Performance comparison of Yb:YAG ceramics and crystal gain material in a large-area, high-energy, high average-power diode-pumped laser.

We compare for the first time the influence of different Yb:YAG gain media on the performance of a large-area, high average-power laser system with an output energy of up to 6 J. Monocrystalline slabs grown by a new technique without central growth defect are compared with ceramics. Small signal gain, maximum output energy and thermal lensing are compared for ceramic slabs with co-sintered amplified spontaneous emission (ASE) absorber cladding, monocrystalline slab with and without optically bonded ASE absorber cladding, and surface structured monocrystalline slabs. We show that these large monocrystals with optically bonded absorber cladding have similar performance to cladded ceramics, so far the only material for high-energy Yb:YAG lasers.

An observational study of cognitive function in patients with irritable bowel syndrome and inflammatory bowel disease.

BACKGROUND: Irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) are associated with several risk factors for developing cognitive impairment. These include altered cytokine levels, concurrent mood disorders, and the presence of chronic pain. This observational study aimed to explore the cognitive profile of patients with these conditions. METHODS: Participants completed the Cardiff Cognitive Battery, a series of computerized neuropsychological performance tests that examine a range of cognitive function including psychomotor speed, memory, and intelligence. A progressive analysis of covariance model was used with demographic details, anxiety and depression scores entered as covariates. Fecal calprotectin levels were measured in IBD patients to determine disease activity. KEY RESULTS: In total 231 participants were recruited (150 IBD patients, 40 IBS patients, and 41 healthy controls). IBD patients had significantly lower scores on fluid (p = 0.01) and crystalline intelligence tests (p = 0.028) compared to healthy volunteers, however, this reflected differences in concurrent mood disorder and level of education. When these factors were added as covariates, there was no significant difference between the groups. Duration and activity of disease did not affect cognitive function in IBD patients. Severity of symptoms had no impact on cognition in patients with IBS. CONCLUSIONS & INFERENCES: The results of this observational study do not support the hypothesis that IBS or IBD have an intrinsic disease process that is associated with cognitive dysfunction. It is possible that concurrent mood disorders, in particular depression, may affect the cognitive performance of patients with IBD in specific tasks.

Symptoms of irritable bowel syndrome in patients with inflammatory bowel disease: examining the role of sub-clinical inflammation and the impact on clinical assessment of disease activity.

BACKGROUND: Symptoms compatible with irritable bowel syndrome (IBS) are frequently present in patients with inflammatory bowel disease (IBD); however, the cause of this phenomenon is unclear. AIM: To determine the different contributions of 'true IBS' and sub-clinical inflammation in producing IBS-type symptoms in IBD patients, and to ascertain the impact these symptoms have on the clinical assessment of IBD activity. METHODS: In this cross-sectional study, 169 IBD patients completed questionnaires to assess disease activity, presence of IBS-type symptoms, and levels of anxiety and depression. Stool samples were collected for analysis of faecal calprotectin (FC). RESULTS: IBS-type symptoms were significantly more common in female patients (OR = 4.64, 1.55-13.88) and were associated with higher levels of anxiety (OR = 1.11, 1.01-1.21). There was no statistical difference between the FC levels of patients in clinical remission with IBS-type symptoms compared with those without (median values = 111 µg/g vs. 45.5 µg/g respectively, P = 0.171). The prevalence of IBS-type symptoms in patients with a normal FC level was 31%. CONCLUSIONS: A substantial number of IBD patients with normal faecal calprotectin level experience IBS-type symptoms. These patients exhibit similar features to people diagnosed with IBS in the general community, suggesting that the conditions are not mutually exclusive and may coexist in a considerable number of IBD patients. A systematic diagnostic approach is required to assess IBD patients with IBS-type symptoms as sub-clinical inflammation may play a role in a proportion of cases.

Effects of feeding strategy on milk production, reproduction, pasture utilization, and economics of autumn-calving dairy cows in eastern North Carolina.

A balance among stocking rate (SR), pasture management, and supplementary feeding is required to optimize overall farm performance and profitability in pasture-based dairying. Beginning in September 2003, a seasonal, autumn-calving, pasture-based farming system was established to address the effects of feeding strategy (FS; i.e., a unique combination of stocking and supplementation rate) on productive, reproductive, and economic performance of lactating herds over 3 yr. Eighty lactating cows (1/3 Holsteins, 1/3 Jerseys, and 1/3 crosses of those breeds) were randomly assigned to either a lesser stocking, lesser supplementation group [LSR; 2.2 cows/ha, 6.3 kg of dry matter (DM) of a corn-based concentrate consumed daily, n=40] or a greater stocking, greater supplementation group (HSR; 3.3 cows/ha, 9.2 kg of DM of a corn-based concentrate consumed daily, n=40). Pasture/forage crop rotations included annual ryegrass and sorghum-Sudan (50%), annual ryegrass and bermudagrass (20%), and a tall fescue-white clover pasture (30%). Pre- and postgrazing herbage mass values and grazing intervals (3,347±255.8 kg of DM/ha, 1,861±160.6 kg of DM/ha, 23.6±1.9 d) did not differ between FS. The nutritive value of fresh and conserved forages was similar between feeding strategies, except for acid detergent fiber in freshly grazed bermudagrass (29.6 vs. 26.3% of DM for LSR and HSR, respectively). Cows on HSR tended to spend more time on an adjacent feeding area where conserved forages were offered (85 vs. 61 d/yr) as opposed to grazing paddocks (204 vs. 228 d/yr). Lactation performance was greater for HSR; cows on HSR produced 10.8% more milk fat and 6.3% more milk protein than cows on LSR. Holstein cows produced the greatest amounts of mature-equivalent milk, but did not differ from crossbred cows in terms of energy-corrected milk, and mature-equivalent fat and protein yields. Reproductive efficiency did not differ among feeding strategy, but breed differences were observed; conception rates at first and all services, as well as pregnancy rates, were greater for Jersey and crossbred cows compared with Holsteins. The greater stocking rate required additional supplemental concentrate and time away from grazing paddocks, but reproductive efficiency was similar and overall lactation performance was greater. The greater stocking rate resulted in increased productivity and greater income over feed costs per unit of land.

Association of lactose sensitivity with inflammatory bowel disease--demonstrated by analysis of genetic polymorphism, breath gases and symptoms.

BACKGROUND: Sensitivity to lactose has been reported in Crohn's disease, but its true role in inflammatory bowel disease (IBD) is unclear. The genetic marker CC13910, on chromosome2, with measurement of breath hydrogen and methane, and gut and systemic symptoms, are now the most comprehensive tests for evaluating sensitivity to lactose. AIM: To investigate, for the first time, the prevalence of lactose sensitivity in IBD, using the most comprehensive tests for diagnosing this condition. METHODS: Prevalence of CC13910 genotype was investigated using RT-PCR in 165 patients (Crohn's disease = 70, ulcerative colitis = 95), and 30 healthy volunteers. Genotype was correlated with breath hydrogen and methane up to 6 h after 50 g of oral lactose, all symptoms being recorded for up to 48 h. Critically, Crohn's disease and ulcerative colitis patients were selected with no record of lactose sensitivity, in remission at the time of the test. RESULTS: Lactose sensitivity occurred in a much higher proportion of patients, (approximately 70%), with IBD than previously thought. Seventeen per cent had raised methane, without raised breath hydrogen; those with ulcerative colitis exhibiting most symptoms. All CC patients were lactose sensitive. There was no correlation between genetic phenotype and IBD. As substantial numbers of IBD patients were CT or TT, and were lactose sensitive, this polymorphism cannot explain full down-regulation of the lactase gene. CONCLUSIONS: Our results have implications for the clinical management of IBD. The high breath methane raised the possibility of a pathogenic role for methanogenic archaebacteria (Archaea) in IBD. This needs to be investigated.

Continuous-wave, multiple-order rotational Raman generation in molecular deuterium.

We demonstrate the generation of ≈10 rotational sidebands using continuous-wave stimulated Raman scattering in molecular deuterium. The generation occurs inside a high-finesse cavity at molecular gas pressures of ≈0.1 atm.

Continuous-wave high-power rotational Raman generation in molecular deuterium.

We report the generation of more than 300 mW of rotational Stokes output power in a CW Raman laser. The generation is achieved in low-pressure molecular deuterium inside a high-finesse cavity.

Performance of growing cattle grazing stockpiled Jesup tall fescue with varying endophyte status.

The objective of this study was to evaluate the performance of growing cattle when intensively grazing stockpiled endophyte-infected (E+), endophyte-free (E-), and nontoxic endophyte-infected (EN) tall fescue during the winter. The experiment was conducted over 5 consecutive winters. In each year, plots (1 ha each, 4 per treatment) were harvested for hay in August, fertilized in September, and forage was allowed to accumulate until grazing was initiated in early December. Each year, 48 Angus-cross tester cattle (4 per plot) were given a daily allotment of forage, under strip-grazing (frontal grazing) management, with a target residual height of 5 cm. Steers were used the first year, and heifers were used in subsequent years. The grazing periods for determination of pasture ADG were 86 d (yr 1), 70 d (yr 2), 86 d (yr 3), 72 d (yr 4), and 56 d (yr 5). Pasture ADG of cattle did not differ among treatments (P = 0.13) and were 0.51, 0.59, and 0.56 kg/d (SEM 0.03) for E+, E-, and EN, respectively. Serum prolactin concentrations of heifers grazing E+ were less (P < 0.05) than those grazing E- and EN during all years except yr 2. In yr 2, E+ and E- did not differ (P = 0.11). Serum prolactin of heifers grazing E- and EN did not differ (P > 0.20) except in yr 4. During yr 4, serum prolactin of heifers grazing E- was greater (P = 0.05) than that of heifers grazing EN. Serum urea-N concentrations (SUN) tended to differ among treatments (P = 0.10) and there was a treatment x year interaction (P = 0.05). During yr 1 through 3, SUN did not differ (P > 0.15) among treatments. However, as the stands aged, E- had a greater invasion of other plant species, which increased the CP content of the sward, thus causing heifers grazing E- during yr 5 to have greater (P < 0.01) SUN than heifers grazing E+ and EN, which did not differ (P = 0.89). Forage disappearance (DM basis) did not differ (P = 0.75) among treatments and was 4.7, 4.7, and 5.0 kg/animal daily (SEM 0.27) for E+, E-, and EN, respectively. Body weight gain per hectare was greater (P = 0.04) for E+ (257 kg) than for E- (220 kg) or EN (228 kg). In most years, animal grazing days on E+ were greater than those on E- or EN. However, in yr 5, animal grazing days did not differ (P > 0.20) among treatments. The use of stockpiled E+ as a source of low-cost winter feed is a viable option for producers, whereas grazing of EN may be more beneficial during the spring and fall, when more severe negative effects of ergot alkaloids have been observed.

Quantifying the 'hidden' lactose in drugs used for the treatment of gastrointestinal conditions.

BACKGROUND: Lactose intolerance affects 70% of the world population and may result in abdominal and systemic symptoms. Treatment focuses predominantly on the dietary restriction of food products containing lactose. Lactose is the most common form of excipient used in drug formulations and may be overlooked when advising these patients. AIM: To identify and quantify the amount of lactose in medications used for the treatment of gastrointestinal disorders and to identify 'lactose-free' preparations. METHODS: Medications used for the treatment of gastrointestinal disorders were identified from the British National Formulary (BNF). Their formulation including excipients was obtained from the Medicines Compendium. The lactose content and quantity in selected medications was measured using high-performance liquid chromatography (HPLC). RESULTS: A wide range of medications prescribed for the treatment of gastrointestinal conditions contain lactose. We have quantified the lactose content in a selection of medications using HPLC. Lactose is present in amounts that may contribute towards symptoms. Lactose-free alternatives were also identified. CONCLUSIONS: Lactose is present in a range of medications and may contribute towards symptoms. This may not be recognized by the prescribing doctor as excipients are not listed in the BNF, and the quantity of lactose is not listed on the label or in the accompanying manufacturer's leaflet.

Refractive index enhancement with vanishing absorption in an atomic vapor.

We report a proof-of-principle experiment where the refractive index of an atomic vapor is enhanced while maintaining vanishing absorption of the beam. The key idea is to drive alkali atoms in a vapor with appropriate control lasers and induce a gain resonance and an absorption resonance for a probe beam in a two-photon Raman configuration. The strength and the position of these two resonances can be manipulated by changing the parameters of the control lasers. By using the interference between these two resonances, we obtain an enhanced refractive index without an increase in the absorption.

Performance of beef heifers grazing stockpiled fescue as influenced by supplemental whole cottonseed.

The objectives of this study were to determine the composition of stockpiled fescue from December through February over 2 yr and to determine the performance of heifers grazing stockpiled fescue with or without supplemental whole cottonseed. In early December, 36 heifers (initial BW 277 +/- 0.70 kg, yr 1; 266 +/- 2.2 kg, yr 2; and initial BCS of 5.0 +/- 0.04) were assigned randomly to 6 groups. Each group was assigned randomly to a 2.4-ha tall fescue pasture (98% endophyte infected), which had received 76 kg of N/ha on September 1. Group was the experimental unit for all measures. Forage DM available during grazing (to ground level) averaged 3,913 and 5,370 kg/ha in yr 1 and 2, respectively. The pasture was strip-grazed for 83 d, with daily forage allocation. Three groups were fed whole cottonseed (0.90 kg of DM/heifer; 24.4% CP, DM basis) daily at 0.33% of BW, and a small amount of a corn-based concentrate (0.19 kg of DM/heifer) to assure complete cottonseed consumption. Nutritive value of forage (dry basis) was determined each week by sampling each pasture to the 5-cm target grazing height. Forage disappearance was estimated every 2 wk from pre- and postgraze forage mass. Forage CP was 16.8% in yr 1 and 12.6% in yr 2. In vitro true organic matter digestibility (IVTOMD) was 82.0 and 71.9%, and ADF was 25.9 and 30.7% in yr 1 and 2, respectively. Most indicators of forage quality declined slightly through the winter, although they recovered in late winter in yr 1. The proportion of fescue that was green declined (P < 0.05) from December (79% in yr 1 and 64% in yr 2) to February (62% in yr 1 and 52% in yr 2). Green tissue averaged 20.4 and 15.2% CP, 91 and 87% IVTOMD, and 22.1 and 23.3% ADF in yr 1 and 2, respectively. Brown tissue averaged 10.3 and 8.5% CP, 64 and 62% IVTOMD, and 35.7 and 37.4% ADF in yr 1 and 2, respectively. Shrunk ADG (0.46 vs. 0.56 kg/d in yr 1 and 0.23 vs. 46 kg/d in yr 2) and change in BCS (- 0.03 vs. 0.33 in yr 1 and 0.13 vs. 0.5 in yr 2) was greater (P < 0.05) for supplemented heifers. Supplemented heifers had greater serum urea nitrogen in yr 1 (9.5 vs. 10.5 mg/dL; P < 0.07) and yr 2 (7.2 vs. 8.6 mg/dL; P < 0.01). Forage disappearance was similar between supplemented and unsupplemented heifers (3.19 vs. 3.39 kg.heifer(-1).d(-1) in yr 1 and 4.14 vs. 4.17 kg.heifer(-1).d(-1) in yr 2, respectively). Heifers responded to supplementation, but performance was lower than expected based on forage nutrient content.

Does endoscopy diagnose early gastrointestinal cancer in patients with uncomplicated dyspepsia?

BACKGROUND: Recent guidelines from NICE have proposed that open access gastroscopy is largely limited to patients with "alarm" symptoms. AIMS AND METHODS: This study reviewed the outcome of all our patients with verified oesophageal or gastric carcinoma who presented with uncomplicated dyspepsia to see if endoscopic investigation is warranted in this group. All patients with histologically verified upper gastrointestinal (GI) cancers who presented over a period from 1998 to 2002 were identified. Their presenting symptoms, treatment, and outcome were analysed. RESULTS: 228 upper GI cancers (119 oesophageal, 109 gastric; mean age 72 years (29-99 years); 130 male, 82 female) were identified in 11 145 endoscopies performed. Only 14 patients (6.2%) presented without alarm symptoms; three patients were under 55 years of age and all had gastric carcinoma-one of these had chronic diarrhoea only. Eleven had dyspepsia or reflux symptoms only, and two were under surveillance for Barrett's oesophagus. Only five patients had a curative surgical resection and are still alive two-six years from diagnosis. A sixth patient had a curative operation but died of a cerebrovascular accident one year later. The remaining eight patients unfortunately had either metastatic disease or comorbidity, which precluded surgery. All of these died within two years of diagnosis, mean survival 10 months. CONCLUSION: Only five patients with dyspepsia and no alarm symptoms had resectable upper GI malignancies over a four year period. Limiting open access gastroscopy to those with alarm features only would "miss" a small number of patients who have curable upper GI malignancy.

Intake, digestion, and N metabolism in steers fed endophyte-free, ergot alkaloid-producing endophyte-infected, or nonergot alkaloid-producing endophyte-infected fescue hay.

A digestion and N balance trial was conducted to compare effects of traditional endophyte-infected (E+), endophyte-free (E-), and nontoxic endophyte infected (NE; MaxQ; Pennington Seed, Inc., Madison, GA) Jesup tall fescue (Festuca arundinacea Schreb.) hay on digestion and N retention in steers. Hay composition (DM basis) was as follows: E+ (10.8% CP, 59.9% NDF, and 29.4% ADF), E- (11.8% CP, 58.5% NDF, and 28.4% ADF), and NE (11.6% CP, 58.6% NDF, and 28.3% ADF). Eight Polled Hereford steers (initial BW 240 +/- 9 kg) were used in a replicated, 3 x 3 Latin square design, with an extra steer allotted to each square. Steers were fed ad libitum for 14 d, followed by a 9-d adaptation to restricted intake (based on the animal with the lowest ad libitum intake for the square) and a 5-d fecal and urine collection. Water intake (20.2 L/d) and urine output (7.40 L/d) did not differ (P > 0.10) during the collection period. Plasma prolactin concentration was less (P < 0.05) for steers on the E+ hay (8.83 ng/mL) than for those on the E- hay (18.03 ng/mL) and intermediate for steers on the NE hay (12.65 ng/mL). Endophyte-infected hay differed (P < 0.05) from E- and NE in ad libitum DMI (5.02 vs. 5.62 and 5.61 kg/d, respectively) and ad libitum DMI as a percentage of BW (1.86 vs. 2.06 and 2.06%, respectively). Restricted DMI during the fecal and urine collection was lower (P < 0.05) for E+ hay than for E- (5.04 vs. 5.24 kg/d), and NE was intermediate (5.19 kg/d). Dry matter digestibility was lower (P < 0.05) for E+ compared with E- and NE (62.3 vs. 67.0 and 65.9%, respectively). Digestibility of ADF was lower (P < 0.05) for E+ than for E-, and was intermediate for NE (61.5, 66.0, and 63.9%, respectively). There were no differences for NDF, cellulose, or hemicellulose digestibilities among hay types. Crude protein digestibility was higher (P < 0.05) for E- and NE than for E+ (54.3 and 52.5 vs. 48.1%, respectively). Nitrogen retention was lower (P < 0.01) for E+ than for E- or NE (15.6 vs. 22.7 or 23.0 g/d, respectively). Hay type did not influence plasma urea N, urine urea N output, or urine urea N as a percentage of urinary N. Results from this study indicate that E+ tall fescue hay was lower in ad libitum DMI, DM digestibility, and N retention than NE or E- hays with similar chemical composition. Hay from NE and E- fescue had nearly identical composition, and did not differ for any variable measured.

Massive pleural effusion and marked increase of CA-125.

The tumour associated CA-125 antigen is widely used in monitoring ovarian carcinoma. In women with a massive pleural effusion and ascites, markedly increased CA-125 levels may lead to an erroneous diagnosis of ovarian cancer. Very high levels of tumour markers may be present in patients with benign pleural effusion, ascites, and chronic liver disease. Raised levels of tumour markers in serum or pleural fluid, in the absence of positive cytology, should be interpreted with caution.

Differential effect of nitric oxide synthase inhibition on sigmoid colon longitudinal and circular muscle responses to nicotine and nerve stimulation in vitro.

BACKGROUND: Nicotine has been shown to release nitric oxide from nerves in human sigmoid colon. This effect has been used to investigate the innervation and functional relationship of the longitudinal and circular muscle layers. METHODS: Strips of longitudinal and circular muscle were obtained from 19 patients with colorectal cancer. The strips from ten patients were subjected to electrical field stimulation (EFS) in vitro using stimulus parameters for selective stimulation of nerves. The effect of nicotine 1-10 micromol/l on EFS responses was then measured in the presence and absence of a nitric oxide synthase inhibitor, nitro-L-arginine methyl ester (L-NAME) 200 micromol/l. The effect of nicotine on spontaneous activity was investigated in the muscle strips from the other nine patients. RESULTS: Both longitudinal and circular strips responded to EFS with contraction. The time to achieve a peak contractile response (time to peak; TTP) was significantly longer (P<0.001) in circular strips. L-NAME reduced the mean(s.e.m.) TTP in circular muscle from 23.3(2.0) to 17.2(1.5) s (P=0.007) and altered its pattern of response to resemble that of longitudinal muscle. Nicotine 10 micromol/l reduced the contraction to EFS in circular (P<0.001) but not in longitudinal (P=0.347) muscle. The nicotine-induced reduction in circular muscle contraction was blocked by L-NAME 200 micromol/l (P=0.005). CONCLUSION: These findings suggest that nitric oxide release on neural stimulation is greater in circular than in longitudinal muscle.

Effect of smoking and transdermal nicotine on colonic nicotinic acetylcholine receptors in ulcerative colitis.

BACKGROUND: Ulcerative colitis (UC) is a disease largely of non-smokers, in which nicotine is of therapeutic value. The mode of action is unknown, but may involve nicotinic acetylcholine receptors (nAChRs) in the bowel wall. AIM: To investigate the presence of nAChRs in rectal mucosa, and the effect of smoking and nicotine on their expression. DESIGN: Prospective case-control study. METHODS: In situ hybridization (ISH) and immunocytochemistry (ICC) were used to show alpha3 nAChRs in colonic mucosa. Rectal mucosa was examined from controls (n=55) and patients with inactive UC (n=62), both smokers and non-smokers, by ICC, using two antibodies to show the density and distribution of receptors in the mucosa. Non-smokers with UC (n=43) were given transdermal nicotine or placebo patches for 6 months, and rectal biopsies, taken before and after treatment, were examined by ICC to show nAChRs. RESULTS: In normal colon, ISH and ICC showed alpha3 subunit in a wide variety of cells, including mucosal epithelium. In rectal biopsies, neither smoking nor nicotine influenced the expression of alpha3 immunoreactivity in epithelium, either in controls or UC. However, controls had a significantly greater density of immunodetectable mucosal epithelium alpha3 subunit, compared with UC patients. DISCUSSION: The presence of nAChRs in colonic epithelium may be pertinent to the beneficial effect of nicotine in UC, but since neither smoking nor nicotine treatment is associated with any change in the expression of epithelial alpha3 nAChRs, the effect may be due to functional changes in the receptor. The decreased number of alpha3 nAChRs in UC compared with controls may be related to an increased cell turnover in UC.

Reproduction, mastitis, and body condition of seasonally calved Holstein and Jersey cows in confinement or pasture systems.

Dairy cows in confinement and pasture-based feeding systems were compared across four spring-calving and three fall-calving replicates for differences in reproduction, mastitis, body weights, and body condition scores. Feeding systems and replicates included both Jersey and Holstein cows. Cows in confinement were fed a total mixed ration, and cows on pasture were supplemented with concentrates and provided baled hay or haylage when pasture supply was limiting. Breeding periods were for 75 d in spring or fall. Reproductive performance did not differ significantly due to feeding system or season. Jerseys had higher conception rates (59.6 vs. 49.5 +/- 3.3%) and higher percentages of cows pregnant in 75 d (78.1 vs. 57.9 +/- 3.9%) than Holsteins. Cows in confinement had 1.8 times more clinical mastitis and eight times the rate of culling for mastitis than did cows on pasture. Jerseys had half as many clinical cases of mastitis per cow as Holsteins. Only 41 +/- 5% of confinement Holsteins remained for a subsequent lactation, starting within the defined calving season compared with 51 +/- 5% of pastured Holsteins and 71 and 72 +/- 5% of Jerseys, respectively. Body weights and condition scores were generally higher for confinement cows than pastured cows, and Jerseys had higher condition scores and lower body weights than Holsteins. In summary, pastured cows had fewer clinical cases of mastitis, lower body condition scores, and lower body weights than confinement cows. Holsteins were less likely to rebreed, had more mastitis, higher culling rates, and lower body condition scores than Jerseys.

Milk production and economic measures in confinement or pasture systems using seasonally calved Holstein and Jersey cows.

This 4-yr study examined total lactation performance of dairy cows in two feeding systems: pasture-based and confinement. Spring and fall calving herds were used and each seasonal herd had 36 cows on pasture and 36 cows in confinement with 282 Holstein and 222 Jersey cows included over seven seasonal replicates. Pasture-fed cows received variable amounts of grain and baled haylage depending upon pasture availability. Confinement cows received a total mixed ration with corn silage as the primary forage. Data were collected on milk production, feed costs, and other costs. Pasture-fed cows produced 11.1% less milk than confinement cows. Across treatments, Jerseys produced 23.3% less milk than Holsteins, but calving season and various interactions were not significant. Feed costs averaged $0.95/cow per day lower for pastured cows than confinement cows. Feed costs were lower for Jerseys than Holsteins and for cows calving in spring. Income over feed costs averaged $7.05 +/- 0.34 for confinement Holsteins, $6.89 +/- 0.34 for pastured Holsteins, $5.68 +/- 0.34 for confinement Jerseys, and $5.36 +/- 0.34 for pastured Jerseys; effects of breed were significant but treatment, season, and interactions were not. Economic factors such as labor for animal care, manure handling, forage management, and cow culling rates favored pastured cows. Higher fertility and lower mastitis among Jerseys partially offsets lower income over feed cost compared with Holsteins. Milk production was lower in this study for pasture-based systems but lower feed costs, lower culling costs, and other economic factors indicate that pasture-based systems can be competitive with confinement systems.

Enteric-release glyceryl trinitrate in active Crohn's disease: a randomized, double-blind, placebo-controlled trial.

BACKGROUND: Mucosal ischaemia may contribute to the pathogenesis of Crohn's disease. Microvascular abnormalities have been found in colonic resection specimens, and mucosal levels of constitutive nitric oxide synthase are reduced. AIM: To assess the efficacy of a novel, enteric-release formulation of the nitric oxide donor, glyceryl trinitrate, aimed at increasing the mucosal circulation and relaxing smooth muscle in the affected bowel. METHODS: The trial was randomized, double-blind and placebo-controlled. Baseline disease activity was assessed by a structured symptom diary, with blood tests and a quality of life assessment. Patients with a Crohn's disease activity index of > or = 150 and < 450 were randomized to receive 12 weeks of either glyceryl trinitrate (initially 6 mg twice daily, increasing to 9 mg twice daily after 6 weeks) or an identical placebo. Assessments were repeated at 6 and 12 weeks. RESULTS: Seventy patients (22 male) entered the study; 34 were given glyceryl trinitrate and 36 placebo. At 12 weeks, there were no differences between the treatment groups in terms of Crohn's disease activity index, pain, stool frequency, inflammatory markers or quality of life scores. CONCLUSIONS: Enteric-release glyceryl trinitrate did not benefit patients with mild to moderately active Crohn's disease. Whilst ischaemia may contribute to the pathogenesis of Crohn's disease, our results fail to provide supportive evidence for this hypothesis.