In vivo imaging of abdominal aortic aneurysms: increased FDG uptake suggests inflammation in the aneurysm wall

PURPOSE: To study the potential of integrated positron emission tomography and computed tomography (PET/CT) to identify aneurysm wall inflammation. METHODS: The level of F18-fluorodeoxyglucose (FDG) uptake was studied in aneurysmal and normal-sized aortas of 34 male patients [17 with abdominal aortic aneurysm (AAA) and 17 age-matched controls] identified in a database of 278 consecutive patients evaluated for staging of primary lung cancer. The maximal standardized uptake value (SUV) was calculated to quantify FDG uptake in the AAA wall. RESULTS: AAAs showed significantly higher FDG uptake than the normal-sized aorta in age-matched controls (SUV 2.52+/-0.52 versus 1.78+/-0.45, respectively; p<0.001). The level of FDG uptake did not correlate with maximal aneurysm diameter (r=0.09; 95% CI -0.42 to 0.56; p=0.7). CONCLUSION: FDG-PET/CT is a promising technique to identify inflammation of the aneurysm wall. Irrespective of aneurysm diameter, asymptomatic AAAs show more FDG uptake and more inflammatory activity in the wall than the non-dilated abdominal aorta of sex/age-matched controls. Future studies will be directed at the predictive value of increased FDG uptake for aneurysm wall strength, rupture risk, and the utility of FDG-PET/CT in assessing the effect of medical interventions.     

Dual-energy computed tomography for the differentiation of uric acid stones: ex vivo performance evaluation

We assessed the potential of dual-energy computed tomography (CT) for the differentiation between uric acid (UA)-containing and non-UA-containing urinary stones. Forty urinary stones of 16 different compositions in two sizes (< and >/= 5 mm) were examined in an ex vivo model. Thirty stones consisted of pure calcium oxalate (whewellite or wheddellite), calcium phosphate (apatite, brushite, or vaterite), ammonium magnesium phosphate (struvite), UA, ammonium acid urate, ammonium phosphate, sodium hydrogen urate, or cystine, and ten stones were of mixed composition (UA-sodium hydrogen urate, whewellite-urate, wheddellite-urate, whewellite-brushite, or whewellite-brushite-struvite). Scans were performed using dual-source CT in a dual-energy mode with the tubes simultaneously operating at 80 and 140 kV. Two readers analysed the data with respect to stone attenuation at each energy level. The stones were classified as UA- or non-UA-containing using manual attenuation measurements and software analysis results. Sensitivity, specificity, PPV, and NPV were calculated using crystallographic stone analysis as the gold standard. Twenty-six out of 40 stones (65%) contained no UA; 14 stones (35%) contained UA. When compared with UA-containing stones, the differences in attenuation values at 80 and 140 kV were significantly (P < 0.001) higher in stones containing no UA. The software automatically mapped 39/40 stones (98%). Only one (2%) 2 mm UA-stone was missed. The software correctly classified all detected stones as UA- or non-UA-containing. The attenuation values of the missed stone were manually plotted into the analysis sheet which allowed for the correct classification of the stone (containing UA). Therefore, the sensitivity, specificity, PPV, and NPV for the detection of UA-containing stones was 100%. Ex vivo experience indicates that differentiation between UA- and non-UA-containing stones can be accurately performed using dual-source dual-energy CT.     

Identification of the putative bryostatin polyketide synthase gene cluster from "Candidatus Endobugula sertula", the uncultivated microbial symbiont of the marine bryozoan Bugula neritina

The bryostatins are protein kinase C modulators with unique structural features and potential anticancer and neurological activities. These complex polyketides were isolated from the marine bryozoan Bugula neritina, but recent studies indicate that they are produced by the uncultured symbiotic bacterium "Candidatus Endobugula sertula" ("E. sertula"). Here we present the putative biosynthetic genes: five modular polyketide synthase (PKS) genes, a discrete acyltransferase, a beta-ketosynthase, a hydroxy-methyl-glutaryl CoA synthase (HMG-CS), and a methyltransferase. The cluster was sequenced in two closely related "E. sertula" strains from different host species. In one strain the gene cluster is contiguous, while in the other strain it is split into two loci, with one locus containing the PKS genes and the other containing the accessory genes. Here, we propose a hypothesis for the biosynthesis of the bryostatins. Thirteen PKS modules form the core macrolactone ring, and the pendent methyl ester groups are added by the HMG-CS gene cassette. The resulting hypothetical compound bryostatin 0 is the common basis for the 20 known bryostatins. As "E. sertula" is to date uncultured, heterologous expression of this biosynthetic gene cluster has the potential of producing the bioactive bryostatins in large enough quantities for development into a pharmaceutical.     

Hypoglycaemic effect of quinolizidine alkaloids--lupanine and 2-thionosparteine on non-diabetic and streptozotocin-induced diabetic rats

The effects of the highly selective histamine H4 receptor antagonists JNJ7777120 and VUF6002 were investigated on the carrageenan-induced inflammation and thermal hyperalgesia in rats. JNJ7777120 (10 and 30 mg/kg, s.c.) and VUF6002 (10 mg/kg, s.c.) significantly reduced paw edema and hyperalgesia provoked by subplantar injection of carrageenan; the effect was evident against the early (2 h) phase of inflammation. An inactive analog of VUF6002, VUF6007 (10 mg/kg, s.c.) slightly aggravated paw edema, while leaving unaltered carrageenan-induced nociception. These findings indicate that histamine H4 receptors participate in the early phase of acute inflammation induced by carrageenan in rats, influencing both edema and thermal hyperalgesia.     

Comparison of two intramedullary nails for tibiotalocalcaneal fusion: anatomic and radiographic considerations

BACKGROUND: Retrograde intramedullary nailing is an established procedure for tibiotalocalcaneal arthrodesis. This study was conducted to see whether, and if so to what extent, nail design modifications would influence the risk to anatomic structures and the bony coverage of the nail base. METHODS: Six pairs of thawed fresh-frozen cadaver legs received two different intramedullary nails (N1: straight nail, lateral-medial tip locking; N2: valgus-curved nail, medial-lateral tip locking) under simulated operative conditions. The specimens were dissected; distances between the at-risk structures and the hardware were measured. The hindfoot axis and the volume of the intracalcaneal nail portion were determined with CT. RESULTS: At the plantar entry site, N2 was significantly farther from the flexor hallucis longus tendon (p=0.047), the medial plantar artery (p=0.026), and the lateral plantar nerve (p=0.026) than N1. The lateral-medial calcaneal locking screw of N1 damaged significantly more often the peroneus brevis tendon (p=0.03) than N2. The proximal tip-locking screw, N2, was significantly farther from the anterior tibial artery (p=0.075) and the deep (p=0.047) and superficial peroneal nerves (p=0.009) than N1; N1 was significantly farther from the great saphenous vein (p=0.075) than N2. The distal tip-locking screw, N1. damaged significantly more often the extensor digitorum longus (p=0.007), the anterior tibial artery(p = 0.04), and the deep and superficial peroneal nerves (p=0.03) than N2. CT did not show any significant changes in the hindfoot axis with either device; intracalcaneal nail volumes were similar. CONCLUSIONS: A curved nail can increase the distance to at-risk plantar structures. Medial-lateral nail-tip locking appears to have less risk to neurovascular structures. CLINICAL RELEVANCE: Safer retrograde intramedullary nailing for tibiotalocalcaneal fusion requires knowledge of the structures at risk and appropriate operative technique.     

Uniform distribution of skin-temperature increase after different regional-anesthesia techniques of the lower extremity

BACKGROUND AND OBJECTIVES: Skin-temperature increase is a reliable but late indicator of success during regional-anesthesia techniques. The goal of this study is to determine the distribution of skin-temperature changes during different regional techniques. Does skin temperature increase in the whole area innervated by the blocked neural structures or only in certain regions within this area with the capability to react preferentially to sympathetic block (i.e., vessel-rich skin)? Although onset time may vary between different regional-anesthetic techniques, we hypothesized that the distribution of skin warming is equal. METHODS: Skin temperature was assessed continuously by infrared thermography in 24 patients who received either combined femoral-nerve and sciatic-nerve block, epidural anesthesia, or spinal anesthesia. RESULTS: Apart from differences in time of onset, no differential spatial distribution of skin-temperature changes could be detected. The earliest and greatest rise of skin temperature occurred at the great toe (10.6 degrees C +/- 0.4 degrees C), became smaller proximally, and was negligible above the ankles, irrespective of the type and extent of block. Video-thermography revealed that cold blood flows through subcutaneous veins immediately after onset of sympathetic block and initially decreases skin temperature (0.6 degrees C +/- 0.3 degrees C) during onset of spinal anesthesia. CONCLUSION: Irrespective of the applied regional-anesthetic technique, skin-temperature changes are more pronounced distally. Thermography prevents false measurements of skin temperature above subcutaneous veins and displays flow of cold blood as the mechanism of initial skin-temperature drop after regional anesthesia. Measurements of skin-temperature increase cannot be used to evaluate the extent of analgesia or sympathetic block.     

Focal segmental glomerulosclerosis due to a relapsing non-Hodgkin's lymphoma diagnosed by positron emission tomography

Glomerulonephritis rarely appears associated with Hodgkin's disease or non-Hodgkin's lymphoma (NHL). We present a patient with a relapse of a non-Hodgkin's lymphoma which first presented as nephrotic syndrome due to focal segmental glomerulosclerosis (FSGS). This case report discusses the unusual association of non-Hodgkin's lymphoma and focal segmental glomerulosclerosis, as well as the crucial role of positron emission tomography in detecting the relapsing lymphoma.