Prognostication of cardiac CT angiography.

The rapidly emerging technique of cardiac computed tomography angiography (CTA) has enabled the anatomical assessment of coronary artery disease. CTA has very good diagnostic accuracy with the ability to detect nonobstructive from obstructive coronary artery disease and provides information on the presence of coronary artery calcification as well as on left ventricular function. Over the last few years, many prognostic studies have reviewed the outcome benefit of different scoring indices in predicting hard cardiac events. The following article will review the most recent literature available on the use of CTA in measuring luminal stenoses, identifying high-risk obstructive CAD, calcium plaque score, and LV function all in different models with their impact on the estimation of clinical risk. More recent data from a large multicenter registry supports the incremental benefit of CAD severity and LVEF as independent predictors of prognosis. Future directions and emerging applications such as the utility of CTA combined with perfusion analysis may lead to a new anatomical-functional diagnostic test that may provide optimal noninvasive assessment of coronary artery anatomy and be superior to invasive coronary angiography.

Degradation of lignified secondary cell walls of lucerne (Medicago sativa L.) by rumen fungi growing in methanogenic co-culture.

AIMS: To compare the abilities of the monocentric rumen fungi Neocallimastix frontalis, Piromyces communis and Caecomyces communis, growing in coculture with Methanobrevibacter smithii, to colonize and degrade lignified secondary cell walls of lucerne (alfalfa) hay. METHODS AND RESULTS: The cell walls of xylem cylinders isolated from stems of lucerne contained mostly xylans, cellulose and lignin together with a small proportion of pectic polysaccharides. All of these major components were removed during incubation with the three fungi, and differing cell wall polysaccharides were degraded to different extents. The greatest dry weight loss was found with N. frontalis and least with C. communis, and scanning electron microscopy revealed that these extensively colonized different cell types. C. communis specifically colonized secondary xylem fibres and showed much less degradation than N. frontalis and P. communis. CONCLUSIONS: Neocallimastix frontalis and P. communis were efficient degraders of the cell walls of lucerne xylem cylinders. Degradation occurred of pectic polysaccharides, xylan and cellulose. Loss of lignin from the xylem cylinders probably resulted from the cleavage of xylan releasing xylan-lignin complexes. SIGNIFICANCE AND IMPACT OF THE STUDY: Unlike rumen bacteria, the rumen fungi N. frontalis, P. communis and C. communis are able to degrade lignified secondary walls in lucerne stems. These fungi could improve forage utilization by ruminants and may have potential in the degradation of lignocellulosic biomass in the production of biofuels.

Fatty acid chain length, postprandial satiety and food intake in lean men.

High-fat diets are associated with obesity, and the weak satiety response elicited in response to dietary lipids is likely to play a role. Preliminary evidence from studies of medium (MCT) and long chain triglycerides (LCT) supports greater appetite suppression on high-MCT diets, possibly a consequence of direct portal access, more rapid oxidation and muted lipaemia. No data is as yet available on high-SCT diets which also have direct hepatic access. In this study SCT- (dairy fats), MCT- (coconut oil) and LCT-enriched (beef tallow) test breakfasts (3.3 MJ) containing 52 g lipid (58 en% fat) were investigated in a randomized, cross-over study in 18 lean men. All participants were required to complete the 3 study days in randomised order. Participants rated appetite sensations using visual analogue scales (VAS), and energy intake (EI) was measured by covert weighing of an ad libitum lunch meal 3.5 h postprandially. Blood samples were collected by venous cannulation. There were no detectable differences between breakfasts in perceived pleasantness, visual appearance, smell, taste, aftertaste and palatability (P>0.05). There was no significant effect of fatty acid chain length on ratings of hunger, fullness, satisfaction or current thoughts of food, nor did energy (mean, sem: SCT: 4406, 366 kJ; MCT: 4422, 306 kJ; LCT: 4490, 324 kJ; P>0.05) or macronutrient intake at lunch differ between diets. The maximum difference in EI between diets was less than 2%. Postprandial lipaemia also did not differ significantly. We conclude that there was no evidence that fatty acid chain length has an effect on measures of appetite and food intake when assessed following a single high-fat test meal in lean participants.

Ethmoid silent sinus syndrome causing inward displacement of the orbit: case report.

OBJECTIVE: We describe a previously unreported case of ethmoid silent sinus syndrome. METHOD: Case report and review of the world literature regarding silent sinus syndrome. RESULTS: A 33-year-old woman developed medial displacement of the left orbital contents in the absence of trauma, surgery or other significant pathology. Imaging showed opacification of the left ethmoid sinus and implosion of the medial orbital wall. Previously reported cases of silent sinus syndrome have all involved the maxillary sinus, with subsequent implosion of the orbital floor. Computed tomography scans of our patient showed wide, flat ethmoidal bulla and surrounding cells, with few horizontal bony septae reinforcing the area of collapse. CONCLUSION: This case represents the first report of ethmoid silent sinus syndrome. We argue that, in anatomically susceptible individuals, the silent sinus syndrome can present due to chronic ethmoidal sinusitis.

A case of late unilateral hematoma and subsequent late seroma of the breast after bilateral breast augmentation.

BACKGROUND: A previously unreported case of unilateral recurrent late collections, namely, a hematoma and a subsequent seroma, in an otherwise healthy female patient after breast augmentation is presented. METHODS: A case is reported together with a review of the world literature published and presented regarding late postoperative breast augmentation complications. RESULTS: The patient was a 49-year-old woman who underwent bilateral breast augmentation in 2006. Spontaneous swelling of the left breast developed 1 year postoperatively. The patient was taken to the operating theater, where a large hematoma was found and drained and the prosthesis reinserted. No cause for the complication was identified at the operation. The patient's symptoms of left-sided breast swelling with discomfort recurred 9 months later. A large seroma was found at surgery but no blood staining. On both occasions, the implant was extracted and examined, with no fault discovered. Capsulectomy was performed, and the pocket was examined, debrided, and cauterized as necessary. On neither occasion was any remarkable pathology found clinically or in laboratory samples sent for analysis. The patient was investigated for any sensitivities or hematologic abnormalities, with no significant results. CONCLUSION: A previously unreported case of recurrent late postaugmentation collections, namely, a seroma and a subsequent hematoma, in an otherwise well female patient is reported. The authors found no obvious reason for the recurrence in this patient.

No effect of an oleoylethanolamide-related phospholipid on satiety and energy intake: a randomised controlled trial of phosphatidylethanolamine.

BACKGROUND: Phosphatidylethanolamine (PE) is a phospholipid which is biosynthesized into long chain N-acylethanolamines (NAEs) including oleoylethanolamide (OEA), a known inhibitor of food intake. The aim of this study was to investigate whether PE-containing lipids can also inhibit intake. This was a 4 treatment intervention where 18 male participants were given a high-fat test breakfast (2.5 MJ, 53 en% fat) containing (i) high-phospholipid, high-PE lipid (ii) high-phospholipid, medium-PE lipid (iii) no-phospholipid, no-PE control lipid or (iv) water control, in a randomised cross-over. Visual analogue scales (VAS) were used to assess post-ingestive hunger and satiety, and energy intake (EI) was measured at an ad libitum lunch meal after 3.5 hours. RESULTS: When compared with the water control, the 3 lipid treatments resulted in lower levels of hunger and thoughts of food, greater fullness and satisfaction (all, treatment*time interaction, P<0.001), and a lower EI (P<0.05). However, there was no difference in any of the VAS measures when the 2 PE lipid treatments were compared with no-PE control lipid, nor when medium-PE was compared with high-PE. Unexpectedly participants ate significantly more energy at the lunch meal when the 2 PE lipid treatments (medium-PE:5406 kJ, 334 sem; high-PE:5288 kJ, 244 sem) were compared with the no-PE control lipid (5072 kJ, 262 sem, P<0.05), although there was no dose effect between the medium- and high-PE treatments. CONCLUSION: Despite the close relationship of PE with OEA, there was no evidence from this acute study that dietary phospholipids containing PE can favourably modify eating behaviour.

Compensatory dynamics are rare in natural ecological communities.

In population ecology, there has been a fundamental controversy about the relative importance of competition-driven (density-dependent) population regulation vs. abiotic influences such as temperature and precipitation. The same issue arises at the community level; are population sizes driven primarily by changes in the abundances of cooccurring competitors (i.e., compensatory dynamics), or do most species have a common response to environmental factors? Competitive interactions have had a central place in ecological theory, dating back to Gleason, Volterra, Hutchison and MacArthur, and, more recently, Hubbell's influential unified neutral theory of biodiversity and biogeography. If competitive interactions are important in driving year-to-year fluctuations in abundance, then changes in the abundance of one species should generally be accompanied by compensatory changes in the abundances of others. Thus, one necessary consequence of strong compensatory forces is that, on average, species within communities will covary negatively. Here we use measures of community covariance to assess the prevalence of negative covariance in 41 natural communities comprising different taxa at a range of spatial scales. We found that species in natural communities tended to covary positively rather than negatively, the opposite of what would be expected if compensatory dynamics were important. These findings suggest that abiotic factors such as temperature and precipitation are more important than competitive interactions in driving year-to-year fluctuations in species abundance within communities.

Effect of high-fat meals and fatty acid saturation on postprandial levels of the hormones ghrelin and leptin in healthy men.

OBJECTIVE: Ghrelin and leptin play a role in control of food intake and adiposity but mechanisms regulating these hormones in man are poorly defined and evidence that dietary fats may have adverse effects is inconclusive. We investigated whether high-fat meals, which differed in saturated fatty acid (SFA) content acutely modified these hormones. DESIGN: Randomised, double-blind, crossover trial. A high-fat (HF) test meal (59 +/- 4 g fat; 71% of energy as fat) was given for breakfast on two occasions. Meals comprised either high (approximately 70:30) or low (approximately 55:45) saturated:unsaturated fatty acid (SFA:USFA) ratio. Fasting and postprandial measurements of serum total ghrelin (RIA), leptin (enzyme-linked immunosorbent assay (ELISA)) and insulin (RIA) were made over 6 h. Postprandial measurements were also made at 10 and 24 h following a fat-exclusion lunch, snack and dinner. SUBJECTS: A total of 18 lean, healthy men. RESULTS: There was no significant effect of the fatty meal (time, P > 0.05), nor a differential effect of SFA:USFA ratio (treatment*time, P > 0.05) on ghrelin over 6h. Leptin decreased in response to both HF treatments (time, P < 0.001) but increased SFA content did not further inhibit hormone secretion (treatment*time, P > 0.05). There was no significant correlation between ghrelin or leptin and circulating insulin (P>0.05). CONCLUSION: We conclude that HF diets may adversely effect serum leptin, although the circadian decrease may account in part for this response. Increasing dietary SFAs had no deleterious effects on leptin or total ghrelin.

Effect of moderate changes in dietary fatty acid profile on postprandial lipaemia, haemostatic and related CVD risk factors in healthy men.

OBJECTIVE: To investigate the effect of moderate changes in dietary fatty acid profile on postprandial risk factors for cardiovascular disease (CVD). DESIGN: Double-blind, randomised, crossover, intervention trial. SETTING: : University of Auckland Human Nutrition Unit, New Zealand. SUBJECTS: A total of 18 lean healthy men. INTERVENTION: A dairy butter fat modified to reduce the saturated:unsaturated fatty acid ratio and a conventional high saturated butter fat were given on two separate occasions as a high-fat test meal (59+/-4 g fat; 71 en% fat) at breakfast. A fat exclusion lunch, dinner and snacks were also given. Blood samples were collected at 0 (baseline), 1, 3, 6, 10 and 24 h. RESULTS: Maximum peak in total triacylglycerol (TAG) occurred 3 h postprandially and was highest on modified treatment (diet, P<0.05) due predominantly to increased TAG within the chylomicron-rich fraction. Transient peaks in total-, LDL- and HDL-cholesterol occurred postprandially, but did not differ between dietary treatments (P>0.05). There were no differential effects of diet on postprandial free fatty acids, apo A, apo B, glucose, insulin, amylin or haemostatic clotting factors (P>0.05). CONCLUSIONS: In a group of healthy young men, replacement of 16% of total saturated fatty acids by mono- and polyunsaturated fats within a dairy lipid did not induce postprandial changes in CVD risk that may be considered beneficial for health. SPONSORSHIP: Fonterra, Wellington; New Zealand.

Pressure in the cuffs of tracheal tubes at altitude.

Pressures in the cuffs of three commonly used tracheal tubes (Portex Profile Softseal, Mallinckrodt Lo-Contour and Mallinckrodt Hi-Contour, size 8.0 mm and 9.0 mm internal diameter), inflated with air, were measured during simulated ascents in an altitude chamber to 10 000 ft. There was no detectable difference in performance between sizes for each type of tracheal tube. When averaged over the two sizes for each type of tube, cuff pressure reached the critical perfusion pressure 50 cmH2O (37 mmHg) for tracheal mucosa at a higher altitude in the Portex Profile Softseal (2837 ft, 95% CI 2488-3186 ft) than in the Mallinckrodt Lo-Contour (2128 ft, 95% CI 1779-2476 ft; p = 0.02) and Mallinckrodt Hi-Contour (1820 ft; 95% CI 1471-2168 ft; p = 0.002) tracheal tubes. When the cuffs of the 9.0-mm tracheal tubes were inflated with saline, much smaller increases in pressure were measured with increasing altitude, although inflation of the cuffs with saline was technically difficult. Commonly used tracheal tubes with air-inflated cuffs can be used for aeromedical retrieval, but air should be evacuated from the cuffs after increases in altitude of as little as 2000-3000 ft.

Lipid-lowering effects of a modified butter-fat: a controlled intervention trial in healthy men.

OBJECTIVE: To investigate the lipid-lowering potential of a butter-fat modified through manipulations in bovine feeding to increase the unsaturated:saturated fatty acid ratio. DESIGN: Double-blind, randomised, cross-over intervention trial. SETTING: University of Auckland Human Nutrition Unit, New Zealand. SUBJECTS: Twenty healthy, male subjects. INTERVENTION: A residential trial in which all foods and beverages were provided during two intervention periods, comprising 3 weeks of high unsaturated 'modified' vs. 3 weeks of saturated 'control' butter feeding separated by a 4 week washout. Diets were of typical composition of 39 percentage energy (en%) fat (20 en% butter-fat), 48 en% CHO, 13 en% protein. RESULTS: There was a significant decrease in both total (P<0.05, -7.9%) and LDL-cholesterol (P<0.01, -9.5%) during modified butter feeding. There was no significant effect of treatment on a range of other risk factors including HDL-cholesterol, triglyceride, apolipoprotein A or B, nonesterified fatty acids (NEFA), haemostatic clotting factor VII and fibrinogen or glucose (P>0.05). Subjects were maintained in energy balance and there was no significant change in body weight during intervention. Butter-fat composition alone differed between treatments. CONCLUSIONS: A significant improvement in cardiovascular risk can be achieved by moderate changes in dietary fatty acid profile, achieved through a common and well accepted food source, butter-fat.

An alternative method for restoring single-tooth implants.

BACKGROUND: Having laboratory technicians prepare soft-tissue casts and implant abutments with or without concomitant removable temporary prostheses during the restorative phase of single-tooth replacement is an accepted practice. It can, however, result in functional and esthetic intraoral discrepancies. CASE DESCRIPTION: Single-tooth implants can be restored with crowns (like those for natural teeth) fabricated at a dental laboratory on casts obtained from final impressions of prepared implant abutments. In the case reported, the restorative dentist restored the patient's single-tooth implant after taking a transfer impression. He constructed a cast simulating the peri-implant soft tissue with final impression material and prepared the abutment on this model. His dental assistant then fabricated a fixed provisional restoration on the prepared abutment. At the patient's next visit, the dentist torqued the prepared abutment onto the implant, took a final impression and inserted the provisional restoration. A crown was made conventionally at the dental laboratory and cemented in place at the following visit. CLINICAL IMPLICATIONS: This alternative method for restoring single-tooth implants enhances esthetics by more accurately simulating marginal gingival architecture. It also improves function by preloading the implant through fixed temporization after the dentist, rather than the laboratory technician, prepares the abutment to the dentist's preferred contours.

Analogs of guanine nucleoside triphosphates for sequencing applications.

We have synthesized more than 30 different deoxyribonucleosides and triphosphates with modifications either in the base or the phosphate moiety as analogs of 2'-dGTP for DNA sequencing applications. All the modified nucleoside triphosphates were tested as substrates for DNA polymerases, including Sequenase T7 DNA polymerase or Thermo Sequenase DNA polymerase. Two of the analogs, 7-ethyl-7-deaza-dGTP and 7-hydroxymethyl-7-deaza-dGTP meet our requirements as better sequencing reagents.

Ubiquitin-specific proteases from Arabidopsis thaliana: cloning of AtUBP5 and analysis of substrate specificity of AtUBP3, AtUBP4, and AtUBP5 using Escherichia coli in vivo and in vitro assays.

A cDNA for a new ubiquitin-specific protease (UBP), AtUBP5, was identified from Arabidopsis thaliana flower mRNA using an oligonucleotide made against the conserved UBP cysteine (Cys) box. The 924-amino-acid AtUBP5 contains the regions characteristic of all UBPs and has 35% identity and 53% similarity overall to a mammalian UBP (Unp), resulting from additional significant similarity outside these regions. AtUBP5 has 48% identity and 58% similarity overall to two uncharacterized Arabidopsis genomic sequences but is distinct outside the UBP conserved regions from two other previously published Arabidopsis UBPs, AtUBP3 and -4. Using in vivo Escherichia coli assays, which allow co-expression of GSTAtUBPs and substrates, we show that all three UBPs were active. AtUBP5 was active without 311 amino acids N-terminal to the active site cysteine, or without 233 nonconserved amino acids between the Cys and His boxes, or without both, indicating the core region was sufficient. In in vivo and in vitro assays, GSTAtUBP3, -4, and -5 exhibited preference for specific Ub-Ub linkages, suggesting accessibility and/or conformation is important and demonstrating that these enzymes cleave post-translationally. A chimeric UBP consisting of the AtUBP5 Cys box with AtUBP3 amino acids was active and exhibited AtUBP3 specificity, indicating that the modular nature of UBPs and specificity for cleavage sites is not determined by the Cys box.

Uniform band intensities in fluorescent dye terminator sequencing.

The use of Cyanine dye (Cy5 and Cy5.5) labeled dideoxy terminators with Thermo Sequenase DNA polymerase in DNA sequencing provides uniform band intensity, improved sequence read-length, and accuracy. It also greatly improves the ability to detect single base heterozygotes with dye-terminator sequencing method.