Isolation of Actinobacillus suis from a Canada goose (Branta canadensis)

Blindness from conjunctivitis caused by Actinobacillus suis was found in a Canada goose (Branta canadensis) from a wildlife refuge in Kentucky. Lesions were not observed elsewhere and other body organs were grossly normal. Actinobacillus spp. in birds is rare and this is apparently the first report of conjunctivitis resulting from this infection in waterfowl.     

Additive and independent responses in a single receptor: aspartate and maltose stimuli on the tar protein

The aspartate and maltose responses of E. coli are mediated through a single membrane receptor, yet the responses are independent and additive. Both stimuli cause methylation of the same 4 glutamic acid residues. More extensive methylation occurs when a cell that has adapted to one stimulus is exposed to the second, or when both stimuli are added simultaneously. The degree of methylation, as well as receptor migration on two-dimensional gels, demonstrates that only one type of protein is involved, rather than two different receptors arising from differential processing of a single gene. A conformational "push-pull" mechanism in which binding of stimulus and covalent modification, producing opposing stresses, can explain these diverse results.     

Vaginal treatment with a prostaglandin F2 alpha derivative (alfaprostol) for inducing labor in pregnancy at term

The effectiveness and acceptability of Alfaprostol (an analog of PGF2 alpha) in inducing labor were assessed in 20 pregnant women at term. All subjects had no spontaneous uterine activity before treatment and the mean (M +/- SE) Bishop score was 2.45 +/- 0.21. The drug was administered by vaginal route at the dose of 10 mg every 3 hours. Regular uterine contractions appeared in all patients and delivery occurred in 85% of the patients after a mean time of 9h50min +/- 0h55min following the start of treatment. The mean dose of Alfaprostol utilized to achieve delivery was 29.4 +/- 2.0 mg. No major side effects were noted in the mothers and their fetuses at any time during treatment. Two patients exhibited vomiting. The Apgar score of all newborns at birth was 8 or more. These results suggest the usefulness of Alfaprostol to induce labor in pregnant women at term, as it has oxytocic activity without adverse effects on either the mother or the fetus.     

Critical considerations in the development of an assay for sulfidopeptide leukotrienes in plasma

A sensitive and specific assay has been developed for measurement of total sulfidopeptide leukotrienes (LT) in plasma. LTC4 and LTD4 in plasma are converted to LTE4 which is then extracted by C18 Sep-Pak binding and elution. Total LTE4 is resolved by reverse phase high performance liquid chromatography (RP-HPLC) and quantitated by radioimmunoassay (RIA). A [3H]LTE4 internal standard is added to the starting plasma sample to allow overall recovery to be calculated and to define the fractions from RP-HPLC to be assayed for LTE4-like immunoreactivity. The correlation between the measured increase in LTE4 concentration after addition of incremental amounts of LTC4 and LTE4 to plasma was 0.989 and 0.978, respectively, with slopes of 1.05 and 1.11. Addition of 51 pg/ml LTE4 to 5 ml plasma was detectable; the measured increase was 48 +/- 12 pg/ml (mean +/- SE, n = 7). The intra-assay coefficient of variation for 341 pg/ml of added LTC4 was 3.2% (n = 6). Sulfidopeptide leukotrienes could not be detected in blood samples taken from 12 normal volunteers in whom the theoretical detection limit, calculated from the sensitivity of the RIA, the overall recovery of LTE4, and the volume of plasma extracted, was 83 +/- 4 pg LTE4/ml plasma (0.19 +/- 0.01 pmol sulfidopeptide leukotriene/ml plasma; mean +/- SE).     

The effect of Ca2+ on the thermal stability of trypsin in phosphate-buffered saline solution used for harvesting of human embryonic lung fibroblast cultures

The stabilizing effect of Ca2+ (264.9 mg CaCl2 X 2H2O ml-1) on a 0.5% solution of twice-crystallized bovine trypsin in phosphate-buffered saline (used for harvesting human embryonic lung fibroblasts) was studied at 7-37 degrees C and at -20 and -70 degrees C. It can be concluded that storage of the enzyme in the buffer (with or without Ca2+) is not advisable at temperatures greater than or equal to 20 degrees C. At 7 degrees C, on the other hand, trypsin can be stored for some weeks in the calcium-containing phosphate-buffered saline if a moderate loss of activity is acceptable. At -20 degrees C and -70 degrees C the stability of the enzyme was good. In the presence of Ca2+ about 90% of the activity remained after 18 weeks. Without Ca2+ the activity was approximately 10% lower.     

Evaluation of the single radial-immunodiffusion assay for measuring the glycoprotein content of rabies vaccines

The glycoprotein content of rabies vaccines containing the Pitman-Moore strain of rabies virus was measured by the single radial immunodiffusion assay and correlated with vaccine potency. The variability of this assay was 6.3% for a single vaccine lot tested over a one-year period. Using sera prepared against rabies virus glycoprotein from different strains of virus, the assay gave different values. These differences could be eliminated by using a homologous vaccine strain as an internal reference. Single radial-immunodiffusion values for Pitman-Moore vaccines correlated with the manufacturers' NIH potency assay, but required a mathematical transformation to convert values from one assay to the other. Single radial-immunodiffusion values for Street Alabama Dufferin and Flury-LEP vaccines did not correlate with NIH values. Modification of the single radial immunodiffusion technique and the feasibility of using this assay for the determination of rabies vaccine potency are discussed.     

Short- and long-term effects of proallatotoxin (ethoxyprecocene II) on Rhodnius prolixus females

Oogenesis and oviposition can be inhibited in female of Rhodnius prolixus by means of short-term experiment (first reproductive cycle) of a single dose of ethoxyprecocene II given by ingestion. The inhibition is dose-dependent as measured by oocyte growth, egg maturation and egg deposition. In a long-term experiment (second and third reproductive cycles) egg production and oogenesis can be partially or totally re-established by subsequent blood meals without ethoxyprecocene II. These findings suggest that in female R. prolixus, damage caused to corpus allatum by ethoxyprecocene II, in certain cases, is not irreversible.     

An abnormal terminal X-Y interchange accounts for most but not all cases of human XX maleness

To determine if human XX maleness results from an abnormal chromosomal X-Y interchange, we studied the inheritance of the paternal pseudoautosomal region in nine patients. Those six patients in whom Y-specific DNA was found (Y(+)) inherited the entire pseudoautosomal region from the paternal Y chromosome and lost that of the paternal X chromosome. Moreover, in three Y(+) cases, we observed the deletion of a paternal Xp locus tightly linked to the pseudoautosomal region. These results definitively show that an abnormal and terminal X-Y interchange during paternal meiosis causes Y(+)XX maleness. In contrast, no abnormal X-Y interchange was observed in any of the three Y(-) cases analyzed, suggesting that maleness can occur in the absence of any Y-specific DNA.     

Additional characteristics of one-carbon-compound utilization by Eubacterium limosum and Acetobacterium woodii

Growth characteristics of Eubacterium limosum and Acetobacterium woodii during one-carbon-compound utilization were investigated. E. limosum RF grew with formate as the sole energy source. Formate also replaced a requirement for CO2 during growth with methanol. Growth with methanol required either rumen fluid, yeast extract, or acetate, but their effects were not additive. Cultures were adapted to grow in concentrations of methanol of up to 494 mM. Growth occurred with methanol in the presence of elevated levels of Na+ (576 mM). The pH optima for growth with methanol, H2-CO2, and carbon monoxide were similar (7.0 to 7.2). Growth occurred with glucose at a pH of 4.7, but not at 4.0. The apparent Km values for methanol and hydrogen were 2.7 and 0.34 mM, respectively. The apparent Vmax values for methanol and hydrogen were 1.7 and 0.11 mumol/mg of protein X min-1, respectively. The Ks value for CO was estimated to be less than 75 microM. Cellular growth yields were 70.5, 7.1, 3.38, and 0.84 g (dry weight) per mol utilized for glucose, methanol, CO, and hydrogen (in H2-CO2), respectively. E. limosum was also able to grow with methoxylated aromatic compounds as energy sources. Glucose apparently repressed the ability of E. limosum to use methanol, hydrogen, or isoleucine but not CO. Growth with mixtures of methanol, H2, CO, or isoleucine was not diauxic. The results, especially the relatively high apparent Km values for H2 and methanol, may indicate why E. limosum does not usually compete with rumen methanogens for these energy sources.(ABSTRACT TRUNCATED AT 250 WORDS)