Effect of sequential implanting with Synovex on steer and heifer performance

Studies were conducted using 72 (Exp. 1) and 248 (Exp. 2) steer and heifer calves from 1 to 2 mo of age through slaughter to determine whether preweaning implants affect postweaning feed conversion of cattle that are rapidly grown and(or) finished in the feedlot. In Exp. 1, treatments were three Synovex (S) implants administered 0, 70, and 140 d postweaning (NSSS) or Synovex-C (C) administered preweaning and three implants administered postweaning (CSSS). In Exp. 2, treatments were no implants (NNNN), implants administered 0, 74, and 148 d postweaning to calves that had either received no preweaning implant (NSSS), or C (CSSS), and CSSS plus trenbolone acetate (TBA) administered with the last S implant (CSSS-TBA). Synovex-S or -H implants were administered postweaning to steers and heifers, respectively. Steer and heifer calves implanted with C in the preweaning phase were 9.0 and 13.0 kg (Exp. 1) and 7.5 and 15.0 kg (Exp. 2) heavier (P < .10), respectively, at weaning than nonimplanted steer and heifer calves. In Exp. 1, preweaning implant had no affect on postweaning performance or quality grade. In Exp. 2, preweaning implants (NSSS vs CSSS) decreased (P < .10) steer postweaning gains, whereas postweaning implants (NSSS vs NNNN) increased (P < .10) DM intake; however, feed:gain ratio was not affected by implant strategy. Heifers in Exp. 2 that received implants had greater postweaning (P < .10) DM intakes and daily gains than heifers not receiving implants (NNNN); however, feed:gain ratios among treatment groups were unaffected.(ABSTRACT TRUNCATED AT 250 WORDS)     

Chicken egg yolk antibodies against F18ab fimbriae of Escherichia coli inhibit shedding of F18 positive E. coli by experimentally infected pigs

F18ab and F18ac are antigenic variants of a colonizing fimbria commonly found on E. coli associated with postweaning diarrhea and edema disease in pigs. Chicken F18ab antibodies were obtained by immunising hens with purified F18ab fimbriae. For their in vitro characterisation antibodies were isolated from diluted egg yolks by ammonium sulfate precipitation. In vitro adhesion tests demonstrated that the chicken F18ab antibodies inhibited attachment of F18ab positive E. coli bacteria to the intestinal mucosa. Just weaned piglets were experimentally infected with an F18ab positive edema disease strain of E. coli, or with an F18ac positive postweaning diarrhea E. coli strain. The animals were infected on the second day of a period during which chicken F18ab antibodies were added to their feed. During the same period, pigs of the control group received commercial eggs in which no F18 antibodies were detected. In both experimental infections the excretion of the F18 positive strain was reduced in pigs that received the F18ab antibodies as compared to the control animals. The F18ab antibodies diminished the cases of diarrhea and death in animals infected with F18ac positive E. coli.     

Paenibacillus apiarius sp. nov

BACKGROUND & AIMS: Steroid dependence and early relapse are frequent after a prednisolone-induces remission in Crohn's disease. The aim of this trial was to test whether mesalamine started at the onset of steroid tapering increases the rate of weaning from prednisolone and reduces the relapse rate after prednisolone cessation. METHODS: One hundred fifty patients with active Crohn's disease were administered oral prednisolone (1 mg.kg(-1). day(-1)) x 3-7 weeks; 129 patients went into clinical remission and were randomized to Pentasa (4 g . day(-1)) or placebo, administered until weaning and for 1 year thereafter. RESULTS: Groups were similar for clinical and biological items collected initially. Weaning failure rate was 30% and 12% in the placebo and mesalamine arms, respectively. At the end of the trial, 9 of 36 patients administered placebo and 14 of 48 administered mesalamine were in remission. Both groups had similar time to relapse curves in the postweaning year; after adjusting for risk factors (high Crohn's Disease Activity Index, white blood cell count of >9 x 10(9) /l-1 at weaning, and use of a medical treatment in the month before inclusion), Pentasa was found to be superior to placebo. CONCLUSIONS: After a prednisolone-induces remission in Crohn's disease, mesalamine facilitates steroid withdrawal and, during the postweaning year, may reduce the relapse rate in certain patient subgroups.     

Column-switching high-performance liquid chromatographic assay for determination of apigenin and acacetin in human urine with ultraviolet absorbance detection

Postweaning social isolation can influence the sensitivity of rats to several effects of drugs of abuse. The present study investigated the influence of postweaning housing conditions on the sensitivity of rats to the aversive effects of a number of psychoactive agents using a conditioned taste aversion (CTA) test procedure. Development of a CTA was assessed by pairing administration of the drug with the consumption of a 0.05% (weight/volume) saccharin solution in water-deprived (18 h) rats in a 20 min drinking period. Saccharin consumption was then measured in 20 min test sessions over the next 4 consecutive days. Consumption of saccharin solution was significantly reduced in both isolated and enriched rats following administration of d-amphetamine (2 mg/kg), cocaine (30 mg/kg), morphine (10 mg/kg), nicotine (1.0 mg/kg), caffeine (20 mg/kg), alcohol (1.5 g/kg), and LiCl (0.15 M, 4 ml/kg). There was no significant effect of housing conditions on the CTA induced by cocaine, nicotine, alcohol, or LiCl; however, isolation-reared rats were found to be less sensitive to the aversive effects of d-amphetamine, morphine, and caffeine in this paradigm. These results suggest that rearing rats in social isolation induces an attenuation in sensitivity to the aversive effects of some psychoactive agents.     

Heart signal recognition by Hidden Markov Models: the ECG case

From December 1989 to May 1990, 315 faecal samples from children under 5 years old with diarrhoea (215) and without diarrhoea (100) seen at paediatric clinics were investigated for bacterial, viral and parasitic enteropathogens. Standard and recently described methods were used for the investigations, which revealed that 74.9% of children with diarrhoea were infected with enteropathogens compared with 28% of controls. In the diarrhoeal group, 59.1% had a bacterial, 26.5% a viral and 2.3% a parasitic aetiology. Rotavirus was the pathogen most frequently detected, accounting for 22.3% of positive findings in the group with diarrhoea versus 9% in the control group. Other important agents were: enterotoxigenic Escherichia coli (ETEC) (14.4 versus 6%), enteropathogenic E. coli (EPEC) (10.7 versus 5%), enteroadherent E. coli (EAEC) (9.3 versus 4%), enterohaemorrhagic E. coli (EHEC) (5.1 versus 3%) and Salmonella spp. (3.3 versus 1%). The following enteropathogens were detected exclusively in the diarrhoeal stools: Shigella spp. (5.1%), Yersinia enterocolitica (0.9%), Aeromonas hydrophila (1.4%), Entamoeba histolytica (0.5%), Giardia lamblia (0.5%), Trichomonas hominis (0.5) and Trichuris trichiura (0.9%). The detection rates of rotavirus, EPEC and EAEC were much greater in the diarrhoeal than in the control patients. No Vibrio cholerae, enteroinvasive E. coli (EIEC), Plesiomonas spp. or Cryptosporidium spp. were detected in this study. Our data suggest that both the traditional and newly recognised diarrhoeal agents are important causes of diarrhoea in the children under 5 years old in Lagos, Nigeria.     

Vasopressin combined with epinephrine decreases cerebral perfusion compared with vasopressin alone during cardiopulmonary resuscitation in pigs

BACKGROUND AND PURPOSE: It is unknown whether a combination of vasopressin and epinephrine may be superior to vasopressin alone by targeting both nonadrenergic and adrenergic receptors. METHODS: After 15 minutes of cardiac arrest (13 minutes of ventricular fibrillation and 2 minutes of pulseless electrical activity) and 3 minutes of chest compressions, 16 animals were randomly treated with either 0.8 U/kg vasopressin (n = 8) or 0.8 U/kg vasopressin combined with 200 microg/kg epinephrine (n = 8). RESULTS: Comparison of vasopressin with vasopressin and epinephrine at 90 seconds and 5 minutes after drug administration resulted in comparable mean (+/-SEM) coronary perfusion pressure (54+/-3 versus 57+/-5 and 36+/-4 versus 35+/-4 mm Hg, respectively), cerebral perfusion pressure (59+/-6 versus 65+/-8 and 40+/-6 versus 39+/-6 mm Hg, respectively), and median (25th to 75th percentiles) left ventricular myocardial blood flow [116 (81 to 143) versus 108 (97 to 125) and 44 (35 to 81) versus 62 (42 to 74) mL x min(-1) x 100 g(-1), respectively], but significantly increased (P<0.05) total cerebral blood flow [81 (77 to 95) versus 39 (34 to 58) and 50 (43 to 52) versus 28 (16 to 35) mL x min(-1) x 100 g(-1), respectively]. Return of spontaneous circulation rates in both groups were comparable (vasopressin, 7 of 8; vasopressin and epinephrine, 6 of 8). CONCLUSIONS: Comparison of vasopressin with vasopressin and epinephrine resulted in comparable left ventricular myocardial blood flow but significantly increased cerebral perfusion.     

Effect of the feeding level during rearing on performance of Large White gilts. Part 1: Growth, reproductive performance and feed intake during the first lactation

Fifty pure-bred Large White gilts were allocated to two feeding levels from 28 kg until service. They were fed a standard growing diet (13.4 MJ digestible energy (DE) per kg; 18.1% crude protein, CP; 0.96% lysine) either to appetite (AP) or at 80% of the AP level (R). Growth rate was reduced by about 20% in R gilts, whereas feed conversion ratio was unaffected by rearing treatment. First oestrus was detected earlier in AP gilts (234 versus 247 d of age). At service, AP females had larger body weight (190 versus 150 kg) and thicker backfat (20.9 versus 13.4 mm). After service, the reproductive performances of 30 of these gilts were studied during the first reproductive cycle. All gilts received 2.6 kg/d of a standard diet (12.6 MJ DE/kg; 13.9% CP; 0.59% lysine) during pregnancy and were fed ad libitum a commercial lactation diet (13.1 MJ DE/kg; 17.1% CP; 0.90% lysine) from day five after farrowing. At farrowing, AP females were larger (257 versus 225 kg) and had more backfat (23.7 versus 17.4 mm) than R ones. Reproductive performance during the first lactation was not affected by rearing treatment, and weaning to oestrus interval was similar in both groups (4.8 d, on average). During lactation, R sows consumed significantly more feed (+650 g/d) and lost less backfat depth (1.5 versus 3.8 mm) than AP ones.     

Comparison of mouse strains for susceptibility to styrene-induced hepatotoxicity and pneumotoxicity

Bioavailability of lead (Pb) has become an issue in quantifying exposure of sensitive populations and, where necessary, establishing cleanup levels for contaminated soil. Immature swine were used as a model for young children to estimate the degree to which Pb from two fully characterized composite samples from the Smuggler Mountain Superfund Site in Aspen, Colorado may be bioavailable to resident children. The composite soils contained 14,200 and 3870 micrograms Pb/g of soil. Relative and absolute enteric bioavailabilities of Pb in soil (oral dose groups of 75,225, and 675 micrograms Pb/kg body wt/day) were estimated by comparison with an orally administered soluble Pb salt (lead acetate = PbAc2.3H2O) (dose groups of 0, 75, and 225 micrograms Pb/kg body wt/day) and an intravenously administered aqueous solution of Pb (100 micrograms Pb/kg/ day) from the same trihydrate salt administered daily for 15 days to 50 juvenile swine. The biological responses (area under the blood Pb concentration-time curve, and the terminal liver-, kidney-, and bone-lead concentrations) produced by Pb from PbAc2.3H2O and lead-contaminated soils were determined. This study revealed Pb from soil containing 14,200 micrograms Pb/g of soil had a bioavailability relative to Pb from PbAc (RBA), ranging from 56% based on the area under the blood lead concentration-time curve (AUC) versus dose, to 86% based on calculations from liver-Pb loading versus dose. Similarly, Pb from soil containing 3870 micrograms Pb/g of soil had an RBA ranging from 58% based on the AUC versus dose, to 74% based on calculations from liver- and kidney-Pb loading versus dose. Bioavailability of Pb in soils may be more or less than EPA's default RBA of 60%, therefore, measuring site-specific RBAs provides a basis for improved exposure and risk assessment.     

Image analysis of Ag-NOR proteins in transitional cell bladder cancer

Cyclosporin (CsA) and azathioprine (AZA) are useful immunosuppressive drugs in the management of kidney and liver transplant recipients. We investigated urinary mutagenicity in three groups of kidney transplant recipients after different immunosuppressive protocols. Urinary mutagenicity was detected in a base-pair strain, E. coli WP2uvrA, in a liquid incubation assay. No mutagenic activity was detected in the urines of patients treated with CsA (4.5 mg/kg); 85% of the urines in the second group treated with AZA (1.26 mg/kg) showed high mutagenic activity, whereas mutagenic activity was found in 40% of the urines of subjects treated with CsA and AZA (3.89 mg/kg + 1.15 mg/kg). These data suggest that immunosuppressive therapy with AZA carriers a high risk of urinary mutagenicity, while immunosuppressive combined treatment with CsA and AZA significantly reduces this risk.     

Pronounced antitumor effects and tumor radiosensitization of double suicide gene therapy

The efficacy of HSV-1 thymidine kinase (TK) and Escherichia coli cytosine deaminase (CD) suicide gene therapies as cancer treatments are currently being examined in humans. We demonstrated previously that compared to single suicide gene therapy, greater levels of targeted cytotoxicity and radiosensitization can be achieved in vitro by genetically modifying tumor cells to express CD and HSV-1 TK concomitantly, as a fusion protein. In the present study, the efficacy of the combined double suicide gene therapy/radiotherapy approach was examined in vivo. Nude mice were injected either s.c. or i.m. with 9L gliosarcoma cells expressing an E. coli CD/HSV-1 TK fusion gene. Double suicide gene therapy using 5-fluorocytosine (500 mg/kg) and ganciclovir (30 mg/kg) proved to be markedly better at delaying tumor growth and achieving a tumor cure than single suicide gene therapy, which used 5-fluorocytosine or ganciclovir administered independently. Importantly, double suicide gene therapy was highly effective against large experimental tumors (>2 cm3), reducing tumor volume an average of 99% and producing a 40% tumor cure. Moreover, double suicide gene therapy profoundly potentiated the antitumor effects of radiation. The results indicate that double suicide gene therapy, particularly when coupled with radiotherapy, may represent a highly effective means of eradicating tumors.     

Dietary supplementation at home improves the regain of lean body mass after surgery

Little is known about nutritional intake after discharge though it takes months to regain preoperative weight after gastrointestinal surgery. We studied whether a 4-mo intervention with dietary advice and protein-rich supplements would increase nutritional intake and gain in lean body mass (LBM) in patients who had undergone gastrointestinal surgery. Patients admitted for gastrointestinal surgery were randomized at discharge to serve as control patients (n = 47) or to receive intervention (n = 40). One month after discharge, the control patients had a nutritional intake (3-d diet record) comparable with the intake of the general population that did not increase further. During the 4 m, the intervention patients had an increased intake of protein (+22%) and energy (+16%), and an enhanced gain of LBM after 2 mo (control 0.8 kg versus intervention 2.1 kg; P = 0.009). After the 4-mo intervention, both LBM and fat were gained (control 1.7 kg LBM and 0.2 kg fat versus intervention 3.1 kg LBM and 1.5 kg fat; LBM: P = 0.029 and fat: P = 0.056). At discharge patients should increase protein intake to 1.5 g.kg-1.d-1 for 2 mo, e.g., by taking protein-rich liquid supplements.     

Pulmonary edema as an acute complication of ritodrine therapy in the presence of maternal intrauterine infection

Side effects and disadvantages of contraceptive methods currently used in zoo- and wild animals are presented and discussed. For the preservation of wild animal populations in captivity, i.e. in zoos, wild animal- and national parks, contraception alone is not suitable without a sensible supplementary postnatal selection.     

The mechanism of potentiation of the antitumor effect of 5-fluorouracil by methionine-free intravenous amino acid solution (AO-90) in rats

AO-90, a methionine-free intravenous amino acid solution (7.43%) showed to potentiate the antitumor effect of 5-fluorouracil (5-FU) when concomitantly used as the nitrogen source in total parenteral nutrition (TPN) in Yoshida sarcoma (YS)-bearing rats. In the present experiment, this potentiation mechanism was studied by determining the serum methionine level and tumor methylenetetrahydrofolate (CH2FH4) content in YS-bearing Donryu rats given AO-90 (nitrogen 0.73g/kg on the 1st day and 1.46g/kg for the remaining 6 days) by TPN for 1 week. The rats were subcutaneously inoculated with 10(4) YS cells in the dorsum 3 days before the start of TPN. Inhibition of thymidylate synthase activity in tumor tissue after dosing of AO-90 (nitrogen 0.68g/kg on the 1st day and 1.36 g/kg for the remaining 6 days) by TPN along with daily intraperitoneal dosing of 5-FU (10 mg/kg) was also evaluated with the inoculation of 10(6) tumor cells. The results were compared with those in tumor-bearing rats given TPN with a commercially available amino acid solution containing methionine. On day 5 of TPN, the tumor-bearing rats given AO-90 showed a significantly lower serum methionine level than the control rats: 101 +/- 11 mumol/l versus 29 +/- 14 mumol/l (p < 0.01); and a higher CH2FH4 content in tumor: 7.0 +/- 2.8 pmol/g protein versus 23.7 +/- 16.6 pmol/g protein (p < 0.05). Thymidylate synthase inhibition was 81.2 +/- 5.1% in the AO-90 group and 30.9 +/- 26.3% in the control group (p < 0.01). The results of the present study suggest that AO-90 potentiate the antitumor effect of 5-FU by biochemical modulation. AO-90 concomitantly given with 5-FU for 7 days was effective not only in the allogeneic tumor model, but also in WKAH and SHR rats previously inoculated with 10(6) of syngeneic KDH-8 hepatoma cells and SST-2 adenocarcinoma cells, respectively. Weight of SST-2 adenocarcinoma in SHR rats after the TPN period was significantly smaller in the AO-90 group than in the control rats given methionine-containing TPN and 5-FU: 2.66 +/- 0.91 versus 5.12 +/- 2.11 (p < 0.05).     

Alcohol tolerance in humans is enhanced by prior caffeine antagonism of alcohol-induced impairment.

The author tested the hypothesis that a history of drug-induced antagonism of alcohol impairment would enhance alcohol tolerance in humans. Groups of participants (N = 21) repeatedly performed a psychomotor task under different drug treatments: 0.65 g/kg alcohol, 4 mg/kg caffeine, or both drugs combined. Tolerance to a 0.65 g/kg alcohol dose challenge was then tested. Results showed that a history of combined alcohol and caffeine administrations increased alcohol tolerance compared with an exposure history to either drug alone. The findings contribute to the understanding of the complexities of polydrug use history and provide a useful model to examine how alcohol tolerance might be affected by a history of coadministration with other drugs (e.g., cocaine and nicotine). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hemophagocytic syndrome: an underestimated cause of the syndrome of non-infectious fever?]

The effects of two ethanol doses (2 and 3 g/kg) on colonic temperature and levels of norepinephrine (NE) and uncoupling protein (UCP) mRNA in the interscapular brown adipose tissue (IBAT) were examined in rats exposed to 20 degrees C or 4 degrees C for 2 h. The controls received 0.9% NaCl solution. Ethanol produced a significant hypothermic effect versus saline at both temperature conditions. The dose at 3 g/kg reduced colonic temperature more in the cold than at room temperature (p < 0.01), whereas the ambient temperature did not affect the decrease in rats that received ethanol 2 g/kg. At room temperature ethanol did not significantly change the levels of NE or UCP mRNA, whereas after cold exposure (4 degrees C) NE levels in the ethanol-treated rats were significantly lower than in the controls (p < 0.001). Ethanol did not prevent a cold-induced increase in the UCP mRNA levels, although it reduced an increase. The magnitude of the reduction in increase was dependent on the dose, being significant at the dose of 3 g/kg (p < 0.05). The results show that the ethanol-induced drop in body temperature is not necessarily related to IBAT thermogenesis, as indicated by the levels of NE and UCP mRNA.     

A synthetic lipopolysaccharide-binding peptide based on the neutrophil-derived protein CAP37 prevents endotoxin-induced responses in conscious rats

The lipid A component of lipopolysaccharide (LPS) derived from Escherichia coli has been implicated as a significant mediator in the development of circulatory and metabolic dysfunction and lethality associated with sepsis. A synthetic peptide corresponding to amino acid residues 20 through 44 of the neutrophil-derived 37-kDa cationic antimicrobial protein (CAP37 P(20-44)) possesses lipid A binding characteristics which may be useful in attenuating in vivo responses induced during circumstances of endotoxemia, including sepsis. The E. coli LPS to be used in the in vivo study was shown to be attenuated by CAP37 P(20-44) in a dose-dependent manner in the in vitro reaction with Limulus amoebocyte lysate. Intravenous infusion of CAP37 P(20-44) (1.5 or 3.0 mg/kg of body weight) with E. coli LPS (250 microg/kg over 30 min) into conscious, unrestrained rats prevented LPS-induced hyperdynamic and hypodynamic circulatory shock, hyperlactacidemia, and leukopenia in a dose-related fashion. CAP37 P(20-44) (0.2, 1.0, and 5.0 mg/kg) administered intravenously to conscious, actinomycin D-sensitized rats following a lethal dose of LPS neutralized LPS toxicity, resulting in dose-dependent 7-day survival rates of 30, 50, and 80%, respectively. CAP37 P(20-44) (5.0 mg/kg) significantly inhibited the endotoxin-induced increase in circulating tumor necrosis factor alpha in sensitized rats. These data demonstrate that CAP37 P(20-44) has the capacity to abolish in vivo biological responses to LPS that are relevant to human sepsis and to significantly neutralize the toxicity of circulating E. coli LPS.     

Rilmenidine normalizes fructose-induced insulin resistance and hypertension in rats

OBJECTIVE: The aim of this study was to determine the effects of rilmenidine (an antihypertensive drug that lowers blood pressure by decreasing sympathetic outflow) in an animal model of hypertension associated with insulin resistance, i.e. rats fed on a high-fructose diet. DESIGN: Wistar rats were fed for 4 weeks either on a standard diet (S group) or on a high-fructose diet (F group; 34.5% fructose). In half of the rats in the F group, rilmenidine (1 mg/kg per day) was added to the drinking water for the last 2 weeks of the diet (FR group). RESULTS: Body weight gain was higher in the F than in the S rats (66+/-8g versus 45+/-8g, P< 0.05), but was prevented by rilmenidine treatment (32+/-2g). Arterial systolic blood pressure was increased in F rats (162+/-2 versus 155+/-2 mmHg, P< 0.05), rilmenidine reduced this value to normal (149+/-3 mmHg). Glucose tolerance, glucose turnover rate, and insulin secretion were not modified by the diet or by the drug. However, during a euglycemic hyperinsulinemic clamp, glucose utilization was lower (10+/-1 versus 14+/-1.5 mg/min per kg; P< 0.05) and hepatic glucose production higher (1+/-0.01 versus 0 mg/min per kg, P< 0.01) in F than in S rats. These changes in insulin action were totally abolished by rilmenidine. CONCLUSIONS: These data demonstrate that rilmenidine can ameliorate the deleterious effects of a high-fructose diet, i.e. weight gain, hypertension, and resistance to the effects of insulin.     

Bacterial translocation is inhibited in inducible nitric oxide synthase knockout mice after endotoxin challenge but not in a model of bacterial overgrowth

BACKGROUND: Studies have shown that nitric oxide (NO) and NO synthase (NOS) inhibitors injure and protect organs after endotoxin (lipopolysaccharide [LPS]) challenge. OBJECTIVE: To test the hypothesis that LPS-induced gut injury and bacterial translocation (BT) are mediated through activation of inducible NOS (iNOS). DESIGN: A randomized, controlled study using genetically altered, iNOS gene knockout mice. SETTING: University research laboratory. METHODS: Forty-five wild-type (iNOS+/+) or homozygous mutant (iNOS-/-) mice weighing 25 to 35 g were challenged with Escherichia coli LPS or saline (10 mg/ kg) intraperitoneally (n = 8/group). In a second set of experiments, a bacterial overgrowth model of BT (E coli monoassociation) was tested (n = 6-7/group). The mesenteric lymph nodes and cecums were cultured, and liver, ileal, and blood nitrite and nitrate levels measured 24 hours after LPS or E coli monoassociation. RESULTS: After LPS challenge, 87.5% of the iNOS+/+ mice but 0% of the iNOS-/- mice had BT to their mesenteric lymph nodes (P < .01; chi 2 analysis). Nitrite and nitrate levels of the liver, ileum, and blood were higher in the iNOS+/+ mice (P < .05). In the E coli overgrowth model, BT to mesenteric lymph nodes occurred in 100% of iNOS-/- and iNOS+/+ mice. CONCLUSIONS: In this limited study, LPS-induced BT did not occur in iNOS-deficient mice, suggesting that LPS induction of increased iNOS activity is necessary for LPS-induced BT to occur. In contrast, iNOS activation does not seem to be necessary in a bacterial overgrowth model of BT.     

Rapid determination of cholesterol in milk and milk products by direct saponification and capillary gas chromatography

The level and nature of the albendazole residues in milk of treated cows were determined as a function of the time of milking (12-h intervals), and the fate of those residues during cheesemaking, ripening, and storage was examined when the obtained milk was used for making Teleme cheese. Ion-pair liquid chromatographic analysis with fluorescence detection showed that the albendazole sulfoxide metabolite reached its maximum (523 +/- 199 micrograms/kg) at the 1st milking and declined below the detection limit by the 4th milking. The sulfone metabolite attained its highest level (812 +/- 99 micrograms/kg) more slowly (at the 2nd milking) and declined below detection limit by the 13th milking. The 2-aminosulfone metabolite, which was present in the milk obtained at the 1st milking, reached its maximum (128 +/- 36 micrograms/kg) at the 3rd milking, and slowly declined to a level below detection limit by the 15th milking. Whey and cheese analysis revealed that about 70% of each major metabolite initially present in milk could be distributed in the whey. The remaining 30% occurred in the cheese at residue levels higher than those initially present in the milk of the 1st or 2nd milking (688 versus 445 or 450 versus 230 micrograms/kg for albendazole sulfoxide; 890 versus 608 or 1502 versus 783 micrograms/kg for albendazole sulfone; 19 versus 15 or 161 versus 105 micrograms/kg for albendazole 2-aminosulfone). Ripening and storage of the cheeses made from milks from the 1st or 2nd milkings results in a decrease of the sulfoxide metabolite (to 225 or 206 micrograms/kg), an increase of the sulfone metabolite (to 1,181 or 1,893 micrograms/kg), and no effect on the 2-aminosulfone metabolite.     

Endogenous synthesis of arginine plays an important role in maintaining arginine homeostasis in postweaning growing pigs

This study was conducted to determine whether endogenous synthesis of arginine plays a role in regulating arginine homeostasis in postweaning pigs. Pigs were fed a sorghum-based diet containing 0. 98% arginine and were used for studies at 75 d of age (28.4 kg body weight). Mitochondria were prepared from the jejunum and other major tissues for measuring the activities of Delta1-pyrroline-5-carboxylate (P5C) synthase and proline oxidase (enzymes catalyzing P5C synthesis from glutamate and proline, respectively) and of ornithine aminotransferase (OAT) (the enzyme catalyzing the interconversion of P5C into ornithine). For metabolic studies, jejunal enterocytes were incubated at 37 degrees C for 30 min in Krebs-Henseleit bicarbonate buffer containing 2 mmol/L L-glutamine, 2 mmol/L L-[U-14C]proline, and 0-200 micromol/L gabaculine (an inhibitor of OAT). The activities of P5C synthase, proline oxidase and OAT were greatest in enterocytes among all of the tissues studied. Incubation of enterocytes with gabaculine resulted in decreases (P < 0.05) in the synthesis of ornithine and citrulline from glutamine and proline. When gabaculine was orally administered to pigs (0.83 mg/kg body weight) to inhibit intestinal synthesis of citrulline from glutamine and proline, plasma concentrations of citrulline (-26%) and arginine (-22%) decreased (P < 0.05), whereas those of alanine (+21%), ornithine (+17%), proline (+107%), taurine (+56%) and branched-chain amino acids (+21-40%) increased (P < 0.05). On the basis of dietary arginine intake and estimated arginine utilization, the endogenous synthesis of arginine in the 28-kg pig provided >/=50.2% of total daily arginine requirement. Taken together, our results suggest an important role for endogenous synthesis of arginine in regulating arginine homeostasis in postweaning growing pigs, as previously shown in neonatal pigs.