Myristylation of rotavirus proteins

After labelling with [3H]myristic acid during replication the structural proteins VP6 and VP2 of purified rotavirus particles were found to be myristylated in an amide bond. [3H]Palmitic acid was converted to myristic acid before bonding to the viral proteins. Possible functions of rotavirus protein myristylation are discussed.

Pharmacodynamic profile of CQP 201-403, a novel 8 alpha-amino-ergoline

The profile of action in animals of CQP 201-403, a novel 8 alpha-amino-ergoline, is in most aspects that of a very potent dopaminomimetic, both as a prolactin secretion inhibitor, and at the levels of the CNS and the cardiovascular system. Qualitatively CQP 201-403 differs slightly from bromocriptine and apomorphine in its effects on the CNS (no influence on serotonin metabolism in the rat cortex; induction of masculine mounting behavior in rats) and the cardiovascular system of the dog (reflex tachycardia in response to a blood-pressure fall). In man the new compound proved to be highly active in lowering prolactin serum levels and be more potent than bromocriptine (Parlodel).

A clinical, histopathologic, and molecular biologic investigation of vulvar intraepithelial neoplasia

The spectrum of vulvar intraepithelial neoplasia (VIN) was investigated with human papillomavirus (HPV) DNA probes by Southern blot hybridization technique. The results of vulvar tissue examinations from 25 patients were compared to prior genital and systemic diseases, clinical presentation, and histopathologic manifestations. The presence of HPV DNA in these lesions was largely associated with multifocality of the lesions, the presence of synchronous and metachronous multicentric genital neoplasia, and depressed immunocompetence. These findings indicate that VIN is associated with HPV and may have an infectious etiology.

Heterogeneity of genome rearrangements in rotaviruses isolated from a chronically infected immunodeficient child

Rotaviruses with genome rearrangements, isolated from a chronically infected immunodeficient child, were adapted to growth in BSC-1 cells. Preparations of viral RNA from fecal extracts showed a mixed atypical rotavirus RNA profile, which was due to the presence of at least 12 subpopulations of viruses grossly differing in genotype. Besides various forms of genome rearrangements involving segment 8-, 10-, and 11-specific sequences, reassortment in vivo was likely to have occurred during the emergence of these viruses. The protein products of viral genomes with various forms of segmental rearrangements seemed to be largely unaltered. Genome rearrangement is proposed to be a third mechanism directing the evolution of rotaviruses.

Antineoplastic effects of tumor necrosis factor alone and in combination with gamma-interferon on tumor biopsies in clonogenic assay

Tumor colony-forming cells were grown from fresh biopsy specimens from 102 patients with a variety of nonhematologic malignant neoplasms and exposed in vitro to pharmacologically achievable doses of recombinant human tumor necrosis factor (rTNF). In 68 instances, the tumor specimens were also tested against recombinant human gamma-interferon (rIFN-gamma), as well as the combination of rTNF and rIFN-gamma. rTNF exhibited dose-dependent and tumor-type-dependent antitumor effects. Sensitivity to rTNF at doses of less than 100 U was observed in 28% of the tumors tested. A higher than average frequency of sensitivity was observed in colorectal and lung cancer. Resistance to rTNF was observed in 42% of the tumors, including 52% of the ovarian cancer specimens tested. In paired experiments, exposure of tumor specimens to rTNF and rIFN-gamma in combination often resulted in a greater antitumor effect than was observed with either agent alone, with at least subadditive effects seen in 62% of the specimens tested against the combination. Antagonism between rTNF and rIFN-gamma was observed in 18% of the studies. Overall, exposure to the combination of rTNF and rIFN-gamma reduced the dose of rTNF required for significant antitumor activity by about threefold. Normal bone marrow granulocyte-macrophage colony-forming cells were also tested against both rTNF and rIFN-gamma and the combination. The bone marrow progenitors were more sensitive to rTNF and the combination with rIFN-gamma than were the tumor cells; however, the significance of this comparison between two different in vitro assay systems is indeterminate. Based on our observations, rTNF warrants phase II clinical trials in selected solid tumors with definite emphasis on colorectal and lung cancer. Additionally, studies of the combination of rTNF and rIFN-gamma are indicated and will be of particular interest in endometrial and breast cancer.

7S IgM in the sera of patients with arthritis

Using radial immunodiffusion in 7% agarose, 7S IgM was quantified in the sera of 45 normal individuals, 37 patients with rheumatoid arthritis (RA), 18 patients with psoriatic arthritis and 11 patients with ankylosing spondylitis. 7S IgM was only found in the sera of patients with RA, 43% of whom had detectable levels of 7S IgM (median 47.5 micrograms/ml). The patients with 7S IgM had significantly higher IgM rheumatoid factor (IgM RF) and C-reactive protein levels in their sera (p less than 0.005). There was a strong correlation between 7S IgM and IgM RF levels in the sera of these patients. These data demonstrate that patients with more active and severe disease have 7S IgM present in their sera but the absence of 7S IgM from the sera of some patients with high levels of IgM RF and CRP suggest that additional factors may influence the synthesis and secretion of 7S IgM by B cells in RA.

Pilot study of phenytoin in rheumatoid arthritis

The anticonvulsant drug phenytoin has several interesting immunological properties which could theoretically be of benefit in the treatment of rheumatoid arthritis. For this reason a pilot study has been carried out on 11 patients with active classical or definite disease. Seven patients completed a 20 week course of treatment and showed continuous improvement at 12 and 20 weeks and some deterioration eight weeks after the drug was stopped. Laboratory and clinical measurements of disease activity responded favourably during the treatment period, suggesting that phenytoin may have second line activity.

Cardiovascular actions of DPI 201-106, a novel cardiotonic agent

DPI 201-106 (4-[3-(4-diphenylmethyl-1-piperazinyl)-2-hydroxypropoxy]-1H-indole -2- carbonitrile) is characterized by a marked cardiotonic activity. The compound exerted positive inotropic effects in anesthetized and conscious dogs, pithed open-chest cats, and isolated hearts of cardiomyopathic hamsters and vanadate-treated guinea-pig atria. Left ventricular dP/dtmax was increased in anesthetized dogs after i.v. injection of 0.2 and 2 mg/kg DPI 201-106 (34 +/- 6 and 104 +/- 18%, respectively) and in unanesthetized dogs after oral doses of 2-8 mg/kg (22 +/- 3 to 50 +/- 5%, respectively). In most experiments, the compound lowered blood pressure and heart rate. Stroke work and left ventricular work were almost unaffected by DPI 201-106, and oxygen consumption and cardiac efficiency remained unchanged in open-chest dogs. Studies of the mechanism of action of DPI 201-106 lead to the conclusion that its positive inotropic effect is not explainable either by beta-stimulation or by liberation of catecholamines. This was shown in anesthetized dogs and pithed open-chest cats pretreated with propranolol and reserpine.

Three-dimensional reformation of skeletal abnormalities using computed tomography

A new technique for evaluation of skeletal pathology is described. The use of three-dimensional reformations based on conventional computed tomographic imaging is a technique that has been used by craniofacial surgeons since 1982 and more recently by orthopedic surgeons at the Adelaide (Australia) Children's Hospital for evaluation of pediatric skeletal pathology. Four cases are presented that demonstrate our early experience with the technique. Three-dimensional reformation is an effective method of translating conventional computed tomographic scans into a readily understood three-dimensional image. We believe that the method will be of increasing value in the evaluation of pediatric skeletal pathology.

Potency of natural and synthetic canine gastrin-releasing decapeptide on canine antral muscle

The carboxyl terminal decapeptide of gastrin-releasing peptide (GRP-10), a small, naturally occurring bombesin-like peptide, has been isolated from canine antral muscle, synthesized, and its bioactivity compared with other synthetic and natural gastrin-releasing peptides on stimulation of spontaneously occurring contractions of canine circular antral muscle in vitro. Concentrations of peptides were verified by amino acid analysis and radioimmunoassay. In this system three forms of natural canine GRP, synthetic GRP-10, synthetic porcine gastrin-releasing heptacosapeptide (GRP-27), [Gln3]GRP-10, and [Arg3]GRP-10 all were similar in potency to synthetic amphibian bombesin. These results differ from the low activity of GRP-10 previously reported in rat brain. The full biological potency on canine antral motility and the presence of GRP-10 in nerve fibers in the gut and in the spinal cord suggest a possible role for this peptide as a neurotransmitter or neuromodulator in regulation of smooth muscle contraction.

Control of biliary phospholipid secretion. Effect of continuous and discontinuous infusion of taurocholate on biliary phospholipid secretion

A major determinant of biliary lipid secretion is bile-salt secretion. Taurocholate (TC), a micelle-forming bile salt, was infused continuously at different rates in both isolated perfused livers and biliary-fistula rats. In both of these systems, infusion of TC brought about an elevated secretion of phosphatidylcholine for the duration of the TC infusion period. Initial phospholipid/bile-salt ratios in the bile were higher in the whole-animal model than in isolated livers, but at the higher infusion rates both secreted approx. 6 mol of phospholipid for every 100 mol of bile salt. The secretion of phospholipid, which was maintained even at high rates of bile-salt infusion, suggest a continuous and regulated phospholipid supply and secretion mechanism. In contrast, however, multiple short pulses of TC to the perfused liver, which brought about relatively equal biliary bile-salt output pulses, did not bring about equal phospholipid outputs, since the phospholipid peak size declined with each bile-salt pulse. These experiments taken together suggest either that a threshold (intracellular) bile-salt concentration may be required to 'switch-on' the phospholipid supply and that it may need to be maintained for continuous biliary phospholipid supply to the canalicular membrane.

Anomalous small-angle-X-ray scattering on Al–Zn and Al–Zn–Ag alloys

Anomalous small-angle scattering (ASAXS) spectra from Al–Zn and Al–Zn–Ag alloys have been recorded at the Stanford Synchrotron Radiation Laboratory (SSRL). The data were obtained at different energies close to the Zn absorption edge. For the binary alloy, the ASAXS intensities follow quantitatively the variation in the atomic scattering factor of zinc. For the ternary alloys, the anomalous effect decreases when the Zn content decreases. Although only weighted sums of the partial structure functions could be determined, it is shown that the results are consistent with the `two-phase' unmixing model and the direction of tie lines of the metastable miscibility gap has been determined. A new method for analyzing ASAXS data for two absorption edges is proposed.

Synthesis of gamma-glutamyldopamine and other peptidoamines in the nervous system of Aplysia californica

The synthesis of a series of gamma-glutamyl amines (gamma-Glu-amines), including gamma-Glu-dopamine, gamma-Glu-5-hydroxytryptamine, gamma-Glu-octopamine, gamma-Glu-tryptamine, gamma-Glu-tyramine, and gamma-Glu-phenylethylamine, by nervous tissue of the marine mollusc Aplysia californica is described. After ganglia were incubated in vitro with 14C-amines, the unchanged amine and a new 14C-labeled product, identified as the gamma-Glu conjugate of the amine, were isolated from the tissue extracts. Identification was made by comparing the chromatographic properties (HPLC, TLC, and LC) of the isolated conjugates with chemically synthesized gamma-Glu-amines before and after acid hydrolysis.

Canine bombesin-like gastrin releasing peptides stimulate gastrin release and acid secretion in the dog

The synthetic mammalian bombesin-like peptides, canine gastrin releasing peptide 27, 23 and 10, and porcine gastrin releasing peptide 27 were compared with amphibian bombesin 14 and 10 during intravenous infusions into six conscious dogs with chronic gastric cannulae. Gastrin and gastrin releasing peptide were measured in peripherally sampled venous blood by radioimmunoassay and gastric acid secretions were collected. All forms of gastrin releasing peptide stimulated gastrin release and gastric acid secretion in a dose-dependent manner. The larger canine and porcine peptides were more potent than the decapeptide. Bombesin 14 was more potent than bombesin 10. A rise in the venous concentration of immunoreactive gastrin releasing peptide of only 20 fmol ml-1 stimulated gastrin release to about 50% of maximal. Gastrin releasing peptide 10 was cleared from the circulation three times faster than the larger forms and this may account for the apparent differences in potency.

Regional distribution of calmodulin activity in rat brain

Calmodulin activity in 68 discrete areas of rat brain, obtained by micropunch technique, was assessed by its capacity to activate a calmodulin-sensitive form of phosphodiesterase. In general, the activity of calmodulin was higher in the telencephalon, limbic system, and hypothalamus than in the mesencephalon, pons, cerebellum, and medulla. However, there were substantial differences in calmodulin activity in discrete nuclei of each region. The regional distribution of calmodulin activity in rat brain does not appear to correlate with that of any of the known putative neurotransmitters or peptides.

An assessment of a toxicological incident in a drug development program and its implications

In an exceptionally thorough program of preclinical toxicity testing in laboratory animals of the anti-allergy drug FPL 52757 (6,8-diethyl-5-hydroxy-4-oxo-4H-1-benzopyran-2-carboxylic acid), no significant hepatotoxic potential was detected. Despite this evidence of safety in a wide range of laboratory animals, the drug produced mild reversible hepatotoxicity in some patients in some clinical trials. Extensive toxicity and investigational studies are described, and the importance of the correct choice of species for toxicology evaluations based on sound pharmacokinetic principles is highlighted. This paper reviews this incident and the lessons to be learned from it in light of current regulatory requirements.

Use of simple analgesics in rheumatoid arthritis

The usefulness of anti-inflammatory drugs in rheumatoid arthritis (RA) is beyond dispute. The role of simple analgesics is less clear and has been disputed. A survey of 21 rheumatologists indicated that a majority sometimes supplemented anti-inflammatory treatment of RA with simple analgesics. A random sample of 120 RA patients treated by the same doctors revealed that 47% ranked pain relief as the most desirable objective of their treatment and 54% were taking analgesics regularly. Of those receiving analgesics as well as non-steroidal anti-inflammatory drugs 48% considered the former to be the more effective preparations. Almost half the patients on analgesics were taking drugs without the knowledge of the rheumatologists, who may have underestimated their patients' desire for pain relief.