Induction of an organ-specific autoimmune disease, lymphocytic hypophysitis, in hamsters by recombinant rubella virus glycoprotein and prevention of disease by neonatal thymectomy.

Glycosylated, membrane-associated E1 (58-kDa) and E2 (47- to 49-kDa) rubella virus proteins and unglycosylated nucleoprotein C (33 kDa), from separately expressed vaccinia virus recombinants, were injected into golden Syrian hamsters. Rubella virus E1 and E2 glycoproteins consistently induced an organ-specific autoimmune disease, autoimmune lymphocytic hypophysitis, which was evidenced by the induction of autoantibodies against pituitary cells and by lymphocytic infiltration of the pituitary. Neonatal thymectomy prevented the disease. In contrast, rubella virus nucleoprotein C did not induce either autoantibodies against pituitary cells or lymphocytic infiltration of the pituitary. This finding raises the possibility that virus-specific protein itself can induce an organ-specific autoimmune disease in certain circumstances.     

A comparison of the frequency and type of chromosomal abnormalities in human sperm after different sperm capacitation conditions.

Human sperm karyotypes can be prepared after fusion of human sperm with Golden hamster oocytes. Most laboratories use one of two methods of sperm capacitation: incubation of freshly-ejaculated sperm in Biggers, Whitten, and Whittingham (BWW) medium for 5-7 h at 37 degrees C or sperm storage in (N-tris [hydroxymethyl]methyl-2-aminoethanesulfonic acid; 2-([2-hydroxy-1,1-bis(hydroxymethyl)ethyl]amino)ethanesulfonic acid) (TES)-Tris yolk buffer (TYB) for 1-3 days at 4 degrees C. Since there have been conflicting reports as to whether there is a difference in the frequency of structural chromosomal abnormalities between BWW capacitation and storage in TYB for 2 days, we analyzed a larger number of karyotypes (8974) from 136 donors to determine if there was any difference in the frequency or type of chromosomal abnormalities in sperm treated by fresh BWW capacitation, storage in TYB for 1 day (TYB-1), or storage in TYB for 2 days (TYB-2). There was no difference in the frequency of numerical chromosomal abnormalities or sex ratio in any of the three treatment groups. However, there was a significantly increased frequency of structural chromosomal abnormalities after storage in TYB-1 and TYB-2. There was no difference in the frequency or type of structural chromosomal abnormalities after sperm storage in TYB-1 compared to TYB-2.     

Arachidonic acid inhibits Cl secretion in cultures of dog tracheal epithelium.

We studied the effects of arachidonic acid (AA) on Cl secretion across primary cultures of dog tracheal epithelium. Cell sheets showed mean values for baseline short-circuit current (Isc) and transepithelial resistance of 33.8 muA/cm2 and 360 omega.cm2 (n = 44). AA (5 x 10(-5) M) added to both sides increased Isc by 27.8 +/- 5.2 muA/cm2 (mean +/- SE, n = 8), and elevated intracellular cAMP levels. In the presence of 5 x 10(-6) M of both indomethacin (INDO) and nordihydroguaiaretic acid (NDGA) (inhibitors of cyclooxygenase and lipoxygenase, respectively), AA reduced Isc by 4.4 +/- 0.6 muA/cm2 (n = 10) without changing cAMP. Both INDO and NDGA were necessary to abolish the Isc increase in response to AA. The effects of AA on Isc were unaffected by amiloride. In the presence of INDO and NDGA, isoproterenol (ISO) raised cAMP and increased Isc by 27.6 +/- 4.3 (transient) and 12.8 +/- 3.2 muA/cm2 (sustained) (n = 9). With AA present as well as INDO and NDGA, the transient and sustained responses to ISO were significantly reduced to 13.2 +/- 2.4 and 3.9 +/- 0.8 muA/cm2 (n = 10), respectively; the increase in cAMP was unaltered. AA approximately halved baseline efflux of 125I from confluent cell sheets in high K medium and reduced the isoproterenol-induced increase in efflux to 20% of control. These data are consistent with the reported inhibitory effect of AA on apical membrane chloride channels.     

Factors Affecting Germination of Oospores of Phytophthora infestans

When oospores from the pairing between A¹ and A² mating types of Phytophthora infestans were treated with 0.25 % KMnO₄ solution for 15 min and incubated at 19 °C under light on a modified S+L medium, germination commenced within 4 days and reached about 70 % after 20 days. Under these conditions, more than 25 % of oospores obtained from a 4-day-old culture germinated. To obtain a high germination rate of P. infestans oospores, light was essential during germination but not during growth and oospore formation. The optimum time for activation of oospores with 0.25 % KMnO₄ was 15 to 30 min and a suitable concentration of KMnO₄ for 15 min activation was 0.25 to 0.45 %.     

Kinetic characterization of a prestart cell division control step in yeast. Implications for the mechanism of alpha-factor-induced division arrest

In Saccharomyces cerevisiae yeast, a cycloheximide-sensitive "prestart" step (Ki = 0.12 +/- 0.05 microM) is passaged greater than or equal to 4 to less than or equal to 13 minutes prior to the alpha-factor-sensitive "Start" step in the cell cycle of normal proliferating cells and in the first and second bud emergence cycles of abnormally large cells that had been arrested for cell division with alpha-factor and allowed to recover. This identifies the chronologically last protein synthetic step of the cell cycle that occurs prior to the completion of Start. This step is named the last synthetic prestart or LSP step. Cells require the completion of the LSP step before they can perform Start during recovery from arrest by alpha-factor. Yet alpha-factor is known to prevent cell division by acting at Start. The combined data suggest that alpha-factor prevents the Start step of cell division by inactivating a protein that is 1) required for the performance of Start, and 2) synthesized shortly prior to Start in the last synthetic prestart step.     

Receptors for Dolichos biflorus agglutinin: New cell surface markers on a spontaneous leukemia

$\text{Dolichos biflorus}$ agglutinin (DBA), which is specific for terminal α-N-acetylgalactosamine, bound to a spontaneous leukemia cell of $\text{GRS}\text{A}$ mice, but not to lymphoid cells of the host. The DBA receptors were isolated from the leukemia cell labeled with [³H]-galactose after detergent solubilization and affinity chromatography on DBA-agarose. The major component of the receptors migrated as a glycoprotein of apparent molecular weight 100,000 upon SDS gel electrophoresis. Alkaline treatment degraded the glycoproteins, releasing oligosaccharides of molecular weight around 1,000.     

Blood oxygen dissociation curve of the frogsRana catesbeiana andRana brevipoda

Summary The blood O₂ dissociation curve was determined with a microphotometric reaction apparatus in two frog species,Rana catesbeiana andRana brevipoda, and formulated in terms of a modified Hill equation. The O₂ dissociation curve was in reasonable agreement with determinations of O₂ content, O₂ capacity, and pH (or ) in blood samples taken from various blood vessels and heart cavities. The blood O₂ affinity inRana catesbeiana (mean body weight 230 g, kept at 25°C) was low:P ₅₀=42 Torr (at 25°C and at ventricular blood pH=7.79). The blood of the smaller frog,Rana brevipoda (mean body weight 16 g), had even lower O₂ affinity,P ₅₀ being 52 Torr (at 25°C, pH=7.72). The decrease ofP ₅₀ with increasing body mass, resulting from comparison of these two frog species, is in accordance with literature data on mammals and birds.     

Structures and fatty acid compositions of neutral glycosphingolipids of human plasma

Major neutral glycosphingolipids were isolated from human plasma and their structures and fatty acid compositions studied. The four neutral glycosphingolipids of plasma were characterized as Glc beta(1 leads to 1)ceramide, Gal beta(1 leads to 1)- ceramide, Gal beta(1 leads to 4) Glc beta (1 leads to 1)ceramide, Gal alpha(1 leads to 4) Gal beta(1 leads to 4) Glc beta(1 leads to 1)ceramide and GalNAc beta(1 leads to 3) Gal (1 leads to 4) Gal (1 leads to 4) Glc beta(1 leads to 1)-ceramide. The glycosphingolipids contained mostly short chain fatty acids of which most prominent was C16. Erythrocyte glucosylceramide and lactosylceramide exhibited similar fatty acid compositions as their plasma counterparts. Triglycosylceramide and globoside of erythrocytes contained almost exclusively long-chain fatty acids. In lactosylceramide obtained from "p" erythrocytes, an accumulation of long-chain fatty acids was found; this accumulation was not observed, however, in lactosylceramide isolated from "p" plasma. It was concluded that plasma and erythrocyte glycosphingolipids are synthesized at separate sites where short- and long-chain fatty acids, respectively, are available. Plasma and erythrocyte glucosylceramide, and probably a fraction of lactosylceramide, exchange between plasma and erythrocyte pools. The latter conclusion is discussed in the light of the relative roles of carbohydrate and lipid moieties of the glycosphingolipids in maintaining their association with erythrocyte membranes.     

Treatment of Taenia saginata infection with mixture of areca nuts and pumpkin seeds.

In January and February 1974, 32 adults (20 males and 12 females) and a 13-year-old girl with taeniasis saginata were treated with the mixture of boiled areca nuts and pumpkin seeds at Mastoban, Jen-ai District, Nantou County, Taiwan. A total of 48 worms including 42 scolices were recovered from 29 cases. Side-effects were observed in 4 cases including 3 with complaints of dizziness, tinnitus, nausea and vomiting, and one with coma and abdominal pain. Mixtures of 75-150 g areca nuts and 50-100 g pumpkin seeds were judged effective and safe.