remodelling after MI. We therefore hypothesised that the distribution of 11C-DAG after MI may be affected by the inhibition of angiotensin converting enzyme, which is one of the most important factors in the development of LV remodelling after MI. Rats were injected with 11C-DAG after 3 or 10 weeks of treatment with captopril or no treatment following coronary artery ligation, and quantitative autoradiography was performed. Cells occupying the infarcted region were identified by immunohistochemistry. Compared with untreated rats, treatment with captopril for 3 weeks after MI elicited a reduction in the 11C-DAG uptake in the infarcted region (P<0.05) but not in the non-infarcted region, and was associated with a 22% decrease in the heart weight/body weight ratio. The thallium-201 distribution in the infarcted area was similarly low in the rats with and rats without the 3-week captopril treatment after MI. Abundant macrophages and myofibroblasts occupied the infarcted area in both rats with and rats without the captopril treatment for 3 weeks after MI. The 11C-DAG radioactivity in the infarcted region in the untreated rats was lower 10 weeks after MI than 3 weeks after MI (P<0.01). This finding was in agreement with the results of immunohistochemistry demonstrating that the number and size of macrophages and myofibroblasts were remarkably reduced in rats 10 weeks after MI compared with 3 weeks after MI. Captopril treatment for 10 weeks after MI did not decrease the 11C-DAG radioactivity in the infarcted area further. These data suggest that 11C-DAG is useful for visually detecting regions with activated PI metabolism after MI, and that captopril reduces PI metabolism in the infarcted region in the relatively early phase of MI, which might contribute to the attenuation of ventricular remodelling.     

Reduction of blood loss using tranexamic acid in total knee and hip arthroplasties

There have been several attempts to reduce postoperative blood loss in patients undergoing total arthroplasty. Benoni et al. reported the usefulness of tranexamic acid in total knee arthroplasty (TKA). We investigated its effect in TKA and total hip arthroplasty (THA). Blood loss was significantly reduced in patients given tranexamic acid in both the TKA and THA groups, and no severe complications, such as venous or pulmonary thrombosis, were noted in any of the patients who received the agent. Administration of tranexamic acid seems to be useful for reducing postoperative blood loss in TKA and THA. Received: 26 May 1999     

Multiple bile duct biopsies using a sheath with a side port: usefulness of intraductal sonography

OBJECTIVE: We clarified the number of biopsies required to determine malignancy of the biliary tract on the basis of the type of bile duct tumor. SUBJECTS AND METHODS: Patients with a biliary tract malignancy (n = 33) and a benign biliary stenosis (n = 3) underwent biopsy via the percutaneous transhepatic route. We performed intraductal sonography using a 20-MHz probe with a 2.0-mm diameter. The sonographic findings were prospectively classified as polypoid, circular, or semicircular. The tip of a long 9-French sheath with a side port was wedged into the stenosis, and six specimens were obtained with a 1.8-mm-diameter forceps with serrated cups. RESULTS: When cholangiography or intraductal sonography showed a polypoid lesion, the sensitivity of two biopsies was 100% (6/6). When cholangiography showed a stenotic lesion, the sensitivity of nine biopsies (96%, 26/27) was superior to that of two biopsies (74%, 20/27; p < 0.05). When intraductal sonography showed a circular lesion, the sensitivity of three biopsies (100%, 14/14) was superior to that of a single biopsy (64%, 9/14; p < 0.05). When it showed a semicircular lesion, the sensitivity of nine biopsies (92%, 12/13) was superior to that of two biopsies (54%, 7/13; p < 0.05). CONCLUSION: Bile duct biopsy using a sheath with a side port has a high sensitivity. However, the number of biopsies required depends on the cholangioscopic and intraductal sonographic appearance of the tumor.     

Regional coupling of blood flow and methionine uptake in an experimental tumor assessed with autoradiography

Regional distribution of L-[methyl-¹⁴C] methionine (¹⁴C-MET) and 4-[¹⁸F] fluoro-antipyrine was compared using experimental rat tumors (AH109A) and a computerized autoradiogram image processor. Tissue distributions of the two tracers were found to be inhomogeneous in the tumor with nearly identical image patterns. Analysis of tissue radioactivities revealed that 82% of ¹⁴C-MET was derived from the acid insoluble fraction at 60 min after injection. The present study showed that ¹⁴C-MET uptake closely relates to tissue blood flow and may depend on its blood to tissue transport. Rapid incorporation of MET in the acid insoluble fraction implies that it is rapidly metabolized after transport into tumor tissue.     

Portal imaging by intravneous three-dimensional computed tomography after pancreaticoduodenectomy: A report of four cases

By employing three-dimensional computed tomography (CT) for portography, we analyzed the portal vein changes during the initial stage after a pancreaticoduodenectomy (PD), which seemed to affect postoperative complications. Four patients underwent PD without portal vein reconstruction with a standard radical lymph node dissection for cancer of the pancreaticoduodenal area. A total of 140 ml of contrast medium was intravenously injected at 2.5 ml/s, and imaging was started after 65 s with a Hitachi W-2000 CT scanner. Three-dimensional portal vein images were then reconstructed by the Voxel Transmission method. Three-dimensional CT showed portal stenosis in our all patients from the first to the third week after PD. In three of the patients, stenosis disappeared by week 7,8, or 15, respectively, without the formation of a bypass. In three patients, portal vein stenosis was severe while in one patient, it was mild. Severe complications such as gastrointestinal hemorrhaging and hepatic abscess occurred in two patients with severe portal stenosis. The onset of portal stenosis might therefore affect postoperative complications after PD.