A double running suture technique for keratoplasty: earlier visual rehabilitation.

The technique of using two continuous sutures of different caliber and relative tightness, running in the same direction, is described for penetrating keratoplasties. The primary purpose of the technique is to allow visual correction earlier in the postoperative period. In addition, graft slippage with override and posterior wound gape, both occurring at suture removal with resultant functional loss, have been eliminated.

Investigations into the cardiac effects of tolazoline in guinea pig atria and ventricular strips.

The positive inotropic, chronotropic and cyclic AMP producing effects of tolazoline were studied on atrial and ventricular preparations obtained from guinea pig heart. (1) The direct positive inotropic effects of tolazoline on the paced left atrial preparation from the guinea pig hearts was blocked by promethazine, but not by burimamide. Tolazoline did not elevate cyclic AMP levels in this preparation.

Reserpine-induced supersensitivity to the activation of cardiac glycogen phosphorylase by calcium.

Rats receiving reserpine (2.5 mg/kg, 24 h before sacrifice) developed a supersensitivity to the phosphorylase activating effect of both noradrenaline and Ca2+. Supersensitivity to the inotropic and chronotropic effects of the agonists did not develop with this dose of reserpine.

Combined scleral ring and blepharostat.

A modified Legrand scleral ring served three important functions: it prevented anterior scleral buckling and collapse, it separated the eyelids to give good surgical field exposure, and it provided firm fixation for the globe during trephining and suturing.

H2-histaminergic activity of clonidine in the guinea pig heart.

Clonidine perfusion (1 muM) or injection (9.4 to 150.4 nmoles) into the isolated perfused guinea pig heart caused an increase in contractile force, phosphorylase a and cyclic adenosine monophosphate (cyclic AMP) levels.

Cyclic AMP and the positive inotropic effect of norepinephrine and phenylephrine.

Time-response studies of the effects of norepinephrine and phenylephrine revealed that both agonists caused an increase in cyclic AMP levels before increases in contractile force in either the electrically stimulated left atria or spontaneously beating right atria of the rat. Norepinephrine caused a nearly sixfold increase in cyclic AMP, whereas phenylephrine produced only a 50% increase in the nucleotide. Pretreatment with reserpine did not affect the norepinephrine cyclic AMP response; however, the phenylephrine cyclic AMP response was abolished.

Enhancement of the cardiac phosphorylase activating effect of dibutyryl cyclic AMP by thyroid hormone.

The injection of dibutyryl cyclic AMP into the perfused rat heart resulted in dose-dependent increases in contractile force and phosphorylase a activity. In hearts from hyperthyroid animals both responses were markedly enhanced. The data indicate that the hyperthyroid state may produce changes in the heart making it more responsive to cyclic AMP.

Vasopressin and angiotensin: reciprocal mechanisms controlling mesenteric conductance.

Intravenous infusions of [Sar1-Ala8]angiotensin II, acute hypophysectomy, and acute intestinal denervation were carried out in 15 pentobarbital-anesthetized cats. Infusion of the angiotensin II antagonist caused only a small increase in superior mesenteric arterial conductance and a small decrease in arterial pressure in intact animals, but the changes were subypophysectomy alone caused only a small intestinal vasodilatation and little change in arterial pressure. However, the responses to hypophysectomy were much larger when the gland was removed during a prolonged infusion of the angiotensin II antagonist.

Cardiac histamine receptors: differences between left and right atria and right ventricle.

Histamine can stiumulate the heart by directly interacting with cardiac histamine receptors. In the present study we have investigated the cardiac effects of histamine, 4-methylhistamine (a specific H2-receptor agonist) and 2-pyridylethylamine PEA, a specific H1-receptor agonist] on spontaneously beating right atria and electrically driven left atria and right ventricle strips of the guinea pig. Left atria were driven at 1 Hz and right ventricle strips at 2.

Experimental disciform edema and necrotizing keratitis in the rabbit.

The development of experimental disciform edema and necrotizing keratitis in the corneas or rabbits following intrastromal inoculation with the RE strain of herpes simplex virus is described. Following an initial episode of conjunctivitis and epithelial keratitis, a mild, centrally localized, stromal edema developed on the fifth day. Stromal edema, opcification, and neovascularization of the cornea reached maximum severity on the seventh to twenty-second day, and began to fade in most eyes thereafter.

Isoproterenol-induced relaxation, phosphorylase activation and cylic adenosine monophosphate levels in the polarized and depolarized rat uterus.

There is some evidence in the literature that catecholamines relax uterine and other types of smooth muscle by increasing tissue levels of cyclic adenosine monophosphate (cyclic AMP). In the present study, isoproterenol completely relaxed uterine strips obtained from estrogen-primed rats and also increased tissue levels of cyclic AMP and phosphorylase a. In uterine strips depolarized and put into contracture for 15 minutes by 127 mM K+, isoproterenol did not increase phosphorylase a or cyclic AMP but was still capable of producing relaxation.

The effects of certain drugs on the uptake and release of [3H]noradrenaline in rat whole brain homogenates.

Twelve drugs were studied with respect to their effects on inhbition of neuronal uptake of [3H]noradrenaline ([3H]NA) and on release of this amine from presynaptic nerve terminals. An in vitro method, using a crude synaptosomal homogenate prepared from rat whole brain, was employed. All drugs tested were found to produce some release of [3H]NA although tyramine was by far the most potent drug in this respect; tripelennamine and cocaine were observed to produce the least release.

The effect of calcium oncardiac phosphorylase activation, contractile force and cyclic AMP in euthyroid and hyperthyroid rat hearts.

Calcium chloride injected into isolated perfused rat hearts produced a positive inotropic effect and increased the levels of phosphorylase a (EC 2.4.1.

Effect of (Sar1, Ala8)-angiotensin II and hypophysectomy on the intestinal resistance vessels and blood pressure following furosemide-induced volume depletion.

Intravenous administration of furosemide (2 mg/kg) caused intestinal vasoconstriction in various groups of pentobarbital-anesthetized cats. (Sar1, Ala 8)-angiotensin II, a specific competitive antagonist of angiotensin II, was infused 60 min after administration of furosemide, a time when the intestinal vasoconstrictor response to the diuretic was maximal or near maximal. In hypophysectomized animals, infusion of the antagonist abolished the intestinal vasoconstriction and caused a significant fall in arterial pressure even when the intestinal nerves and adrenal glands remained intact.

Actions and interactions of theophylline and imidazole on cardiac contractility, phosphorylase activation and cyclic AMP.

Injection of 1.0 mg theophylline and 1.6 mg imidazole into guinea-pig hearts perfused by the Langendorff technique increased cardiac contractile force by 20.

Biochemical and mechanical effects of phenylephrine on the heart.

Injections of phenylephrine into isolated perfused guinea pig hearts increased cyclic AMP and phosphorylase a. Reserpine pretreatment or propranolol decreased or abolished the phenylephrine-induced biochemical changes without affecting the contractile response. Phentolamine, on the other hand, shifted the phenylephrine dose-response curve for contractility to the right without affecting the other parameters.

The effect of histamine, isoproterenol and tyramine on rat uterine cyclic AMP.

Isoproterenol (10(-4) M), histamine (10(-3) M) and tyramine (10(-3) M) elevated cyclic AMP levels in incubated rat urerine segments. Promethazine (10(-6) M) an H1-receptor antagonist was ineffective in blocking the increase in cyclic AMP due to isoproterenol, histamine and tyramine. Buriamide (10(-6) M), an H2 receptor antagonist, was effective in almost abolishing the cyclic AMP elevation due to histamine, whereas burimamide did not affect the cyclic AMP levels elevated by tyramine and only slightly reduced the isoproterenol response.

Epileptiform seizures in domestic fowl. V. The anticonvulsant activity of delta9-tetrahydrocannabinol.

The anticonvulsant activity of delta9-tetrahydrocannabinol (delta9-THC) has been determined against seizures induced in epileptic chickens by intermittent photic stimulation (IPS) and in epileptic and nonepileptic chickens by Metrazol. Intravenous administration of the drug reduced both the severity and incidence of seizures evoked by IPS in epileptic chickens. This anticonvulsant action was accompanied by a reduction in frequency of inter-ictal slow-wave high-voltage electroencephalographic activity and by the absence of spiking during IPS.

Histamine2 receptors in rat uterus.

Histamine and three histamine analogs (4-methylhistamine, 3-beta-aminoethyl 1,2,4 triazole (TD) and betazole) all produced relaxation in depolarized rat uterine strips. The rank order obtained was the same as that noted previously in the heart and gastric mucosa and the effects of the agonists were blocked by burimamide. The uterine histamine receptor thus appears to be of the H2-type.