Branched-chain amino acid supplementation during bed rest: effect on recovery.

Bed rest is associated with a loss of protein from the weight-bearing muscle. The objectives of this study are to determine whether increasing dietary branched-chain amino acids (BCAAs) during bed rest improves the anabolic response after bed rest. The study consisted of a 1-day ambulatory period, 14 days of bed rest, and a 4-day recovery period. During bed rest, dietary intake was supplemented with either 30 mmol/day each of glycine, serine, and alanine (group 1) or with 30 mmol/day each of the three BCAAs (group 2). Whole body protein synthesis was determined with U-(15)N-labeled amino acids, muscle, and selected plasma protein synthesis with l-[(2)H(5)]phenylalanine. Total glucose production and gluconeogenesis from alanine were determined with l-[U-(13)C(3)]alanine and [6,6-(2)H(2)]glucose. During bed rest, nitrogen (N) retention was greater with BCAA feeding (56 +/- 6 vs. 26 +/- 12 mg N. kg(-1). day(-1), P < 0.05). There was no effect of BCAA supplementation on either whole body, muscle, or plasma protein synthesis or the rate of 3-MeH excretion. Muscle tissue free amino acid concentrations were increased during bed rest with BCAA (0.214 +/- 0.066 vs. 0.088 +/- 0.12 nmol/mg protein, P < 0.05). Total glucose production and gluconeogenesis from alanine were unchanged with bed rest but were significantly reduced (P < 0.05) with the BCAA group in the recovery phase. In conclusion, the improved N retention during bed rest is due, at least in part, to accretion of amino acids in the tissue free amino acid pools. The amount accreted is not enough to impact protein kinetics in the recovery phase but does improve N retention by providing additional essential amino acids in the early recovery phase.

Removal of lipopolysaccharide from acellular Bordetella pertussis vaccine by detergent treatment.

Protective antigen was extracted from Bordetella pertussis cells with 1.0 M NaCl and precipitated with ammonium sulfate, 20-40% saturation (designated fraction 15A-1B). The protective antigen was purified further by detergent (Emulphogene BC720) treatment and adsorption to aluminum hydroxide gel (designated fraction 15A-108A). Compared with B. pertussis vaccine and fraction 15A-1B, fraction 15A-108A retained protective activity as assessed by the mouse protection test, but had reduced protein and markedly reduced endotoxin content. Fraction 15A-108A also had reduced leukocytosis-promoting, histamine sensitizing splenomegaly-inducing, and adjuvant activities. Emulphogene treatment provided a relatively simple method for removing endotoxin from a potential acellular B. pertussis vaccine.

Antiviral activity of Bordetella pertussis vaccine-elicited peritoneal exudate cells.

Peritoneal exudate cells collected from mice 7 days after treatment with Bordetella pertussis vaccine exhibited significant in vitro antiviral activity against vesicular stomatitis virus (VSV). Vaccine-induced peritoneal exudate cells exhibited both intrinsic and extrinsic antiviral activity in culture with target VSV-infected L cells. Virus replication was poor in the vaccine-induced exudate cells. Coculture of vaccine-induced exudate cells and VSV-infected L cell targets decreased virus yield. The activity appeared specific for infected cells and at least a portion of the antiviral activity was directed against the initial infection cycle. Nonadherent vaccine-induced exudate cells showed an increase in antiviral activity over total vaccine-induced exudate cells.

Characterization of aldehyde dehydrogenase from HTC rat hepatoma cells.

We have proposed developing rat hepatoma cell lines as an in vitro model for studying the regulation of changes in aldehyde dehydrogenase activity occurring during hepatocarcinogenesis. Aldehyde dehydrogenase purified in a single step from HTC rat hepatoma cells is identical to the aldehyde dehydrogenase isolated from rat hepatocellular carcinomas. HTC aldehyde dehydrogenase is a 100 kDa dimer composed of 54-kDa subunits, prefers NADP+ as coenzyme, and preferentially oxidizes benzaldehyde-like aromatic aldehydes but not phenylacetaldehyde. The substrate and coenzyme specificity, effects of disulfiram, pH profile and isoelectric point of HTC aldehyde dehydrogenase are also identical to these same properties of the tumor aldehyde dehydrogenase. In immunodiffusion, both isozymes are recognized with complete identity by anti-HTC aldehyde dehydrogenase antibodies. Having established that HTC aldehyde dehydrogenase is very similar, if not identical, to the aldehyde dehydrogenase found in hepatocellular carcinomas, simplifies the development of molecular probes for examination of the regulation of tumor aldehyde dehydrogenase activity in vivo and in vitro.

Resistance to adenovirus infection after administration of Bordetella pertussis vaccine in mice.

Treatment of mice with Bordetella pertussis vaccine rendered mice resistant to mouse adenovirus infection. The resistant state took at least 5 days to develop, and susceptibility returned to a portion of the test population 35 days after treatment. Transient resistance developed in congenitally athymic mice also. Treatment with a dose of 25 micrograms (dry weight) of B. pertussis vaccine protected approximately 50% of the test population. Vaccines prepared from several different strains of B. pertussis were capable of inducing resistance, and the induction of resistance was not dependent on the mouse strain used for testing. Cross-reacting antibodies capable of neutralizing the virus or protecting against a challenging infection were not induced by treatment with B. pertussis vaccine.

Immunomodulation by Bordetella pertussis: antiviral effects.

Treatment of mice by intraperitoneal inoculation of pertussis vaccine or lipopolysaccharide extracted from B. pertussis will effect resistance to rabies virus, encephalomyocarditis virus, Semliki Forest virus, and Herpes simplex virus. Our previous observations indicated that treatment of C3H/HeN (+/nu) and BDF1 mice with pertussis vaccine injected i.p. five days prior to a mouse adenovirus lethal dose i.p. challenge elicited resistance to clinical disease and death. Susceptibility returned to a portion of the test population 35 days after pertussis vaccine treatment. The pertussis vaccine induced resistance developed in athymic (nude) mice also; however, the population succumbed to infection 35 days later. Titration of pertussis vaccine with respect to induction of resistance indicated the median effective dose (ED50) was approximately 25 micrograms dry weight. This report describes the antiviral activity of acellular components extracted from pertussis vaccine. Extraction of B. pertussis cells with 1.0M NaCl and ammonium sulfate fractionation (20-40% saturation) of the extract resulted in an acellular preparation that induced resistance to lethal dose mouse adenovirus infection. The resistance inducing activity was retained after treatment of the extract with detergent (GAF Emulphogene BC 720) to remove lipopolysaccharide and adsorption to alum gel. Comparison of endotoxin content of pertussis vaccine acellular fractions, polysaccharide fraction and purified lipopolysaccharide suggested that endotoxin probably plays a role in the induction of resistance. The endotoxin content of a Emulphogene-treated preparation that protected 80% of a test population was 39 ng. The lipopolysaccharide extracted from Escherichia coli, Vibrio cholerae, Salmonella typhimurium, and Salmonella minnesota did not induce a resistant state seven days after administration; however, lipopolysaccharide extracted from B. pertussis induced a resistant state.(ABSTRACT TRUNCATED AT 250 WORDS)