Comparison of class and subclass antibody response to live and UV-inactivated RSV administered intranasally in mice.

To determine the effect of viral dose and replication on the subclass antibody response to RSV, mice were immunized intranasally with different doses of live RSV (10(4)-10(6) pfu) and compared to mice given an immunizing regimen of UV-inactivated RSV. Mice given the 10(6) pfu dose of live RSV and mice given the 40 micrograms dose of UV-inactivated RSV had comparable class specific antibody responses to whole RSV in serum and respiratory secretions. Serum from these two groups of mice were then compared for IgG subclass response to whole RSV.

Similar subclass antibody responses after intranasal immunization with UV-inactivated RSV mixed with cholera toxin or live RSV.

To determine the effect of cholera toxin as a mucosal adjuvant on the class and subclass antibody response to RSV, mice were immunized intranasally with different doses of live RSV or UV-inactivated RSV mixed with cholera toxin. A single 10(6) pfu dose of live RSV and a single 50 micrograms dose of UV-inactivated RSV mixed with cholera toxin produced comparable serum IgG and respiratory secretion IgG and IgA antibody titers. Subclass antibody titers to whole RSV were also comparable between these two immunizing regimens.

Octimibate inhibition of platelet aggregation: stimulation of adenylate cyclase through prostacyclin receptor activation.

Octimibate inhibited ADP- and collagen-induced platelet aggregation in human, rabbit and rat platelet-rich plasma. Washed human platelets treated with octimibate had elevated cyclic AMP (cAMP) levels and cAMP-dependent protein kinase activity. When whole platelets were incubated with radiolabeled phosphate, octimibate produced an increase in the phosphorylation of platelet proteins with relative molecular weights of 22, 26, 50 and 80 kilodaltons.

Rapid recovery in mice after combined nasal/oral immunization with killed respiratory syncytial virus.

Based on the concept of a common mucosal immune system, the murine gastrointestinal tract was inoculated (oral) with three doses (5, 20, and 40 micrograms) of UV-inactivated respiratory syncytial virus (RSV) in order to elicit a virus-specific immune response in the respiratory tract. Only the 40 micrograms dose induced significant (P less than 0.01) anti-RSV-IgG rises in serum and lung wash compared to controls.

Influenza-specific ELISA IgA and IgG predict severity of influenza disease in subjects prescreened with hemagglutination inhibition.

Four influenza A challenge studies were performed over a period of three years using the same dose of one virus pool. The first three studies were conducted two influenza seasons apart from the last study. In all four studies only subjects with screening hemagglutination inhibition (HAI) antibody titers less than or equal to 1:8 in sera were accepted as study subjects.

Isolation and characterization of mouse nasal lymphocytes.

A method for isolation of mouse nasal lymphocytes is described. Lymphocyte-enriched suspensions are examined for their morphologic, surface immune staining and mitogenic characteristics. This method will allow testing of immune function in the upper respiratory tract of the mouse.

Pharmacology of a potent, new antithrombotic agent, 1,3-dihydro-7,8-dimethyl-2H-imidazo[4,5-b]quinolin-2-one (BMY-20844).

The effects of 1,3-dihydro-7,8-dimethyl-2H-imidazo[4,5-b]quinolin-2-one (BMY-20844) on platelet function and experimental thrombosis were evaluated in a series of in vitro, ex vivo and in vivo experiments. The compound inhibited platelet aggregation in vitro in platelet rich plasma obtained from humans, rats and rabbits with EC50s of less than 1 microgram/ml when aggregation was induced by ADP, collagen or thrombin. Supra-additive interaction against ADP aggregation was also observed when BMY-20844 was combined with prostacyclin.

Assessment of signs of influenza illness in the ferret model.

The ferret model of influenza A infection was evaluated to determine whether physical signs of influenza illness in addition to fever could be adequately followed. Ferrets were evaluated for nasal and systemic signs of influenza infection in a blinded, randomized protocol. Nasal signs were scored depending on the degree of nasal discharge and congestion.

Differential effect of amantadine hydrochloride on the systemic and local immune response to influenza A.

Anti-influenza serum and nasal antibody titers were followed during a double-blind, placebo-controlled, randomized study assessing the prophylactic efficacy of 50, 100, and 200 mg/day of amantadine hydrochloride against experimental challenge with influenza A/Beth/1/85. The geometric mean titers (GMT) of serum hemagglutination inhibition antibody (P = .05) as well as serum influenza-specific IgG (P = .

2-Ethynylbenzenealkanamines. A new class of calcium entry blockers.

A series of 2-(aryl- or alkylethynyl)benzenealkanamines were synthesized. They exhibit antihypertensive activity in spontaneously hypertensive rats and coronary vasodilator activity with minimal negative inotropic activity in the "Langendorff" guinea pig heart in vitro. They have been shown to exert their activity by inhibition of Ca2+ influx across cell membranes.

Effects of anagrelide on platelet cAMP levels, cAMP-dependent protein kinase and thrombin-induced Ca++ fluxes.

Anagrelide (BL-4162A, 6,7-dichloro-1,5-dihydroimidazo[2, 1-6] quinazolin-2[3H]one monohydrochloride hydrate) is a potent and broad spectrum inhibitor of platelet aggregation. Prior studies showed that anagrelide inhibited platelet cyclic AMP (cAMP) phosphodiesterase activity but did not appreciably elevate platelet cAMP levels. We examined the effects of anagrelide on washed human platelets and found that anagrelide caused significant elevation of cAMP levels.

Effects of acetylcholine and nitroprusside on cGMP-dependent protein kinase in the perfused rat heart.

The effects of acetylcholine and sodium nitroprusside on the activity of cGMP-dependent protein kinase were studied in the perfused rat heart. Acetylcholine produced a dose-dependent increase in cGMP levels and cGMP-dependent protein kinase activity, and reduced the force of contraction. Both acetylcholine and sodium nitroprusside produced rapid increases in cardiac cGMP, with nitroprusside being the more potent agent.

Involvement of cAMP-dependent protein kinase in the regulation of heart contractile force. II.

The effects of histamine on heart cAMP-dependent protein kinase activity, cAMP levels, phosphorylase activity, and contractile force was investigated in the perfused guinea pig heart. To accurately determine the protein kinase activity ratio in guinea pig heart, it was necessary to measure kinase activity in whole homogenates immediately after homogenization of the tissue. Histamine produced a rapid dose-dependent increase in cAMP and the protein kinase activity ratio followed by increased in contractile force and phosphorylase activity.

On the question of cyclic GMP as the mediator of the effects of acetylcholine on the heart.

The effects of acetylcholine and sodium nitroprusside on cyclic GMP levels, contractile force, and glycogen metabolism were investigated in the perfused rat heart. While both agents produced time- and concentration-dependent increases in cyclic GMP, only acetylcholine significantly decreased contractile force. Neither agent altered the basal cyclic AMP concentration, cyclic AMP-dependent protein kinase activity ratio, or phosphorylase activity.

Interaction of acetylcholine and epinephrine on heart cyclic AMP-dependent protein kinase.

In the isolated perfused rat heart, epinephrine produced a rapid, concentration-dependent increase in cyclic adenosine 3',5'-monophosphate (cAMP), activation of cAMP-dependent protein kinase, activation of phosphorylase, and increase in contractile force. At epinephrine concentrations of 1 micron or less, acetylcholine antagonized all these beta-adrenergic effects and also increased cyclic guanosine 3',5'-monophosphate (cGMP) levels. When used alone, acetylcholine produced a rapid elevation of cGMP and markedly diminished contractile force but did not significantly lower basal cAMP levels or cAMP-dependent protein kinase activity.

Activation of cAMP-dependent protein kinase without a corresponding increase in phosphorylase activity.

The effect of prostaglandin E1(PGE1) and epinephrine on glycogen metabolism has been investigated in the perfused rat heart. Both agents produced increases in cAMP and the cAMP-dependent protein kinase activity ratio. When dosages were adjusted to give equal increases in the protein kinase activity ratio from a basal value of 0.

Involvement of cAMP-dependent protein kinase in the regulation of heart contractile force.

The effects of perfusate epinephrine, 1-methyl-3-isobutylxanthine, calcium, and filling pressure were investigated in the perfused working rat heart. Epinephrine produced a rapid increase in cAMP, in the protein kinase activity ratio, and in active phosphorylase. These effects preceded the increase in contractile force produced by the hormone.

Compartmentalization of adenosine 3':5'-monophosphate and adenosine 3':5'-monophosphate-dependent protein kinase in heart tissue.

In rabbit heart homogenates about 50% of the cAMP-dependent protein kinase activity was associated with the low speed particulate fraction. In homogenates of rat or beef heart this fraction represented approximately 30% of the activity. The percentage of the enzyme in the particulate fraction was not appreciably affected either by preparing more dilute homogenates or by aging homogenates for up to 2 h before centrifugation.

Characterization and regulation of heart adenosine 3':5'-monophosphate-dependent protein kinase isozymes.

There is broad species variation in the type of cAMP-dependent protein kinase isozyme present in supernatant fractions of heart homogenates as determined by DEAE-cellulose chromatography, Isozyme I, which elutes at less than 0.1 M NaCl, is predominant in mouse and rat hearts; while isozyme II, which elutes at greater than 0.1 M NaCl, is the predominant type in beef and guinea pig.

Regulation of adenosine 3:5-monophosphate-dependent protein kinase.

The effects of epinephrine, glucagon, insulin and 1-methyl-3-isobutylxanthine on adenosine 3:5-monophosphate (cAMP)-dependent protein kinase activity were investigated in the perfused rat heart. The conditions for homogenization of heart tissue and assay of protein kinase are described. The activation state of the enzyme is expressed as the ratio of the rate of phosphorylation of histone in the absence to that in the presence of 2 mu-M cAMP.

On the question of translocation of heart cAMP-dependent protein kinase.

Rat hearts were perfused with epinephrine and/or 1-methyl-3-isobutylxanthine for 2 min. These agents raised the concentration of cAMP and increased the fraction of cAMP-dependent protein kinase (EC 2.7.

The distribution and dissociation of cyclic adenosine 3':5'-monophosphate-dependent protein kinases in adipose, cardiac, and other tissues.

In crude extracts of adipose tissue the protein kinase dissociates slowly at 30 degrees into regulatory and catalytic subunits in the presence of 700 mug per ml of histone or 0.5 M NaCl. If the kinase is first dissociated by adding 10 muM adenosine 3':5'-monophosphate (cAMP), reassociation occurs instantaneously after removal of the cAMP by Sephadex G-25 chromatography.