PSVI-4 Efficacy of Medium Chain Fatty Acids and Fatty Acid-based Feed Additives as a Mitigation Strategy Against Porcine Epidemic Diarrhea Virus and Porcine Reproductive and Respiratory Syndrome Virus

Recent research has demonstrated that swine viruses can be transmitted via feed. Chemical feed additives have been suggested for the mitigation of these viruses in complete feed. Therefore, the objective of this study was to evaluate the efficacy of a commercially available formaldehyde-based feed additive, medium chain fatty acid blend (MCFA), and commercially available fatty acid-based products for mitigation of porcine epidemic diarrhea virus (PEDV) and porcine reproductive and respiratory syndrome virus (PRRSV) in a feed matrix. Treatments consisted of: 1) non-treated positive control, 2) 0.33% commercial formaldehyde-based product (Sal Curb; Kemin Industries, Inc.; Des Moines, IA), 3) 0.5% MCFA blend (1:1:1 ratio of C6:0, C8:0, and C10:0, Sigma Aldrich, St. Louis, MO), 4) 0.25%, 5) 0.5%, or 6) 1% of commercial dry mono and diglyceride-based product (Furst Strike; Furst-McNess Company, Freeport, IL), 7) 0.25%, 8) 0.5%, or 9) 1% of commercial dry mono and diglyceride-based product (Furst Protect; Furst-McNess Company, Freeport, IL), 10) 0.25%, 11) 0.5%, or 12) 1% dry mono and diglyceride-based experimental product (Furst-McNess Company, Freeport, IL) with 3 replications/treatment. Treatments were applied to complete swine feed before inoculation with 106 TCID50/g of feed with PEDV or PRRSV. Post inoculation feed was held at ambient temperature for 24 h before being analyzed via qRT-PCR. The analyzed values represent the cycle threshold. Formaldehyde and MCFA decreased (P < 0.05) the detectable RNA of PEDV and PRRSV compared to all other treatments. Furst Strike, Furst Protect, and the experimental product did not significantly impact detectability of PEDV or PRRSV RNA. In conclusion, MCFA and formaldehyde treatments are effective at reducing detection of RNA from PEDV and PRRSV in feed.

PSVI-7 Evaluation of Feed Mitigant Efficacy for Control of Porcine Epidemic Diarrhea Virus and Porcine Reproductive and Respiratory Syndrome Virus When Inoculated Either Alone or Together

Research has demonstrated that swine feed can be a fomite for viral transmission and certain feed additives can effectively reduce viral contamination. However, additional information is needed to evaluate the efficacy of additives when feed is inoculated with more than one virus. The objective of this study was to evaluate the efficacy of two feed additives for mitigation of porcine epidemic diarrhea virus (PEDV) and porcine reproductive and respiratory syndrome virus (PRRSV) when inoculated individually or together. Feed additives included: 1) no treatment, 2) 0.33% commercial formaldehyde-based product (Sal Curb, Kemin Industries, Des Moines, IA), and 3) 0.50% medium chain fatty acids blend (MCFA; 1:1:1 ratio of C6:C8:C10, Sigma Aldrich, St. Louis, MO). Samples were inoculated with PEDV and PRRSV alone or together at an inoculation concentration of 106 TCID50/g for all viruses. Once inoculated, feed was stored at ambient temperature for 24-h before analyzed via qRT-PCR. For samples inoculated with PEDV or PRRSV alone, a qRT-PCR assay was used which was designed to detect PEDV or PRRSV nucleic acid. For co-inoculated samples, an assay was designed to independently detect both PEDV and PRRSV within a single reaction. For PEDV alone, there was marginally significant evidence that feed additives resulted in differences in cycle threshold (Ct) value (P = 0.052), but no evidence was observed for pairwise differences. For PRRSV alone, formaldehyde increased Ct compared to the untreated control and MCFA treatment (P < 0.05). For co-infection of PRRSV and PEDV, MCFA and formaldehyde increased Ct (P < 0.05) in comparison to non-treated feed. In summary, formaldehyde increased Ct values in feed when contaminated with PRRSV while both mitigants increased Ct value in feed when co-inoculated with PRRSV and PEDV.

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A comprehensive review of oral glucosamine use and effects on glucose metabolism in normal and diabetic individuals

Glucosamine (GlcN) is a widely utilized dietary supplement that is used to promote joint health. Reports that oral GlcN supplementation at usual doses adversely affects glucose metabolism in subjects with impaired glucose tolerance have raised concerns that GlcN should be contraindicated in individuals with diabetes and those at risk for developing it. This review addresses its potential, when used at typical doses, to affect glucose metabolism and insulin sensitivity in healthy individuals and those with diabetes or 'pre-diabetes'. Publicly available scientific information and data on GlcN were systematically compiled using the electronic search tool, Dialog , and reviewed with special emphasis on human studies. In long-term clinical trials, including those containing subjects with type 2 diabetes or 'pre-diabetes', GlcN produced a non-significant lowering of fasting blood glucose concentrations in all groups of subjects treated for periods of up to 3 years. Owing to limitations in study design, conclusions based on studies that report adverse affects of GlcN on insulin sensitivity and glucose tolerance in pre-diabetic subjects are suspect. However, no definitive long-term studies of GlcN use for individuals with pre-diabetes are available. Nevertheless, based on available evidence, we conclude that GlcN has no effect on fasting blood glucose levels, glucose metabolism, or insulin sensitivity at any oral dose level in healthy subjects, individuals with diabetes, or those with impaired glucose tolerance.

Adenosine 5'-sulphatophosphate kinase activity in spinach leaf tissue

1. An F(-)-insensitive 3'-nucleotidase was purified from spinach leaf tissue; the enzyme hydrolysed 3'-AMP, 3'-CMP and adenosine 3'-phosphate 5'-sulphatophosphate but not adenosine 5'-nucleotides nor PP(i). The pH optimum of the enzyme was 7.5; K(m) (3'-AMP) was approx. 0.8mm and K(m) (3'-CMP) was approx. 3.3mm. 3'-Nucleotidase activity was not associated with chloroplasts. Purified Mg(2+)-dependent pyrophosphatase, free from F(-)-insensitive 3'-nucleotidase, catalysed some hydrolysis of 3'-AMP; this activity was F(-)-sensitive. 2. Adenosine 5'-sulphatophosphate kinase activity was demonstrated in crude spinach extracts supplied with 3'-AMP by the synthesis of the sulphate ester of 2-naphthol in the presence of purified phenol sulphotransferase; purified ATP sulphurylase and pyrophosphatase were also added to synthesize adenosine 5'-sulphatophosphate. Adenosine 5'-sulphatophosphate kinase activity was associated with chloroplasts and was released by sonication. 3. Isolated chloroplasts synthesized adenosine 3'-phosphate 5'-sulphatophosphate from sulphate and ATP in the presence of a 3'-nucleotide; the formation of adenosine 5'-sulphatophosphate was negligible. In the absence of a 3'-nucleotide the synthesis of adenosine 3'-phosphate 5'-sulphatophosphate was negligible, but the formation of adenosine 5'-sulphatophosphate was readily detected. Some properties of the synthesis of adenosine 3'-phosphate 5'-sulphatophosphate by isolated chloroplasts are described. 4. Adenosine 3'-phosphate 5'-sulphatophosphate, synthesized by isolated chloroplasts, was characterized by specific enzyme methods, electrophoresis and i.r. spectrophotometry. 5. Isolated chloroplasts catalysed the incorporation of sulphur from sulphate into cystine/cysteine; the incorporation was enhanced by 3'-AMP and l-serine. It was concluded that adenosine 3'-phosphate 5'-sulphatophosphate is an intermediate in the incorporation of sulphur from sulphate into cystine/cysteine.

The Effect of Genetic Increases in Egg Production and Age and Sex on Breast Muscle Development of Turkeys

Pectoralis major muscle morphology was studied in both sexes of a turkey line (E) selected long-term for increased egg production and its randombred control (RBC1) from 25 d of incubation through 20 wk posthatch. Pectoralis major muscle samples from 10 individuals from each line-sex-age subgroup were obtained in a manner to prevent contraction. The muscle samples were dehydrated, cleared, embedded in paraffin, sectioned, incubated, and rehydrated before staining with hematoxylin and eosin. Representative sections were given a score by 4 individuals based on breast muscle morphology. The scores ranged from 1 (little extracellular matrix and indistinct muscle fibers) to 5 (large extracellular space and distinct muscle fibers). Scores from 2 to 4 were intermediate to these extremes. The pectoralis major muscle morphology scores were highest at 25 d of incubation and declined greatly at 1 wk of age. The scores increased from 1 to 4 wk of age and remained constant through 20 wk of age. Males had higher scores than females. In the current study, there was no significant difference between the E and RBC1 lines. Based on the results of 3 experiments (2 published and the present one) using the E and RBC1 lines, it appears that genetic increases in egg production may be associated with a slight reduction in pectoralis major muscle morphology scores at 16 wk of age.

Health and safety intervention with first-time mothers

A health education program was evaluated which used child development specialists as home visitors and served a population of first-time mothers living in rural communities. The evaluation compared health and safety outcomes between intervention and control groups. The research staff, separate from the intervention staff, collected data in the homes of 156 intervention and 107 control mothers when the infants were 6 and 12 months old. Significant group differences were found on health and safety outcomes. As compared with controls, the intervention mothers (i) had safer homes; (ii) were more likely to use birth control, thus had fewer pregnancies since birth of their first child; (iii) reported smoking fewer cigarettes; (iv) knew more about effects of smoking on their child's health and (v) were more likely to use health department services. In sum, mothers who received early education home visits from child development specialists experienced positive health and safety outcomes. It is highly recommended that a program such as this be implemented as part of health delivery program with new mothers and infants.

Genetics of growth and reproduction in the turkey. 16. Effect of repeated backcrossing of an egg line to a commercial sire line

The turkey industry's view of the relative economic importance of growth and egg production has changed rapidly, and genetic changes by selection within lines may not be rapid enough to meet the changing needs. The objective of the present study was to determine the feasibility of rapidly increasing the BW of dam lines by repeated backcrossing of a dam line (E) to a commercial sire line (B). The experimental E line was selected long-term for increased egg production and was used as the model for a turkey dam line. The B line was larger (more than 3-fold) in BW at 8, 16, and 20 wk of age, had wider breasts (approximately 1.8-fold) at 16 wk of age, and had lower egg production for 180 d (about 3-fold) than the E line. Based on additive genetic variation, males in the F1 generation of the B x E cross did not differ from expected in BW at any age, but females of this cross had BW less than expected at 16 and 20 wk of age. In the F1 generation, breast width of the cross did not differ from the expected value, but egg production for 180 d was greater than expected (126.6 vs.102.3 eggs/hen). After 3 generations of backcrossing, the backcrosses exhibited a gain in 20-wk BW of 12.5 and 8.8 kg, respectively, for males and females; a gain of 5.9 and 5.3 cm in breast width at 16 wk of age for males and females, respectively; and a loss of 74.1 eggs per hen over a 180-d production period. Based on the results of the current and a previous study, limited backcrossing of a dam line to a sire line may be an economically feasible method to greatly increase the BW of dam lines without unduly sacrificing egg production. For maximum gains per generation, backcrossing probably should be used for a maximum of 2 or 3 generations.

Weight loss and long-term follow-up of severely obese individuals treated with an intense behavioral program

OBJECTIVE

To review weight loss and maintenance for severely obese individuals enrolled in intensive behavioral weight loss program using very-low or low-energy diets.

DESIGN

Chart review of consecutively treated patients between 1995 and 2002 seen at three weight loss centers.

SUBJECTS

One thousand five hundred and thirty one patients with severe obesity (>or=40 kg/m(2)) treated in three cities ('Study Group'). Of these, 1100 completed the 12-week core curriculum ('Completer Group'). Weight loss >or=100 lbs (>45 kg) was seen in 268 patients ('100-Pound Group').

MEASUREMENTS

Charts were reviewed for baseline characteristics, weekly weights, follow-up weights and side effects.

RESULTS

In the Study Group, average weight loss+/-s.e. for 998 women was 23.9+/-0.6 kg (18.5% of initial body weight (IBW)) and for 533 men was 36.0+/-1.0 kg (22.5%) over 30 weeks. For Completers, average weight loss for women was 30.8+/-0.6 kg (23.9%) and for men was 42.6+/-1.1 kg (26.7%) over 39 weeks. In the 100-Pound Group, average weight loss for women was 58.2+/-1.2 kg (41.5%) in 65 weeks and for men was 65.7+/-1.5 kg (37.5%) in 51 weeks. Side effects, assessed in 100 patients losing >45 kg, were mild to moderate in severity. Severe adverse events unrelated to the diet were noted in 5% of patients and during weight loss 1% had elective cholecystectomies. Follow-up weights were available for 86% of Completers at an average of 72 weeks with average maintenance of 23 kg or 59% of weight loss; follow-up weights were available for 94% of the 100-Pound Group at an average of 95 weeks with average maintenance of 41 kg or 65% of weight loss maintained.

CONCLUSIONS

Intensive behavioral treatment with meal replacements is a safe and effective weight-loss strategy for selected severely obese individuals.

Investigating the fundamentals of IMRT decomposition using ten simple collimator models

The fundamentals of IMRT collimation have been studied using ten conceptual collimators. Spanning a range of complexities from the LINAC jaws alone to a full multi-leaf collimator (MLC), these collimators were designed with two abilities in mind: (1) to be able to define arbitrary field shapes, and (2) to be able to irradiate multiple, disconnected regions in a single segment. The collimators were tested by finding decompositions of random and clinical intensity-modulated beams (IMBs), and collimator performance was measured using both the number of segments required to complete the IMB and the monitor-unit efficiency of the treatment. The decompositions were run on 10 x 10 IMBs with integer bixel values randomly between 1 and 10, and clinical IMBs of varying sizes from lung, head and neck, and pelvic patients taken from a Pinnacle treatment-planning system. Results confirmed that although treatment performance improves with increased collimator complexity, it is not solely dependent on the number of segment shapes deliverable by the collimator but instead on how well these shapes lend themselves to IMRT delivery.

Genetic variation in pure lines and crosses of large-bodied turkeys. 4. Body shape and carcass traits

An experimental line (F) of turkeys selected long-term for increased 16-wk BW was reciprocally crossed with a primary breeding sire line (C) from a major international turkey breeder to study the inheritance of carcass traits and body shape. The birds were weighed and killed at 16 wk of age, and various measurements of muscling, leg bones, and body shape were made. The BW of males were 16.0 and 15.1 kg, respectively, in the C and F lines. The respective BW for females were 12.2 and 11.2 kg. Additive genetic variation, as indicated by differences between the F and C line, was a more important source of variation for measurements of muscling than for measurements of leg bones. The anterior and posterior depth of the body and the ratio of these measurements differed between the F and C lines. Body cavity volume index (length x width x height) differed between lines in females and sexes combined. The weights of some internal organs (gizzard, heart, liver, pancreas, and spleen), but not others (proventriculus and lungs), differed between lines, and the total weight of these organs was greater in the C line than in the F line. However, the ratio of total demand organs (muscles and bones) to the total weight of the supply organs was less in the F line than in the C line. Heterosis was a more important source of variation in body weight and weights of the pectoralis major and pectoralis minor muscle weights in males than in females. Heterosis for some body shape measurements (keel length, body depth 1, body depth 2, body depth ratio, body cavity height, and body cavity volume index) was significant in some comparisons. Heterosis (range = 3.64 to 3.99%) for leg muscle measurements (thigh muscles, drumstick muscles, and total leg muscles) was highly significant (P < or = 0.01) based on the analysis for both sexes. Differences between the reciprocal crosses of the F and C lines were more frequent in the present study than in previous studies in which the F line was reciprocally crossed with sire lines from 2 other commercial breeders. However, when the data from the previous studies and the current study were summarized, it appeared that the only reciprocal effect that was consistent was for the weight of the drumstick muscles, indicating sex linkage or maternal effects may influence the weight of these muscles.

Comparative efficiency of the multi-leaf collimator and variable-aperture collimator in intensity-modulated radiotherapy

The potential of the variable-aperture collimator (VAC) in intensity-modulated radiation therapy (IMRT) has been evaluated by comparing its performance with that of the multi-leaf collimator (MLC). This comparison used a decomposition algorithm to find the series of collimator segments that would treat a given intensity-modulated beam (IMB). Collimator performance was measured using both the number of segments required to complete the IMB and the monitor-unit efficiency of the treatment. The VAC was modelled with aperture sizes from 4 x 4 cm to 20 x 20 cm, and these apertures were allowed to be located anywhere within the IMB. To enable a direct comparison, a similar scanning MLC was modelled at the same range of aperture sizes. Using both collimators, decompositions were run on 10 x 10 and 20 x 20 random IMBs with integer bixel values ranging from 1 to 10. Clinical IMBs from lung, head and neck, and pelvic patients were taken from a Pinnacle treatment-planning system and tested in the same manner. It was found that for all treatment sites, a small, scanning MLC performs as well or better than an equivalent sized VAC in both number of segments and monitor-unit efficiency, and would be an efficient choice for centres looking for a simple collimator for IMRT.

Genetic variation in pure lines and crosses of large-bodied turkey lines. 3. Growth-related measurements on live birds

An experimental line (F) selected over 34 generations for increased 16-wk BW was reciprocally crossed with a primary breeding sire line (C) from a large international turkey breeder to study the inheritance of growth-related traits measured on live birds. All genetic groups were grown intermingled in confinement with sexes reared in different houses. The traits measured included BW at 8, 16, and 20 wk of age and shank length, shank width, shank depth, breast width, and walking ability scores at 16 wk of age. Walking ability was rated from 1 to 5 with 1 representing birds with no leg defects and no difficulty walking and 5 indicating birds with extreme lateral deviations of the legs and great difficulty walking. Ratings of 2, 3, and 4 represented intermediate values. The F line had a different growth pattern than the C line with the F line being larger than the C line at 8 wk of age, but the reverse was true at 16 and 20 wk of age. The difference in BW between the C and F lines increased from 16 to 20 wk of age. The C line had wider breasts than the F line at 16 wk of age. The F line had longer shanks than the C line. Shank width was larger in the C line than the F line for females but not males. No line difference in shank depth was observed. Walking ability scores at 16 wk of age were lower (better) in the C line than in the F line for males but not females. Significant heterosis in BW of the crosses of the F and C lines was observed at all ages in males (range = 3.3 to 5.6%) and only at 8 wk of age in females (3.6%). These results were similar to an earlier study in which the F line was crossed with a primary-breeding sire line from 2 other international turkey breeders. No significant heterosis in the crosses of the C and F line was observed for breast width and shank measurements. Heterosis was significant for walking ability scores of females (-3.0%) but not males. Reciprocal effects, a measure of sex linkage and maternal influences, were noted only for shank length and the direction of the difference was not the same in the 2 sexes.

Effect of soy protein-rich diet on renal function in young adults with insulin-dependent diabetes mellitus

BACKGROUND

Diabetic nephropathy is the most frequent cause of end-stage renal disease in the Western world. Dietary intake, including protein amount and type, seems to affect the progression of renal disease. This pilot study tested the hypothesis that substituting soy protein for animal protein in the diets of diabetics would help correct glomerular hyperfiltration.

METHODS

Twelve young adults (aged 29.9 +/- 2.4 years) with type 1 diabetes mellitus (duration of diabetes 15.1 +/- 2.3 years) and hyperfiltration (glomerular filtration rate, GFR > 120 ml/min/1.73 m2) completed a crossover, dietary intervention trial. After a four-week assessment of baseline characteristics and dietary habits, subjects were assigned to either a control or soy diet for eight weeks after which each subject was crossed over to the alternative diet for another eight-week period.

RESULTS

Mean GFR was significantly reduced (p < 0.02) after eight weeks on the soy diet (143 +/- 7.4 ml/min/1.73 m2) compared with baseline (159 +/- 7.7 ml/min/ 1.73 m2) and control diets (161 +/- 10.0 ml/min/1.73 m2). Urinary excretion of the soy isoflavones was significantly higher (p < 0.01) at the end of the soy diet (genistein 1,014.6 +/- 274.1 nmol/h, daidzein 2,645.1 +/- 989.6 nmol/h) compared with baseline (genistein 53.7 +/- 31.1 nmol/h, daidzein 151.1 +/- 74.1 nmol/h) and control diets (genistein 41.1 +/- 13.3 nmol/h, daidzein 127.5 +/- 54.0 nmol/h). The soy diet significantly reduced total and LDL cholesterol by 7% and 9%, respectively.

CONCLUSIONS

Implementation of a soy-based diet appears to reduce the GFR and total and LDL cholesterol of young adults with type 1 diabetes and glomerular hyperfiltration, thus affecting positively their clinical profile.

Glucosamine effects in humans: a review of effects on glucose metabolism, side effects, safety considerations and efficacy

Glucosamine is widely used to relieve symptoms from osteoarthritis. Its safety and effects on glucose metabolism are critically evaluated in this review. The LD50 of oral glucosamine in animals is approximately 8000 mg/kg with no adverse effects at 2700 mg/kg for 12 months. Because altered glucose metabolism can be associated with parenteral administration of large doses of glucosamine in animals and with high concentrations in in vitro studies, we critically evaluated the clinical importance of these effects. Oral administration of large doses of glucosamine in animals has no documented effects on glucose metabolism. In vitro studies demonstrating effects of glucosamine on glucose metabolism have used concentrations that are 100-200 times higher than tissue levels expected with oral glucosamine administration in humans. We reviewed clinical trial data for 3063 human subjects. Fasting plasma glucose values decreased slightly for subjects after oral glucosamine for approximately 66 weeks. There were no adverse effects of oral glucosamine administration on blood, urine or fecal parameters. Side effects were significantly less common with glucosamine than placebo or non-steroidal anti-inflammatory drugs (NSAID). In contrast to NSAID, no serious or fatal side effects have been reported for glucosamine. Our critical evaluation indicates that glucosamine is safe under current conditions of use and does not affect glucose metabolism.

Genetic Variation in Body Weight and Egg Production in an Experimental Line Selected Long Term for Increased Egg Production, a Commercial Dam Line, and Reciprocal Crosses Between Lines

A line (E) of turkeys selected long term (40 generations) for increased egg production was reciprocally crossed with a commercial dam line (BD). The BD line was larger and had better conformation than the E line, but the E line laid more eggs than the BD line. Heterosis was negative and significant for BW at 8, 16, and 20 wk of age (both sexes) and at 50% production (females only). Values for heterosis ranged from -3.1 to -5.5%. Negative heterosis was observed for breast width at 16 wk of age (10.8 and 3.0% for males and females, respectively). Positive heterosis values of 9.2, 10.2, and 11.3% were observed for egg production when based on 84, 120, and 180 d, respectively. Heterosis (-8.2%) was significant for rate of response to stimulatory lighting of 14 h light per day (days from stimulatory lighting to production of first egg). Based on data for a 180-d production period, heterosis was observed in average clutch length (12.6%) and rate of lay [number of eggs laid: (180 - total days broody)] (8.2%) but not in total days lost from broodiness or the effective length of the laying period (180 minus days lost in periods of 5 or more consecutive days at the end of the laying period). The present results along with those in the literature suggest that more heterosis in egg production traits might be expected in crosses of lines exhibiting extreme differences in BW and body conformation. The negative heterosis in BW in the BD and E reciprocal crosses reduces the commercial importance of such a cross to improve egg production.

Preovulatory surge patterns of luteinizing hormone, progesterone, and estradiol-17β in broiler breeder hens fed ad libitum or restricted fed

Spontaneous ovulations are induced by preovulatory surges of luteinizing hormone (LH) and progesterone (P4) during ovulatory cycles in birds, but estradiol-17beta (E2) levels are relatively constant. Egg production is enhanced in restricted fed (RF) in comparison with ad libitum fed (FF) broiler breeder hens, but changes in concentrations and peripheral patterns of LH, P4, and E2 during ovulatory cycles in broiler breeder hens are poorly documented. The hypothesis of this study was that high resolution patterns of peripheral LH, P4, and E2 during preovulatory surges would not be different between FF and RF broiler breeder hens. Seven FF and 6 RF broiler breeder hens were photostimulated with 16 L:8 D at 22 wk of age. At 28 wk of age, the hens were cannulated for serial blood sampling and switched to a 24L:0D photoperiod to allow preovulatory surges of LH and P4 to run freely. Three days after cannulation, hens were serially bled every 12 min for 36 h. The FF hens were heavier than the RF hens (5.60 +/- 0.35 vs. 3.60 +/- 0.28 kg, respectively; P < 0.01). During the 10 d before cannulation, total egg production of the FF and RF hens (8.3 +/- 1.4 and 6.8 +/- 1.3 eggs, respectively; P = 0.08) and normal egg production (5.6 +/- 1.8 and 6.5 +/- 1.8 eggs, respectively; P = 0.37) were not different. The FF hens, however, had more abnormal eggs than the RF hens (2.7 +/- 1.7 and 0.3 +/- 0.8 eggs, respectively; P < 0.01). None of the hormonal measurements was different between the FF and RF hens (P > 0.05). The concentrations of hormones for the FF and RF hens, respectively, were as follows: baseline LH (2.79 +/- 0.45 vs. 2.94 +/- 0.60 ng/mL) and P4 (1.68 +/- 0.56 vs. 1.41 +/- 0.43 ng/mL), overall mean LH (3.18 +/- 0.45 vs. 3.10 +/- 0.46 ng/mL) and P4 (2.32 +/- 0.55 vs. 2.09 +/- 0.91 ng/ mL), preovulatory surge amplitude of LH (5.43 +/- 1.27 vs. 3.88 +/- 1.24 ng/mL) and P4 (6.08 +/- 2.09 vs. 6.71 +/- 3.91 ng/ mL), preovulatory surge duration of LH (7.52 +/- 1.80 vs. 5.74 +/- 3.18 h) and P4 (7.52 +/- 1.42 vs. 8.20 +/- 1.24 h), and overall mean E2 (0.25 +/- 0.05 vs. 0.23 +/- 0.05 ng/mL). In conclusion, there were no differences in total egg production or normal egg production between FF and RF broiler breeder hens, but the FF hens laid more abnormal eggs. Also, there were no differences in the concentrations or peripheral patterns of LH, P4, and E2 during preovulatory surges between the FF and RF broiler breeder hens.

Development of a cannulation procedure for broiler breeder hens

A cannulation and serial bleeding procedure has been developed to monitor the peripheral patterns of hormones associated with reproduction for up to 10 d in broiler breeder hens. Hens were cannulated via the jugular vein and returned to individual cages. The unrestrained cannulated hens were connected to a tether and swivel system that permitted constant infusion for maintenance of the cannula prior to serial bleeding and unrestrained long-term serial bleeding for up to 10 d. In a short-term experiment hens were bled every 12 min for 36 h, and in a long-term experiment hens were bled hourly for 10 d. In these experiments, 1.5-mL blood samples were collected at each time point with sodium citrate as the anticoagulant. To avoid hemodilution, after removal of plasma the red blood cells were reconstituted with saline to the original volume and returned to the hen of origin. Collection of serial blood samples was successful from 94% of hens in the short-term experiment and 79% of hens in the long-term experiment. Egg production was not affected (P > 0.05) during the 6 wk following serial bleeding in the short-term experiment. For hens that continued laying, egg production for 10 d prior to cannulation was not different (P > 0.05) from egg production for the 10 d during serial bleeding in the long-term experiment. However, late in the reproductive cycle many hens (25%) stopped laying when serially bled. It is concluded that this cannulation procedure can be used to study short-term or long-term peripheral patterns of hormones associated with oviposition and ovulation in laying broiler breeder hens.

Effect of selection for growth rate and inheritance on posthatch muscle development in turkeys

The inheritance of, and effect of selection for increased BW on, measurements of muscle fibers and extracellular space in turkeys were studied using a randombred control line (RBC2), a subline (F) of RBC2 selected long-term only for increased 16 wk BW, a commercial sire line (B), and reciprocal crosses of the F and B lines. Measures of additive genetic variation were obtained by comparing all of the pure lines or just the large-bodied F and B lines. Estimates of nonadditive genetic variation were obtained by contrasting the average of the reciprocal crosses with the average of the parental lines. A contrast of the reciprocal crosses provided estimates of sex linkage or maternal effects. Samples of pectoralis major muscle were obtained from three males and three females of each genetic group at 1, 4, 8, and 16 wk of age in a manner to avoid muscle contraction. After fixing and cross sectioning, the muscle samples were stained with hematoxylin and eosin to view muscle morphology. The stained sections were analyzed for muscle fiber width, muscle fiber bundle width (except at 16 wk of age), number of fibers within a 136-microm2 area, and extracellular matrix perimysial (PW) and endomysial (EW) width. Additive genetic variation, as measured by line differences, of measures of muscle fibers and extracellular matrix was a more important source of variation when the RBC2 line was included in the comparison. When all of the pure lines were compared, line differences were significant for fiber bundle width at 4 wk of age; individual fiber width and number of fibers in a given area at 4, 8, and 16 wk of age; PW at all ages; and EW at 1, 8, and 16 wk of age. With the possible exception of PW, nonadditive genetic variation was not an important source of variation for muscle measurements. For PW, the estimates of heterosis were -14.6, 26.4, 14.5, and 17.3% at 1, 4, 8, and 16 wk of age, respectively, but none of the values was significant (P > 0.05). Genetic increases in BW were associated with an increase in muscle fiber width, a smaller number of fibers in a given area, and less extracellular space at older ages. Apparent differences in growth patterns among the genetic groups may have been responsible for the different patterns of change in muscle measurements in the various genetic groups over ages.

Effect of selection for growth rate on muscle damage during turkey breast muscle development

Damage to the turkey pectoralis major muscle was studied in a randombred control line (RBC2), a subline (F) from the RBC2 line selected long-term for increased 16-wk BW only, and a commercial sire line (B) at 25 d of incubation and at 1, 4, 8, 16, and 20 wk posthatch. Pectoralis major muscle samples were obtained from three females and three males from each line in a manner to avoid contraction. After being fixed and sectioned, the muscle samples were stained with hematoxylin and eosin to view muscle fiber and muscle fiber bundle morphology. Beginning at 8 wk posthatch, differences in muscle fiber morphology were observed among the different lines. The RBC2 line throughout the duration of the study maintained well-organized muscle fibers and muscle fiber bundles with large capillary networks. In contrast, the growth-selected F line began to show muscle fiber degeneration at 8 wk posthatch, and limited capillary beds were observed as development proceeded. The B line had intermediate muscle morphology between the RBC2 and F lines, but by 20 wk posthatch significant muscle fiber degeneration was present with limited capillary supply. The degenerative muscle fiber changes were predominant in the growth-selected F-line, suggesting that growth selection for just BW may be associated with posthatch muscle damage.

Effect of selection for growth rate on embryonic breast muscle development in turkeys

Muscle development at 20 and 25 d of incubation was studied in a randombred control line (RBC2), a subline (F) of RBC2 selected only for increased 16-wk BW, a commercial sire line (B), and reciprocal crosses of the F and B lines. Muscle samples from three males and three females of each genetic group were collected in such a manner to avoid contraction. After fixing, the muscles were stained with hematoxylin and eosin, measurements of muscle fiber width, muscle fiber bundle length and width, number of fibers within a 15.6 microm2 area, and extracellular matrix perimysial (PW) and endomysial (EW) width were taken with an Olympus XI 70 microscope equipped with an Olympus Magna Fire digital camera linked to Image Pro software. From each slide, 20 measurements were taken for each characteristic analyzed. In most of the muscle traits measured, additive genetic variation, as indicated by line differences, occurred when the RBC2 line was included in the comparison of pure lines. However, when only the B and F lines were compared, line differences were less frequent. In comparisons of the B and F lines and their reciprocal crosses, heterosis, as measured by contrasts of the average of the pure lines and the average of the reciprocal crosses, was an important source of variation for individual fiber measurements (negative) and extracellular space (positive) at 20 d of incubation but was less important at 25 d of incubation. No significant interactions between genetic group and sex were noted at 20 d of incubation, but such interactions were frequent at 25 d of incubation. These results suggest that muscle organizational differences between the two sexes begin to occur between these two ages and are not the same for different genetic groups.

Rosiglitazone amplifies the benefits of lifestyle intervention measures in long-standing type 2 diabetes mellitus

AIMS

To evaluate the efficacy of a lifestyle intervention programme including meal replacements and increased physical activity upon body weight, diabetes control and other cardiovascular risk factors in obese, poorly controlled, insulin-treated, type-2-diabetic individuals and to assess the impact of concomitant rosiglitazone (RSG) therapy.

METHODS

This 6-month intervention study included 21 patients with type 2 diabetes mellitus (DM) requiring insulin therapy with haemoglobin A1c (HbA1c) > 7% and with a body mass index (b.m.i.) > 27. All subjects were enrolled in a 6-month lifestyle intervention programme and randomized to placebo or RSG 4 mg/day. Participation in the lifestyle programme included meal replacements, increased intake of fruits and vegetables and increased daily physical activity. Measured end-points included body weight, waist circumference, blood pressure, HbA1c and serum lipids, before entry into the study.

RESULTS

The baseline mean b.m.i. was 36.4 and the mean HbA1c was 9.0%. The greatest weight losses occurred during the first 12 weeks (19 lbs for RSG, 13.4 lbs for placebo) with a greater weight loss at each point for the group receiving RSG. Waist circumference declined by 2.8 and 4.0 inches for the placebo and RSG groups. Systolic BP declined 16.2 mmHg in the placebo group and 14.3 mmHg in the RSG group. Diastolic blood pressure decreased by 12.8 mmHg in the placebo group. HbA1c was reduced significantly by 1.3% for the placebo group and 1.1% in the RSG group.

DISCUSSION

This study demonstrates the benefits of lifestyle intervention using meal replacements and increased physical activity with resultant modest weight loss in long-standing, poorly controlled type 2 diabetes. RSG did not impede weight loss and, in fact, amplified some of the positive benefits of lifestyle intervention.

Effect of selection for increased body weight and increased plasma yolk precursor on developmental stability in Japanese quail

Developmental stability of several Japanese quail lines was measured by bilateral asymmetry. Lines included in the study were as follows: a randombred control (R1), sublines of R1 selected for increased (HW line) and decreased (LW line) 4-wk BW, and sublines of R1 selected for increased (HP line) or decreased (LP line) total plasma phosphorus (TPP; a measure of yolk precursor in the blood) at the beginning of lay. In sublines of the HW line, the males were selected for increased 4-wk BW and the females for increased (HW-HP line) or decreased (HW-LP line) TPP. The HW, LW, HP, and LP lines were in their 41st generation of selection and the HW-HP and HW-LP lines in their 31st generation of selection. The number of birds in each line and sex subgroup was 30. The adult breeders (28 to 32 wk of age) were weighed and killed, and bilateral measurements were made of shank length, width (laterally at the dew claw), and depth (perpendicular to the dew claw), face length, and pectoralis major and p. minor weights. Data on asymmetry was expressed for the right side minus the left side as signed and absolute differences. In order to correct for the correlation between trait size and asymmetry, relative asymmetry (RA) was obtained by dividing the absolute differences between sides by the average value of both sides and multiplying by 100. All lines differed in BW at 4 wk of age with the ranking HW > HW-LP > HW-HP > LP > R1 > HP > LW. Line rankings of adult breeders were similar, except the HP and LP lines did not differ from the R1 line and the order of ranking of the HW-HP and HW-LP lines was opposite that at 4 wk of age. Line differences in signed and absolute differences were significant for most bilateral traits. However, after adjustment for trait size, line differences in RA were less frequent. In general, there were few significant differences in RA for the R1 line versus the selected lines, even though inbreeding of the R1 line (19%) was less than half that of the selected lines (44 to 57%), suggesting that homozygosity did not influence developmental stability. Selection for increased or decreased BW had little influence on RA. Developmental stability tended to be higher in the lines (LP and HW-LP) selected for decreased TPP. The data indicated that bilateral asymmetry was not a good measure of developmental stability in the current study.

Subfornical organ neurons projecting to paraventricular nucleus: whole-cell properties

The subfornical organ (SFO) has been repeatedly identified as a CNS site that plays a critical role in sensing multiple physiological variables of the "milieu interieur" and, through efferent projections to other CNS sites, initiating physiological responses to change. Many recent in vitro patch-clamp studies have examined the cellular mechanisms underlying the sensory abilities of these specialized CNS neurons. The primary limitation of these studies, however, has been the inability to identify homogeneous groups of SFO neurons for such investigation. We report here the development of techniques to permit patch clamp recording from dissociated SFO neurons identified according to their in vivo projection site. SFO neurons were labeled by injection of fluorescently labeled, retrogradely transported microspheres into the hypothalamic paraventricular nucleus (PVN) 3 days prior to cell dissociation. Patch-clamp recordings from these SFO-PVN neurons revealed both sodium currents, potassium currents, action potentials, input resistance and membrane potential which were all similar to SFO cells prepared from animals with no prior tracer injection. Labeled SFO-->PVN cells were also found to be osmosensitive and responsive to angiotensin II, suggesting specific functional roles for this anatomically defined group of SFO neurons. Intriguingly, our post hoc analysis also demonstrated that all labeled neurons demonstrated a unique electrophysiological profile dominated by a large transient potassium conductance such that the transient/sustained potassium current ratio, or degree of inactivation was, on average, greater than 4.0. Utilization of these tracing techniques to permit the in vitro recording from cells with known in vivo connections will permit study of intrinsic mechanisms that underlie physiological responses of anatomically defined populations of neurons.

Quantitative PCR assay to measure Aspergillus fumigatus burden in a murine model of disseminated aspergillosis: demonstration of efficacy of caspofungin acetate

Caspofungin acetate (MK-0991) is an antifungal antibiotic that inhibits the synthesis of 1,3-beta-D-glucan, an essential component of the cell wall of several pathogenic fungi. Caspofungin acetate was recently approved for the treatment of invasive aspergillosis in patients who are refractory to or intolerant of other therapies. The activity of 1,3-beta-D-glucan synthesis inhibitors against Aspergillus fumigatus has been evaluated in animal models of pulmonary or disseminated disease by using prolongation of survival or reduction in tissue CFU as assay endpoints. Because these methods suffer from limited sensitivity or poor correlation with fungal growth, we have developed a quantitative PCR-based (qPCR) (TaqMan) assay to monitor disease progression and measure drug efficacy. A. fumigatus added to naïve, uninfected kidneys as either ungerminated conidia or small germlings yielded a linear qPCR response over at least 4 orders of magnitude. In a murine model of disseminated aspergillosis, a burden of A. fumigatus was detected in each of five different organs at 4 days postinfection by the qPCR assay, and the mean fungal load in these organs was 1.2 to 3.5 log(10) units greater than mean values determined by CFU measurement. When used to monitor disease progression in infected mice, the qPCR assay detected an increase of nearly 4 log(10) conidial equivalents/g of kidney between days 1 and 4 following infection, with a peak fungal burden that coincided with the onset of significant mortality. Traditional CFU methodology detected only a marginal increase in fungal load in the same tissues. In contrast, when mice were infected with Candida albicans, which does not form true mycelia in tissues, quantitation of kidney burden by both qPCR and CFU assays was strongly correlated as the infection progressed. Finally, treatment of mice with induced disseminated aspergillosis with either caspofungin or amphotericin B reduced the A. fumigatus burden in infected kidneys to the limit of detection for the qPCR assay. Because of its much larger dynamic range, the qPCR assay is superior to traditional CFU determination for monitoring the progression of disseminated aspergillosis and evaluating the activity of antifungal antibiotics against A. fumigatus.

Slowly inactivating potassium conductance (I(D)): a potential target for stroke therapy

BACKGROUND AND PURPOSE

Excessive accumulation of extracellular glutamate results in the death of most, but not all, neurons in the central nervous system. Understanding the unique properties of cells that can withstand this excitotoxic challenge may identify specific targets for novel stroke therapies.

METHODS

A combination of in vivo methods for analysis of excitotoxic cell death after activation of N-methyl-D-aspartate (NMDA) receptors and in vitro patch-clamp analysis of specific conductances in hypothalamic slices and dissociated cells has been used to assess the roles of specific potassium conductances in delayed cell death after NMDA receptor activation.

RESULTS

We report that a specific D-type potassium conductance (I(D)), necessary for the rapid repolarization of the membrane after a strong depolarization, serves such a protective purpose in magnocellular neurons of the paraventricular nucleus. Manipulations that inhibit this current (4-aminopyridine or angiotensin II) increase neuronal excitability and augment cell death after NMDA receptor activation. In addition, this protection is not observed in magnocellular neurons of spontaneously hypertensive rats, and intriguingly it can be reestablished by blocking angiotensin II receptors in these animals.

CONCLUSIONS

These observations provide a persuasive experimental explanation for the unexpected finding that therapeutic treatments for hypertension that block central as well as peripheral angiotensin type 1 receptors reduce the severity and occurrence of stroke.

Obesity and disease management: effects of weight loss on comorbid conditions

OBJECTIVE

This review is designed to quantitate the effects of obesity and weight gain on risk for coronary heart disease (CHD) and to review the effects of weight loss on CHD risk factors.

RESEARCH METHODS AND PROCEDURES

After a comprehensive review of the literature related to body weight and weight gain on CHD risk, the relative risks (RRs) were tabulated. Values were averaged and meta-analysis techniques were used to estimate the variance-adjusted RR.

RESULTS

Young persons with higher body mass index values have a significantly higher risk for CHD than do slender young people. For every 1% above a desirable body mass index, the risk for CHD increases by 3.3% for women and by 3.6% for men. Every kilogram of weight gain after high school increases risk for CHD by 5.7% for women and 3.1% for men. Weight loss significantly decreases major CHD risk factors. For every kilogram of weight loss the following favorable changes occur: fasting serum cholesterol, -1.0%; low-density lipoprotein cholesterol, -0.7%; triglycerides, -1.9%; high-density lipoprotein cholesterol, +0.2%; systolic blood pressure, -0.5%; diastolic blood pressure, -0.4%; and blood glucose, -0.2 mM.

DISCUSSION

Obesity and/or weight gain are associated with major risk for CHD. Weight loss significantly improves serum lipid parameters, blood pressure, and fasting blood glucose values. Effective treatment approaches are available for most overweight or obese individuals but a major challenge is to enable these individuals to engage in these programs. Professional and consumer education is essential for advancing effective intervention strategies for overweight individuals.

Long-term weight-loss maintenance: a meta-analysis of US studies

BACKGROUND

Current perception is that participants of a structured weight-loss program regain all of their weight loss within 5 y.

OBJECTIVE

The objective was to examine the long-term weight-loss maintenance of individuals completing a structured weight-loss program.

DESIGN

Studies were required to 1) have been conducted in the United States, 2) have included participants in a structured weight-loss program, 3) have provided follow-up data with variance estimates for > or =2 y. Primary outcome variables were weight-loss maintenance in kilograms, weight-loss maintenance as a percentage of initial weight loss, and weight loss as a percentage of initial body weight (reduced weight).

RESULTS

Twenty-nine studies met the inclusion criteria. Successful very-low-energy diets (VLEDs) were associated with significantly greater weight-loss maintenance than were successful hypoenergetic balanced diets (HBDs) at all years of follow-up. The percentage of individuals at 4 or 5 y of follow-up for VLEDs and HBDs were 55.4% and 79.7%, respectively. The results for VLEDs and HBDs, respectively, were as follows: weight-loss maintenance, 7.1 kg (95% CI: 6.1, 8.1 kg) and 2.0 (1.5, 2.5) kg; percentage weight-loss maintenance, 29% (25%, 33%) and 17% (13%, 22%); and reduced weight, 6.6% (5.7%, 7.5%) and 2.1% (1.6%, 2.7%). Weight-loss maintenance did not differ significantly between women and men. Six studies reported that groups who exercised more had significantly greater weight-loss maintenance than did those who exercised less.

CONCLUSIONS

Five years after completing structured weight-loss programs, the average individual maintained a weight loss of >3 kg and a reduced weight of >3% of initial body weight. After VLEDs or weight loss of > or =20 kg, individuals maintained significantly more weight loss than after HBDs or weight losses of <10 kg.

Topographic distribution and developmental timecourse of auditory event-related potentials in two subtypes of attention-deficit hyperactivity disorder

The effect of age on the topographic distribution of auditory event-related potentials (ERPs) recorded during a two-tone discrimination, or oddball, task was examined in two subtypes of attention deficit/hyperactivity disorder (AD/HD) as defined by the most recent diagnostic manual, DSM-IV. EEG was recorded at 17 sites from AD/HD predominantly inattentive type (n=50) and AD/HD combined type (n=50) subjects aged from 8 to 17 years 11 months. ERP components were quantified at each site. Results revealed topographic differences from controls (n=50) that were common to both subtypes (e.g. target and standard P2 amplitude, and standard P2 latency) or unique to a particular subtype of AD/HD (Inattentive type: target N1, N2, P3b and standard N2 amplitude, target P2 latency; Combined type: target N1, P2, N2 and P3b amplitude, target N2 and standard N1 latency). These group differences showed different age effects. The across-region results revealed differing patterns of abnormal component development for each subtype, indicating a qualitative difference in information processing stage deficits in each of these AD/HD subtypes.

Genetic variation in pure lines and crosses of large-bodied turkey lines. 2. Carcass traits and body shape

An experimental line (F) of turkeys was reciprocally crossed with sire lines (designated A and B) from each of two commercial breeders in order to study the inheritance of carcass traits and body shape. The birds were weighed and killed at 17 wk of age, and various measurements of muscling, leg bones, and body shape were made. Additive genetic variation, as indicated by line differences, was an important source of variation in most traits. The only traits that did not exhibit a line difference in any comparison were weight of the drumstick muscles, tarsometatarsal width, keel length, and Body Depth 2 (body depth at a point 2.54 cm anterior to the posterior end of the keel). Heterosis of live BW was greater in males than in females. Heterosis in the weight of the pectoralis major and p. minor muscles were similar to those of live BW, but heterosis in the weight of the leg muscles were higher than that of live BW. The average heterosis for bone measurements (length of the femur, tarsometatarsal, and tibiotarsal bones and tarsometatarsal width) was very low and ranged from -0.3 to 1.4%. For measurements of body shape [keel length, Body Depth 1 (body depth measured at the cranial process of the keel), Body Depth 2, ratio of Body Depth 1 to Body Depth 2, length, width, and height of the body cavity, and body cavity volume index), heterosis was low and the average ranged from -2.7 to 2.6%. Based on an analysis of both sexes combined, the commercial sire lines differed in BW, weights of the p. minor and drumstick muscles, weights of the tarsometatarsal, femur, and tibiotarsal bones, lengths of the tarsometatarsal and femur bones, and various measurements of body shape (Body Depth 1, body depth ratio, body cavity length and height, and body cavity volume index). Relative to the commercial sire lines, the F line was smaller, had less breast and leg muscling, and, in general, larger leg bones when sexes were combined. The carcass of the F line was deeper than that of the commercial sire lines when measured at the cranial process of the keel but not at 2.54 cm anterior to the posterior portion of the keel. Body cavity height and body cavity volume index were larger in the F line than in the commercial sire lines.

Genetic variation in pure lines and crosses of large-bodied turkey lines. 1. Body weight, walking ability, and body measurements of live birds

An experimental line of turkeys selected for increased BW (F) was reciprocally crossed with sire lines (designated A and B) from each of two major commercial breeders in order to study the inheritance of growth traits. All genetic groups were grown intermingled in confinement with the sexes reared in different houses. Traits measured included BW at 8, 16, and 20 wk of age; shank length, width, and depth; breast width; and walking ability scores at 16 wk of age. The F line had a different growth pattern than the two commercial sire lines. The F line had higher (males) or similar (females) BW in comparison to Line A at 8 wk of age, but by 16 wk of age, Line A was heavier than Line F in both sexes. The difference in BW between the F and A lines increased from 16 to 20 wk of age. Lines F and B did not differ in BW at 8 wk of age, but at 16 and 20 wk of age, Line B birds were heavier than those of F line. Reciprocal effects, a measure of sex linkage and maternal effects, were noted only for breast width of females in crosses of Lines A and F and for shank width and depth of males and 8-wk BW and shank depth of females in crosses of Lines B and F. Heterosis was an important source of variation in BW for males from both crosses. The percentage heterosis at the various ages ranged from 3.1 to 7.5. For females, heterosis (range = 2.6 to 4.9%) was only significant at younger ages (8 wk for the crosses of the A and F lines and 8 and 16 wk for the crosses of the B and F lines). No heterosis for breast width was observed in either cross. Heterosis in walking ability scores was significant only for males from the crosses of Lines B and F. The presence of heterosis was inconsistent for shank measurements.

Sulphur nutrition affects delivery and metabolism of S in developing endosperms of wheat

Experiments were conducted to investigate the effect of S nutrition and availability on the forms of S and N in the endosperm cavity and endosperm of wheat, and on the capacity of the endosperm to utilize those compounds for the synthesis of proteins. Plants were grown in solution culture with 2 mM N and either 200 microM S (high-S) or 50 microM S (low-S) and all nutrients were withdrawn at various times from booting until 8 d post-anthesis. Sulphate was the major form of soluble S in the endosperm cavity and endosperm of high-S plants during the time of rapid grain development. By contrast, glutathione (GSH) was the major form of soluble S in the endosperm cavity and in the endosperm in low-S plants. Crude extracts of endosperm tissue from both high-S and low-S plants supported (i) the hydrolysis of GSH to gamma-glutamyl cysteine and glycine, and of gamma-glutamyl cysteine to glutamate and cysteine, and (ii) sulphate-dependent PPi-ATP exchange and the sulphydration of O-acetylserine catalysed by ATP sulphurylase and cysteine synthase, respectively. High-S nutrition enhanced the in vitro rates of ATP sulphurylase and cysteine synthase.

Effect of selection for increased body weight in turkeys on lymphoid organ weights, phagocytosis, and antibody responses to fowl cholera and Newcastle disease-inactivated vaccines

The influence of selection was studied for increased 16-wk BW in turkeys on in vivo phagocytic activity, antibody responses to vaccines, and weight of the spleen and bursa of Fabricius. A line (F) of turkeys selected long term for increased 16-wk BW and its corresponding randombred control (RBC2) were compared. Phagocytic activity was evaluated by the carbon clearance assay. Antibody responses to inactivated Newcastle disease virus and Pasteurella multocida vaccines were examined by ELISA. Body weight and relative weights of spleen and bursa of Fabricius of the two lines were also compared. The F line had lower phagocytic activity than the RBC2 line (P < 0.05). In addition, the F line had greater BW, relative weight of spleen, and ratio of spleen to bursa of Fabricius weight (P < 0.01) but had a lower relative weight of bursa of Fabricius at 9 wk of age. However, there were no line differences in the antibody responses to Newcastle disease virus or P. multocida vaccines at 1, 2, 3, 4, 5, or 12 wk after vaccination. Based on the present results, it is suggested that long-term selection for increased 16-wk BW might have resulted in changes in the immune system, as indicated by changes in the relative weights of the spleen and bursa of Fabricius and phagocytic activity. The decreased phagocytic activity in the F line may be partially responsible for increased susceptibility to specific diseases in this line.

Intrinsic osmosensitivity of subfornical organ neurons

The constancy of plasma osmolality demands that salt and water concentration within the extracellular fluid be constantly monitored and regulated within a few percentage points. The circumventricular organs in general, and the subfornical organ in particular, have long been proposed to be the site of the osmosensitivity. Isolated subfornical organ neurons of male rats were studied using the whole-cell patch-clamp technique and both action potential frequency and whole cell currents were measured as bath osmolality was changed, from 240 to 330mOsm, by altering the amount of mannitol and maintaining the concentrations of electrolytes constant. Out of 64 cells, 66% responded to changes in bath osmolality in a predictable manner, exhibiting a hyperpolarization and decrease in spike frequency in hypo-osmotic solutions and a depolarization and increase in action potential frequency during hyperosmotic exposure. Cells (34%) defined as non-responders exhibited no significant modulation during identical changes in extracellular osmolality. The responses to changing extracellular osmolality were dose dependent; the activity of subfornical organ neurons was significantly modulated by changes in extracellular osmolality of less than 10mOsm. By regression analysis, this osmosensitivity was approximately 0. 1Hz/mOsm change throughout a +/-10mOsm range and was maintained throughout the range of osmolalities studied (270-330mOsm). The mechanism underlying this osmosensitivity remains unclear, although the non-selective cation conductance and the volume-activated chloride conductance do not seem to be involved.This intrinsic osmosensitivity of subfornical organ within the normal physiological range supports the view that this circumventricular structure plays a role in normal osmoregulation.

Induction of the P450 reporter gene system bioassay by polycyclic aromatic hydrocarbons in Ulsan Bay (South Korea) sediments

Polycyclic aromatic hydrocarbons (PAHs) and induction of the P450 reporter gene system (RGS) for 6- and 16-h exposure periods were determined in organic extracts of Ulsan Bay (South Korea) sediments to assess the utility of this bioassay as a screening tool for PAH contamination. The sum of the concentrations of 23 individual PAHs in 30 sediment samples (sigma PAH) based on GC-MS analysis ranged from 0.05 to 6.1 micrograms/g dry wt. P450 RGS fold induction ranged from 4.0 to 320 micrograms/g based on benzo[a]pyrene toxic equivalents (BaPEq). P450 RGS BaPEq and the 'chemical BaPEq', defined as the sum of the products of individual PAH concentrations and pre-determined toxic equivalency factors, exhibited very strong positive correlations with sigma PAH (r2 > 0.90; P < 0.001). Fold induction did not increase (and in some cases decreased) after the optimal incubation period (6 h) for PAHs, indicating that other compounds known to induce the P450 RGS (e.g. chlorinated organics) were not present at levels effecting significant induction. This was supported by GC-ECD analysis where non-ortho and mono-ortho polychlorinated biphenyls (PCBs) known to be strong P450 RGS inducers were found to be at very low or non-detectable levels in samples with the highest P450 RGS responses. The profound difference in PAH profiles for the two most contaminated sites suggested that this assay is especially sensitive for selected PAHs with greater than four rings. Combined with previous results, the P450 RGS shows promise as a useful screening tool for predicting deleterious biological effects resulting from CYP1A1-inducing, sediment-associated chemicals, particularly high molecular weight PAHs.

A subthreshold persistent sodium current mediates bursting in rat subfornical organ neurones

It is widely accepted that while release of amino acid neurotransmitters occurs with relatively high fidelity, peptidergic synapses require clustered bursts of action potentials for optimal transmitter release. Here we describe for the first time the occurrence and mechanisms of bursting by neurones in the subfornical organ (SFO), cells that utilize the peptide angiotensin II (ANG) in neurotransmission in autonomic pathways. In current clamp recording of isolated SFO neurones in vitro, 53 % (n = 74) showed either spontaneous or evoked burst-like discharge patterns. Bursts typically appeared as shifts in bistable membrane potential, with action potentials superimposed on a depolarizing afterpotential (DAP). Similarly, in vivo single unit recordings of identified SFO neurones showed that 9 of 15 neurones fired in bursts. The pattern of bursting, as well as duration of evoked DAPs was strongly dependent upon membrane potential, suggesting that the DAP contributes to burst generation. Based on our previous observation of calcium-sensing receptor (CaR)-activated bursts, we investigated the effects of NPS R-467, an allosteric agonist of the CaR, on evoked DAPs. NPS R-467 (1 microM) potentiated DAP duration throughout the voltage range tested. We observed a dependence of evoked DAPs upon Na+ channels, as shown by sensitivity to tetrodotoxin (0.5 microM) or reduction of external [Na+] from 140 to 40 mM. The duration of DAPs suggested that a persistent Na+ current mediates these events. Voltage-clamp analysis revealed the presence of a subthreshold sodium current, INaP. Pharmacological blockade of INaP with 100 microM lidocaine reduced the duration of evoked DAPs, and inhibited bursting in SFO neurones. Facilitation of INaP with 10 nM anemone toxin (ATX) increased DAP duration and led to marked excitation of bursting cells. These data indicate that INaP is the main current underlying bursting in SFO neurones. Our observations of receptor-mediated facilitation of bursting by SFO neurones represents an intriguing mechanism through which the release of the peptide neurotransmitter ANG may be regulated.

Dietary fiber prevents carbohydrate-induced hypertriglyceridemia

Plant foods rich in carbohydrate and dietary fiber have many health benefits. One concern often expressed about higher carbohydrate, lower fat diets is that they may increase fasting serum triglycerides. Recently the importance of hypertriglyceridemia as an independent risk factor for coronary heart disease has been reaffirmed. For 40 years, clinicians have noted "carbohydrate-induced hypertriglyceridemia" when persons were fed high-carbohydrate, low-fiber diets. The role of fiber in protecting from carbohydrate-induced hypertriglyceridemia has not been discussed by many reviewers. Systematic review of the literature documents that high fiber intakes clearly protect from carbohydrate-induced hypertriglyceridemia. These are reviewed. Thus, recent and earlier research indicates that use of a higher carbohydrate, higher fiber diet compared with a lower carbohydrate, higher fat diet is associated with a small reduction in fasting serum triglyceride values.

Dipeptide binding to the extended active site of the Streptomyces R61 D-alanyl-D-alanine-peptidase: the path to a specific substrate

Bacterial cell walls are cross-linked in the final step of biosynthesis by specific D-alanyl-D-alanine(DD)-peptidases/transpeptidases. The natural substrates of these enzymes should therefore be segments of peptidoglycan, but high specificity for such structures has yet to be demonstrated. The binding of dipeptides to the extended substrate binding site of the Streptomyces R61 DD-peptidase has been studied by means of a fluorescent beta-lactam probe. It was found that dipeptides of structure Gly-L-Xaa have affinity for a subsite adjacent to the beta-lactam binding site. Hydrophobic peptides such as Gly-L-Met and Gly-L-aminocaprylic acid had the greatest affinity for this site, with dissociation constants in each case of 0.19 mM. A combination of this motif with the C-terminal D-alanyl-D-alanine moiety required of a DD-peptidase substrate yielded a new substrate, glycyl-L-alpha-amino-epsilon-pimelyl-D-alanyl-D-alanine. Steady-state kinetic measurements established this compound as the most specific peptide substrate yet discovered for a DD-peptidase by at least 3 orders of magnitude (k(cat) = 69 s(-1), K(m) = 7.9 microM, k(cat)/K(m) = 8.7 x 10(6) s(-1) M(-1)); acylation was rate-determining at saturation. This substrate, presumably not coincidentally, contains the acyl donor and acceptor moieties, appropriately separated, of the Streptomyces peptidoglycan structure. This general method of approach should be of value in the search for specific substrates and inhibitors (antibiotics) of other DD-peptidases.

Health advantages and disadvantages of weight-reducing diets: a computer analysis and critical review

BACKGROUND

Some weight-loss diets are nutritionally sound and consistent with recommendations for healthy eating while others are "fad" diets encouraging irrational and, sometimes, unsafe practices.

OBJECTIVE

The purpose of the study was to compare several weight loss diets and assess their potential long-term effects.

DESIGN

Eight popular weight-loss diets were selected (Atkins, Protein Power, Sugar Busters, Zone, ADA Exchange, High-Fiber Fitness, Pritikin and Omish) to be non-clinically analyzed by means of a computer to predict their relative benefits/potential harm. A summary description, menu plan and recommended snacks were developed for each diet. The nutrient composition of each diet was determined using computer software, and a Food Pyramid Score was calculated to compare diets. The Mensink, Hegsted and other formulae were applied to estimate coronary heart disease risk factors.

RESULTS

Higher fat diets are higher in saturated fats and cholesterol than current dietary guidelines and their long-term use would increase serum cholesterol levels and risk for CHD. Diets restricted in sugar intake would lower serum cholesterol levels and long-term risk for CHD; however, higher carbohydrate, higher fiber, lower fat diets would have the greatest effect in decreasing serum cholesterol concentrations and risk of CHD.

CONCLUSIONS

While high fat diets may promote short-term weight loss, the potential hazards for worsening risk for progression of atherosclerosis override the short-term benefits. Individuals derive the greatest health benefits from diets low in saturated fat and high in carbohydrate and fiber: these increase sensitivity to insulin and lower risk for CHD.

The calcium receptor modulates the hyperpolarization-activated current in subfornical organ neurons

Here we report that neurons of the subfornical organ (SFO), a circumventricular structure devoid of a blood-brain barrier, show time-dependent, inward rectification indicative of the presence of a subthreshold, hyperpolarization-activated inward current (Ih). In whole-cell patch clamp experiments of isolated SFO neurons, we observed a Cs+-sensitive Ih in 47% of cells tested. Furthermore, we show that Ih is involved in the generation of evoked bursts in SFO neurons. An allosteric agonist of the extracellular calcium-sensing receptor (CaR) was found to potentiate Ih consistent with our previous observations of CaR-mediated bursting in SFO neurons. These studies indicate that a proportion of SFO neurons express Ih, and this may be one ionic mechanism through which bursting is regulated by various extracellular messengers.

Self-help weight loss versus a structured commercial program after 26 weeks: a randomized controlled study

PURPOSE

There have been few randomized controlled trials of commercial weight-loss programs. This ongoing study compares the effects of a self-help program and a commercial program on weight loss and other measures of obesity in overweight and obese men and women.

SUBJECTS AND METHODS

We report the results of the first 26 weeks of a multicenter, randomized, 2-year study of 423 subjects who had a body mass index of 27 to 40 kg/m(2). Subjects were randomly assigned to either a self-help program, consisting of two 20-minute sessions with a nutritionist and provision of printed materials and other self-help resources, or to attendance at meetings of a commercial program (Weight Watchers). Outcome measures were changes in body weight, body mass index, waist circumference, and body fat. Changes in serum homocysteine levels were measured in a subsample of participants during the first 12 weeks.

RESULTS

After 26 weeks, subjects in the commercial program, as compared with those in the self-help program, had greater decreases in body weight [mean (+/- SD) -4.8+/-5.6 vs -1.4+/-4.7 kg] and body mass index (-1.7+/-1.9 vs -0.5+/-1.6 kg/m(2), both P<0.001) in intention-to-treat analyses. Among subjects measured at week 26, mean waist circumference (-4.3+/-10.5 vs -0.7+/-12.7 cm) and fat mass (-3.8 +/-7.0 vs -1.5+/-7.6 kg, both P<0.05) also decreased more among subjects in the commercial program. Mean serum homocysteine levels improved in the commercial program compared with self-help (-0.5+/-1.3 vs 0.9+/-1.8 microM, P<0.05).

CONCLUSIONS

A structured commercial weight-loss program is more likely to be effective for managing moderately overweight patients than brief counseling and self-help.

Effects of selection for increased body weight, egg production, and shank width on developmental stability in turkeys

Bilateral asymmetry was measured at 20 wk of age for shank length, shank width (width laterally at the dew claw), shank depth (width perpendicular to the dew claw), and face length (between auditory canal opening and the posterior junction of the upper and lower mandible) in three randombred control lines and three selected lines of turkeys. The data were based on 50 or 51 individuals per line and sex subgroup from a single hatch. The lines were grown intermingled with the sexes being grown in different houses. The selected lines had been selected for increased egg production (38 generations), increased 16-wk BW (32 generations), or increased shank width (19 generations) and had a higher level of inbreeding (average = 36.9%) than the randombred controls (RBC; average = 11.6%). The bilateral differences (right minus left) were analyzed for the presence of fluctuating asymmetry (FA; zero signed mean with normal variation), directional asymmetry (DA; signed mean not zero with normal variation), and antisymmetry (AS; zero mean with non-normal distribution). In order to adjust for possible scaling effects, relative asymmetry (RA), in which the mean of the absolute differences between sides was divided by the mean of the two sides and the resulting value was multiplied by 100, was used as a measure of bilateral asymmetry. The randombred control and selected lines were contrasted to study the effect of homozygosity on RA. Likewise, the large-bodied lines (F, FL, and RBC3) were contrasted to the small-bodied lines (RBC1, E, and RBC2) to study the effect of BW on RA. Only two types (FA and DA) of asymmetry were observed in the present study. The level of asymmetry for the traits was ranked as follows: face length > shank width = shank depth > shank length. The individual lines differed in RA for shank length and shank width for both sexes and for shank depth and face length in females. In general, the influence of BW, as measured in the contrast of large-bodied and small-bodied lines, on RA was larger than that of homozygosity, as measured by the contrast of the selected and randombred control lines.

Whole grain foods and heart disease risk

Coronary heart disease (CHD) is the leading cause of death in most developed nations and is rapidly increasing in prevalence in developing countries. Death rates from cardiovascular disease exceed 1 million annually in the United States and account for the largest disease-related cost to health with total costs estimated to exceed $120 billion per annum. Many dietary factors, including total and saturated fat consumption, fruit and vegetable intake and dietary fiber, have been shown to contribute to risk for CHD. We have systematically reviewed literature from the past 20 years evaluating an association between dietary fiber and CHD. Foods that are rich in dietary fiber, including fruits, vegetables, legumes and whole grain cereals, also tend to be a rich source of vitamins, minerals, phytochemicals. antioxidants and other micronutrients. Each of these factors may be independently contributing to the cardiovascular protective effects of fiber-rich foods.

Long-term cholesterol-lowering effects of psyllium as an adjunct to diet therapy in the treatment of hypercholesterolemia

BACKGROUND

Hypercholesterolemia is a major risk factor for coronary heart disease and nutrition management is the initial therapeutic approach.

OBJECTIVE

This multicenter study evaluated the long-term effectiveness of psyllium husk fiber as an adjunct to diet in the treatment of persons with primary hypercholesterolemia.

DESIGN

Men and women with hypercholesterolemia were recruited. After following an American Heart Association Step I diet for 8 wk (dietary adaptation phase), eligible subjects with serum LDL-cholesterol concentrations between 3.36 and 4.91 mmol/L were randomly assigned to receive either 5.1 g psyllium or a cellulose placebo twice daily for 26 wk while continuing diet therapy.

RESULTS

Serum total and LDL-cholesterol concentrations were 4.7% and 6.7% lower in the psyllium group than in the placebo group after 24-26 wk (P < 0.001). Other outcome measures did not differ significantly between groups.

CONCLUSIONS

Treatment with 5.1 g psyllium twice daily produces significant net reductions in serum total and LDL-cholesterol concentrations in men and women with primary hypercholesterolemia. Psyllium therapy is an effective adjunct to diet therapy and may provide an alternative to drug therapy for some patients.

Antibody responses to sheep red blood cell and Brucella abortus antigens in a turkey line selected for increased body weight and its randombred control

Turkeys from a randombred control line (RBC2) and its subline (F) selected for increased 16-wk BW were tested for primary and secondary antibody responses to SRBC antigen and Brucella abortus antigen (BA). Previous studies have shown that the F line was more susceptible to Pasteurella multocida and Newcastle disease virus than was the RBC2 line. Individuals from the RBC2 and F lines were intravenously injected with 1 mL 5% SRBC antigen or 0.1 mL undiluted BA at 4 and 6 wk of age; blood samples were collected at 0, 4, 7, and 10 d post-immunization. Total, IgG, and IgM titers were measured by agglutination assays. Compared with the RBC2 line, the F line had generally higher total anti-SRBC titers; the differences were significant at 14 d postprimary immunization (PPI) (females); at 10 d postsecondary immunization (PSI) (males); and 4, 7, and 10 d PSI (females) (P < or = 0.05). The F line also had higher IgM titers at 14 d PPI (females) and at 10 d PSI (males) (P < or = 0.05). For IgG titers, a line difference was evident in females at 4 and 10 d PSI (P < or = 0.05); the F line had higher titers than did the RBC2 line. For the antibody response to BA in males, the F line had lower total and IgM titers at 10 d PPI (P < 0.05) than did the RBC2 line. No significant line differences in response to the BA were found in total and IgM titers in female turkeys or in IgG titers in both sexes at any time. These results suggest that selection for fast growth rate of turkeys might have resulted in changes in humoral immunity to the SRBC antigen and BA.