Effect of diet type and added copper on growth performance, carcass characteristics, energy digestibility, gut morphology, and mucosal mRNA expression of finishing pigs

A total of 757 pigs (PIC 337 × 1050; initially 27.6 kg BW) were used in a 117-d experiment to determine the effects of added Cu from tribasic copper chloride and diet type on growth performance, carcass characteristics, energy digestibility, gut morphology, and mucosal mRNA expression of finishing pigs. Pens of pigs were allotted to 1 of 4 dietary treatments, balanced on average pen weight in a randomized complete block design with 26 to 28 pigs per pen and 7 replications per treatment. Treatments were arranged in a 2 × 2 factorial with main effects of diet type, a corn-soybean meal-based diet (corn-soy) or a high by-product diet (by-product) with 30% distillers dried grains with solubles (DDGS) and 15% bakery meal, and added Cu (0 or 150 mg/kg added Cu). There were no Cu × diet type interactions for growth performance. Overall, neither added Cu nor diet type influenced growth performance. However, caloric efficiency was decreased (P = 0.001) for pigs fed the by-product diet compared to the corn-soy diet. Pigs fed the by-product diet had decreased (P < 0.05) carcass yield and carcass G:F) and marginally decreased (P < 0.07) HCW and carcass ADG compared to pigs fed the corn-soy diet. A Cu × diet type interaction (P < 0.05) existed for DM and GE digestibility during the early finishing period as added Cu improved (P < 0.05) digestibility of DM and GE in the corn-soy diet, but not in the by-product diet. During the late finishing period, added Cu marginally increased (P = 0.060) DM and GE digestibility while pigs fed the by-product diet had decreased DM and GE digestibility (P = 0.001) compared to those fed the corn-soy diet. For gut morphology, pigs fed added Cu had decreased crypt depth (P = 0.017) in the distal small intestine compared to those fed no added Cu. Furthermore, relative mRNA expression of intestinal fatty acid binding protein (iFABP) was decreased (P = 0.032) in pigs fed added Cu compared to those fed no added Cu. In summary, adding 150 mg/kg added Cu or including 30% DDGS and 15% bakery meal into a corn-soy diet did not influence growth performance. However, HCW ADG and HCW G:F were reduced in pigs fed the by-product diet compared to the corn-soy diet. Only minor differences in gut morphology or mRNA expression were observed from feeding diets with high levels of Cu or by-products compared to a corn-soy diet.

Interaction between supplemental zinc oxide and zilpaterol hydrochloride on growth performance, carcass traits, and blood metabolites in feedlot steers

Interactive effects of supplemental Zn and zilpaterol hydrochloride (ZH) were evaluated in feedlot steers ( = 40; 652 kg ± 14 initial BW) to determine their impact on feedlot performance, blood constituents, and carcass traits. The study was conducted as a randomized complete block design with a 2 × 2 factorial treatment arrangement. Steers were blocked by BW and randomly assigned to treatments. Factors consisted of supplemental Zn (60 or 300 mg/kg diet DM) and ZH (0 or 8.33 mg/kg) in the diets. For diets supplemented with 300 mg Zn/kg DM, 60 mg Zn/kg was supplemented as zinc sulfate and 240 mg Zn/kg was supplemented as zinc oxide, and the diet was fed for 24 d. Zilpaterol hydrochloride was fed for 21 d followed by a 3-d withdrawal. Cattle were housed in partially covered individual feeding pens equipped with automatic waterers and fence-line feed bunks and were fed once daily for ad libitum intake. Plasma samples were collected on d 0 and 21 to assess changes in Zn, plasma urea nitrogen (PUN), glucose, and lactate concentrations, and serum samples were collected on d 21 to assess IGF-1 concentration. On d 25, cattle were weighed and transported 450 km to a commercial abattoir for harvest; HCW and incidence of liver abscesses were recorded. Carcass data were collected after 36 h of refrigeration. Data were analyzed as a mixed model with Zn, ZH, and Zn × ZH as fixed effects; block as a random effect; and steer as the experimental unit. No interaction or effects of Zn or ZH were observed for IGF-1 concentration, plasma glucose, or lactate concentrations ( ≥ 0.25). No interaction between Zn and ZH was observed for PUN concentration, but PUN decreased with ZH ( < 0.01). There were no effects of ZH or Zn on ADG, DMI, final BW, feed efficiency, HCW, back fat, KPH, quality grade, or incidence of liver abscesses ( > 0.05). Zinc supplementation tended ( = 0.08) to improve the proportion of carcasses grading USDA Choice. Feeding ZH decreased yield grade ( = 0.05) and tended to increase LM area ( = 0.07). In conclusion, increasing dietary concentrations of Zn does not impact response to ZH, but feeding ZH altered circulating concentrations of PUN.

Effect of Brahman genetics on myofibrillar protein degradation, collagen crosslinking, and tenderness of the longissimus lumborum

The objective of this study was to examine the effect of percent Brahman genetics on Warner-Bratzler shear force (WBSF), desmin and troponin-T (TnT) degradation, hydroxylysyl pyridinoline (HP) crosslink content, and perimysial collagen melting temperature. Steers ( = 131) produced in 2012 and 2013 were harvested at 1.27 cm of visual s.c. back fat thickness. Steers were divided into 4 genetic categories consisting of steers that contained 6/32 or less Brahman genetics, 12/32 Brahman genetics, 14/32 to 18/32 Brahman genetics, and 23/32 to 32/32 Brahman genetics. Twenty-four hours after harvest, a 7.62-cm piece of the longissimus lumborum beginning at the 13th rib was collected and aged for 14 d. Following aging, three 2.54-cm steaks were cut for WBSF, trained sensory panel, and laboratory analyses. Laboratory analyses steaks were used to determine protein degradation, HP crosslink analysis, and perimysial collagen melting temperature. Data were analyzed using a polynomial regression for unequally spaced treatments. As the percent Brahman genetics increased, WBSF increased (linear, = 0.01). As percent Brahman genetics increased, tenderness score decreased (less tender) and connective tissue score increased (more connective tissue; linear, = 0.01). As the percentage of Brahman genetics increased, the amount of degraded desmin (38 kDa) and TnT (34 and 30 kDa) decreased (linear, < 0.03) whereas the amount of immunoreactive 36 kDa TnT increased (linear, = 0.04). Percent Brahman genetics had no effect ( = 0.14) on HP crosslink content but did tend to increase ( = 0.07) perimysial collagen melting temperature as the percent Brahman increased. The percentage of Brahman genetic influence was positively correlated to WBSF ( = 0.25), 36 kDa immunoreactive TnT ( = 0.26), and perimysial collagen melting temperature ( = 0.25, = 0.01). Sensory panel tenderness ( = -0.44), juiciness ( = -0.26), and connective tissue scores ( = -0.63); 38 kDa degraded desmin ( = -0.34), 34 ( = -0.36) and 30 kDa degraded TnT ( = -0.29); and HP collagen crosslinks ( = -0.20) were negatively correlated to percent Brahman genetic influence ( < 0.03). Increasing Brahman genetic influence in steers negatively affects tenderness, partially through a reduction in degradation of desmin and TnT. Although HP collagen crosslinks are unaffected by Brahman genetics, a tendency for increased perimysium melting temperature indicates that other collagen-stabilizing crosslinks may be affected.

Interactive effects of supplemental Zn sulfate and ractopamine hydrochloride on growth performance, carcass traits, and plasma urea nitrogen in feedlot heifers

Interactive effects of supplemental Zn and ractopamine hydrochloride (RH) were evaluated using 156 crossbred heifers (initial BW = 527 kg ± 6.61; gross BW × 0.96) to determine the impact on feedlot performance, plasma urea nitrogen (PUN), and carcass characteristics. The study was conducted as a randomized complete block design with a 2 × 2 factorial arrangement of treatments. Factors consisted of 1) 30 or 100 mg supplemental Zn/kg diet DM (30Zn or 100Zn) as Zn sulfate and 2) 0 or 200 mg RH/heifer daily. Heifers were blocked by BW and assigned randomly within block to treatments for a 43-d trial. Heifers were housed in partially covered feeding pens (3 heifers/pen; 13 pens/treatment) and provided ad libitum access to feed. Ractopamine hydrochloride was fed for 42 d and removed from the diet until cattle were harvested on d 43. Zinc treatments were fed until harvest. Plasma samples were collected on d 0 and 36 to assess changes in plasma Zn and PUN. On d 43, heifers were weighed, then transported to a commercial abattoir where HCW and incidence of liver abscesses were recorded. Carcass data were collected after 32 h of refrigeration. No Zn × RH interactions were observed for plasma Zn or PUN ( ≥ 0.58); however, there was a tendency for a RH × day interaction for PUN ( = 0.08). Supplementing 100Zn resulted in increased plasma Zn ( = 0.02) compared to 30Zn. No RH × Zn interactions were observed for feedlot performance ( ≥ 0.24). Final BW and ADG increased with RH supplementation ( ≤ 0.02), but DMI was not affected ( = 0.63); thus, feed efficiency improved ( < 0.01) when heifers were fed RH. Supplementing 100Zn tended to reduce ADG ( = 0.07) but did not affect other measures of feedlot performance ( ≥ 0.12). Zinc × RH interactions were observed for LM area and yield grade ( ≤ 0.01); LM area decreased and yield grade increased when heifers were supplemented 100Zn with no RH compared to other treatments. A tendency for a Zn × RH interaction was observed for dressed yield ( = 0.08), but no other interactions or effects of Zn were detected for carcass traits ( ≥ 0.11). Supplementing RH increased HCW ( = 0.03) but did not affect other carcass traits ( ≥ 0.13). In conclusion, supplemental Zn had little impact on feedlot performance or PUN concentration but may alter muscle and fat deposition when fed in conjunction with RH.

Marbling Texture’s Effects on Beef Palatability

The objective of this study was to evaluate the effects of marbling texture on consumer and trained sensory panel ratings of beef strip loin steaks from 3 USDA quality grades. Beef strip loins (n = 117) were selected from 3 quality grades [Top Choice (Modest00 – Moderate100 marbling), Low Choice (Small00 – Small100 marbling), and Select (Slight00 – Slight100 marbling)] to equally represent three different marbling texture groups: fine, medium, and coarse, via visual appraisal. There were no quality grade × texture interactions (P > 0.05) for all of the traits evaluated. Consumers (n = 104) rated all marbling texture groups similar (P > 0.05) for tenderness, juiciness, flavor, and overall liking, as well as rated a similar (P > 0.05) percentage of samples from each marbling texture group acceptable for each palatability trait. Moreover, consumers indicated no preference (P > 0.05) among marbling texture groups for visual desirability or likelihood to purchase. However, trained sensory panelists rated coarse marbled steaks higher (P < 0.05) than fine or medium marbled steaks for both beef flavor intensity and sustained juiciness, as well as higher (P < 0.05) for initial juiciness than medium textured steaks. There were no differences (P > 0.05) among marbling texture groups for Warner-Bratzler shear force, slice shear force, and pressed juice percentage. Low Choice steaks were rated higher (P < 0.05) than Select steaks by consumers for tenderness, flavor liking, and overall liking, but similar (P > 0.05) to Top Choice. Results from this study indicate marbling texture had no impact on consumer evaluations of eating quality and only minimal effects on trained sensory panel palatability ratings and therefore provides no palatability-based evidence for the exclusion of coarse marbled carcasses from current and future branded beef programs.

Effects of Marbling Texture on Muscle Fiber and Collagen Characteristics

The objective of this study was to evaluate the effects of marbling texture on muscle fiber morphometrics, adipocyte cross-sectional area, perimysial thickness, collagen solubility, and thermal transition temperature of perimysial collagen of beef strip loin steaks from 3 marbling scores. Beef strip loins (n = 117) were selected from three marbling scores [Top Choice (Modest00 – Moderate100 marbling), Low Choice (Small marbling), and Select (Slight marbling)] to equally represent 3 different marbling texture groups: fine, medium, and coarse, via visual appraisal. There were no marbling texture × marbling score interactions for all traits evaluated. Marbling texture impacted (P < 0.05) adipocyte cross-sectional area, where coarse steaks displayed larger adipocytes in comparison to fine marbled steaks, but medium marbled steaks were similar (P > 0.05) to both coarse and fine marbled steaks for the same trait. However, marbling texture did not impact (P > 0.05) perimysial thickness. Marbling texture did not affect collagen traits, as no differences (P > 0.05) were found among marbling texture treatments for soluble collagen, insoluble collagen, and total collagen concentrations. Furthermore, all marbling texture groups (fine, medium, and coarse) were similar (P > 0.05) for the peak thermal transition phase of the perimysial fraction of collagen. Marbling score affected adipocyte size, as Top Choice and Low Choice possessed larger (P < 0.05) adipocytes than Select steaks. There were no differences (P > 0.05) among marbling scores for fiber type; nor were differences found among marbling textures or marbling scores for fiber cross-sectional area. These results indicate that marbling texture does not contribute to differences in collagen characteristics or fiber cross-sectional area that may impact eating quality of beef strip loin steaks.

Repeatability and Accuracy of the Pressed Juice Percentage Method at Sorting Steaks into Juiciness Categories

The objective of this study was to evaluate the repeatability of the Pressed Juice Percentage (PJP) as well as to determine the accuracy of previously determined PJP thresholds at sorting beef strip loin steaks into categories based on the probability of being rated juicy by sensory panelists. Beef strip loin steaks representing 3 USDA quality grades (Prime, Low Choice, and Low Select) and Low Select strip loin steaks enhanced to 108% of the raw weight with a water, salt, and alkaline phosphate solution were cooked to three degrees of doneness [DOD; Rare (60°C), Medium (71°C), Very Well-Done (82°C)] to maximize variation in juiciness. Paired steaks were evaluated for PJP, Slice Shear Force (SSF), and Warner-Bratzler shear force (WBSF). Additionally, steaks representing Prime, Low Choice, and Low Select that were non-enhanced or enhanced with the same enhancement solution cooked to three DOD [Rare (60°C), Medium (71°C), Very Well-Done (82°C)] from a previously conducted sensory study were used to evaluate the ability of PJP to sort steaks into juiciness categories. Results indicated PJP had a high repeatability coefficient of 0.70, indicating only a small portion (30%) of the variation observed was due to sample measurement differences between paired samples. The repeatability of SSF and WBSF were 0.68 and 0.85, respectively. The evaluated PJP threshold values accurately segregated strip loin steaks by the probability of a sample being rated as juicy (mean juiciness rating of > 50) by consumers. The actual percentage of juicy samples was determined to be 41.67, 72.31, 89.33, and 98.08% for the predicted < 50%, 50 to 75%, 75 to 90%, and > 90% categories, respectively. Results of this study indicate the PJP juiciness measure is both repeatable and accurate in sorting beef strip loin steaks based on the likelihood of a steak being classified as juicy by consumers.

Sensory Evaluation of Enhanced Beef Strip Loin Steaks Cooked to 3 Degrees of Doneness

The objective of this study was to evaluate the impact of marbling level in combination with enhancement on beef palatability when strip loin steaks were cooked to 3 degrees of doneness. Consumer and trained sensory panelists evaluated strip steak palatability traits of 3 USDA quality grades: Prime, Low Choice, and Low Select. Additional strip loins from each grade were enhanced to 108% with a water, salt, and alkaline phosphate solution. Steaks from each treatment were cooked to 3 degrees of doneness (DOD; Rare: 60°C, Medium: 71°C, or Very Well-Done: 82°C). Consumer panelists rated all enhanced treatments similar (P > 0.05) for each palatability trait. Enhanced steaks had greater (P < 0.05) juiciness, tenderness, flavor liking, and overall liking ratings than all non-enhanced treatments, regardless of grade. Consumer juiciness, tenderness, and overall liking scores increased (P < 0.05) as DOD decreased. Trained sensory panelists rated all enhanced treatments similar (P > 0.05) for initial and sustained juiciness, myofibrillar tenderness, and overall tenderness and greater (P < 0.05) than all non-enhanced treatments, other than non-enhanced Prime, for the same traits. Trained sensory panel ratings increased (P < 0.05) as DOD decreased for sustained juiciness, and both myofibrillar and overall tenderness. Moreover, Warner-Bratzler shear force values were similar (P > 0.05) among all enhanced treatments, and lower (P < 0.05) than non-enhanced Low Choice and Low Select treatments. Results from this study indicate marbling level has no impact on the palatability traits of enhanced strip loin steaks. Therefore, enhancement of higher valued, high marbled cuts does not provide additional palatability benefits over low marbled cuts, as enhancement does not provide an additive effect with marbling on beef eating quality.

Software for improved field surveys of nesting marine turtles

Field data are still recorded on paper in many worldwide beach surveys of nesting marine turtles. The data must be subsequently transferred into an electronic database, and this can introduce errors in the dataset. To minimize such errors, the "Turtles" software was developed and piloted to record field data by one software user accompanying one Tortuguero in Akumal beaches, Quintana Roo, Mexico, from June 1^st to July 31^st during the night patrols. Comparisons were made between exported data from the software with the paper forms entered into a database (henceforth traditional). Preliminary assessment indicated that the software user tended to record a greater amount of metrics (i.e., an average of 18.3 fields ± 5.4 sd vs. 8.6 fields ± 2.1 sd recorded by the traditional method). The traditional method introduce three types of "errors" into a dataset: missing values in relevant fields (40.1%), different answers for the same value (9.8%), and inconsistent data (0.9%). Only 5.8% of these (missing values) were found with the software methodology. Although only tested by a single user, the software may suggest increased efficacy and warrants further examination to accurately assess the merit of replacing traditional methods of data recording for beach monitoring programmes.

G-POEM with antro-pyloromyotomy for the treatment of refractory gastroparesis: mid-term follow-up and factors predicting outcome

BACKGROUND

Gastric peroral endoscopic pyloromyotomy (G-POEM) was introduced for treating refractory gastroparesis.

AIM

To present a series of patients focussed on clinical mid-term efficacy and predictive outcomes factors.

METHODS

This was a single centre study of 29 patients operated on between January 2014 and April 2016, with disturbed gastric emptying scintigraphy (GES) and/or elevated Gastroparesis Cardinal Symptoms Index (GCSI). The procedures were performed as previously described. The primary endpoint was the efficacy at 3 and 6 months, based on GCSI and symptoms. The secondary endpoints were GES evolution, procedure reproducibility and safety, and identification of predictive factors for success.

RESULTS

There were 10 men, 19 women (mean age 52.8±18). The technical success rate was 100% (average 47 minutes). There were two complications managed conservatively: one bleeding and one abscess. The median follow-up was 10±6.4 months. The clinical success rate was 79% at 3 months, 69% at 6 months, with a significant decrease in the mean GCSI compared to pre-operatively (3.3±0.9 vs 1±1.2 and 1.1±0.9 respectively). The GES (n=23) normalised in 70% of cases, with a significant improvement of the mean half emptying time and retention at 2 hours, and a discordance in 21% of the cases. In univariate analysis, diabetes and female gender were significantly associated with risk of failure, but not confirmed in multivariate analysis.

CONCLUSIONS

The mid-term efficacy of G-POEM reaches 70% at 6 months. The procedure remains reproducible and safe. Diabetes and female gender were predictive of failure.

Effects of yeast combined with chromium propionate on growth performance and carcass quality of finishing steers

A combination of yeast and chromium propionate (Y+Cr) was added to the diets of crossbred finishing steers ( = 504; 402 kg ± 5.76 initial BW) to evaluate impact on feedlot performance and carcass traits. We hypothesized supplementation of Y+Cr would increase growth of feedlot steers. Steers with initial plasma glucose concentrations ≤6.0 m were stratified by initial BW and randomly allocated, within strata, to receive 0 (control) or 3.3 g/d Y+Cr. Steers were further divided into heavy and light weight blocks with 6 pens/diet within each weight block. Cattle were housed in dirt-surfaced pens with 21 steers/pen and had ad libitum access to feed. Body weights were measured at 21-d intervals. Blood samples were collected on d 49 and 94 from a subset of steers (5/pen) for analyses of plasma glucose and lactate concentrations. At the end of the finishing phase, animals were weighed and transported 450 km to an abattoir in Holcomb, KS. Severity of liver abscesses and HCW were collected the day of harvest, and after 36 h of refrigeration, USDA yield and quality grades, LM area, and 12th rib subcutaneous fat thickness were determined. There were no treatment × time × weight block interactions ( > 0.05) and no treatment × block interaction for ADG, DMI, or final BW ( ≥ 0.06), but a treatment × block interaction ( = 0.03) was observed for G:F, in which control, light cattle had poorer efficiency compared with other groups. Treatment × weight group interactions were observed for overall yield grade and carcasses that graded yield grade 1 ( ≤ 0.04). Light steers supplemented with Y+Cr had decreased overall yield grade and increased percentage of carcasses grading yield grade 1 compared with their control counterparts, with no differences observed for heavy steers. Regardless of weight group, a greater percentage of carcasses from steers supplemented with Y+Cr graded yield grade 2 ( = 0.03) and fewer carcasses from steers supplemented Y+Cr graded yield grade 3 ( < 0.01) than control steers. No interactions or effects of treatment were detected for other carcass measurements ( ≥ 0.07). There were no treatment × weight group interactions or effects of treatment for plasma glucose or lactate concentrations on d 49 or 94 ( > 0.10). Overall, yeast in combination with chromium propionate may improve feed efficiency and decrease yield grade of light cattle but had no effect on remaining carcass traits and blood constituents.

Use of electromyography to detect muscle exhaustion in finishing barrows fed ractopamine HCl

The objectives of this study were to determine the effects of dietary ractopamine HCl (RAC) on muscle fiber characteristics and electromyography (EMG) measures of finishing barrow exhaustion when barrows were subjected to increased levels of activity. Barrows ( = 34; 92 ± 2 kg initial BW) were assigned to 1 of 2 treatments: a conventional swine finishing diet containing 0 mg/kg ractopamine HCl (CON) or a diet formulated to meet the requirements of finishing barrows fed 10 mg/kg RAC (RAC+). After 32 d on feed, barrows were individually moved around a track at 0.79 m/s until subjectively exhausted. Wireless EMG sensors were affixed to the deltoideus (DT), triceps brachii lateral head (TLH), tensor fasciae latae (TFL), and semitendinosus (ST) muscles to measure median power frequency (MdPF) and root mean square (RMS) as indicators of action potential conduction velocity and muscle fiber recruitment, respectively. After harvest, samples of each muscle were collected for fiber type, succinate dehydrogenase (SDH), and capillary density analysis. Speed was not different ( = 0.82) between treatments, but RAC+ barrows reached subjective exhaustion earlier and covered less distance than CON barrows ( < 0.01). There were no treatment × muscle interactions or treatment effects for end-point MdPF values ( > 0.29). There was a treatment × muscle interaction ( = 0.04) for end-point RMS values. The RAC diet did not change end-point RMS values in the DT or TLH ( > 0.37); however, the diet tended to decrease and increase end-point RMS in the ST and TFL, respectively ( < 0.07). There were no treatment × muscle interactions for fiber type, SDH, or capillary density measures ( > 0.10). Muscles of RAC+ barrows tended to have less type I fibers and more capillaries per fiber ( < 0.07). Type I and IIA fibers of RAC+ barrows were larger ( < 0.07). Compared with all other muscles, the ST had more ( < 0.01) type IIB fibers and larger type I, IIA, and IIX fibers ( < 0.01). Type I, IIA, and IIX fibers of the ST also contained less SDH compared with the other muscles ( < 0.01). Barrows fed a RAC diet had increased time to subjective exhaustion due to loss of active muscle fibers in the ST, possibly due to fibers being larger and less oxidative in metabolism. Size increases in type I and IIA fibers with no change in oxidative capacity could also contribute to early exhaustion of RAC+ barrows. Overall, EMG technology can measure real-time muscle fiber loss to help explain subjective exhaustion in barrows.

Determination of the effect of brand and product identification on consumer palatability ratings of ground beef patties

The objective of this study was to determine the effect of brand and product identification on consumer palatability ratings of ground beef patties. Six treatments were used in the study: 90/10 Certified Angus Beef (CAB) ground sirloin, 90/10 ground beef, 80/20 CAB ground chuck, 80/20 ground chuck, 80/20 ground beef, and 73/27 CAB ground beef. Ground beef was processed into 151.2-g patties using a patty former with 2 consecutively formed patties assigned to blind consumer testing and the following 2 assigned to informed testing. Following cooking to 74°C, patties were cut into quarters and served to consumers. Consumers ( = 112) evaluated samples in 2 rounds for tenderness, juiciness, flavor liking, texture liking, and overall liking. Each trait was also rated as either acceptable or unacceptable. In the first round of testing, samples were blind evaluated, with no information about the treatments provided to consumers, but in the second round, product type and brand were disclosed prior to sample evaluation. Additionally, texture profile and shear force analyses were performed on patties from each treatment. Few differences were observed for palatability traits during blind consumer testing; however, during informed testing, 90/10 CAB ground sirloin was rated greatest ( < 0.05) for all palatability traits other than juiciness. Also, 90/10 CAB ground sirloin had increased ( < 0.05; (consumer informed score - consumer blind score)/consumer blind score) ratings for tenderness (17.4%), juiciness (36.5%), flavor liking (23.3%), texture liking (18.2%), and overall liking (24.7%) due to brand disclosure. Increased ( < 0.05) ratings were found for CAB products for multiple traits due to treatment disclosure, whereas the only non-CAB-branded product that received increased ( < 0.05) ratings during informed testing was 90/10 ground beef for tenderness and juiciness. Texture results indicated that decreased fat level increased hardness, cohesiveness, gumminess, and chewiness. These results indicate that when sampling ground beef without brand and product information, few consumers find differences in eating quality among ground beef treatments; however, when consumers are aware of the brand, fat level, and subprimal blend prior to sampling, these factors have a large impact on consumer eating satisfaction.

The effect of branding on consumer palatability ratings of beef strip loin steaks

The objective of this study was to determine the influence of knowing the brand or USDA grade on consumer palatability ratings of beef strip loin steaks. Strip loins were selected to represent 5 USDA grades and brands, USDA Select, Choice, Prime, Certified Angus Beef (CAB; upper 2/3 Choice), and Select, from carcasses of cattle classified as Angus on the basis of phenotype. After 21 d of aging, 2.5-cm-thick steaks were cut, consecutively cut steaks were paired for consumer evaluation. Consumer panelists ( = 112) evaluated samples for tenderness, juiciness, flavor liking, and overall liking. Additionally, consumers rated each palatability trait as either acceptable or unacceptable. Samples were fed in 2 rounds on the same day: blind and informed testing. In the first round, blind testing, consumers were served 1 sample from each treatment, with no product information provided. In the second round, consumers were informed of the brand or quality grade prior to sampling. During blind testing, CAB rated similar ( > 0.05) to Choice for all palatability traits; however, CAB rated greater ( < 0.05) than Choice for all traits during informed testing. Additionally, Angus Select and Select were rated similar > 0.05) for all traits when tested blind, but Angus Select was rated greater ( < 0.05) than Select for flavor and overall liking when brand was declared. When comparing blind and informed ratings, Angus Select and CAB had greater ( < 0.05) ratings for juiciness, flavor liking, and overall liking, and Prime had increased ( < 0.05) ratings for flavor liking and overall liking because of brand disclosure. However, ratings for Choice and Select samples were unaffected ( > 0.05) when brand was disclosed. Brand knowledge increased ( < 0.05) the percentage of Prime samples rated as acceptable for flavor and the percentage of Angus Select samples rated as acceptable for flavor and overall liking. Conversely, there was no difference ( > 0.05) in the percentage of Choice and Select samples rated as acceptable for all palatability traits. These data indicate that Prime, CAB, and Angus Select steaks receive an increase in consumer palatability perception, or "brand lift," which does not occur for Choice and Select beef.

Feeding microalgae meal (All-G Rich; CCAP 4087/2) to beef heifers. I: Effects on longissimus lumborum steak color and palatibility

The objective of this study was to examine effects of 4 levels of microalgae meal (All-G Rich, CCAP 4087/2; Alltech Inc., Nicholasville, KY) supplementation to the diet of finishing heifers on longissimus lumborum (LL) steak PUFA content, beef palatability, and color stability. Crossbred heifers ( = 288; 452 ± 23 kg initial BW) were allocated to pens (36 pens and 8 heifers/pen), stratified by initial pen BW (3,612 ± 177 kg), and randomly assigned within strata to 1 of 4 treatments: 0, 50, 100, and 150 g·heifer·d of microalgae meal. After 89 d of feeding, cattle were harvested and LL were collected for determination of fatty acid composition and Warner-Bratzler shear force (WBSF), trained sensory panel evaluation, and 7-d retail color stability and lipid oxidation analyses. Feeding microalgae meal to heifers increased (quadratic, < 0.01) the content of 22:6-3 and increased (linear, < 0.01) the content of 20:5-3. Feeding increasing levels of microalgae meal did not impact total SFA or MUFA ( > 0.25) but tended ( = 0.10) to increase total PUFA in a quadratic manner ( = 0.03). Total omega-6 PUFA decreased (linear, = 0.01) and total omega-3 PUFA increased (quadratic, < 0.01) as microalgae meal level increased in the diet, which caused a decrease (quadratic, < 0.01) in the omega-6:omega-3 fatty acid ratio. Feeding microalgae meal did not affect WBSF values or sensory panel evaluation of tenderness, juiciness, or beef flavor scores ( > 0.16); however, off-flavor intensity increased with increasing concentration of microalgae meal in the diet (quadratic, < 0.01). From d 5 through 7 of retail display, steaks from heifers fed microalgae meal had a reduced a* value and oxymyoglobin surface percentage, with simultaneous increased surface metmyoglobin formation (quadratic, < 0.01). Lipid oxidation analysis indicated that at d 0 and 7 of display, as the concentration of microalgae meal increased in the diet, the level of oxidation increased (quadratic, < 0.01). Muscle fiber type percentage or size was not influenced by the inclusion of microalgae meal in diets ( > 0.19); therefore, the negative effects of microalgae on color stability were not due to fiber metabolism differences. Feeding microalgae meal to finishing heifers improves PUFA content of beef within the LL, but there are adverse effects on flavor and color stability.

Feeding microalgae meal (All-G Rich; CCAP 4067/2) to beef heifers. II: Effects on ground beef color and palatability

The objective of this study was to examine the effects of feeding microalgae meal (All-G Rich, CCAP 4087/2; Alltech Inc., Nicholasville, KY) to finishing heifers on 85% lean and 15% fat (85/15) ground beef PUFA content, palatability, and color stability. Crossbred heifers ( = 288; 452 ± 23 kg initial BW) were allocated to pens (36 pens and 8 heifers/pen), stratified by initial pen BW (3,612 ± 177 kg), and randomly assigned within strata to 1 of 4 treatments: 0, 50, 100, and 150 g·heifer·d of microalgae meal. After 89 d of feeding, a subset of heifers (3/pen) was harvested and the rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius were collected for processing into ground beef. At 42 d postmortem, 85/15 ground beef was formulated and formed into 112-g patties and fatty acid composition, subjective palatability, and 96-h retail color stability analyses were conducted. Increasing dietary microalgae meal concentration increased ground beef 20:5-3 and 22:6-3 fatty acids (quadratic, < 0.01). There was a treatment × hour interaction for all color attributes ( < 0.01). On d 0, microalgae tended ( = 0.08) to decrease L*, but patties had similar L* values the remainder of display ( > 0.12). Feeding microalgae meal affected ( = 0.02) b* at 24 h and decreased (linear, = 0.08) b* at 48 h. From h 0 to 36 of display, microalgae affected redness of patties ( < 0.02), and from 48 to 72 h, microalgae meal decreased a* value (linear, < 0.04). Microalgae meal did not impact sensory panel firmness, overall tenderness, or juiciness scores ( > 0.20) but tended to affect ( = 0.10) cohesiveness scores. As the amount of microalgae meal fed to heifers increased, beef flavor intensity decreased (linear, < 0.01) and off-flavor intensity increased (quadratic, < 0.05). Surface oxymyoglobin and metmyoglobin were impacted by microalgae meal from 12 to 36 h of display ( < 0.01). From 48 to 84 h of display, feeding microalgae meal to heifers decreased (linear, < 0.09) surface oxymyoglobin and increased (linear, < 0.02) surface metmyoglobin of patties. Although feeding microalgae meal to heifers increases the PUFA content of 85/15 ground beef, there are undesirable effects on flavor and color stability.

Reduced skeletal muscle fiber size following caloric restriction is associated with calpain-mediated proteolysis and attenuation of IGF-1 signaling

Caloric restriction decreases skeletal muscle mass in mammals, principally due to a reduction in fiber size. The effect of suboptimal nutrient intake on skeletal muscle metabolic properties in neonatal calves was examined. The longissimus muscle (LM) was collected after a control (CON) or caloric restricted (CR) diet was cosnumed for 8 wk and muscle fiber size, gene expression, and metabolic signal transduction activity were measured. Results revealed that CR animals had smaller (P < 0.05) LM fiber cross-sectional area than CON, as expected. Western blot analysis detected equivalent amounts of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC1α) but reduced (P < 0.05) amounts of the splice-variant, PGC1α-4 in CR LM. Expression of IGF-1, a PGC1α-4 target gene, was 40% less (P < 0.05) in CR than CON. Downstream mediators of autocrine IGF-1 signaling also are attenuated in CR by comparison with CON. The amount of phosphorylated AKT1 was less (P < 0.05) in CR than CON. The ratio of p4EBP1^T37/46 to total 4EBP1, a downstream mediator of AKT1, did not differ between CON and CR. By contrast, protein lysates from CR LM contained less (P < 0.05) total glycogen synthase kinase-3β (GSK3β) and phosphorylated GSK3β than CON LM, suggesting blunted protein synthesis. Smaller CR LM fiber size associates with increased (P < 0.05) calpain 1 (CAPN1) activity coupled with lower (P < 0.05) expression of calpastatin, the endogenous inhibitor of CAPN1. Atrogin-1 and MuRF expression and autophagy components were unaffected by CR. Thus CR suppresses the hypertrophic PGC1α-4/IGF-1/AKT1 pathway while promoting activation of the calpain system.

Induction of cellular proliferation in a human astrocytoma cell line by a Trypanosoma cruzi-derived antigen: a mechanism of pathogenesis?

Trypanosoma cruzi can compromise the human central nervous system (CNS) during acute infection or reactivation in immune-suppressed hosts. Astrocytes have been identified as targets of T. cruzi's CNS infection in humans. Despite a high degree of parasitism and cellular lysis by T. cruzi in vitro the number of astrocytoma cells did not change when compared to uninfected cultures. This work evaluated cellular proliferation, changes in Major Histocompatibility Complex (MHC) expression as a reflection of antigen processing, and cytokine (IL-6 &amp; IL-8) secretion in a human astrocytoma cell line exposed to a trypomastigote-derived antigen. Light microscopy was used to evaluate the number of cells; MHC molecule expression, cell cycle and cytokine secretion were assessed by flow cytometry. The number of astrocytoma cells increased proportional to the amount of antigen used and the percentage of cells in G2/M phase was higher when compared to control cultures. Antigen exposure increased expression of MHC class II, but not MHC class I in comparison to cultures incubated without antigen. Astrocytoma cell secretion of IL-6 and IL-8 was unaffected by antigen exposure. These results suggest the participation of a trypomastigote-derived mediator that induces astrocytoma cell proliferation without an inflammatory response; which may contribute to the pathogenesis of neurologic Chagas disease.

Comparing preferences for outcomes of psoriasis treatments among patients and dermatologists in the U.K.: results from a discrete-choice experiment

BACKGROUND

Plaque psoriasis can have a significant negative effect on patients' quality of life, and treatments can result in serious toxicities. Although there have been several studies of patients' and physicians' relative preferences for the benefits and risks of psoriasis treatments, it is unclear how and whether patients' and physicians' preferences for the outcomes of psoriasis treatments differ.

OBJECTIVES

To quantify patient and dermatologist preferences for improvements in psoriasis symptoms and for increases in the risk of treatment-related serious adverse events.

METHODS

Members of the U.K. Psoriasis Association and U.K. dermatologists with experience prescribing biologics completed a web-enabled discrete-choice experiment survey in which they evaluated efficacy and safety features of biological treatments for psoriasis. Choices between hypothetical treatment options were used to estimate preference weights indicating respondents' relative trade-off preferences among treatment outcomes. These outcomes included improvements in the severity and coverage of psoriatic plaques and treatment-related risks of tuberculosis, serious infections and lymphoma. Preference estimates were used to derive the maximum level of side-effect risks that respondents would accept for improvements in psoriasis symptoms.

RESULTS

Respondents' tolerance for side-effect risks varied with side-effect severity and location of plaques, and risk tolerance for serious side-effects was greater for patients than for dermatologists.

CONCLUSIONS

Estimates of patients' risk tolerance for serious side-effects indicate that patients valued psoriasis symptom control highly and suggest that psoriasis symptoms have a significant effect on patients' quality of life. In light of research showing increased treatment satisfaction and improved treatment adherence among patients who receive therapies that are consistent with their preferences, our findings suggest that greater communication between dermatologists and patients about risk tolerance could help improve patient care.

Influence of dietary fat source and feeding duration on finishing pig growth performance, carcass composition, and fat quality

A total of 160 finishing pigs (PIC 327 × 1050; initially 45.6 kg) were used in an 84-d experiment to evaluate the effects of dietary fat source and feeding duration on growth performance, carcass characteristics, and carcass fat quality. There were 2 pigs per pen with 8 pens per treatment. The 10 dietary treatments were a corn-soybean meal control diet with no added fat and a 3 × 3 factorial with main effects of fat source (4% tallow, 4% soybean oil, or a blend of 2% tallow and 2% soybean oil) and feeding duration (d 0 to 42, 42 to 84, or 0 to 84). The control corn-soybean meal diet was fed in place of added fat diets when needed for duration treatment purposes. On d 0, 1 pig was identified in each pen and fat biopsy samples of the back, belly, and jowl were collected on d 0, 41, and 81 for fatty acid analysis. At the conclusion of the study, all pigs were harvested, carcass characteristics were determined, and back, belly, and jowl fat samples were collected for analysis. Overall (d 0 to 84), there were no differences among pigs fed the different fat sources for growth and carcass characteristics; however, pigs fed diets with added fat for the entire study had improved ( = 0.036) G:F compared with pigs fed the control diet without added fat. Pigs fed supplemental fat throughout the entire study also had improved ( < 0.05) ADG and G:F as well as heavier d-84 BW ( = 0.006) compared with pigs fed additional fat during only 1 period. Adding fat for the entire study increased ( = 0.032) backfat and tended to reduce ( = 0.079) the fat free lean index compared with pigs fed the control diet without added fat. Added fat also increased ( < 0.05) the iodine value (IV) when compared with pigs fed the control diet. Increasing the feeding duration of soybean oil lowered MUFA and increased PUFA concentrations for all fat depots, whereas these values remained relatively unchanged by the addition of tallow (duration × fat source interactions, < 0.05). Our study failed to show any feeding period × fat source interactions ( < 0.05) in fatty acid composition or IV for jowl fat, whereas this interaction occurred for belly fat and backfat, which would indicate a longer turnover rate for jowl fat. In conclusion, feeding additional fat improved ADG and G:F; however, feeding soybean oil for an increased duration, either alone or in combination with tallow, negatively affected the fatty acid composition and IV of different fat depots.

Equations generated to predict iodine value of pork carcass back, belly, and jowl fat

Data from existing literature were used to generate equations to predict finishing pig back, belly, and jowl fat iodine values (IV) and an experiment was conducted to evaluate these equations. The final database included 24, 21, and 29 papers for back, belly, and jowl fat IV, respectively. For experiments that changed dietary fatty acid composition, initial (INT) diets were defined as those fed before the change in diet composition and final (FIN) diets were those fed after. The predictor variables tested were divided into 5 groups: 1) diet fat composition (dietary percent C16:1, C18:1, C18:2, C18:3, EFA, unsaturated fatty acids, and IV product) for both INT and FIN diets, 2) day feeding the INT and FIN diets, 3) ME or NE of the INT and FIN diet, 4) live performance criteria (initial BW, final BW, ADG, ADFI, and G:F), and 5) carcass criteria (HCW and backfat thickness). The PROC MIXED procedure of SAS (SAS Inst., Inc., Cary, NC) was used to develop regression equations. Evaluation of models with significant terms was then conducted based on the Bayesian information criterion. The optimum equations to predict back, belly, and jowl fat IV were backfat IV = 84.83 + (6.87 × INT EFA) - (3.90 × FIN EFA) - (0.12 × INT days) - (1.30 × FIN days) - (0.11 × INT EFA × FIN days) + (0.048 × FIN EFA × INT days) + (0.12 × FIN EFA × FIN days) - (0.0060 × FIN NE) + (0.0005 × FIN NE × FIN days) - (0.26 × backfat depth); belly fat IV = 106.16 + (6.21 × INT EFA) - (1.50 × FIN days) - (0.11 × INT EFA × FIN days) - (0.012 × INT NE) + (0.00069 × INT NE × FIN days) - (0.18 × HCW) - (0.25 × backfat depth); and jowl fat IV = 85.50 + (1.08 × INT EFA) + (0.87 × FIN EFA) - (0.014 × INT days) - (0.050 × FIN days) + (0.038 × INT EFA × INT days) + (0.054 × FIN EFA × FIN days) - (0.0066 × INT NE) + (0.071 × INT BW) - (2.19 × ADFI) - (0.29 × backfat depth). Dietary treatments from the evaluation experiment consisted of a corn-soybean meal control diet with no added fat or a 3 × 3 factorial arrangement with main effects of fat source (4% tallow, 4% soybean oil, or a blend of 2% tallow and 2% soybean oil) and feeding duration (d 0 to 42, 42 to 84, or 0 to 84). The back, belly, and jowl fat IV equations tended to overestimate IV when observed IV were less than approximately 65 g/100 g and underestimate belly fat IV when actual IV are greater than approximately 74 g/100 g or when the fat blend was fed from d 0 to 84 or 42 to 84. Overall, with the exceptions noted, the regression equations were an accurate tool for predicting carcass fat quality based on dietary and pig performance factors.

Effects of Added Zinc on Skeletal Muscle Morphometrics and Gene Expression of Finishing Pigs Fed Ractopamine-HCL

Finishing pigs (n = 320) were used in a 35-day study to determine the effects of ractopamine-HCl (RAC) and supplemental Zinc (Zn) level on loin eye area (LEA) and gene expression. Pens were randomly allotted to the following treatments for the final 35 days on feed: a corn-soybean meal diet (CON), a diet with 10 ppm RAC (RAC+), and RAC diet plus added Zn at 75, 150, or 225 ppm. Sixteen pigs per treatment were randomly selected for collection of serial muscle biopsies and carcass data on day 0, 8, 18, and 32 of the treatment phase. Compared to CON carcasses, RAC+ carcasses had 12.6% larger (P = 0.03) LEA. Carcasses from RAC diets with added Zn had a tendency for increased (quadratic, P < 0.10) LEA compared to the RAC+ carcasses. Compared to RAC+ pigs, relative expression of IGF1 decreased with increasing levels of Zn on day 8 and 18 of treatment, but expression levels were similar on day 32 due to Zn treatments increasing in expression while the RAC+ treatment decreased (Zn quadratic × day quadratic, P = 0.04). A similar trend was detected for the expression of β1-receptor where expression levels in the RAC+ pigs were greater than Zn supplemented pigs on day 8 and 18 of the experiment, but the magnitude of difference between the treatments was reduced on day 32 due to a decrease in expression by RAC+ pigs and an increase in expression by the Zn pigs (Zn quadratic × day quadratic, P = 0.01). The ability of Zn to prolong the expression of these two genes may be responsible for the tendency of Zn to increase LEA in RAC supplemented pigs.

Analysis of three genomes within the thermophilic bacterial species Caldanaerobacter subterraneus with a focus on carbon monoxide dehydrogenase evolution and hydrolase diversity

Background

The Caldanaerobacter subterraneus species includes thermophilic fermentative bacteria able to grow on carbohydrates substrates with acetate and L-alanine as the main products. In this study, comprehensive analysis of three genomes of C. subterraneus subspecies was carried in order to identify genes encoding key metabolic enzymes and to document the genomic basis for the evolution of these organisms.

Methods

Average nucleotide identity and in silico DNA relatedness were estimated for the studied C. subterraneus genomes. Genome synteny was evaluated using R2CAT software. Protein conservation was analyzed using mGenome Subtractor. Horizontal gene transfer was predicted through the GOHTAM pipeline (using tetranucleotide composition) and phylogenetic analyses (by maximum likelihood). Hydrolases were identified through the MEROPS and CAZy platforms.

Results

The three genomes of C. subterraneus showed high similarity, although there are substantial differences in their gene composition and organization. Each subspecies possesses a gene cluster encoding a carbon monoxide dehydrogenase (CODH) and an energy converting hydrogenase (ECH). The CODH gene is associated with an operon that resembles the Escherichia coli hydrogenase hyc/hyf operons, a novel genetic context distinct from that found in archetypical hydrogenogenic carboxydotrophs. Apart from the CODH-associated hydrogenase, these bacteria also contain other hydrogenases, encoded by ech and hyd genes. An Mbx ferredoxin:NADP oxidoreductase homolog similar to that originally described in the archaeon Pyrococcus furiosus was uniquely encoded in the C. subterraneus subsp. yonseiensis genome. Compositional analysis demonstrated that some genes of the CODH-ECH and mbx operons present distinct sequence patterns in relation to the majority of the other genes of each genome. Phylogenetic reconstructions of the genes from these operons and those from the ech operon are incongruent to the species tree. Notably, the cooS gene of C. subterraneus subsp. pacificus and its homologs in C. subterraneus subsp. tengcongensis and C. subterraneus subsp. yonseiensis form distinct clades. The strains have diverse hydrolytic enzymes and they appear to be proteolytic and glycolytic. Divergent glycosidases from 14 families, among them amylases, chitinases, alpha-glucosidases, beta-glucosidases, and cellulases, were identified. Each of the three genomes also contains around 100 proteases from 50 subfamilies, as well about ten different esterases.

Conclusions

Genomic information suggests that multiple horizontal gene transfers conferred the adaptation of C. subterraneus subspecies to extreme niches throughout the carbon monoxide utilization and hydrogen production. The variety of hydrolases found in their genomes indicate the versatility of the species in obtaining energy and carbon from diverse substrates, therefore these organisms constitute a remarkable resource of enzymes with biotechnological potential.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1955-9) contains supplementary material, which is available to authorized users.

Effects of the Programmed Nutrition Beef Program on feedlot performance and carcass characteristics

The objective of this study was to examine the effects of alternative finishing strategies on feedlot performance and carcass characteristics. Beef steers (64 pens; 8 steers/pen) were allocated to a randomized complete block design with a 2 × 2 factorial treatment arrangement. Factor 1 consisted of diet, with cattle fed a conventional (CON) diet or a diet consisting of Programmed Nutrition Beef Program (PN) supplements. The PN treatment included Programmed Nutrition Beef Receiver fed from d 1 through 20 of feeding and Programmed Nutrition Beef Finisher fed from d 21 to harvest. Factor 2 evaluated the presence (EGP+) or absence (EGP-) of exogenous growth promotants (ExGP) in the production system. Steers in the EGP+ treatments were initially implanted with Component E-S, reimplanted with Component TE-IS, and fed 400 mg·animal·dof ractopamine hydrochloride for the final 28 d before harvest. Steers were harvested on d 175, and strip loins were removed from 2 carcasses selected at random from each pen for transport to Kansas State University. One 1.27-cm-thick steak was removed from the anterior face for proximate and long-chain fatty acid analysis. There were no diet × ExGP interactions ( > 0.10) for feedlot performance except for DMI ( = 0.02). Steers in the PN/EGP+ treatment consumed more feed than all other treatments ( < 0.05). Both diet and ExGP affected DMI ( < 0.05), with PN and EGP+ steers consuming more feed than their contemporaries. Gain:feed and ADG were unaffected ( > 0.10) by diet, but ExGP improved these measures ( < 0.01). There were no diet × ExGP interactions for carcass characteristics except KPH fat and percentages of yield grade 3 and 4 carcasses ( < 0.05). Diet affected total incidence of liver abscesses because PN steers had a greater ( = 0.05) incidence of liver abscesses than steers in the CON treatment. Diet did not affect the other carcass characteristics ( > 0.10). Use of ExGP increased ( < 0.05) HCW, LM area, and 12th-rib fat but did not affect ( > 0.10) marbling score. Using ExGP reduced the percentage carcasses grading Premium Choice ( < 0.05). No diet × ExGP interactions or diet effects were detected for long-chain fatty acid profiles ( > 0.10). Use of ExGP increased ( < 0.05) the ratio of saturated:unsaturated fatty acids. In summary, the alternative feeding strategy presented in this study produced similar feedlot performance and carcass characteristics compared with a conventional feedlot system.

Bacterial distribution along a 50 °C temperature gradient reveals a parceled out hot spring environment

Understanding the distribution of bacteria is a major goal of microbial ecology which remains to be fully deciphered. In this study, a model 50 °C temperature gradient at a Northern Thailand hot spring was analyzed to determine how the bacterial communities were structured in the environment. Communities were examined through 16S rRNA gene amplification, denaturing gradient gel electrophoresis, and sequencing. The two major phyla, Cyanobacteria and Chloroflexi, showed characteristic distributions along the temperature gradient. Different clades were allocated at specific portions of the gradient. Comparisons of the bacterial communities along the temperature gradient showed sharp decreases of similarity at increasing temperature difference. Peaks of maximum richness were observed at 50 and 70 °C. This study contributes to explain how environmental conditions and microbial interactions can influence the distribution of specific bacterial clades and phyla shaping the structure of microbial communities in nature.

Effect of dietary zinc and ractopamine hydrochloride on pork chop muscle fiber type distribution, tenderness, and color characteristics

A total of 320 finishing pigs (PIC 327 × 1050; initially 98 kg) were used to determine the effects of adding Zn to diets containing ractopamine HCl (RAC) on muscle fiber type distribution, fresh chop color, and cooked meat characteristics. Dietary treatments were fed for approximately 35 d and consisted of a corn-soybean meal-based negative control (CON), a positive control diet with 10 mg/kg of RAC (RAC+), and the RAC+ diet plus 75, 150, or 225 mg/kg added Zn from either ZnO or Availa-Zn. Loins randomly selected from each treatment (n = 20) were evaluated using contrasts: CON vs. RAC+, interaction of Zn level × source, Zn level linear and quadratic polynomials, and Zn source. There were no Zn source effects or Zn source × level interactions throughout the study (P > 0.10). Pigs fed RAC+ had increased (P < 0.02) percentage type IIX and a tendency for increased (P = 0.10) percent type IIB muscle fibers. Increasing added Zn decreased (linear, P = 0.01) percentage type IIA and tended to increase (P = 0.09) IIX muscle fibers. On d 1, 2, 3, 4, and 5 of display, pork chops from pigs fed the RAC+ treatment had greater (P < 0.03) L* values compared to the CON. On d 0 and 3 of display, increasing added Zn tended to decrease (quadratic, P = 0.10) L* values and decreased (quadratic, P < 0.03) L* values on d 1, 2, 4, and 5. Pigs fed RAC+ had decreased (P < 0.05) a* values on d 1 and 4 of display and tended to have decreased (P < 0.10) a* values on d 0 and 2 compared to CON pork chops. Pork chops from the RAC+ treatment had a tendency for increased (P < 0.08) oxymyoglobin percentage compared to CON pork chops on d 1, 2, 4, and 5. On d 0, as dietary Zn increased in RAC+ diets, there was a decrease (linear, P < 0.01) in the formation of pork chop surface oxymyoglobin percentage. Metmyoglobin reducing ability (MRA) of pork chops on d 5 was decreased in the RAC+ group. Chops from pigs fed added Zn had increased (quadratic, P < 0.03) MRA on d 3 and 5 of the display period. There was a trend for increased (linear, P = 0.07) cooking loss with increasing Zn in RAC diets and treatments did not affect tenderness as measured by Warner-Bratzler shear force (P > 0.07). In conclusion, RAC+ diets produced chops that were lighter and less red but maintained a greater percentage of surface oxymyoglobin throughout a 5-d simulated retail display. Ractopamine reduced MRA at the end of the display period, but supplementing Zn to RAC diets restored MRA to near CON treatment levels at the end of the display period.

Effects of the Programmed Nutrition Beef Program on meat quality characteristics

The objective of this study was to examine the effects of alternative finishing strategies on beef steak color and cooked meat characteristics. Beef steers (n = 64 pens; 8 steers/pen) were allocated to a randomized complete block design with a 2 × 2 factorial treatment arrangement and initial body weight serving as the blocking factor. Factor 1 consisted of dietary treatment with cattle either being fed a conventional feedlot diet (CON) or a diet that included Programmed Nutrition Beef Program supplements. Cattle in the Programmed Nutrition (PN) treatments were fed in two-stages: 1) the basal diet with Programmed Nutrition Beef Receiver from d 1 to 20 and the basal diet with Programmed Nutrition Beef Finisher from d 21 to harvest. Factor 2 consisted of the inclusion (EGP+) or absence (EGP-) of an exogenous growth promoting program. Steers in the EGP+ treatments were implanted initially with Component E-S, reimplanted with Component TE-IS, and fed 400 mg · d(-1) · steer(-1) of ractopamine hydrochloride for the final 28 d before harvest. Steers were harvested on d 175 of feeding and 1 strip loin was removed from 2 carcasses selected at random from each pen for transport to Kansas State University. After 14 d of aging, loins were fabricated into 2.54-cm thick steaks for objective and trained sensory panel measurement of cooked meat characteristics and objective color measurements during 7 d retail display. There were no interactions (P > 0.10) between feeding strategy and exogenous growth promotants for all objective measures of color and cooked meat characteristics. Throughout the display period, PN steaks were darker (P = 0.02) than CON steaks, but surface percentages of oxymyoglobin and metmyoglobin and metmyoglobin reducing ability were unaffected by feeding strategy (P > 0.10). Loins and steaks from PN cattle possessed decreased moisture loss during aging and cooking (P < 0.01). Trained sensory panel evaluation of cooked meat revealed a dietary program × growth promotant interaction for myofibrillar tenderness, connective tissue amount, and overall tenderness (P = 0.01). Compared to the CON/EGP- and PN/EGP- treatments, steaks from the CON/EGP+ and PN/EGP+ treatments were evaluated by panelists as being less myofibrillar and overall tender (P < 0.05). The alternative feeding strategies presented in this study can favorably impact water-holding capacity without negatively compromising retail display discoloration.

Substrate elasticity affects bovine satellite cell activation kinetics in vitro

Satellite cells support efficient postnatal skeletal muscle hypertrophy through fusion into the adjacent muscle fiber. Nuclear contribution allows for maintenance of the fiber myonuclear domain and proficient transcription of myogenic genes. Niche growth factors affect satellite cell biology; however, the interplay between fiber elasticity and microenvironment proteins remains largely unknown. The objective of the experiment was to examine the effects of hepatocyte growth factor (HGF) and surface elasticity on bovine satellite cell (BSC) activation kinetics in vitro. Young's elastic modulus was calculated for the semimembranosus (SM) and LM muscles of young bulls (5 d; n = 8) and adult cows (27 mo; n = 4) cattle. Results indicate that LM elasticity decreased (P < 0.05) with age; no difference in Young's modulus for the SM was noted. Bovine satellite cells were seeded atop polyacrylamide bioscaffolds with surface elasticities that mimic young bull and adult cow LM or traditional cultureware. Cells were maintained in low-serum media supplemented with 5 ng/mL HGF or vehicle only for 24 or 48 h. Activation was evaluated by proliferating cell nuclear antigen (PCNA) immunocytochemistry. Results indicate that BSC maintained on rigid surfaces were activated at 24 h and refractive to HGF supplementation. By contrast, fewer (P < 0.05) BSC had exited quiescence after 24 h of culture on surfaces reflective of either young bull (8.1 ± 1.7 kPa) or adult cow (14.6 ± 1.6 kPa) LM. Supplementation with HGF promoted activation of BSC cultured on bioscaffolds as measured by an increase (P < 0.05) in PCNA immunopositive cells. Culture on pliant surfaces affected neither activation kinetics nor numbers of Paired box 7 (Pax7) immunopositive muscle stem cells (P > 0.05). However, with increasing surface elasticity, an increase (P < 0.05) in the numbers of muscle progenitors was observed. These results confirm that biophysical and biochemical signals regulate BSC activation.

Discriminating primary clinical states in bipolar disorder with a comprehensive symptom scale

OBJECTIVE

We assessed the spectrum and severity of bipolar symptoms that differentiated bipolar disorder (BD) clinical states, employing the Bipolar Inventory of Symptoms Scale (BISS) which provides a broader item range of traditional depression and mania rating scales. We addressed symptoms differentiating mixed states from depression or mania/hypomania.

METHOD

One hundred and sixteen subjects who met DSM-IV-TR criteria for BD and were currently in a depressed, manic/hypomanic, mixed episode, or recovered state were interviewed using the BISS.

RESULTS

A subset of manic items differed between mixed episodes and mania/hypomania or depression. Most anxiety items were more severe in mixed subjects. BISS Depression and Manic subscales differentiated episodes from recovered status. The majority of depression and manic symptoms differentiated mood states in the predicted direction. Mixed episodes had overall greater mood severity than manic/hypomanic episodes or depressed episodes.

CONCLUSION

These results indicate that a small subset of symptoms, several of which are absent in DSM-IV-TR criteria and traditional rating scales for bipolar studies, aid in distinguishing mixed episodes from depressive or manic/hypomanic episodes. The results also support the utility of a comprehensive BD symptom scale in distinguishing primary clinical states of BD.

Mutualistic growth of the sulfate-reducer Desulfovibrio vulgaris Hildenborough with different carbohydrates

Desulfovibrio vulgaris Hildenborough genome presents a phosphotransferase system putatively involved in the transport of carbohydrates. However, utilization of sugars by this sulfate-reducing bacterium has never been reported. Herein, we have observed proliferation of D. vulgaris Hildenborough with some carbohydrates, in mutualism with Stenotrophomonas maltophilia, a non-fermentative, gram-negative gammaproteobacterium, or Microbacterium, a gram-positive actinobacterium. These results suggest the importance of feedback interactions between different heterotrophic bacterial species including the alternative for D. vulgaris of exploiting additional organic resources and novel habitats. Thus, D. vulgaris strongly participates in the mineralization of carbohydrates both in complex natural and artificial systems.

Presence and potential role of thermophilic bacteria in temperate terrestrial environments

Organic sulfur and nitrogen are major reservoirs of these elements in terrestrial systems, although their cycling remains to be fully understood. Both sulfur and nitrogen mineralization are directly related to microbial metabolism. Mesophiles and thermophiles were isolated from temperate environments. Thermophilic isolates were classified within the Firmicutes, belonging to the Geobacillus, Brevibacillus, and Ureibacillus genera, and showed optimum growth temperatures between 50°C and 60°C. Sulfate and ammonium produced were higher during growth of thermophiles both for isolated strains and natural bacterial assemblages. They were positively related to organic nutrient load. Temperature also affected the release of sulfate and ammonium by thermophiles. Quantitative, real-time reverse-transcription polymerase chain reaction on environmental samples indicated that the examined thermophilic Firmicutes represented up to 3.4% of the total bacterial community RNA. Temperature measurements during summer days showed values above 40°C for more than 10 h a day in soils from southern Spain. These results support a potential role of thermophilic bacteria in temperate terrestrial environments by mineralizing organic sulfur and nitrogen ruled by the existence and length of warm periods.

Simultaneous grayscale and subharmonic ultrasound imaging on a modified commercial scanner

OBJECTIVE

To demonstrate the feasibility of simultaneous dual fundamental grayscale and subharmonic imaging on a modified commercial scanner.

MOTIVATION

The ability to generate signals at half the insonation frequency is exclusive to ultrasound contrast agents (UCA). Thus, subharmonic imaging (SHI; transmitting at f(0) and receiving at f(0)/2) provides improved visualization of UCA within the vasculature via suppression of the surrounding tissue echoes. While this capability has proven useful in a variety of clinical applications, the SHI suppression of surrounding tissue landmarks (which are needed for sonographic navigation) also limits it use as a primary imaging modality. In this paper we present results using a commercial ultrasound scanner modified to allow imaging in both grayscale (f(0)=4.0 MHz) and SHI (f(0)=2.5 MHz, f(0)/2=1.25 MHz) modes in real time.

METHODS

A Logiq 9 ultrasound scanner (GE Healthcare, Milwaukee, WI) with a 4C curvilinear probe was modified to provide this capability. Four commercially available UCA (Definity, Lantheus Medical Imaging, North Billerica, MA; Optison, GE Healthcare, Princeton, NJ; SonoVue, Bracco Imaging, Milan, Italy; and Sonazoid, GE Healthcare, Oslo, Norway) were all investigated in vitro over an acoustic output range of 3.34 MPa. In vivo the subharmonic response of Sonazoid was investigated in the portal veins of four canines (open abdominal cavity) and four patients with suspected portal hypertension.

RESULTS

In vitro, the four UCA showed an average maximum subharmonic amplitude of 44.1±5.4 dB above the noise floor with a maximum subharmonic amplitude of 48.6±1.6 dB provided by Sonazoid. The average in vivo maximum signal above the noise floor from Sonazoid was 20.8±2.3 dB in canines and 33.9±5.2 dB in humans. Subharmonic amplitude as a function of acoustic output in both groups matched the S-curve behavior of the agent observed in vitro. The dual grayscale imaging provided easier sonographic navigation, while the degree of tissue suppression in SHI mode varied greatly on a case by case basis.

CONCLUSIONS

These results demonstrate the feasibility of dual grayscale and SHI on a modified commercial scanner. The ability to simultaneously visualize both imaging modes in real time should improve the applicability of SHI as a future primary clinical imaging modality.

Aims and results of the NIMH systematic treatment enhancement program for bipolar disorder (STEP-BD)

The Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD) was funded as part of a National Institute of Mental Health initiative to develop effectiveness information about treatments, illness course, and assessment strategies for severe mental disorders. STEP-BD studies were planned to be generalizable both to the research knowledge base for bipolar disorder and to clinical care of bipolar patients. Several novel methodologies were developed to aid in illness characterization, and were combined with existing scales on function, quality of life, illness burden, adherence, adverse effects, and temperament to yield a comprehensive data set. The methods integrated naturalistic treatment and randomized clinical trials, which a portion of STEP-BD participants participated. All investigators and other researchers in this multisite program were trained in a collaborative care model with the objective of retaining a high percentage of enrollees for several years. Articles from STEP-BD have yielded evidence on risk factors impacting outcomes, suicidality, functional status, recovery, relapse, and caretaker burden. The findings from these studies brought into question the widely practiced use of antidepressants in bipolar depression as well as substantiated the poorly responsive course of bipolar depression despite use of combination strategies. In particular, large studies on the characteristics and course of bipolar depression (the more pervasive pole of the illness), and the outcomes of treatments concluded that adjunctive psychosocial treatments but not adjunctive antidepressants yielded outcomes superior to those achieved with mood stabilizers alone. The majority of patients with bipolar depression concurrently had clinically significant manic symptoms. Anxiety, smoking, and early age of bipolar onset were each associated with increased illness burden. STEP-BD has established procedures that are relevant to future collaborative research programs aimed at the systematic study of the complex, intrinsically important elements of bipolar disorders.

Evidence of heterogeneity within bovine satellite cells isolated from young and adult animals

Satellite cells are a heterogeneous population of myogenic precursors responsible for muscle growth and repair in mammals. The objectives of the experiment were to examine the growth rates and degree of heterogeneity within bovine satellite cells (BSC) isolated from young and adult animals. The BSC were harvested from the semimembranosus of young (4.3 ± 0.5 d) and adult (estimated 24 to 27 mo) cattle and cultured en masse. Young animal BSC re-enter the cell cycle sooner and reach maximal 5-ethynyl-2'-deoxyuridine (EdU) incorporation earlier (P < 0.05) than adult contemporaries. Adult BSC contain fewer (P < 0.05) MyoD and myogenin immunopositive nuclei than BSC isolated from young animals after 3, 4, and 5 d in culture. These results indicate that BSC from young animals activate, proliferate, and differentiate sooner than isolates from adult animals. Lineage heterogeneity within BSC was examined using antibodies specific for Pax7 and Myf5, lineage markers of satellite cells, and myoblasts. Immunocytochemistry revealed the majority of Pax7-expressing BSC also express Myf5; a minor population (~5%) fails to exhibit Myf5 immunoreactivity. The percentage of Pax7:Myf5 BSC from young animals decreases sooner (P < 0.05) in culture than adult BSC, indicating a more rapid rate of muscle fiber formation. A subpopulation immunopositive for Myf5 only was identified in both ages of BSC isolates. The growth kinetics and heterogeneity of young BSC was further evaluated by clonal analysis. Single cell clones were established and analyzed after 10 d. Colonies segregated into 2 groups based upon population doubling time. Immunostaining of the slow-growing colonies (population doubling time ≥ 3 d) revealed that a portion exhibited asymmetric distribution of the lineage markers Pax7 and Myf5, similar to self-renewable mouse muscle stem cells. In summary, these results offer insight into the heterogeneity of BSC and provide evidence for subtle differences between rodent and bovine myogenic precursors.

Frequency of specific CD8+ T cells for a promiscuous epitope derived from Trypanosoma cruzi KMP-11 protein in chagasic patients

The K1 peptide is a CD8(+)T cell HLA-A*0201-restricted epitope derived from the Trypanosoma cruzi KMP-11 protein. We have previously shown that this peptide induces IFN-gamma secretion by CD8(+)T cells. The aim of this study was to characterize the frequency of K1-specific CD8(+)T cells in chagasic patients. Nineteen HLA-A2(+)individuals were selected from 50 T. cruzi infected patients using flow cytometry and SSP-PCR assays. Twelve HLA-A*0201(+)noninfected donors were included as controls. Peripheral blood mononuclear cells were stained with HLA-A2-K1 tetramer, showing that 15 of 19 infected patients have K1-specific CD8(+)T cells (0.09-0.34% frequency) without differences in disease stages or severity. Of note, five of these responders were A*0205, A*0222, A*0226, A*0259 and A*0287 after molecular typing. Thus, a phenotypic and functional comparison of K1-specific CD8(+)T cells from non-HLA-A*0201 and HLA-A*0201(+)infected patients was performed. The results showed that both non-HLA-A*0201 and HLA-A*0201(+)individuals have a predominant effector memory CD8(+)T cell phenotype (CCR7-, CD62L-). Moreover, CD8(+)T cells from non-HLA-A*0201 and HLA-A*0201(+)individuals expressed IL-2, IFN-gamma and perforin without any differences. These findings support that K1 peptide is a promiscuous epitope presented by HLA-A2 supertype molecules and is highly recognized by chagasic patients.

Academic-community partnership: an orientation for employees of a community mental health agency to its research program

CONTEXT

Community agency employees' interest and involvement in academic-community research partnerships are keys to successful collaborations. One main barrier to success can be employees' lack of knowledge about research. We present data on an "orientation to research" program for community agency employees in a large U.S. city designed to improve knowledge about research in general and that specific to the agency.

METHODS

We developed an agency intranet website, a scavenger hunt to facilitate learning through the intranet research website, and a ten-item quantitative knowledge assessment tool. Academic and agency partners were actively involved in the design of the program and its evaluation.

FINDINGS

More educated and long-term employees had higher pre-test scores but not post-test scores. Significant improvement in post-test scores was observed for employees after completion of the program. Informal feedback about course content and the academic-community partnership was positive.

CONCLUSIONS

This report examines the feasibility of a structured knowledge program targeted at community agency employees at all levels within an agency. We believe that this approach is generalizable to other settings to the extent that there are shared interests, resources, and investment of the academic partner and agency.

In situ reverse transcription, an approach to characterize genetic diversity and activities of prokaryotes

Reverse transcription of RNA molecules inside intact bacterial cells was carried out by using reverse transcriptase with a single oligonucleotide complementary to specific 16S rRNA or mRNA sequences. Fluorescently labeled nucleotides were incorporated into each transcribed cDNA inside cells. This protocol is termed in situ reverse transcription (ISRT). In this study, by using species-specific primers targeting unique regions of the 16S rRNA sequences, ISRT was used successfully to detect and enumerate the two lignin-degrading bacteria Microbulbifer hydrolyticus IRE-31 and Sagittula stellata E-37 in culture mixtures and complex enrichment communities selected for lignin degradation. Image analysis revealed that M. hydrolyticus IRE-31 and S. stellata E-37 accounted for approximately 30 and 2%, respectively, of the total bacterial cells in lignin enrichment communities. Populations estimated by ISRT were comparable to those estimated by in situ hybridization (ISH) techniques and to those estimated by hybridization against extracted community DNA. ISRT was also successfully used to detect Pseudomonas putida F1 expressing the todC1 gene in seawater exposed to toluene vapor. ISRT provided a higher signal intensity than ISH, especially when targeting mRNA. The calculated pixel intensities resulting from ISRT were up to 4.2 times greater than those from ISH. This suggests that multiple incorporation of fluorescently labeled nucleotides into cDNA provides a high sensitivity for phylogenetic identification of bacterial populations as well as detection of cells expressing a specific functional gene within complex bacterial communities.

CRISPR elements in the Thermococcales: evidence for associated horizontal gene transfer in Pyrococcus furiosus

The presence and distribution of CRISPR (clustered regularly interspaced short palindrome repeat) elements in the archaeal order Thermococcales were analyzed. Four complete genome sequences from the species Pyrococcus abyssi, P. furiosus, P. horikoshii, and Thermococcus kodakaraensis were studied. A fragment of the genome of P. furiosus was flanked by CRISPR elements upstream and by a single element downstream. The composition of the gene sequences contained in this genome fragment (positions 699013 to 855319) showed significant differences from the other genes in the P. furiosus genome. Differences were observed in the GC content at the third codon positions and the frequency of codon usage between the genes located in the analyzed fragment and the other genes in the P. furiosus genome. These results represent the first evidence suggesting that repeated CRISPR elements can be involved in horizontal gene transfer and genomic differentiation of hyperthermophilic Archaea.

Influence of Ala54Thr polymorphism of fatty acid-binding protein 2 on histological alterations and insulin resistance of non alcoholic fatty liver disease

A transition G to A at codon 54 of fatty acid binding protein type 2 (FABP2) produces an amino acid substitution (Ala 54 to Thr 54). This amino acid substitution was associated with modifications of insulin resistance, adipokines and insulin concentrations. The aim of this study was to evaluate the influence of Ala54Thr polymorphism in the FABP2 gene on the histological alterations of non-alcoholic fatty liver disease (NAFLD) and insulin resistance. Thirty subjects with the presence of biopsy-proven NAFLD were enrolled for this study. Glucose, Insulin, Insulin resistance (HOMA), total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, resistin, leptin, adiponectin, interleukin-6 and TNF-alfa serum levels were measured at basal time. A tetrapolar bioimpedance, BMI, waist circumference, waist to hip ratio, blood pressure and a prospective serial assessment of nutritional intake with 3 days written food records were examined. Genotype of Ala54Thr FABP2 gene polymorphism was studied. The mean age was 41.6 +/- 11 years and the mean BMI 29.2 +/- 6.6 with 24 males (80%) and 6 females (20%). Fifteen patients (50%) had the genotype Ala54/Ala54 (wild type group) and 15 (50%) patients Ala54/Thr54 (13 patients) or Thr54/Thr54 (2 patients) (mutant type group). Both genotype groups have the similar anthropometric parameters. Serum aspartate aminotransferase and alcaline phosfatase were higher in wild type group than mutant type group, with an unclear explanation. Dietary intake was similar in both groups. A non-statistical significant low levels of adiponectin in mutant group was observed. No differences were detected among other adipokines. There were no differences between genotypes in histological results of inflammation (portal or lobular inflammation) or grade of steatosis or fibrosis. In conclusion, the present study demonstrates that the polymorphism Ala54Thr of FABP in patients with NAFLD doesn't predict liver histological changes, nor both insulin resistance and serum adipokines variations.

Three different phototrophic microbial communities colonizing a single natural shelter containing prehistoric paintings

Three different cases of deterioration were identified in a single natural shelter containing prehistoric paintings. The microbial communities induced by run-off water, a black crust covering a portion of the shelter, and a cryptoendolithic microbial community, were studied. Molecular analyses based both on DNA and RNA were performed to identify the major components of these microbial communities present and metabolically active, respectively, at the studied location. While similar microbial communities were expected due to the proximity of the studied sites, clearly different communities were detected suggesting that specific microorganisms adapt to different micro-environments. Phototrophic microorganisms represented the major portion of total RNA and DNA in the studied microbial communities. Run-off water induced the presence of a large proportion of putative photosynthetic bacteria belonging to Chloroflexi. Different groups of bacteria were associated to phototrophs and were represented by Alpha, Beta, Delta, and Gammaproteobacteria, Acidobacteria, Actinobacteria, Bacteroidetes, and Planctomycetes. The present study confirms a need for careful monitoring of microbial communities associated to distinct cases of deterioration even within a single location, underlining the interest of phototrophic microorganisms as indicators of colonization on cultural heritage at natural shelters.

Pigment profiles and bacterial communities from Thailand thermal mats

Differently colored layers of freshwater hot spring mats at Boekleung (Western Thailand) were studied. Temperatures ranged from over 50 up to 57 degrees C. Two mats were characterized: a laminated mat with a green and a red layers, and a monolayer, greenish-yellow mat. Bacterial communities in green, red, and yellow layers were investigated using molecular, culturing and pigment analysis methods. Pigment profiles covered a wide spectrum from chlorophylls to carotenoids. A green mat layer showed higher relative content of chlorophyll than yellow and red layers which presented higher proportion of carotenoids. Cyanobacterial isolates grow up to 55-56 degrees C and their pigment profiles showed a relatively high content of chlorophylls suggesting the importance of other bacterial groups in the mat pigment profiles. Bacterial communities were analyzed by 16S rDNA surveys showing Cyanobacteria and Chloroflexi as the mayor components of the community. Other significant members were Candidate Division OP10, Bacteroidetes, Planctomycetes and Actinobacteria. These results highlight a major participation of Cyanobacteria and Chloroflexi in thermal mat communities, and the preferential presence of Candidate Division OP10 in green mat layers. Differently colored mat layers showed characteristic bacterial communities which could be discriminated from pigment profiles and molecular surveys.

Effect of ractopamine-hydrochloride on the fiber type distribution and shelf-life of six muscles of steers

The goal of this study was to evaluate the effects of ractopamine-hydrochloride (RAC) supplementation on the myosin heavy chain isoform distribution and shelf-life properties of muscles from beef top round, knuckle, and loin. Thirty-four steer carcasses were selected from 4 separate slaughter groups. Within each slaughter group (3 groups, n = 8; 1 group, n = 10), steers were separated into pens (n = 8) and fed 0 or 200 mg x animal(-1) x d(-1) of RAC for the final 28 d of feeding. Seventy-two hours postmortem, the longissimus lumborum, semimembranosus (SM), adductor, gracilis, vastus lateralis (VL), and rectus femoris were removed from each carcass. A subsample of each muscle was collected for immunohistochemical analysis. Whole muscles were vacuum packaged and wet aged at 1 +/- 2 degrees C for 13 d before processing into steaks for a 5-d simulated retail display study. Daily, steaks were analyzed for reduction of nitric oxide metmyoglobin, lean color, fat color, and surface discoloration. Objective measures of metmyoglobin, oxymyoglobin, L*, a*, and b* values were recorded daily. Ractopamine significantly (P < 0.05) changed the fiber type isoform distribution in all muscles except the SM. The VL and gracilis presented the greatest fiber type switch with approximately 21% of type I fibers switching to type IIA fibers. However, the fiber type shifts induced by RAC supplementation had little to no effect on subjective and objective color measurements during the 5-d retail display period. Metmyoglobin and oxymyoglobin accumulation, L*, a*, and b*-values were not affected (P > 0.05) by RAC supplementation. Percent nitric oxide metmyoglobin reduction data indicate that reducing ability of RAC-treated steaks from the adductor and longissimus lumborum were significantly affected (P < 0.05). Visual panel data suggest that RAC tended (P < 0.10) to have the most detrimental effect on the lean color and surface discoloration scores of steaks from the VL during the last 3 d of display. Ractopamine significantly (P < 0.05) increased the surface discoloration of the rectus femoris and SM on d 5. Although RAC supplementation had no effect on objective color measurements, subjective measurements indicate that it may have some effect on surface discoloration of some muscles.

Isolation of five Rubrobacter strains from biodeteriorated monuments

In the last few years, the microbial colonisation of mural paintings in ancient monuments has been attracting the attention of microbiologists and conservators. The genus Rubrobacter is commonly found in biodeteriorated monuments, where it has been reported to cause rosy discolouration. However, to date, only three species of this genus have been isolated, all from thermophilic environments. In this paper, we studied three monuments: the Servilia and Postumio tombs in the Roman Necropolis of Carmona (Spain), and Vilar de Frades church (Portugal), in search of Rubrobacter strains. In all cases, biodeterioration and the formation of efflorescences were observed, and five Rubrobacter strains were isolated. These isolates showed different physiology and migration in denaturing gradient gel electrophoresis, suggesting they might represent new species within this genus. The isolates reproduced some biodeterioration processes in the laboratory and revealed their biomediation in crystal formation.

Effect of a hypocaloric diet in transaminases in nonalcoholic fatty liver disease and obese patients, relation with insulin resistance

OBJECTIVE

The aim of our study was to examine the changes in hypertransaminasemia after weight reduction in obese patients with and without nonalcoholic fatty liver disease (NAFLD) and the relation with insulin resistance.

RESEARCH METHODS

A population of 142 obesity nondiabetic was treated with a hypocaloric diet (1520 kcal) during 3 months. Patients were classified as group I (control, n=112) when serum (alanine aminotransferase) ALT activity was normal or group II (NAFLD, n=30) when serum ALT activity was greater than the upper limit of normal reference laboratory (>or=43 UI/L).

RESULTS

In control group, body mass index (BMI) (35.3+/-5.6 vs. 33.5+/-5.5: p<0.05), weight (89.6+/-17.2 kg vs. 85.6+/-16.5 kg: p<0.05) and insulin (15+/-7.9 mUI/L vs. 13.1+/-7.4 mUI/L: p<0.05) levels decreased. In NAFLD group, BMI (37.1+/-4.2 vs. 35.1+/-4.6: p<0.05), weight (101+/-22 kg vs. 96.4+/-11.6 kg: p<0.05), insulin (26.8+/-8.9 mUI/L vs. 12.7+/-8.4 mUI/L: p<0.05) and HOMA (3.1+/-1.6 vs. 1.9+/-1.7: p<0.05) decreased. Liver function improved in both groups (ALT; group I 19.9+/-4.6 UI/L vs. 18.3+/-3.9 UI/L: p<0.05 and group II 37.8+/-4.2 UI/L vs. 27.1+/-7.8 UI/L: p<0.05), (aspartate aminotransferase activity, AST) group I 22.1+/-8.2 UI/L vs. 19.9+/-7.1 UI/L: p<0.05 and group II 73.3+/-11.3 UI/L vs. 38.1+/-11.6UI/L: p<0.05).

CONCLUSION

We showed that weight reduction secondary to a hypocaloric diet were associated with improvement in hypertransaminasemia and insulin resistance in NAFLD patients.

Metabolically active microbial communities of yellow and grey colonizations on the walls of Altamira Cave, Spain

AIMS

To determine the major components of total and metabolically active microbial communities of yellow and grey colonizations threatening the conservation of palaeolithic paintings in Altamira Cave (Spain).

METHODS AND RESULTS

Micro-organisms present in yellow and grey colonizations were determined from DNA analysis with those showing metabolic activity determined from RNA analysis. Microbial community fingerprints were obtained by denaturing gradient gel electrophoresis (DGGE) and 16S rDNA libraries were constructed from PCR amplified products. Proteobacteria was the most frequent bacterial phylum. Other phyla detected from RNA-based microbial surveys were Acidobacteria, Actinobacteria, Firmicutes, Nitrospirae and Gemmatimonadetes. The detected metabolically active micro-organisms represented only a fraction of the total bacterial community present in the studied colonizations as compared from DGGE analysis.

CONCLUSIONS

The major bacterial participants in the development of yellow and grey colonizations in Altamira Cave were determined using RNA-based molecular techniques. Micro-organisms showing undetectable activity represent a potential risk for the conservation of these paintings if environmental conditions experience variations.

SIGNIFICANCE AND IMPACT OF THE STUDY

Caves with palaeolithic paintings are affected by microbial deterioration. Assessing the composition of the microbial communities colonizing these caves represents a first stage to understand and control these colonizations.