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Sorghum [Sorghum bicolor (L.) Moench] lines N619 to N636 (A lines; Reg. No. GS-699 to GS-716, PI 670134 to PI 670151); N619 to N636 (B lines; Reg. No. GS-721 to GS-738, PI 671777 to PI 671794); and N637 to N640 (R lines; Reg. No. GS-717 to GS-720, PI 670152 to PI 670155) comprise nine pairs of seed parent (A/B) lines, and two pairs of pollinator (R) lines (11 pairs total) that are near-isogenic for waxy (low-amylose) or wildtype endosperm. Breeding work was conducted jointly by the USDA–ARS and the Agricultural Research Division, Institute of Agriculture and Natural Resources, University of Nebraska, and the lines were released in May 2014. Release of these lines makes available two different waxy (wx) alleles (wxa and wxb) for development of grain sorghum as a source of lowamylose starch, whose end use is targeted to the ethanol and food industries. In particular, the release of wx and wild-type near-isogenic pairs facilitates the evaluation of agronomic performance of wx genotypes, and the release of both A/B and R lines facilitates the production of waxy grain hybrids.

Four near-isogenic Wheatland x Tx430 grain sorghum [Sorghum bicolor (L.) Moench] hybrids differing in allelic status at the Waxy locus were grown in yield trials to determine their potential to expand existing sources of low-amylose starch. The hypothesis tested was that agronomic performance and grain yield do not differ among hybrid genotypes. Hybrids were generated in a two-by-two factorial design using wxb and wild-type (WT) Wheatland as female parents with wxa and WT Tx430 as male parents. Yield trials were conducted at two Nebraska locations in 2009 and 2010. No differences were observed for field emergence, but grain yield of the interallelic waxy (wxb x wxa) hybrid was 330 kg ha−1 greater than the WT x WT hybrid (P = 0.0482). The wxb x Wx hybrid had the highest grain yield, 633 kg ha−1 greater than the WT (P = 0.0003). Amylose starch content was lowest for wxb x wxa (7.66 g kg−1), intermediate for wxb x Wx and Wx x wxa (25.06 and 27.20 g kg−1, respectively); and highest for WT x WT (34.80 g kg−1) (n = 4, P < 0.0001). The waxy and heterowaxy hybrids evaluated in this study are promising options for commercial production of starches with reduced amylose contents in a drought-tolerant crop.

Loss-of-function mutations in the granule-bound starch synthase gene result in an endosperm with a waxy appearance and a near absence of starch amylose. Three waxy grain sorghum [Sorghum bicolor (L.) Moench] lines, AN641 (Reg. No. GS-741, PI 672150), BN641 (Reg. No. GS-742, PI 672151), and RN642 (Reg. No. GS-743, PI 672152) were developed jointly by the USDA–ARS and the Agricultural Research Division, Institute of Agriculture and Natural Resources, University of Nebraska, and were released in June 2014. AN641 and BN641 have the waxyb (wxb) allele and are near-isogenic to ‘Wheatland’. RN642 has the waxya (wxa) allele and is nearisogenic to ‘Tx430’. Release of these lines with cytoplasmic male-sterile (A), maintainer (B), and fertility restorer (R) fertility reactions to A1 cytoplasm facilitates the production and evaluation of interallelic (wxb × wxa) waxy and heterowaxy [wxb × wild-type (WT) and WT × wxa] hybrids as a source of low-amylose starch for the ethanol and food industries.

Lignin content of crop plants has been reduced by traditional plant breeding, natural and induced mutations, and insertion of transgenes. The effects of these genes and associated lower lignin content have been examined in terms of agricultural fitness or with regard to economically harvestable yields of useful plant products, or, in the case of some perennial species, survivability over multiple years. In general, crop yields are depressed by significant reductions in lignin content. Other negative effects observed in plants with lowered lignin contents include lodging and reduction of long-term survival of some perennial species. However, the interactions of genes involved in lignin metabolism with genetic background and the environment in which the low-lignin crop is cultivated are substantial. Examples are provided that demonstrate that lignin can be reduced in specific lines or populations without damaging fitness. It is concluded that it will be essential to incorporate lignin reducing genes into numerous genetic background and combinations, and evaluate the resulting lines in diverse environments, to discover optimal combinations and to obtain a true measure of value and fitness in agricultural systems.

BACKGROUND: GLP-1 (glucagon-like peptide-1) and GLP-2 (glucagon-like peptide-2) are released in equimolar amounts in response to meal ingestion. GLP-1 inhibits gastric emptying and reduces postprandial gastric and exocrine pancreatic secretion and may play a physiological regulatory role in controlling appetite and energy intake in humans. The role of GLP-2 is more uncertain. Based on the results of animal studies, it has been suggested that GLP-2 may induce intestinal epithelial growth and inhibit gastric motility. The aim of this study was to determine to what extent GLP-2 alone or together with GLP-1 inhibits gastric emptying and the sensation of hunger in man.METHODS: Eight healthy volunteers were tested in a double-blind, placebo-controlled fashion. Antral emptying of a liquid meal and hunger ratings were determined using ultrasound technology and visual analogue scales scoring during infusions of saline, GLP-2 (0.5, and 1.0 pmol kg body wt(-1) min(-1)), GLP-1 (0.5 pmol kg body wt(-1) min(-1)) or GLP-1 and GLP-2 (0.5 pmol kg body wt(-1) min(-1)).RESULTS: The GLP-2 infusions resulted in a dose-dependent increase in antral emptying time (35%; ns and 75%; P = 0.049) compared to saline, but GLP-2 was less potent than GLP-1, which increased the antral emptying time by 192% (P < 0.001). Addition of GLP-2 to the GLP-1 infusion did not alter the antral emptying time compared with GLP-1 alone. The GLP-1 infusion decreased the sensation of hunger compared with saline (P = 0.023), whereas the two GLP-2 infusions had no significant effect. Addition of GLP-2 to the GLP-1 infusion did not decrease the sensation of hunger further.CONCLUSIONS: Both GLP-1 and GLP-2 inhibit antral emptying in man, but GLP-1 is more potent.

Udgivelsesdato: 2003-Mar, Increased muscle tenderness is the most prominent finding in patients with tension-type headache, and it has recently been shown that muscle blood flow is diminished in response to static exercise in tender points in these patients. Although tenderness has been ascribed to local inflammation and release of inflammatory mediators, the interstitial concentration of inflammatory mediators has not previously been studied in tender muscles of patients with tension-type headache. The aim of the present study was to investigate in vivo concentrations of prostaglandin E2 (PGE2), adenosine 5'-triphosphate (ATP), glutamate, bradykinin and other metabolites in a tender point of patients with chronic tension-type headache, in the resting state as well as in response to static exercise, and to compare findings with measurements in a matched non-tender point of healthy controls. We recruited 16 patients with chronic tension-type headache and 17 healthy control subjects. Two microdialysis catheters were inserted into the trapezius muscle and dialysates were collected at rest, 15 and 30 min after start of static exercise (10% of maximal force) and 15 and 30 min after end of exercise. All samples were coded and analysed blindly. There was no difference in resting concentration of any inflammatory mediators or metabolites between tender patients and non-tender controls (P > 0.05). We also found no difference in change in interstitial concentration of ATP, PGE2, glutamate, glucose, pyruvate and urea from baseline to exercise and post-exercise periods between patients and controls (P > 0.05). The present study provides in vivo evidence of normal interstitial levels of inflammatory mediators and metabolites in tender trapezius muscle in patients with chronic tension-type headache during both rest and static exercise. Thus, our data suggest that tender points in these patients are not sites of ongoing inflammation.

The aim of this study was to ascertain whether a new ultrasound technique, namely pulse inversion imaging, could assess the arrival of a contrast agent in the hepatic veins, and to describe possible advantages of this procedure in determining transit time over a previously described method based upon spectral Doppler quantification. 15 subjects were scanned using pulse inversion imaging. A bolus injection of 2.5 g Levovist (Schering AG, Berlin, Germany) 300 mg ml-1 was given into an antecubital vein. Median transit times of 16 s (range 14-20 s) were found in patients with liver cirrhosis (n=4), 22 s (range 16-27 s) in patients with focal liver lesions (n=8) and 31 s (range 30-32 s) in control subjects (n=3). The maximum interobserver variation was 2 s and the maximum intraobserver variation was 3 s (n=10). Transit time was assessed by both pulse inversion imaging and spectral Doppler quantification in six patients. Comparison of the two methods showed transit times within 2 s apart in five patients and within 5 s apart in one patient. In conclusion, it is possible to assess transit time using pulse inversion imaging. This method is simpler than a previously described method requiring computer analysis. Moreover, several liver veins can be assessed simultaneously. Different transit times were observed in different liver veins in two patients with liver tumours. A short transit time (<27 s) appears to be found only in patients with liver disease. After transit time assessment, it is possible to use the injected contrast agent for late phase imaging of the liver parenchyma.