The effects of recombinant bovine interferon-alpha on fertility in ewes

Recombinant bovine interferon-alpha(I)1 (rBolFN-alpha) may be useful for enhancing fertility in sheep because it has extensive sequence homology with ovine trophoblast protein-1. To test the effectiveness of rBolFN-alpha, several experiments were performed in which bred females were given intramuscular injections of rBolFN-alpha around the time of maintenance of the corpus luteum. Treatment with rBolFN-alpha enhanced the fertility of ewes that were bred via natural service or embryo transfer of whole or demi-embryos. Interferon treatment was successful in enhancing lambing rate if injections were given twice daily from Days 11 to 18, 12 to 14, 12 to 15 or 12 to 16. Overall, the lambing rate for ewes bred via natural service was 94/126 (74.6%) for control ewes and 101/126 (80.2%) for rBolFN-alpha treated ewes. Litter size was not affected by treatment. Interferon treatment was not successful in increasing the lambing rate if given as a single injection on Day 12 or as a series of once-daily injections from Days 11 to 16. These results demonstrate that rBolFN-alpha can increase the lambing rate in ewes.     

Amino acid analysis by dinitrophenylation and reverse-phase high-pressure liquid chromatography

The determination of amino acids has been achieved by reverse-phase high-pressure liquid chromatography of their dinitrophenyl derivatives. The methods developed permit the quantitation of all amino acids commonly encountered in a protein hydrolysate and the effect of various parameters on this separation was systematically evaluated. The procedure eliminates the need for specialized postcolumn equipment as employed in conventional amino acid analysis and can be obtained by a simple gradient high-pressure chromatograph. The sensitivity obtained is comparable to that available by methods in common usage, being able to determine amino acids quantitatively in the low picomole range.     

Age-related involution and terminal disorganization of the human thymus

The terminal involution pattern of the human thymus was studied based on autopsy cases (both sexes, age range 63-91 years). Large sections through the entire thymic fat body were examined with the help of both conventional histological and immunohistochemical techniques. The findings demonstrate that thymic atrophy in old humans (a) goes far beyond the degree of involution observed in small rodents; (b) results in a system of thin, branching, in part interrupted, non-keratinizing epithelial plates containing no typical Hassall bodies; (c) concerns all components of the thymus except fat tissue which progressively replaces original thymic structures; and (d) involves various types of disorganization of individual lobules with T and B lymphocytes often located outside rather than within epithelial remnants. Effects of low-level radiation on this final regression of the human thymus are unknown.     

Applicability of imprints to immuno-ultrastructural studies of lymphoid tissues

In order to evaluate the applicability of imprints to immuno-ultrastructural studies of lymphoid tissues, we compared distribution pattern and morphology of B cells, T cells, T-cell subsets, and follicular dendritic reticulum cells (DRC) at the light and ultrastructural level in imprints and sections of tonsils and lymph nodes. The surface antigenic profile of lymphoid cells was revealed with monoclonal antibodies in an avidin-biotin-peroxidase complex (ABC) method. Distribution of lymphoid cells in coherent areas of imprints recapitulated their disposition in sections of respective lymphoid tissues. Preservation of microanatomical relationships and ultrastructure of lymphoid cells in imprints allowed evaluation of associations and fine structural detail of lymphoid cells. Morphologic configurations of B cells in imprints, confined to round aggregates, were similar to fine structural morphology of B cells in mantle zones (MZ) and germinal centers (GC). Processes of DRCs in imprints formed conformations resembling their meshwork within follicles and mantled lymphoid cells. In imprints and sections, lymphocytes of cytotoxic/suppressor phenotype had a large amount of cytoplasm with many organelles. In contrast, cells of helper/inducer phenotype displayed a high nucleocytoplasmic (N/C) ratio and small numbers of organelles. Thus, imprints represent an easy, fast, and reliable method that lends itself to immunoultrastructural studies of lymphoid tissues.     

Effects of temperature on the development,growth, and survival of larvae and pupae of a north-temperate chrysomelid beetle

Summary Developoment, growth, and survival of larvae and pupae of the red turnip beetle, Entomoscelis americana Brown, were studied in 10 constant and four alternating temperature regimes (10 to 32.5° C), in field-cages, and in natural populations in Manitoba. This beetle has a northtemperate distribution in North America. Larval and pupal development occurs in spring and normally is completed before the end of June. Growth and development occurred at all constant temperatures tested, but survival was low at the extreme temperatures. Therefore, the threshold and upper limit were near 10 and 32.5° C. The developmental times of the sexes did not differ and decreased with temperature, except possibly at 32.5° C. The average weight of adult females increased with temperature up to 32.5° C and those of males up to 25° C. Considering developmental rate, survival, adult weight, and incidence of malformed adults, the optimum temperature was estimated to be near 27.5° C.Development was accelerated significantly (6 to 9%) in alternating regimes with temperatures differing by 10° C, but not in regimes differing by 5 and 15° C. All alternating regimes increased adult weight, 5 to 17% for females and 2 to 10% for males. Field cage studies confirmed the increase in adult weight, but not the acceleration in development.A three-parameter normal function described accurately the relationship between developmental rate and constant temperature. A computer simulation model based on this equation estimated developmental times in field cages to within one to five days. For natural populations the model overestimated the developmental times by five to 16 days. The discrepancies between model estimates and observed developmental times in natural populations apparently were due to the elevation of larval and pupal body temperatures above air temperatures by behavioral thermoregulation. The elevation of body temperature was estimated to be equivalent to the addition of 5 to 6° C to the maximum daily air temperature. The adaptations and responses of this beetle to the cool spring temperatures of the north-temperate region are discussed.Contribution No. 1164, Agriculture Canada, Research Station, Winnipeg, Manitoba, Canada     

Histamine-induced pulmonary edema distal to pulmonary arterial occlusion

Histological studies provide evidence that the bronchial veins are a site of leakage in histamine-induced pulmonary edema, but the physiological importance of this finding is not known. To determine if a lung perfused by only the bronchial arteries could develop pulmonary edema, we infused histamine for 2 h in anesthetized sheep with no pulmonary arterial blood flow to the right lung. In control sheep the postmortem extravascular lung water volume (EVLW) in both the right (occluded) and left (perfused) lung was 3.7 +/- 0.4 ml X g dry lung wt-1. Following histamine infusion, EVLW increased to 4.4 +/- 0.7 ml X g dry lung wt-1 in the right (occluded) lung (P less than 0.01) and to 5.3 +/- 1.0 ml X g dry wt-1 in the left (perfused) lung (P less than 0.01). Biopsies from the right (occluded) lungs scored for the presence of edema showed a significantly higher score in the lungs that received histamine (P less than 0.02). Some leakage from the pulmonary circulation of the right lung, perfused via anastomoses from the bronchial circulation, cannot be excluded but should be modest considering the low pressures in the pulmonary circulation following occlusion of the right pulmonary artery. These data show that perfusion via the pulmonary arteries is not a requirement for the production of histamine-induced pulmonary edema.     

Purification and characterization of human T-lymphocyte-derived erythroid-potentiating activity

The human T-lymphoblast cell line, Mo, secretes a number of lymphokines, including erythroid-potentiating activity (EPA), an important early regulator of erythropoiesis. We report purification of EPA to homogeneity, from serum-free Mo-conditioned medium. Purification was accomplished by sequential concentration, ammonium sulfate precipitation, lentil lectin affinity chromatography, gel filtration, and reverse-phase high-performance liquid chromatography. EPA was assayed by its ability to stimulate the growth of large erythroid colonies (bursts) from normal human peripheral blood. The purified EPA has a molecular weight of 28,000 and appears as a single band when analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing or nonreducing conditions. Purified EPA stimulates the growth of both early and late erythroid precursors from human bone marrow, as well as colony formation by the K562 human erythroleukemia cell line. Purified EPA has no colony-stimulating factor activity nor does it appear to be a structural protein of the human T-cell leukemia virus subtype II which infects the Mo cells.     

The effect of propranolol on whole-body microvibrations during examination stress

Whole-body microvibrations (MV) in three dimensions were measured in 51 volunteers, all medical students, 26 without and 25 with beta-receptor blockade (propranolol), immediately before a practical physiology examination and during the ensuing vacation. Propranolol impeded the increase in MV values in all three axes, significantly those in the z axis (vertical), the differences in MV values between the two measurements being minimal in the beta-receptor blocked group. On the other hand, propranolol enhanced MV in the x axis (anteroposterior) and the y axis (transverse), the y axis difference being significant only in females. Propranolol obviously relieves examination stress: the majority of candidates (52%) felt "quieter" in the examination with than in other similar situations without beta-receptor blockade. Propranolol was, however, without effect on the examination results. The rectified impulse in the z axis when related to body weight (Jz) correlates linearly with the calculated cardiac output. Propranolol, however, reduced cardiac output more than Jz, pointing to a Jz component non-sensitive to beta-receptor blockade. The part played by muscle tonus, mainly reflected in the y axis, thus remains unknown. The large and slow oscillations in the x and y axes, observed particularly in beta-receptor blocked females, might be attributed to diminution in standing ability.