Interferon-gamma induction of major histocompatibility complex antigens on cultured bovine luteal cells.

To investigate immunological mechanisms that may be involved in luteal function, the presence of Class I and Class II major histocompatibility complex (MHC) antigens on cultured bovine luteal cells was examined. After 72 h in serum-free culture, Class I antigens were markedly expressed on luteal cells, as determined by indirect immunofluorescence, whereas expression of Class II antigens was limited. The expression of MHC antigens on luteal cells was increased by treatment with the T-lymphocyte factor, interferon-gamma (IFN-gamma).

Australian micro stilt plants.

The diminutive 'micro stilt plant' life form, recently recognized in a range of taxa throughout many ecosystems of SW Australia, has been reported rarely, if at all, in other locations in or outside Australasia. The growth form itself, its phenology, and the morphological variation that its member species collectively express, present a fascinating example of convergent evolution in response to the exacting edaphic and climatic conditions of an extreme mediterranean-type environment.

Chest wall injuries.

Chest wall injuries range from relatively trivial to fatal flail chest or huge defects. Significant chest wall injury is present in about one third of patients admitted after severe trauma. In management, the principal areas to be considered are pain control, open wounds, pneumothorax, flail chest, and pulmonary contusion.

Tracheobronchial and esophageal injuries.

Tracheobronchial injury was considered rare until the last two decades but is becoming more common (or is being recognized more often). The author reviews diagnosis and the principles of management, among which infection prevention is stressed.

Pathways of assimilation and transfer of fixed nitrogen in coralloid roots of cycad-Nostoc symbioses.

Freshly detached coralloid roots of several cycad species were found to bleed spontaneously from xylem, permitting identification of products of nitrogen transfer from symbiotic organ to host. Structural features relevant to the export of fixed N were described for Macrozamia riedlei (Fisch. ex Gaud.

Inhibition of nodule functioning in cowpea by a xanthine oxidoreductase inhibitor, allopurinol.

Allopurinol (1H-pyrazolo-[3,4-d]pyrimidine-4-ol), an inhibitor of xanthine oxidation in ureide-producing nodulated legumes, was taken up from the rooting medium, translocated in xylem, and transferred to nodules of both the ureide-forming cowpea (Vigna unguiculata L. Walp.) and the amide-forming white lupin (Lupinus albus L.

Regulation of prostaglandin synthesis by progesterone in the bovine corpus luteum.

The objective of the present study was to investigate the influence of progesterone on prostaglandin synthesis by the corpus luteum (CL). Corpora lutea were obtained from dairy cows on days 4, 6, 10, and 18 of the estrous cycle, dissociated, and placed in serum-free culture. The addition of luteinizing hormone (LH) resulted in a slight, but non-significant (p greater than 0.

Investigation of passive venovenous shunts during the anhepatic period of canine hepatic transplantation.

The anhepatic period of canine orthotopic hepatic transplantation is usually accompanied by cardiovascular instability due to occlusion of both the portal and inferior systemic venous systems. The present study was undertaken in order to determine some of the hemodynamic and renal alterations that occur during a 2 hour anhepatic period in the dog and to investigate the use of a passive endoportal, endocaval venovenous shunt that places both the portal and infrahepatic vena caval limbs of the shunt directly into the divided ends of these vessels. Three groups of experimental animals were studied.

Response competition and target word detection during shadowing in a dichotic listening task.

College students (N = 24) served as subjects in a within-subjects study of auditory attention in which four tasks were performed. In the easiest task, a single passage was presented and shadowed while target word detections were indicated by pressing a key. The other three tasks also required target word detection, but a second passage was presented simultaneously.

Chest wall resection for Ewing's sarcoma of the rib: an unnecessary procedure.

Approximately 10% of all cases of Ewing's sarcoma arise from a rib. Conventional management has included chest wall resection (3 or more ribs) and radiation therapy. These forms of therapy have led to complications such as scoliosis and local deformity.

Effects of in vivo and in vitro administration of prostaglandin F2 alpha on lipoprotein utilization in cultured bovine luteal cells.

Two experiments were conducted to determine if a loss in the ability to utilize lipoprotein-cholesterol is one mechanism whereby prostaglandin F2 alpha (PGF2 alpha) decreases steroidogenesis in bovine luteal cells. In the first experiment, serum-free cultures of bovine luteal cells were treated with PGF2 alpha (100 ng/ml) for 5 days prior to addition of lipoproteins. Exposure to PGF2 alpha completely suppressed low-density lipoprotein (LDL)- and high-density lipoprotein (HDL)-stimulated progesterone production (p less than 0.

Temperate phages and bacteriocins of the gliding bacterium Cytophaga johnsonae.

A collection of 30 independently isolated strains of Cytophaga johnsonae was screened for the presence of temperate bacteriophages. Two strains were found to harbour phages. The newly isolated phages differ in several respects from the 43 previously isolated phages for C.

Establishment of symbolic communication in persons with severe retardation.

For persons with severe retardation, learning to communicate symbolically is a complex long-term process requiring the coordination of many components to succeed. Three of four institutionalized adolescents and young adults with severe retardation who participated in this study learned to use lexigrams to request foods and, subsequently, objects. Although their request skill did not initially generalize to labeling and to comprehension tasks, additional request experience with lexigrams resulted in consistent improvement in performance in both tasks.

Pathways of Nitrogen Assimilation in Cowpea Nodules Studied using N(2) and Allopurinol.

In the presence of 0.5 millimolar allopurinol (4-hydroxypyrazolo [3,4-d]pyrimidine), an inhibitor of NAD:xanthine oxidoreductase (EC 1.2.

Mechanism of calcium and magnesium translocation in acute pancreatitis: a temporal correlation between hypocalcemia and membrane-mediated excessive intracellular calcium accumulation in soft tissues.

Hypocalcemia frequently occurs in acute pancreatitis (AP), but its pathogenesis remains unknown. Since AP is often accompanied by acute alteration in the structure and function of cellular membranes, we investigated whether hypocalcemia associated with AP can be explained by acute translocation of Ca from extracellular to intracellular compartments. AP was induced in dogs by injection of autologous bile into the pancreatic duct, and in rats by controlled infusion of artificial bile containing Na-taurochlorate, Keflin, and trypsin into the cannulated bile duct.

Addendum to "Summation in the chimpanzee (Pan troglodytes)".

Rumbaugh, Savage-Rumbaugh, and Hegel (1987) reported that two chimpanzees (Pan troglodytes) could select, with better than 90% accuracy, the greater of two paired quantities of chocolate chips. In that study, no one quantity of chocolates (from 0 through 5) was used in both pairs on a given trial. We investigated the effect of having one quantity in common (CQ) in both pairs.

Cell density influences hormonal responsiveness but not lipoprotein utilization in cultured bovine luteal cells.

The objective of the present study was to investigate the effect of cell density on hormonal responsiveness and lipoprotein utilization by cultured bovine luteal cells. Luteal cells obtained from regularly cycling dairy cows were plated at three culture densities: 0.5 X 10(6), 1 X 10(6) and 2 X 10(6) cells/flask in serum-free Ham's F-12 culture medium, and maintained for 9 days.

Electrocardiographic, biochemical, and morphologic abnormalities in dystrophic hamsters with cardiomyopathy.

Electrocardiographic (EKG) changes were investigated in 7-month-old dystrophic hamsters (DH) with cardiomyopathy and were correlated with biochemical and histologic aberrations. Abnormally tall R-I and R-aVL amplitudes, deep S-III and S-aVR waves, and elongated PR-I, QT-I, and QRS-I intervals (all at P less than 0.0001) were noted in DH compared with normal hamsters.

Nitrogen Nutrition and Xylem Sap Composition of Peanut (Arachis hypogaea L. cv Virginia Bunch).

The principal forms of amino nitrogen transported in xylem were studied in nodulated and non-nodulated peanut (Arachis hypogaea L.). In symbiotic plants, asparagine and the nonprotein amino acid, 4-methyleneglutamine, were identified as the major components of xylem exudate collected from root systems decapitated below the lowest nodule or above the nodulated zone.

Amino acid transport by prosthecae of Asticcacaulis biprosthecum: evidence for a broad-range transport system.

Prosthecae purified from cells of Asticcaulis biprosthecum possess active transport systems that transport all 20 amino acids tested. Using ascorbate-reduced phenazine methosulphate in the presence of oxygen, all 20 amino acids are accumulated against a concentration gradient by isolated prosthecae. Results of experiments testing the inhibition of transport of one amino acid by another, and of experiments testing the exchange of exogenous amino acids with those preloaded in prosthecae, along with characteristics of mutants defective in amino acid transport, suggest the presence in prosthecae of three amino acid transport systems.

Gliding motility in Cytophaga.

Gliding motility in Cytophaga depends on a motility machinery that keeps surfaces of cells in motion and on a surface slime that allows motile cells to translocate over a substratum. The unusual nature of the moving cell surfaces appears to be responsible for several cell-surface properties being motility dependent.

The extrafloral nectaries of cowpea (Vigna unguiculata (L.) Walp.) II. Nectar composition, origin of nectar solutes, and nectary functioning.

Nectar was collected from the extrafloral nectaries of leaf stipels and inflorescence stalks, and phloem sap from cryopunctured fruits of cowpea plants. Daily sugar losses as nectar were equivalent to only 0.1-2% of the plant's current net photosynthate, and were maximal in the fourth week after anthesis.