Gelatinisation of starch in mixtures of sugars. II. Application of differential scanning calorimetry

Differential scanning calorimetry was used to investigate the effect of mixtures of glucose and fructose, and five types of honeys on starch gelatinisation. At a 1:1 starch:water ratio, glucose generally increased the enthalpy (DeltaH(gel)) and temperatures (T-onset, T-peak and T-end) of gelatinisation more than fructose. Upon mixing, DeltaH(gel) of the low-temperature endotherm decreased in comparison to the sole sugars, but was fairly constant (7.7 +/- 0.33 J/g dry starch). DeltaH(gel) of the high-temperature endotherm increased with the fructose content. For both endotherms, the gelatinisation temperatures were unchanged (CV less than or equal to 3%) for the mixtures. With the honeys (moisture, 14.9-18.0%; fructose, 37.2-44.0%; glucose, 28.3-31.9%) added at 1.1-4.4 g per g dry starch, the enthalpy and temperatures of gelatinisation did not vary significantly (CV less than or equal to 6%). Typical thermograms are presented, and the results are interpreted in the light of the various proposed mechanisms for starch gelatinisation in sugar-water systems, total sugar content and possible sugar-sugar interactions. The thermograms were broader in the presence of the sugars and honeys, and a biphasic character was consistently exhibited. The application of an exponential equation to the gelatinisation temperatures of the starch-honey mixtures revealed an opposing influence of fructose and glucose during gelatinisation. The mechanism of starch gelatinisation may be better understood if techniques could be perfected to quantify breakage and formation of hydrogen bonds in the starch granules, and suggested techniques are discussed. (C) 2004 Elsevier Ltd. All rights reserved.

Glucocorticoid receptor polymorphisms and post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is reported in some studies to be associated with increased glucocorticoid (GC) sensitivity. Two common glucocorticoid receptor (GR) potymorphisms (N363S and 8cll) appear to contribute to the population variance in GC sensitivity. There is some evidence that there may be a genetic predisposition to PTSD. Hence we studied 118 Vietnam war veterans with PTSD for (i) GR polymorphisms, particularly the N363S and the Bcll polymorphisms which are thought to be GC sensitising, and (ii) two measures of GC sensitivity, the tow-dose 0.25 mg dexamethasone suppression test (LD-DST) and the dermal vasoconstrictor assay (DVVA). The DST and GR polymorphisms were also performed in 42 combat exposed Vietnam war veterans without PTSD. Basal plasma cortisol levels were not significantly different in PTSD (399.5 +/- 19.2 nmol/L, N=75) and controls (348.6 +/- 23.0 nmol/L, N = 33) and the LD-DST resulted in similar cortisol suppression in both groups (45.6 +/- 3.2 vs. 40.8 +/- 4.1%). The cortisol suppression in PTSD patients does not correlate with Clinician Administered PTSD Scores (CAPS), however there was a significant association between the Bcll GG genotype and low basal cortisol levels in PTSD (P=0.048). The response to the DVVA was similar to controls (945 +/- 122, N = 106 vs. 730 +/- 236, N = 28, P = 0.42). PTSD patients with the GG genotype, however, tended to be more responsive to DVVA and in this group the DVVA correlated with higher CAPS scores. The only exon 2 GR polymorphisms detected were the R23K and N363S. Heterozygosity for the N363S variant in PTSD, at 5.1% was not more prevalent than in other population studies of the N363S polymorphism in Caucasians (6.0-14.8%). The GG genotype of the Bcll polymorphism found to be associated with increased GC sensitivity in many studies showed a tendency towards increased response with DVVA and correlated with higher CAPS scores. In conclusion, the N363S and Bcll GR polymorphisms were not more frequent in PTSD patients than controls and reported population frequencies. Our PTSD group did not display GC hypersensitivity, as measured by the LD-DST and DVVA. In a subset of PTSD patients with the Bcll GG genotype, CAPS scores and basal cortisol Levels were negatively correlated. (C) 2004 Elsevier Ltd. All rights reserved.

Australian and New Zealand practice in intensive care (ANZPIC II: The spectrum of practice in the diagnosis and management of pneumonia in patients requiring mechanical ventilation

This study of ventilated patients investigated current clinical practice in 476 episodes of pneumonia (48% community-acquired pneumonia, 24% hospital-acquired pneumonia, 28% ventilator-associated pneumonia) using a prospective survey in 14 intensive care units (ICUs) within Australia and New Zealand. Diagnostic methods and confidence, disease severity, microbiology and antibiotic use were assessed. All pneumonia types had similar mortality (community-acquired pneumonia 33%, hospital-acquired pneumonia 37% and ventilator-associated pneumonia 24%, P = 0.15) with no inter-hospital differences (P = 0.08-0.91). Bronchoscopy was performed in 26%, its use predicted by admission hospital (one tertiary: OR 9.98, CI 95% 5.11-19.49, P < 0.001; one regional: OR 629, CI 95% 3.24-12.20, P < 0.001), clinical signs of consolidation (OR 3.72, CI 95% 2.09-662, P < 0.001) and diagnostic confidence (OR 2.19, CI 95% 1.29-3.72, P = 0.004). Bronchoscopy did not predict outcome (P = 0.11) or appropriate antibiotic selection (P = 0.69). Inappropriate antibiotic prescription was similar for all pneumonia types (11-13%, P = 0.12) and hospitals (0-16%, P = 0.25). Blood cultures were taken in 51% of cases. For community-acquired pneumonia, 70% received a third generation cephalosporin and 65% a macrolide. Third generation cephalosporins were less frequently used for mild infections (OR 0.38, CI 95% 0.16-0.90, P = 0.03), hospital-acquired pneumonia (OR 0.40, CI 95% 0.23-0.72, P < 0.01), ventilator-associated pneumonia (OR 0.04, CI 95% 0.02-0.13, P < 0.001), suspected aspiration (OR 0.20, CI 95% 0.04-0.92, P = 0.04), in one regional (OR 0.26, CI 95% 0.07-0.97, P = 0.05) and one tertiary hospital (OR 0.14, CI 95% 0.03-0.73, P = 0.02) but were more commonly used in older patients (OR 1.02, CI 95% 1.01-1.03, P = 0.01). There is practice variability in bronchoscopy and antibiotic use for pneumonia in Australian and New Zealand ICUs without significant impact on patient outcome, as the prevalence of inappropriate antibiotic prescription is low. There are opportunities for improving microbiological diagnostic work-up for isolation of aetiological pathogens.