Outbred Hartley male guinea pigs (300-400 g) were infected intradermally with various concentrations of Treponema pallidum Nichols strain in the pubic region. The median lethal dose (ID50) was approximately 10(5). The animals produced lesions visible by darkfield microscopy, treponemal antibodies (IgG only), and histopathological changes in the lymphoid organs. Though less susceptible to T pall...

The chemotherapeutic study of a limited series of steroidal sapogenins from several endemic species of the flora of the Canary Islands is presented here. On the whole, they possess a very weak antibacterial activity, a slight antifungal effect and one of them, vespertilin, displays interesting cytostatic activity (ID50 = 5 micrograms/ml). A pharmacodynamic screening carried out on this product ...

Anisaldehyde characterized in the seeds of Pimpinella anisum L. (Umbelliferae), also known as aniseed, was found to inhibit the oxidation of L-3,4-dihydroxyphenylalanine (L-DOPA) by mushroom tyrosinase (EC 1.14.18.1) with an ID50 of 43 μg/mL (0.32 mM). The inhibition kinetics analyzed by a Lineweaver-Burk plot established anisaldehyde to be a noncompetitive inhibitor for this oxidation. On the ...

The isolated mouse vas deferens possesses an adrenergic excitatory motor innervation which can be inhibited by low concentrations of morphine (ID50=0.5 muM). This effect of morphine is mediated by specific receptors which are blocked by naloxone. Activation of the morphine receptors inhibits noradrenaline release. It is concluded that adrenergic neurotransmission in the mouse vas deferens diffe...

In order to assess a possible role for copper as a regulator of muscarinic receptors in vitro, the receptor was characterized in rats made copper deficient by a dietary regimen. In forebrain regions there was a decrease in both the affinity of the receptors for [3H]-1-quinuclidinyl benzilate and the density of receptors in the copper-deficient animals compared with control animals. Copper treat...

Foot-and-mouth disease virus (FMDV) infection is responsible for the heavy economic losses in stockbreeding each year. Because of the limited effectiveness of existing vaccines and antiviral drugs, the development of new strategies is needed. RNA interference (RNAi) is an effective means of suppressing virus replication in vitro. Here we demonstrate that treatment with recombinant, replication-...

Experimental leptospirosis with Leptospira icterohaemorrhagiae Shibaura strain was studied in guinea pigs. When the pathogen was inoculated intracutaneously to the back of the animals, localized haemorrhage was observed at the inoculated site before the appearance of general haemorrhage. The severity of the local lesion increased progressively until the 7th day of inoculation. The minimum infec...

A phosphatidylinositol-4-phosphate (PIP) kinase activity was purified from rat brain extract through several chromatographic steps to yield an active preparation (specific activity 1 mumol of 32P incorporated into phosphatidylinositol 4,5-bisphosphate/min per mg of protein) with an apparent molecular size of 100-110 kDa in the native form. The isolated PIP kinase required Mg2+ (optimally 20-30 ...

The therapy of Pneumocystis carinii (PC) pneumonia is often unsuccessful, particularly in patients with acquired immune deficiency syndrome (AIDS). Because of difficulties in growing the organism in vitro or obtaining purified organisms, current treatment choices have been made with little information on the metabolic effects of therapeutic agents on PC. This report quantitates the effects of t...

Isolated canine parietal cells were used to evaluate inhibition of acid secretion by both endogenously synthesized and exogenously added prostaglandins (PGs). Uptake of [14C]aminopyrine by the parietal cells was used as an index of acid secretion. The effect of increasing endogenous PG synthesis was determined by incubating arachidonic acid with histamine-stimulated parietal cells. Arachidonic ...