Postexposure prophylaxis against anthrax: evaluation of various treatment regimens in intranasally infected guinea pigs

The efficiency of postexposure prophylaxis against Bacillus anthracis infection was tested in guinea pigs infected intranasally with either Vollum or strain ATCC 6605 spores (75 times the 50% lethal dose [LD(50)] and 87 times LD(50,) respectively). Starting 24 h postinfection, animals were treated three times per day for 14 days with ciprofloxacin, tetracycline, erythromycin, cefazolin, and trimethoprim-sulfamethoxazole (TMP-SMX). Administration of cefazolin and TMP-SMX failed to protect the animals, while ciprofloxacin, tetracycline, and erythromycin prevented death. Upon cessation of treatment all erythromycin-treated animals died; of the tetracycline-treated animals, two of eight infected with Vollum and one of nine infected with ATCC 6605 survived; and of the ciprofloxacin group injected with either 10 or 20 mg/kg of body weight, five of nine and five of five animals, respectively, survived. To test the added value of extending the treatment period, Vollum-infected (46 times the LD(50)) animals were treated for 30 days with ciprofloxacin or tetracycline, resulting in protection of eight of nine and nine of nine animals, respectively. Once treatment was discontinued, only four of eight and five of nine animals, respectively, survived. Following rechallenge (intramuscularly) of the survivors with 30 times the LD(50) of Vollum spores, all ciprofloxacin-treated animals were protected while none of the tetracycline-treated animals survived. In an attempt to confer protective immunity lasting beyond the termination of antibiotic administration, Vollum-infected animals were immunized with a protective antigen (PA)-based vaccine concurrently with treatment with either ciprofloxacin or tetracycline. The combined treatment protected eight of eight and nine of nine animals. Following cessation of antibiotic administration seven of eight and eight of eight animals survived, of which six of seven and eight of eight resisted rechallenge. These results indicate that a combined treatment of antibiotics together with a PA-based vaccine could provide long-term protection to prevent reoccurrence of anthrax disease.     

VIP and drug design

The following review outlines the physiological outcome of VIP and VIP gene manipulations. Previously, we reviewed the various VIP receptors associated with biological functions ranging from growth regulation, sexual function, bronchodilation, vasodilation and immune interactions to neurotrophism. VIP-based drug design is discussed below.     

Prevention of fetal demise and growth restriction in a mouse model of fetal alcohol syndrome

Two peptides [NAPVSIPQ (NAP) and SALLRSIPA (ADNF-9)], that are associated with novel glial proteins regulated by vasoactive intestinal peptide, are shown now to provide protective intervention in a model of fetal alcohol syndrome. Fetal demise and growth restrictions were produced after intraperitoneal injection of ethanol to pregnant mice during midgestation (E8). Death and growth abnormalities elicited by alcohol treatment during development are believed to be associated, in part, with severe oxidative damage. NAP and ADNF-9 have been shown to exhibit antioxidative and antiapoptotic actions in vitro. Pretreatment with an equimolar combination of the peptides prevented the alcohol-induced fetal death and growth abnormalities. Pretreatment with NAP alone resulted in a significant decrease in alcohol-associated fetal death; whereas ADNF-9 alone had no detectable effect on fetal survival after alcohol exposure, indicating a pharmacological distinction between the peptides. Biochemical assessment of the fetuses indicated that the combination peptide treatment prevented the alcohol-induced decreases in reduced glutathione. Peptide efficacy was evident with either 30-min pretreatment or with 1-h post-alcohol administration. Bioavailability studies with [(3)H]NAPVSIPQ indicated that 39% of the total radioactivity comigrated with intact peptide in the fetus 60 min after administration. These studies demonstrate that fetal death and growth restriction associated with prenatal alcohol exposure were prevented by combinatorial peptide treatment and suggest that this therapeutic strategy be explored in other models/diseases associated with oxidative stress.     

Antagonism of VIP-stimulated cyclic AMP formation in chick brain

Of eight peptides tested (0.01-5 microM), only two, that is, pituitary adenylate cyclase-activating polypeptide (PACAP27) and chicken vasoactive intestinal peptide (cVIP), potently stimulated cyclic AMP (cAMP) production in cerebral cortical slices of the chick. Mammalian VIP (mVIP) showed some activity only at the highest dose tested, whereas truncated forms of PACAP or VIP, that is, PACAP6-27, cVIP6-28, and mVIP6-28, or hybrid compounds, that is, neurotensin6-11-cVIP7-28 (NT-cVIP) and neurotensin6-11-mVIP7-28 (NT-mVIP), were inactive. Thirty-minute preincubation of chick cortical slices with 5 microM PACAP6-27, NT-cVIP, or NT-mVIP competitively antagonized the cAMP effects of cVIP (0.03-1 microM), with the truncated form of PACAP being the best antagonist. Preincubation of slices with 5 microM mVIP6-28 also produced a significant inhibition of the cVIP (0.1-1 microM)-induced increase in cAMP production; however its action was independent of the concentration of cVIP. In contrast to mVIP6-28, cVIP6-28 showed no antagonistic activity against the full-length peptide. In parallel experiments, 30-min pretreatment of cortical slices with 5 microM PACAP6-27 significantly antagonized the PACAP38-evoked increase in cAMP formation, whereas mVIP6-28 or the NT-mVIP hybrid was ineffective. It has been concluded that in the chick brain, PACAP and cVIP stimulate cAMP biosynthesis via PAC1 and VPAC-type receptors, respectively, and PACAP6-27 seems to be the most potent, yet PACAP/VIP receptor-nonselective antagonist. Unlike truncated PACAP, the NT-VIP hybrid peptides tested may represent VPACtype receptor-selective blocking activity.     

Surgical scrub. Surgical scrub is always mandatory and must be done before contact with the sterile field

Surgical washing is the process which removes habitual bacterial flora from the surface of the skin on hands and forearms. This technique centers on the mechanical action of water and a sterile surgical brush combined with the antiseptic action of chemical agents. Its practice is not limited to, as its name appears to indicate, professionals related to sterile wards and surgical rooms, but pertains to delivery rooms, pain clinics, etc., in which the diagnostic and therapeutic procedures require a strict control over the quality of the environment.     

Pharmaceutical VIP: prospects and problems.

Recently, multiple receptors for vasoactive intestinal peptide (VIP) have been molecularly cloned and our understanding of VIP chemistry and mechanisms of action has been broadened. The following review outlines the physiological effects of the hormone from growth regulation, reproduction, bronchodilation, vasodilation and immune interactions to neurotrophism. VIP-based drug design and non-invasive innovative delivery modes are discussed with emphasis on tumor diagnosis and treatment, impotence treatment and neuroprotection.