Cryptic plasmids in Lactobacillus strains isolated from the murine gastrointestinal tract.

Ten of twenty Lactobacillus strains isolated from the gastrointestinal tracts of animals of several species contained plasmids of 80 to 90 megadaltons or less than 2.6 megadaltons in size, as analyzed by agarose gel electrophoresis. The large plasmids were found only in strains originally isolated from the keratinized epithelium of the murine stomach.     

Purification and characterization of flagella from Roseburia cecicola, an obligately anaerobic bacterium

Flagella from Roseburia cecicola, an obligately anaerobic bacterium originally isolated from murine caecal mucosa, were purified by mechanical shearing followed by differential centrifugation. Purity of the flagellar preparation was determined by polyacrylamide gel electrophoresis, electron microscopy and chemical analysis. The flagella were composed of a single protein subunit (flagellin) with an estimated molecular weight of 42 000. The amino acid composition of the flagellin was similar to that of some facultatively anaerobic and aerobic bacteria.     

Lymphokine-activated killer cells are generated before classical cytotoxic T lymphocytes after bone marrow transplantation in mice

Lymphokine-activated killer (LAK) cells are demonstrable within 2 wk after syngeneic or allogeneic (H-2-compatible) bone marrow transplantation in mice. Classical cytotoxic T lymphocytes (CTL) are not active until at least 4 wk after transplant. Both LAK cells and CTL bear the Thy-1 marker and do not possess the murine natural killer cell marker asialo GM.     

Some observations on the localization of mitomycin C-induced aberrations in human lymphocytes

Actively cycling human lymphocytes were treated with mitomycin C for 1 h (1.4 μg/ml) and then grown in medium containing 10 μg/ml bromodeoxyuridine. Serial 5-h colcemid accumulation samples were taken up to 35 h and the air-dried methaphase spreads stained for replication banding. A complete cell-cycle subphasing analysis was made, and classified cells scored for all categories of chromatid-type aberrations and their location.

Inspite of the high dose which produced massive delay and cycle perturbation, there was no evidence for selectively lethality of early-S cells, in fact such cells were in excess. Extreme localization of aberrations to late-replicating (mostly centromeric) regions was found at all subphases and in pre-S cells. This rules out ‘localization by default’ as an explanation for the observed preferential occurence of ‘break points’ in these regions.

The frequency of incomplete intrachanges, low in late S, rises dramaticallyin early S to become maximal in pre-S cells.     

Expansion of cyclophosphamide-resistant cytotoxic precursors in vitro and in vivo by purified human interleukin 2

Precursors of cytotoxic lymphoid cells obtained from mice treated with cyclophosphamide (CY) can be expanded in culture by alloantigens in the presence of purified human interleukin 2 (IL 2). Similarly, IL 2 delivered in vivo in a rate-controlled manner enhances cytotoxic activity in mice that are immunosuppressed by high doses of CY. The effector cells are Thy-1.2+ and are not elicited in the absence of antigen.     

The effect of season and technique on synchronized and induced estrus and the induction of lambing in the ewe in a commercial setting

At 40 day intervals, groups of 87 to 142 commercial ewes of mixed breeding were subjected to a 5 day breeding period, following one of three estrus inducing or synchronizing treatments (intravaginal sponges containing 60 mg of medroxyprogesterone acetate) for 12 days with (progestin P.M.S.G. group) or without pregnant mares serum gonadotropin (P.M.S.G.) (Progestin group) at sponge removal, or a single injection of prostaglandin F(2alpha) (breeding season and early anestrus only) (PGF(2alpha) group)). Mean pregnancy rates (ewes lambing of those treated) and lambing percentages (lambs born per 100 ewes lambing) were 31 +/- 4%, 169 +/- 6%, 20 +/- 5%, 105 +/- 2% and 18 +/- 8%, 118 +/- 3%, respectively, for the three treatment groups above. Pregnancy rates for the progestin, P.M.S.G. group were 52% in late July, prior to the breeding season, 52% in September and declined to 14% in March (early anestrus). The time from the first of two daily injections of estradiol benzoate to lambing was 34.5 +/- 4.4 hours in ewes 142 to 146 days pregnant.     

Pregnancy diagnosis and assessment of fetal numbers in the ewe in a commercial setting

Jugular plasma progesterone concentrations were used to accurately predict open ewes (96 +/- 3%) in early pregnancy, but they less accurately predicted subsequent lambing especially during the late breeding season and most of the seasonal anestrus. Progesterone values clearly indicated that 500 I.U. of P.M.S.G. elevated ovulation rate in synchronized ewes, but did not clearly indicate fetal numbers. During late pregnancy (88-108 days), abdominal palpation, doplar ultrasound and serum progesterone analysis were equally efficacious in predicting lambing (86 +/- 9.8%, 90 +/- 9.0% and 87 +/- 4.1%, respectively), but a high percentage of ewes lambed that were diagnosed as nonpregnant (30 +/- 15.0%, 48 +/- 17.3% and 25 +/- 8.4%, respectively). Accuracy of the serum progesterone test improved the later the test was performed, although considerable individual overlap existed. Progesterone values for ewes bearing 1, 2, or greater than 2 fetuses at 94 to 95 days of gestation differed (5.5 +/- 0.3, 8.0 +/- 0.4 and 12.4 +/- 2.1, respectively (P < 0.05), whereas at 103 to 108 days values for ewes carrying two or more fetuses did not differ.     

Epidermal growth factor receptor binding is not a simple one-step process

The binding kinetics of 125I-labeled mouse epidermal growth factor (EGF) to receptors on human fibroblast cells in monolayer culture were measured at 4 degrees C. Initial binding rates as a function of hormone concentration allowed estimation of simple two-state on-off rate constants of 1.2 x 10(6) M-1 s-1 and 4.9 x 10(-3) s-1, respectively. These two-state parameters gave inadequate computer fits to long term kinetic and equilibrium-binding data, suggesting that an additional process(es) was occurring. Nonlinear equilibrium Scatchard plots and transient "pseudo-Scatchard" plots taken at pre-equilibrium times support the idea that at least one other process is occurring during receptor binding. 125I-EGF-receptor dissociation kinetic plots were biphasic, yielding rate constants of 1.5 x 10(-2) s-1 and 5.6 x 10(-5) s-1 with the ratio of the two components changing with the time of initial incubation with 125I-EGF. Application of a ternary complex model which assumed complexation of the bound receptor with a cell surface interaction molecule gave satisfactory fits to all data.     

Somatostatin inhibits neutrophil elastase release in vitro

The influence of the long-acting somatostatin analogue, SMS 201-995, on FMLP-induced neutrophil elastase release in vitro has been investigated. Doses from 150 ng/ml upwards inhibited elastase release, with 100% inhibition by 2500 ng/ml. Inhibition was demonstrated both by an assay measuring elastase immunometrically and by an assay based on its enzyme activity. The demonstration that SMS 201-995 inhibits protease release from polymorphonuclear leukocytes may have implications for the long-term clinical use of this somatostatin analogue.