Slide staining device for use during space flight.

A slide staining device is described that performs Gram and Wright stains during space flight. Reagents and liquid wastes are contained within a closed system.     

Estrus and ovulation in gilts fed a synthetic progestogen

A synthetic progestogen, allyl trenbolone (AT), was fed to sexually mature gilts to determine the effective doses for the control of estrus and ovulation. Gilts were assigned to a control group and 5 treatment groups receiving 10.0, 12.5, 15.0, 17.5 or 20.0 mg of AT mixed in .45 kg of feed/head/day for 18 consecutive days. Ovarian morphology was determined by laparotomy following estrus or at 10 days post-treatment. AT suppressed estrus in all gilts during treatment. Estrus was effectively synchronized in treated gilts. The average interval from withdrawal of progestogen treatment to estrus was 4.5 days for 48 of 50 treated gilts that were in estrus within 10 days after treatment. The average ovulation rate in treated gilts was similar to control gilts. No detrimental side effects, due to treatment, were observed with the possible exception of a slight increase in the incidence of cystic follicles.     

Pyruvate and malate transport and oxidation in corn mitochondria

Pyruvate oxidation and swelling in pyruvate solutions by corn (Zea mays) mitochondria were inhibited by α-cyano-4-hydroxy-cinnamic acid, an inhibitor of pyruvate transport in animal mitochondria; however, there was no inhibition of pyruvate dehydrogenase activity, and malate and NADH oxidation were not affected. These results suggest the presence of a pyruvate⁻-OH⁻ exchange transporter which supplies the mitochondrion with oxidizable substrate. Lactate appears to be transported also, but not dicarboxylate anions or inorganic phosphate. The rate of pyruvate transport was much slower than that of malate, however, and valinomycin was required to elicit appreciable swelling in potassium pyruvate.     

Mutation of asparagine 111 of rubisco from Rhodospirillum rubrum alters the carboxylase/oxygenase specificity.

The conserved asparagine 111 of ribulose-1,5-bisphosphate carboxylase/oxygenase from the photosynthetic bacteria Rhodospirillum rubrum was identified as a candidate for a side-chain that might be involved in the carboxylase/oxygenase specificity. It was replaced by site-directed mutagenesis with aspartic acid, leucine, glutamine or glycine residues. The mutant enzymes exhibit a very low carboxylase activity compared with the wild-type enzyme. The values of Km(RuBP) and kcat for Asn111----Gly, the most active mutant, are 420 microM and 0.034 s-1, compared with 13 microM and 3.0 s-1 for wild-type. The mutation of Asn111----Gly causes a more than tenfold decrease in the CO2/O2 specificity factor, tau, tau Asn111----Gly = 0.56 and tau wild-type = 6.7. This is the first reported change in rubisco specificity by a single site-directed mutation alone and suggests a target for future protein engineering studies.     

Effects of calorie restriction on immunologic functions and development of autoimmune disease in NZB mice.

Chronic energy (calorie) intake restriction (CEIR) prolonged life, inhibited autoimmune disease, and influenced immunologic and hematologic parameters in NZB mice. Abnormalities in numbers and proportions of T and B cells populations were corrected. Deficient responses to phytomitogens, mixed lymphocyte reactions, formation of plaque-forming cells to sheep red blood cells in vitro, production of cytotoxic T lymphocytes after in vitro stimulation, and interleukin 2 production were also corrected. CEIR prevented the extreme splenomegaly that normally occurs with age in NZB mice. This influence was associated with reduction of a greatly expanded non-T, non-B lymphoid cell population. Calorie restriction also prevented in NZB mice the rapid decrease in total numbers of colony-forming B cells in bone marrow that is also characteristic of mice of this strain. The influences of CEIR on immune parameters and hematopoiesis were generally less marked in non-autoimmune-prone DBA/2 mice than in autoimmune-prone NZB mice. CEIR has been shown to produce profound influences on several strains of autoimmune-prone mice (NZB x NZW)F1, MRL/lpr, BXSB, and NZB herein). In each of these strains, the pathogenesis and manifestations of autoimmune disease are dissimilar. Therefore, it seems likely that calorie restriction acts on an as yet elusive mechanism that operates to foster development of the diseases associated with aging common to each of these autoimmune strains as well as autoimmune-resistant mice and rats. Further investigation of the molecular and cellular bases of the benefits of CEIR seems urgent.     

Chromosomal deletion 4p15.32----p14 in a Treacher Collins syndrome patient: exclusion of the disease locus from and mapping of anonymous DNA sequences to this region.

Treacher Collins syndrome is an autosomal dominant condition of bilateral craniofacial abnormalities of structures derived from the first and second branchial arches. A patient with severe manifestations of Treacher Collins syndrome and a de novo chromosomal deletion in region 4p15.32----p14 was identified. Anonymous DNA sequences of loci D4S18, D4S19, D4S20, D4S22, and D4S23 were mapped to the deleted region. DNA probes previously mapped to loci on chromosome 4p (D4S10, D4S15, D4S16, D4S26, D4S35, D4S95, D4S144, RAF1P1, QDPR, and HOX7) were not deleted in this patient. Linkage analysis between the D4S18, D4S23, and QDPR loci and Treacher Collins syndrome in eight families excluded the Treacher Collins syndrome locus from the region of the deletion.     

Transport of 3-phosphoglyceric acid,phosphoenolpyruvate, and inorganic phosphate in maize mesophyll chloroplasts,and the effect of 3-phosphoglyceric acid on malate and phosphoenolpyruvate production

Maize mesophyll chloroplasts loaded with radioactively labeled 3-phosphoglycerate or phosphoenolpyruvate exchange these compounds for externally provided inorganic phosphate, 3-phosphoglycerate, phosphoenolpyruvate, and dihydroxyacetone phosphate. These exchanges are inhibited by pyridoxal phosphate. 3-Phosphoglycerate uptake, which leads to accumulation of this substance in the stroma, is competitively inhibited by inorganic phosphate and phosphoenolpyruvate. These results are consistent with the transport of 3-phosphoglycerate, phosphoenolpyruvate, inorganic phosphate, and dihydroxyacetone phosphate being mediated by a common carrier (the phosphate translocator). The activation energy of 3-phosphoglycerate uptake as determined from its temperature dependence is 19.5 kcal (4–15 °C). In isolated chloroplasts malate and phosphoenolpyruvate production from oxalacetate and pyruvate, respectively, is inhibited by 3-phosphoglycerate, the extent of inhibition being dependent on the relative concentrations of inorganic phosphate and 3-phosphoglycerate. We propose that 3-phosphoglycerate from bundle-sheath cells may serve as a feedback regulator of mesophyll cell photosynthesis.