Metabolic Fates of Ammonia–N in Ruminal Epithelial and Duodenal Mucosal Cells Isolated from Growing Sheep

The objective of this experiment was to determine the capability of ruminant gut tissues to detoxify ammonia-N using short-term incubations of isolated cells in vitro. Ruminal epithelial cells (REC) and duodenal mucosal cells (DMC) were isolated from growing Texel-Polypay ram lambs (n = 4) fed a pelleted forage:concentrate-based diet. Immediately after isolation, primary cells were incubated for 60 min with glucose (1mM), glutamate (1mM), [15N]ammonium chloride (5, 10, 20, or 40 mM), and 1 of 4 combinations of substrates (1 mM each) that could support urea synthesis [control, N-carbamoylglutamate (NCG); NCG + ornithine (ONCG); and ONCG + aspartate (AONCG)]. Treatments were arranged in a 4 x 4 factorial design. Incorporation of ammonia-15N into alanine, citrulline, arginine, and urea was determined by gas chromatography-mass spectrometry. For both cell types, ammonia-N transfer to alanine was lower when incubation medium contained NCG compared with control, whereas use of ammonia-N for net alanine synthesis increased quadratically with ammonia concentration regardless of substrate treatment. For REC, ammonia-N was not incorporated into citrulline, arginine, or urea, nor into arginine or urea by DMC. Ammonia-N use for net citrulline synthesis exhibited an inverse relationship with ammonia concentration, decreasing linearly as media ammonia concentration increased. Thus, ala-nine synthesis may be a significant metabolic pathway for ruminant gut tissues to detoxify ammonia-N when it is presented luminally at high concentrations as compared with detoxification by the ornithine-urea cycle. Furthermore, DMC do exhibit a metabolic capability to incorporate ammonia-N into citrulline, but low or absent activity of downstream enzymes of the ornithine-urea cycle appears to limit ammonia-N transfers to urea.

Oxidation of glucose, glutamate, and glutamine by isolated ovine enterocytes in vitro is decreased by the presence of other metabolic fuels

The objective of this study was to evaluate oxidative metabolism of glucose, glutamate, and glutamine by isolated ovine enterocytes in the presence of other metabolic fuels in vitro. A mixed mucosal primary cell culture containing enterocytes was isolated from crossbred wether sheep (n = 6) fed a mixed forage-concentrate diet and incubated for 90 min with 1 mM U-14C-glucose, -glutamate, or -glutamine and additional substrates (water as negative control, acetate, propionate, butyrate, glucose, glutamate, or glutamine) at concentrations of 0.1, 1.0, and 10.0 mM. Oxidation of labeled substrates to CO2 and net production of lactate and pyruvate in incubation media were measured. Oxidation of glucose and glutamine to CO2 was decreased (P < 0.05) by 5 to 40% in the presence of additional substrates except acetate. Our observation that glutamine oxidation can be decreased by the presence of additional substrates is contrary to observations in the literature using enterocytes from nonruminants, indicating that ruminant enterocytes might rely on glutamine to a lesser extent as an energy source. Net glucose utilization was decreased (P < 0.05) 16% by propionate (10 mM) compared with control but was not affected by the other additional substrates. Glutamate oxidation to CO2 was decreased 28% (P < 0.05) in the presence of propionate (10 mM) or by 17 and 33% in the presence of glutamine (1.0 and 10 mM, respectively), but not by that of the other additional substrates. Acetate did not affect the oxidation of glucose, glutamate, and glutamine. Propionate decreased (P < 0.05) the oxidation of glucose and glutamate only at the highest concentration (10 mM), indicating that the sparing effects of propionate on substrate oxidation are affected by its concentration in the incubation media. These observations indicate that ruminant enterocytes possess metabolic flexibility for oxidative metabolism of glucose, glutamine, and glutamate depending on the type and concentration of available additional substrates.

Urea Synthesis by Ruminal Epithelial and Duodenal Mucosal Cells from Growing Sheep

The objective was to determine whether ruminant gut tissues have the capability to synthesize urea in a short-term incubation. Mixed primary cell cultures containing ruminal epithelial (REC) or duodenal mucosal cells (DMC) were isolated from growing sheep (n = 4) fed a mixed forage-concentrate diet. Cells were incubated (90 min) in a Krebs salts-based buffer with either acetate (5 mM) or propionate (5 mM) plus a combination of substrate intermediates (5 mM) for urea synthesis: arginine, aspartate + citrulline (AspC), aspartate + ornithine + ammonia (AspON), or AspON + N-carbamoylglutamate (AspONG) in a 2 x 4 factorial arrangement of treatments. Volatile fatty acid, propionate vs. acetate, did not influence net urea synthesis. For REC, net urea synthesis (nmoles x (10(6) cells)(-1) x 90 min(-1)) was greatest with Arg (54.5 +/- 6.3) followed by AspC (4.6 +/- 1.1) and AspONG (3.6 +/- 1.4). For DMC, net urea synthesis for Arg (2.1 +/- 0.7) and AspONG (1.9 +/- 0.7) treatments was greater than for AspC (0.3 +/- 0.7) and AspON (-0.6 +/- 0.7) treatments. Thus, for both REC and DMC, arginase activity appeared to be sufficient for catabolism of arginine to urea. Furthermore, greater urea synthesis from ammonia, ornithine and aspartate in the presence of the N-acetylglutamate analogue suggests that carbamoyl phosphate synthetase is probably rate-limiting for urea synthesis and ammonia detoxification by ruminant gut tissues.

Dose-Response Effects of Intrauminal Infusion of Propionate on Feeding Behavior of Lactating Cows in Early or Midlactation

The objective of this experiment was to evaluate whether dose-response effects of intraruminal infusion of propionate on feeding behavior and dry matter intake (DMI) differ by stage of lactation. Six cows in early lactation (EL) and six cows in midlactation (ML) were assigned to blocks in a duplicated 6 x 6 Latin square design experiment. Treatments were mixtures of sodium propionate and sodium acetate containing sodium propionate at 0, 20, 40, 60, 80, and 100% of total volatile fatty acids (VFA), infused into the rumen continuously for 18 h starting 6 h before feeding at a rate of 21.7 mmol of sodium VFA/min. All cows were ruminally cannulated prior to the experiment. The diet was formulated to contain 30% NDF, and dry cracked corn was the major source of starch. We hypothesized that hypophagic effects of propionate infusion were greater for EL compared with ML because of greater plasma concentration of nonesterified fatty acids (275 vs. 76 microMeq/L) and expected greater basal oxidative metabolism in the liver for EL compared to ML. Propionate infusion decreased DMI for EL and ML, but a quadratic effect of propionate infusion was observed for ML but not EL. This indicated a greater marginal reduction in DMI at higher doses of propionate for ML compared to EL, contrary to our hypothesis. Propionate infusion decreased meal size similarly for both stages of lactation, but linearly increased intermeal interval for ML but not EL. We speculate that lower milk yield for ML compared with EL (30.8 vs. 42.0 kg/d) decreased glucose demand by the mammary gland and increased the proportion of infused propionate oxidized in the liver for ML compared to EL.

Effects of intraruminal infusion of sodium, potassium, and ammonium on hypophagia from propionate in lactating dairy cows

The objective of this experiment was to evaluate effects of salt type on hypophagic effects of intraruminal infusion of propionate in lactating dairy cows. Our working hypothesis is that oxidative metabolism of propionate causes satiety by increasing hepatic ATP concentration and decreasing the discharge rate of the hepatic vagus. We hypothesized that hypophagic effects of propionate are reduced by ammonium and potassium. We speculated that ammonium infusion lowers hepatic ATP concentration because ATP is used for urea synthesis and potassium increases the discharge rate of the hepatic vagus. Eight ruminally cannulated Holstein cows in midlactation were used in a duplicated 4 x 4 Latin square design experiment. Treatments were intraruminal infusion of propionic acid, ammonium propionate, sodium propionate, and potassium propionate. Treatment solutions were 0.93 M for propionate and 0.67 M for salts among the treatments except for propionic acid. Treatment solutions were infused over 14 h starting 2 h before feeding at 17.9 ml/min, which is equivalent to 16.7 and 11.9 mmol/min for propionate and salts, respectively. Infusion of ammonium propionate decreased dry matter intake compared with sodium propionate and potassium propionate (P < 0.04; 11.0 vs. 14.0 and 13.9 kg/12 h) by decreasing meal frequency without affecting meal size, indicating that ammonium delayed the sense of hunger. No difference in DMI and feeding behavior was observed between infusion of sodium and potassium propionate. Contrary to the hypothesis, ammonium infusion did not reduce hypophagic effects of propionate, possibly because the urea cycle indirectly stimulated oxidative metabolism in the liver by generating oxidizable carbon from amino acid catabolism.

Effects of diet fermentability on efficiency of microbial nitrogen production in lactating dairy cows

Effect of diet fermentability on efficiency of microbial N production was evaluated. Eight ruminally and duodenally cannulated Holstein cows (55 +/- 15.9 days in milk; mean +/- SD) were used in a duplicated 4 x 4 Latin square design with a 2 x 2 factorial arrangement of treatments. Experimental diets contained either ground high moisture corn (HM) or dry ground corn (DG) at two dietary starch concentrations (32 vs. 21%). All diets were formulated for 18% CP, and the sources of dietary protein were alfalfa silage (50% of forage at DM basis), soybean meal, distillers grain, and blood meal. The amount of OM truly fermented in the rumen varied from 7.7 (DG at 21% dietary starch) to 11.3 kg/d (HM at 32% dietary starch) among treatments, and was greater for high starch diets and HM treatments compared with low starch diets and DG treatments, respectively. Microbial N flow was greater for high starch diets compared with low starch diets, but was not affected by corn grain treatment. Microbial efficiency was lower for HM compared with DG treatment (39.7 vs. 48.4 g of microbial N/kg of true ruminally degraded OM), but was not affected by dietary starch concentration. Microbial efficiency was positively correlated with rate of passage for OM and starch (r = 0.77 and 0.75, respectively). Rapid passage rate may have decreased microbial turnover in the rumen, enhancing microbial efficiency. Microbial efficiency was negatively correlated with rate of starch digestion (r = -0.55), consistent with the energy spilling theory. However, energy spilling did not appear to be from lack of ammonia or low ruminal pH. Microbial efficiency was not related to ruminal ammonia concentration, daily mean ruminal pH, or minimum ruminal pH. Rate of starch availability and rates of passage for starch and OM from the rumen are important determinants of efficiency of microbial protein synthesis in vivo.

Effects of corn grain conservation method on feeding behavior and productivity of lactating dairy cows at two dietary starch concentrations

Effects of conservation method of corn grain and dietary starch concentration on dry matter intake (DMI) and productivity of lactating dairy cows were evaluated. Eight ruminally and duodenally cannulated Holstein cows (55 +/- 15.9 d in milk; mean +/- SD) were used in a duplicated 4 x 4 Latin square design with a 2 x 2 factorial arrangement of treatments. Experimental diets contained either ground high-moisture corn (HM) or dry ground corn (DG) at two dietary starch concentrations (32 vs 21%). Mean particle size and dry matter (DM) concentration of corn grain were 1863 pm and 63.2%, and 885 microm and 89.7%, for HM and DG, respectively. DMI was lower for HM compared to DG treatment in high-starch diets (20.8 vs 22.5 kg/d), but similar for the HM and DG treatments in low-starch diets (19.7 vs 19.6 kg/d). This reduction in DMI is attributed to smaller meal size for HM compared to DG in high-starch diets (1.9 vs 2.3 kg of DM for high-starch diets; 2.1 vs 2.0 kg of DM for low-starch diets). Faster starch fermentation for HM in high-starch diets might result in satiety with smaller meal size. Milk yield was greater when cows were fed high-starch diets compared to low-starch diets (38.6 vs 33.9 kg/d) regardless of corn grain treatment. High-starch diets increased solids-corrected milk yield by 3.3 kg (35.2 vs 31.9 kg/d) compared to low-starch diets for cows fed DG, but did not increase for cows fed HM. This was because of a lower milk fat concentration for cows fed HM in high-starch diets. Reducing ruminal starch fermentation by substituting DG for HM can increase the productivity of lactating cows fed high-starch diets.

Effects of corn grain conservation method on ruminal digestion kinetics for lactating dairy cows at two dietary starch concentrations

Effects of conservation method of corn grain and dietary starch concentration on ruminal digestion kinetics were evaluated. Eight ruminally and duodenally cannulated Holstein cows (55 +/- 15.9 days in milk; mean +/- SD) were used in a duplicated 4 x 4 Latin square design with a 2 x 2 factorial arrangement of treatments. Experimental diets contained either ground high moisture corn (HM) or dry ground corn (DG) at two dietary starch concentrations (32 vs. 21%). Mean particle size and dry-matter concentration of corn grain were 1,863 microm and 63.2%, and 885 microm and 89.7%, for HM and DG, respectively. Starch digestibility in the rumen was greater for HM treatments compared with DG treatments, but starch digestibility in the total tract was not affected by conservation method of corn grain because of compensatory digestion in the intestines. The difference in ruminal starch digestibility between HM and DG treatment was greater for high-starch diets (71.1 vs. 46.9%) compared with low-starch diets (58.5 vs. 45.9%). This interaction is attributed to a greater difference in first-order digestion rate of starch between HM and DG treatment in high-starch diets (28.2 vs. 14.6%/h) compared with low-starch diets (16.8 vs. 12.2%/h). This suggests that ruminal starch digestion is a second-order reaction limited by enzyme activities as well as substrate availability; ruminal contents of cows fed low-starch diets may have insufficient amylolytic activity for maximal starch digestion when readily fermentable starch is available. Rate of neutral detergent fiber digestion in the rumen was slower for high-starch diets and HM treatments compared with low-starch diets and DG treatments, respectively. Effects of corn grain conservation method on ruminal digestion kinetics are greatly altered by starch concentration of diets.

Solid-state conformation of a hybrid tripeptide between beta-amino acid; 8-aminocyclooct-4-enecarboxylic acid and 2-aminoisobutyric acid

An eight-membered cyclic beta-amino acid, 8-aminocyclooct-4-enecarboxylic acid, was designed as a conformationally restricted non-proteinogenic amino acid. A hybrid tripeptide containing this eight-membered cyclic beta-amino acid and 2-aminoisobutyric acids was synthesized by conventional solution methods. The conformation of the tripeptide was studied using X-ray analysis and was shown to form an eleven-membered hydrogen-bonded turn (3(11)-helical structure) in the solid state.

Analysis of tumor necrosis factor-alpha gene promoter polymorphisms in anorexia nervosa

Elevated plasma tumor necrosis factor-alpha (TNFalpha) levels and enhanced spontaneous TNFalpha release from peripheral blood mononuclear cells in patients with anorexia nervosa (AN) have been reported. TNFalpha activates the hypothalamic-pituitary-adrenal axis and reduces food intake, which is characteristic of eating disorders. Recently, three novel polymorphisms in the 5'-flanking region of the TNFalpha gene were reported at positions -1031 (T --> C substitution), -863 (C --> A) and -857 (C --> T). Differences in these alleles are reportedly related to altered TNFalpha-transcriptional promoter activity. Therefore, we performed a case-control association analysis to determine whether any of those three polymorphisms in the TNFalpha promoter region were involved in a predisposition to AN. The results of our analysis of a cohort of 79 female Japanese AN sufferers and 127 normal female control subjects provide no support for the hypothesis that -1031T/C, -863 C/A and -857C/T polymorphisms in the TNFalpha gene promoter region influence the susceptibility to AN.

Asymmetric synthesis of alpha,alpha-disubstituted alpha-amino acids using (S,S)-cyclohexane-1,2-diol as a chiral auxiliary

Diastereoselective alkylation of ethyl 2-methyl- and/or 2-ethylacetoacetates using the (S,S)-cyclohexane-1,2-diol as an acetal chiral auxiliary afforded enol ethers (2a-f and 5a-f) of 92->95% de in 31-70% yields. Removal of the cyclohexane-1,2-diol with BF(3)-OEt(2) afforded beta-keto esters (3 and 6) bearing a chiral quaternary carbon. The beta-keto esters could be easily converted into optically active alpha-methylated and/or alpha-ethylated alpha,alpha-disubstituted amino acids (12 and 13) in 21-99% yields using Schmidt rearrangement.

A case of cutaneous Exophiala spinifera infection

A 66-year-old female had a solitary dark-red nodule measuring 1 cm in diameter on her left forearm. She often had trauma to her hands and arms. A histopathologic examination demonstrated granulomatous changes in the dermis. Under the high-power magnification yeast-like cells and short toruloid hyphal elements were observed in the granuloma. A few giant cells contained fungal elements. No sclerotic cells were found. On the basis of the histopathologic and mycologic findings, the lesion was diagnosed as a dematiaceous fungal infection caused by Exophiala spinifera. She was treated with oral itraconazole (200 mg/day) and topical heat therapy. The lesion was clinically improved within 58-days. However, E. spinifera was still isolated from the excisional specimen 92-days later. We believe that surgical excision is the choice of therapy if the lesion is small.

Effects of brown midrib 3 mutation in corn silage on productivity of dairy cows fed two concentrations of dietary neutral detergent fiber: 3. Digestibility and microbial efficiency

The effects of digestibility of corn silage neutral detergent fiber (NDF) and dietary NDF content on ruminal digestion kinetics, site of nutrient digestion, and microbial N production efficiency were evaluated with eight multiparous high producing dairy cows in a duplicated 4 x 4 Latin square design with 21-d periods. Experimental diets contained corn silage from a brown midrib (bm3) hybrid or its isogenic normal control at two concentrations of dietary NDF (29 and 38%). The NDF digestibility estimated by a 30-h in vitro fermentation was higher for bm3 corn silage by 9.4 units (55.9 vs. 46.5%). Neither ruminal nor total tract NDF digestibility was affected by corn silage treatment. The bm3 corn silage diet decreased starch digestibility in the rumen and in the total tract, but increased postruminal starch digestibility compared with control diet. The bm3 corn silage diets increased microbial N flow to the duodenum and tended to decrease ruminal ammonia concentration. Microbial efficiency was greater for cows fed bm3 corn silage in spite of lower ruminal pH. Higher efficiency of microbial nitrogen production might be attributed to faster passage rate of NDF for cows fed bm3 corn silage compared with those fed control corn silage. Higher in vitro NDF digestibility might predict enhanced NDF fragility and ease of NDF hydrolysis in vivo. Enhanced in vitro NDF digestibility does not necessarily result in increased NDF digestibility either in the rumen or in the total tract, but possibly increases rate of passage and DMI, improving efficiency of microbial N production.

Effects of brown midrib 3 mutation in corn silage on productivity of dairy cows fed two concentrations of dietary neutral detergent fiber: 1. Feeding behavior and nutrient utilization

The effects of digestibility of corn silage neutral detergent fiber (NDF) and dietary NDF content on feeding behavior, dry matter intake (DMI), and energy utilization were evaluated with eight multiparous high producing dairy cows in a duplicated 4 x 4 Latin square design with 21-d periods. Experimental diets contained corn silage from a brown midrib (bm3) hybrid or its isogenic normal control at two concentrations of dietary NDF (29 and 38%). Both low NDF diets and bm3 corn silage treatments increased DMI and milk yield. However, an interaction between corn silage treatment and dietary NDF content was observed for meal size and for interval between meals, implying that different mechanisms regulating DMI dominate depending on the fermentation characteristics of diets. The bm3 treatment depressed milk fat concentration when fed in a low NDF diet. The bm3 corn silage increased solids-corrected milk yield, but did not affect daily body weight gain compared with control, whereas low NDF diets increased daily body weight gain, but did not affect solids-corrected milk yield compared to high NDF diets. Both bm3 treatments and low NDF diets reduced ruminal pH, but low NDF treatments increased fluctuation of ruminal pH and bm3 treatments did not. Feeding bm3 corn silage increased the energy utilized for milk production, possibly because of a consistent supply of metabolic fuels from the rumen. The beneficial effects of bm3 corn silage on productivity of lactating cows were greater for the cows fed a high NDF diet.

Effects of brown midrib 3 mutation in corn silage on productivity of dairy cows fed two concentrations of dietary neutral detergent fiber: 2. Chewing activities

The effects of digestibility of corn silage neutral detergent fiber (NDF) and dietary NDF content on chewing activities were evaluated with eight multiparous high producing dairy cows in a duplicated 4 x 4 Latin square design with 21-d periods. Experimental diets contained corn silage from a brown midrib (bm3) hybrid or its isogenic normal control at two concentrations of dietary NDF (29 and 38%). The NDF digestibility estimated by 30-h in vitro fermentation was higher for bm3 corn silage by 9.4 units (55.9 vs. 46.5%). Feeding behavior of animals and ruminal pH were monitored continuously for 4 d in each period by a computerized data acquisition system. Ruminal digesta were evacuated twice per period to determine the ruminal NDF pool and its turnover rate. There was no effect of NDF digestibility on total chewing time either per day or per kilogram of NDF intake, or on ruminating time either per day or per kilogram of NDF intake. Although bm3 treatments increased the turnover rate of NDF in the rumen, they increased dry matter intake and had no effect on ruminal NDF pool size. Total chewing time and ruminating time per day were related positively to NDF intake and ruminal NDF pool size, but were not related to ruminal turnover rate of NDF. These results provide no evidence that enhanced NDF digestibility decreases the physical effectiveness of NDF of corn silage.

Acute infectious urticaria: clinical and laboratory analysis in nineteen patients

We treated 19 Japanese patients with acute urticaria presumably caused by infection during the five years from 1994 to 1998. The patients' ages ranged from 2 to 66 years (8 males and 11 females). Most of them had urticaria, angioedema, high fever, neutrophilia, and high serum levels of C reactive protein (CRP). The skin rash lasted more than 24 hours. In four patients, a flow cytometric analysis revealed that the percentage of circulating T cells bearing T-cell receptor V beta 3 was decreased during the active stage and that this decrease was sustained for at least 2 to 3 weeks. This suggests that certain T-cell populations were numerically altered in association with the occurrence of the disease. A retrospective review indicated that the combination therapy with corticosteroid and antibiotics was more effective than the single use of either agent.

Degraded diet induced thermogenesis induced by 20 days of 6 degrees head down bed rest and effect of resistance training

In the 21st century, our dream of living in a space will finally become reality. To understand the effects of microgravity on energy expenditure and possible countermeasure against them is important to maintain human health in space. Diet Induced Thermogenesis (DIT) is an increase in energy expenditure after ingestion of a meal, and accounts for 10% of total daily energy expenditure. Recently, the important role of DIT in regulating obesity is suggested. Basal Energy Expenditure (BEE), on the other hand, is the minimum energy expenditure required to keep on living, and accounts for 60-75% of total energy expenditure. Despite the importance of DIT, no information about DIT in microgravity and possible effects of exercise training is available. Therefore, we aimed to investigate, first, the effects of 20-days of 6 degrees head down tilting bed rest (HDBR) on postabsorptive energy expenditure (PEE), DIT, and BEE. Second, the effects of resistance training during HDBR on DIT and BEE.

Evaluation of the importance of the digestibility of neutral detergent fiber from forage: effects on dry matter intake and milk yield of dairy cows

Effects of the digestibility of neutral detergent fiber (NDF) from forage on performance of dairy cows were evaluated statistically using treatment means for 13 sets of forage comparisons reported in the literature. All comparisons reported significant differences in NDF digestibilities of forages in situ or in vitro. Treatment means were blocked by study or by additional factorial treatment within a study to remove variation among experiments. The statistical model included random effect of block, fixed factorial effect of NDF digestibility (high or low), and dietary NDF concentration as a covariate. Enhanced NDF digestibility of forage significantly increased dry matter intake (DMI) and milk yield. A one-unit increase in NDF digestibility in vitro or in situ was associated with a 0.17-kg increase in DMI and a 0.25-kg increase in 4% fat-corrected milk. Differences in NDF digestibility between treatments were greater when measured in vitro or in situ than when measured in vivo. Digestibility of NDF in vitro or in situ might be a better indicator of DMI than NDF digestibility in vivo because forages with high in vitro or in situ NDF digestibilities might have shorter rumen retention times, allowing greater DMI at the expense of NDF digestibility in vivo. Digestibility of NDF is an important parameter of forage quality.

Effects of brown midrib 3 mutation in corn silage on dry matter intake and productivity of high yielding dairy cows

The effects of enhanced in vitro neutral detergent fiber (NDF) digestibility of corn silage on dry matter intake (DMI) and milk yield were evaluated using 32 Holstein cows in a crossover design with 28-d periods. At the beginning of the experiment, cows were 89 d in milk and yielded 45.6 kg/d of milk. Experimental diets contained either brown midrib (bm3) corn silage or isogenic normal corn silage (control) at 44.6% of DM. The NDF digestibility estimated by 30-h in vitro fermentation was higher for bm3 corn silage by 9.7 units. Contents of NDF and lignin were lower for bm3 corn silage by 1.8 and 0.8 units, respectively. Diets were formulated to contain 19% crude protein and 31% NDF and to have a forage to concentrate ratio of 56:44. Daily DMI, milk yield (3.5% fat-corrected milk), and solids-corrected milk were 2.1, 2.6, and 2.7 kg higher, respectively, for cows fed bm3 corn silage. The milk protein and lactose contents were greater for bm3 treatment, but milk fat content was not. Individual milk yield responses of the cows to bm3 treatment were positively related to pretrial milk yield, and DMI response tended to be positively related to pretrial milk yield. Enhanced in vitro NDF digestibility was associated with higher energy intake, which resulted in increased milk yield.

Determination of peptide phi angles in solids by relayed anisotropy correlation NMR

A solid state NMR method is presented for determination of a backbone dihedral angle phi in peptides, being based on the previously reported method, relayed anisotropy correlation (RACO) NMR [Y. Ishii et al., Chem. Phys. Lett. 256 (1996) 133]. In the present method, the 15N-1H and the 13C-1H dipolar tensors in the 1H-15N-13C-1H system are two-dimensionally (2D) correlated via polarization transfer from 15N to 13C under magic angle spinning (MAS). This method was applied to N-acetyl[1,2-13C,15N]D,L-valine, and the H-C-N-H dihedral angle was determined to be 154.0 +/- 1.4 degrees or 206.0 +/- 1.4 degrees, the former agreeing with the X-ray value of 154 +/- 5 degrees.

Symptomatic monostotic fibrous dysplasia of the thoracic spine

STUDY DESIGN

A case report of monostotic fibrous dysplasia of the thoracic spine with symptoms of chest and back pain.

OBJECTIVE

To treat this lesion with surgery.

SUMMARY OF BACKGROUND DATA

Monostotic fibrous dysplasia of the thoracic spine is rarely seen. Few reports of this disorder appear in the literature. This is the fifth case of monostotic fibrous dysplasia of the thoracic spine presented to date.

METHODS

The patient was a 48-year-old woman with monostotic fibrous dysplasia involving the thoracic spine of the 10th vertebral body and the 10th left rib. Surgical removal of the tumor was carried out. The defect was packed with hydroxyapatite graft material. Arthrodesis or internal fixation was not made.

RESULTS

The diagnosis of fibrous dysplasia was made histologically. No obvious recurrence of the lesion has been seen for 3 years.

CONCLUSION

Surgical removal of the tumor and transplantation of hydroxyapatite was effective treatment for the reported patient.

Tyrosine kinase, phosphatidylinositol 3-kinase, and protein kinase C regulate insulin-stimulated NaCl absorption in the thick ascending limb

We have previously shown a direct stimulatory effect of insulin on NaCl absorption in the medullary thick ascending limb of Henle's loop (mTAL). To further investigate the signal transduction involved, we determined whether tyrosine kinase, phosphatidylinositol 3-kinase (PI3-kinase), and/or protein kinase C (PKC) regulate insulin-stimulated NaCl absorption in the mTAL by in vitro microperfusion methods. In control experiments, insulin increased transepithelial voltage (V(te)) and net lumen-to-bath Cl- flux (J(Cl)). Genistein and methyl 2,5-dihydroxycinnamate, two specific tyrosine kinase inhibitors, abolished the effects of insulin. Wortmannin, a specific PI3-kinase inhibitor, inhibited the action of insulin. The effects of insulin also were inhibited by staurosporin and calphostin C, which are dissimilar inhibitors of PKC. These results indicate that insulin stimulates NaCl absorption in the mTAL through tyrosine kinase, PI3-kinase, and PKC-mediated mechanisms. Moreover, because we have reported previously that insulin causes no detectable change in cytosolic free Ca2+ in the mTAL cells, the present results also suggest that insulin-induced PKC activation is not related to inositol 1,4,5-triphosphate (IP3) production.

Clinical experience of functional electrical stimulation in complete paraplegia

Percutaneous intramuscular electrodes and a portable multichannel system were used to restore the function of the paralyzed lower extremities in six patients with complete paraplegia. The total number of inserted electrodes was 168. All of the patients could stand, two could walk in parallel bars, and two could walk with a walker. The rate of breakage of electrodes was only 0.6% in our series. There were 10 (6.0%) superficial infections, and 10 (6.0%) movement of electrodes which required reimplantation. The results suggest that the ultrafine intramuscular electrode is practical for long term use with paraplegic patients. Although the system can be used for paraplegic patients during the activities of daily living, it will be necessary to develop a closed-loop controller to reduce the amount of stimulation to the extensor muscles and extend the endurance of upright activity to reduce fatigue.

[Histological changes, muscle force and fatigability after electrical stimulation to experimentally paralyzed muscles]

In order to use functional electrical stimulation effectively in paralyzed muscle treatment, changes in the maximal muscle force, muscle fatigue, and histological changes were evaluated in electrically stimulated muscles. Study 1. Tissue damage by percutaneous intramuscular electrodes implanted into the quadriceps muscle was examined in rat. Stimulation was conducted at various output voltages, and for various durations of time, in order to assess the histological changes in the muscle around the electrodes. Study 2. Electrodes were implanted into the bilateral quadriceps and gastrocnemius muscles of adult cat, and the unilateral muscles were then stimulated from 3 weeks following the transection of the spinal cord at the T9 level. Stimulus parameters were divided into two groups; as "A" stimulation: at -8V for 15min twice/week, and as "B" stimulation: at -16V for 30 min 4 times/week. The histological changes were examined using the myofibrillar ATPase method to determine the diameters and occupation ratios for each muscle fiber type. RESULTS. Study 1. Significant tissue damage began to occur when the voltage output created the maximum muscle contraction force. Until that critical voltage point was reached, tissue damage was not significant, regardless of the duration of the stimulation. Study 2. The maximum muscle force decreased until 4 weeks after the transection, then increased regardless of the presence of electrical stimulation. The muscle fatigability of the non-stimulated muscle was greater than that of the stimulated muscle. High voltage, long duration, and frequent stimulation was effective in controlling fatigue. The ratio of type I fibers was higher in the stimulated muscle. There was no evidence, however, of suppressing muscle fiber atrophy after electrical stimulation. These results suggested that electrically stimulating paralyzed muscles was effective for suppressing muscle fatigue, and for reducing the ratio of type I fibers. In clinical use, the output voltage should be kept below the voltage that induces the maximum muscle contraction to prevent tissue damage.