Feasibility of direct venous inoculation of the radiation-attenuated Plasmodium falciparum whole sporozoite vaccine in children and infants in Siaya, western Kenya

PfSPZ Vaccine, composed of radiation-attenuated, aseptic, purified, cryopreserved Plasmodium falciparum sporozoites, is administered by direct venous inoculation (DVI) for maximal efficacy against malaria. A critical issue for advancing vaccines that are administered intravenously is the ability to efficiently administer them across multiple age groups. As part of a pediatric safety, immunogenicity, and efficacy trial in western Kenya, we evaluated the feasibility and tolerability of DVI, including ease of venous access, injection time, and crying during the procedure across age groups. Part 1 was an age de-escalation, dose escalation trial in children aged 13 months-5 years and infants aged 5-12 months; part 2 was a vaccine efficacy trial including only infants, using the most skilled injectors from part 1. Injectors could use a vein viewer, if needed. A total of 1222 injections (target 0.5 mL) were initiated by DVI in 511 participants (36 were 5-9-year-olds, 65 were 13-59-month-olds, and 410 infants). The complete volume was injected in 1185/1222 (97.0%) vaccinations, 1083/1185 (91.4%) achieved with the first DVI. 474/511 (92.8%) participants received only complete injections, 27/511 (5.3%) received at least one partial injection (<0.5 mL), and in 10/511 (2.0%) venous access was not obtained. The rate of complete injections by single DVI for infants improved from 77.1% in part 1 to 92.8% in part 2. No crying occurred in 51/59 (86.4%) vaccinations in 5-9-year-olds, 25/86 (29.1%) vaccinations in 13-59-month-olds and 172/1067 (16.1%) vaccinations in infants. Mean administration time ranged from 2.6 to 4.6 minutes and was longer for younger age groups. These data show that vaccination by DVI was feasible and well tolerated in infants and children in this rural hospital in western Kenya, when performed by skilled injectors. We also report that shipping and storage in liquid nitrogen vapor phase was simple and efficient. (Clinicaltrials.gov NCT02687373).

TMS: Neue Einsatzmöglichkeiten in der neurophysiologischen Charakterisierung von Psychopharmaka und der biologischen Phänotypisierung psychischer Erkrankungen

Zwei Aspekte der transkraniellen Magnetstimulation (TMS) finden zunehmend Einzug in die Psychiatrie. Zum einen die repetitive transkranielle Magnetstimulation (rTMS) zur Behandlung psychischer Erkrankungen, zum anderen die diagnostische Variante des Verfahrens. Methodische Erweiterungen dieser diagnostisch ausgerichteten TMS eröffnen die Möglichkeit, schmerzfrei und nichtinvasiv die kortikale Exzitabilität des motorischen Systems zu messen. Damit lassen sich neue Erkenntnisse zur Wirkungsweise von Psychopharmaka gewinnen. Besonders interessant erscheint zudem die Möglichkeit der biologischen Phänotypisierung mittels dieses Verfahrens. Hierbei lassen sich so genannte neurophysiologische Endophänotypen definieren, die zum Teil genetisch determiniert sind.

Evolution of sensory complexity recorded in a myxobacterial genome

Myxobacteria are single-celled, but social, eubacterial predators. Upon starvation they build multicellular fruiting bodies using a developmental program that progressively changes the pattern of cell movement and the repertoire of genes expressed. Development terminates with spore differentiation and is coordinated by both diffusible and cell-bound signals. The growth and development of Myxococcus xanthus is regulated by the integration of multiple signals from outside the cells with physiological signals from within. A collection of M. xanthus cells behaves, in many respects, like a multicellular organism. For these reasons M. xanthus offers unparalleled access to a regulatory network that controls development and that organizes cell movement on surfaces. The genome of M. xanthus is large (9.14 Mb), considerably larger than the other sequenced delta-proteobacteria. We suggest that gene duplication and divergence were major contributors to genomic expansion from its progenitor. More than 1,500 duplications specific to the myxobacterial lineage were identified, representing >15% of the total genes. Genes were not duplicated at random; rather, genes for cell-cell signaling, small molecule sensing, and integrative transcription control were amplified selectively. Families of genes encoding the production of secondary metabolites are overrepresented in the genome but may have been received by horizontal gene transfer and are likely to be important for predation.

Advanced glycation end-products pentosidine and N epsilon-carboxymethyllysine are elevated in serum of patients with osteoporosis

OBJECTIVE

To investigate serum levels of the advanced glycation end-products (AGEs) pentosidine and N epsilon-carboxymethyllysine (CML) in patients classified into different osteoporosis subgroups according to histomorphometric data.

METHOD

Serum samples were obtained from 116 osteoporotic patients (34 men, 82 women) classified by bone histomorphometry into subgroups with high turnover (HTO, n = 32), low turnover (LTO, n = 39), normal turnover (NTO, n = 9) and cellular uncoupled osteoporosis (CUO, n = 36). Pentosidine was measured by high-performance liquid chromatography, and CML by a competitive enzyme-linked immunoassay.

RESULTS

The entire osteoporosis group had significantly higher pentosidine and CML serum concentrations than healthy subjects. In contrast to healthy subjects, no correlation between levels of AGEs and age could be found. In subgroups characterized by increased bone resorption (HTO, CUO), serum pentosidine correlated significantly with the histomorphometric marker reflecting osteoclast activity/bone resorption (eroded surface as a percentage of trabecular surface). Moreover, in CUO a strong correlation between pentosidine and the mineral apposition rate was found. Surprisingly, in HTO the levels of CML and percentage of eroded surface were significantly negatively correlated.

CONCLUSION

AGE-modified proteins may be a cause of disturbed bone remodelling in osteoporosis. Our findings do not support the alternative hypothesis that increased AGEs in serum indicate only a more intensive releasing of AGEs in circumstances of increased bone resorption.

A phase I clinical trial of spicamycin derivative KRN5500 (NSC 650426) using a phase I accelerated titration "2B" design

The spicamycin derivative KRN5500 was considered as a potential anti-cancer agent based on in vitro and preclinical studies. A Phase I study involving 24 cancer patients in whom tumors were refractory to all other conventional therapies was conducted to determine the dose limiting toxicity, maximum tolerated dose, effectiveness, and pharmacokinetic parameters of this drug administered by 1-h IV infusion daily for five consecutive days every 3 weeks. Using an accelerated dose titration strategy, 8.4 mg/m2/d x 5 days was the maximum administered dose. Severe gastrointestinal and hepatic toxicities were observed at doses at or above 4.3 mg/m2/d x 5. The recommended Phase II dose i s 4.3mg/m2/d x 5. The distribution of KRN5500 followed a two-compartment model, and clearance did not decrease significantly over the dose range 0.8-8.4 mg/m2/d x 5. No significant correlation was observed between plasma levels and toxicity. No tumor responses were observed among the 14 patients evaluable for response.

Sleep deprivation in depression stabilizing antidepressant effects by repetitive transcranial magnetic stimulation

Partial sleep deprivation (PSD) has a profound and rapid effect on depressed mood. However, the transient antidepressant effect of PSD - most patients relapse after one night of recovery sleep - is limiting the clinical use of this method. Using a controlled, balanced parallel design we studied, whether repetitive transcranial magnetic stimulation (rTMS) applied in the morning after PSD is able to prevent this relapse. 20 PSD responders were randomly assigned to receive either active or sham stimulation during the following 4 days after PSD. Active stimulation prolonged significantly (p < 0.001) the antidepressant effect of PSD up to 4 days. This finding indicates that rTMS is an efficacious method to prevent relapse after PSD.

A novel linear amphipathic beta-sheet cationic antimicrobial peptide with enhanced selectivity for bacterial lipids

All known naturally occurring linear cationic peptides adopt an amphipathic alpha-helical conformation upon binding to lipids as an initial step in the induction of cell leakage. We designed an 18-residue peptide, (KIGAKI)3-NH2, that has no amphipathic character as an alpha-helix but can form a highly amphipathic beta-sheet. When bound to lipids, (KIGAKI)3-NH2 did indeed form a beta-sheet structure as evidenced by Fourier transform infrared and circular dichroism spectroscopy. The antimicrobial activity of this peptide was compared with that of (KIAGKIA)3-NH2, and it was better than that of GMASKAGAIAGKIAKVALKAL-NH2 (PGLa) and (KLAGLAK)3-NH2, all of which form amphipathic alpha-helices when bound to membranes. (KIGAKI)3-NH2 was much less effective at inducing leakage in lipid vesicles composed of mixtures of the acidic lipid, phosphatidylglycerol, and the neutral lipid, phosphatidylcholine, as compared with the other peptides. However, when phosphatidylethanolamine replaced phosphatidylcholine, the lytic potency of PGLa and the alpha-helical model peptides was reduced, whereas that of (KIGAKI)3-NH2 was improved. Fluorescence experiments using analogs containing a single tryptophan residue showed significant differences between (KIGAKI)3-NH2 and the alpha-helical peptides in their interactions with lipid vesicles. Because the data suggest enhanced selectivity between bacterial and mammalian lipids, linear amphipathic beta-sheet peptides such as (KIGAKI)3-NH2 warrant further investigation as potential antimicrobial agents.

Electroencephalography correlates in tinnitus

This study was conducted in an attempt to determine whether the quantitative electroencephalograph activity differs between normal control subjects and subjects suffering from tinnitus. Results indicated that male tinnitus patients as a group had a significantly reduced average total power as compared to control subjects. This finding contrasted with female tinnitus patients, who as a group had a higher average total power as compared to normal female control subjects. Topographical maps (control value-tinnitus value) indicate that with male patients, the frontocentral regions of the brain show the greatest difference. For the female tinnitus patients, the brain regions most affected are the central, parietal, temporal, and occipital regions.

Preclinical pharmacokinetic, antitumor and toxicity studies with CI-994 (correction of CL-994) (N-acetyldinaline)

CI-994, a substituted benzamide derivative, is a compound that showed solid tumor selectivity for a variety of solid tumor models compared to L1210 leukemia. Due to its lack of aqueous solubility, it requires oral administration. Female B6D2F1 mice were treated with CI-994 once daily by oral administration of 50 mg/kg for 14 days. Following treatment mice were evaluated for pharmacodynamic effects as well as the pharmacokinetic behavior of CI-994 and the de-acetylated derivative dinaline. Mice samples (plasma, urine, feces) were analyzed using solid phase extraction, reverse phase HPLC and ultraviolet detection. The plasma distribution and elimination half-lives for CI-994 were 51 minutes and 9.4 hours, respectively, on D-1; 31 minutes and 3.4 hours, respectively on D-14. The apparent plasma distribution and elimination half-lives for dinaline were 27 minutes and 2.4 hours, respectively, on D-1; 40 minutes and 7.3 hours, respectively on D-14. The CI-994 AUC on D-1 and D-14 were 2879 and 2407 micrograms/ml x minutes, respectively; while the dinaline AUC on D-1 and D-14 were 87 and 92 micrograms/ml x minutes, respectively. Urinary excretion for CI-994 and dinaline was higher on D-14, while the fecal excretion was the same on both days. The Colon #38 tumor growth in treated mice was reduced to 22% of that observed in the controls by D-19. The levels of all blood cells were reduced in the treated mice when compared to controls and the total WBC was the most affected (median 38%). Recovery to pretreatment levels occurred quickly following treatment cessation. Phase I evaluation of chronic oral administration of CI-994 is currently ongoing.

Identification and antitumor activity of a reduction product in the murine metabolism of pyrazoloacridine (NSC-366140)

PURPOSE

Pyrazoloacridine (PZA) is a newly developed anticancer agent currently undergoing clinical trials. Its mode of action has not been elucidated but the presence in its chemical structure of a 5-nitro functional group and its activity against oxygen-deficient cancerous cells argue in favor of enzymatic nitro reduction as a possible pathway for its antitumor activity. In order to assess the involvement of the nitro functionality in PZA activity, as well as to determine other metabolic products, a pharmacological and chemical study of PZA was designed.

METHODS

Urine and stool samples were collected from mice before and after treatment with PZA. Samples were fractionated using chromatographic methods and then evaluated using mass spectrometry (MS). One of the characterized metabolites was synthesized and tested in vitro and in vivo for anticancer activity.

RESULTS

One major fraction from mouse stool was initially characterized by MS as the 5-aminopyrazoloacridine (5-APZ). This compound was chemically synthesized by catalytic hydrogenation of PZA was stabilized as the hydrochloride salt. 5-APZ was marginally cytotoxic in vitro and was inactive in vivo against a tumor cured by PZA (Panc 03).

CONCLUSIONS

Bioreduction of the nitro group to an amine compound from PZA represents a pathway in the metabolic sequence of PZA. The inactivity of the chemically generated amine product does not provide conclusive evidence that this pathway is not involved in the cytotoxicity of PZA because other intermediates in the nitro reduction pathway may have a role in the activity of PZA. In particular, the hydroxylamine derivative of PZA could give answers to the involvement of this pathway in PZA cytotoxicity.

Nystatin stimulates prostaglandin E synthesis and formation of diacylglycerol in human monocytes

The effect of the channel forming antibiotic nystatin on human monocytes was studied. Monocytes isolated from the peripheral blood (Mo), the monocytic cell line U937 and the promyelocytic cell line HL60 were used. Each cell type could be lysed with nystatin. The dose of nystatin required, however, was different for each cell line. In sublytic doses nystatin induced a rise of intracellular Ca2+, measured with the calcium indicator quin2. The rise of intracellular Ca2+ was followed by the release of prostaglandin E. By preincubation of the cells with quin2 the prostanoid synthesis could be inhibited suggesting that the increased Ca2+-levels could function as a signal. The prostanoid synthesis was also suppressed by inhibitors of the arachidonic acid pathway. Furthermore, nystatin induced an increase of diacylglycerol and a decrease of phosphatidylinositol. The generation of diacylglycerol, however, was not due to hydrolysis of the polyphosphoinositides because no increase of the second messenger inositol-1,4,5-triphosphate could be detected.

Laser-induced fusion of mammalian cells and plant protoplasts

An ultraviolet-laser microbeam was shown to be suitable for inducing fusion of individually selected plant protoplasts or of B-lymphocytes with myeloma cells. The fusion took place in normal culture medium and the fusogenic condition perturbed the cells only for a fraction of a millisecond. Without manipulating the cell culture except for exposing the cells to laser light, fusion products between preselected individual pairs may be produced.

Ribonucleic acid and other polyanions facilitate chromatin assembly in vitro

Crude extracts of Drosophila embryos are a rich source of both DNA topoisomerase I and chromatin assembly activity [Nelson, T., Hsieh, T., & Brutlag, D.L. (1979) Proc. Natl. Acad. Sci. U.S.A. 76, 5510-5514; Hseih, T., & Brutlag, D. L. (1980) Cell (Cambridge, Mass.) 21, 115-125]. Purified topoisomerase I from Drosophila embryos, however, is not sufficient for chromatin assembly. Rather, the ability of Drosophila embryo extracts to mediate chromatin assembly in vitro requires an anionic fraction which we demonstrate to be RNA. Exogenous natural and homopolymer RNAs, if of sufficient length, can also mediate chromatin assembly in vitro. The RNA acts stoichiometrically in assembly, being required in amounts at least equal in weight to the amount of histones present. Natural and homopolymer DNAs, whether single or double stranded, are inactive under the same conditions. The arginine-rich histones H3 and H4 or histone H4 alone is sufficient to produce nucleoprotein complexes with physiological numbers of supertwists in the DNA. Complexes containing these subsets of the core histones also resemble assembled complexes containing all four core histones with respect to some patterns of nuclease sensitivity, although complexes containing all four core histones more closely resemble native chromatin in nuclease digestions.

Incorporation of dietary cis and trans isomers of octadecenoate in lipid classes of liver and hepatoma

Groups of rats bearing Morris minimal deviation hepatoma 7288CTC were fed a fat-free diet supplemented with either 0.5% safflower oil (diet A), 15% safflower oil or free acids (diets Band C), or 15% safflower oil or free safflower fatty acids (diet D) for 4 weeks. A group of normal rats was also fed diet D. Triglycerides, cholesteryl esters, phosphatidylcholines, and phosphatidylethanolamines isolated from livers and hepatomas of animals on each diet were analyzed quantitatively for positional isomers in the cis- and trans-octadecenoate fractions. When sufficient samples could be obtained, the cis- and trans-hexadecenoate fractions were also analyzed. Plasma from normal rats on diet D was analyzed in the same manner. The octadecenoate fractions of all hepatoma and liver lipid classes from animals fed diets A, B, and C were greater than 95% the cis isomers. Trans isomers accounted for approximately 15, 30, 50, and 70% of the octadecenoate fractions isolated from liver triglycerides, cholesteryl esters, phosphatidylcholines, and phosphatidylethanolamines, respectively, of animals fed diet D. In contrast, all hepatoma lipid classes from animals on diet D contained the same approximate percentage of trans isomers (15 to 20%). Oleic and vaccenic acids were the major positional cis-octadecenoate isomers of all liver and hepatoma lipid classes from animals fed diets A, B, and C. The ratios of oleic to vaccenic, unaffected by diets A, B, and C, differed for each lipid class in liver, but the ratios were similar for the two hepatoma neutral lipid classes and for the two phospholipid classes. The cis-octadecenoate fractions from all liver and hepatoma lipid classes of animals fed diet D consisted predominantly of the delta9, delta11, and delta12 isomers. The cis delta10 isomer, which was a major isomer of the diet, was almost excluded from liver, hepatoma, and plasma lipids. The positional isomers of the trans-octadecenoate fractions from liver and hepatoma triglycerides and cholesteryl esters exhibited the same approximate distribution as the trans fatty acids of diet D. In contrast, the 10-trans-octadecenoate, like 10-cis-octadecenoate, was almost excluded from the phospholipids of liver and plasma. Unlike liver, the hepatoma phospholipids contained 10-trans-octadecenoate at approximately half the percentage of neutral lipids. Because diet D contained no hexadecenoic fatty acids, the occurrence of trans-hexadecenoate isomers in liver and plasma lipids indicated a chain shortening process. Predominance of the 8-trans-hexadecenoate isomer indicated a preference of the 10-trans-octadecenoate isomer for chain shortening.

Uptake of homologous single-stranded fragments by superhelical DNA: a possible mechanism for initiation of genetic recombination

Superhelical [3-H]DNA (replicative form I, RFI) of bacteriophage phiX174 slowly but spontaneously took up 32-P-labeled homologous single-stranded fragments at 4 degrees. Uptake was accelerated by heating to 75 degrees. RFI did not take up single-stranded fragments derived from DNA of Escherichia coli or from separated strands of phage lambda. Uptake was inhibited by low concentrations of ethidium bromide. Relaxed circular phiX174 DNA did not take up homologous fragments. Per molecule of RFI, the complexes contained as much as 90 nucleotide residues of homologous fragment. The 32-P-lebeled fragments were largely resistant to digestion by exonuclease I, and were not displaced by heating complexes at 60 degrees for 1 min in 16 mM or 100 mM NaCl. Under comparable conditions of temperature and salt all of the fragments were displaced from complexes in which at least one phosphodiester bond was cleaved by pancreatic DNase, but a significant fraction of the fragments was retained in complexes that were relaxed by digestion with S1 nuclease. These observations are interpreted to mean that S1 nuclease digested the plus (viral) strand of the recipient RF at the site of uptake in some instances. Transfection of E. coli by heterozygous complexes produced recombinant progeny, thereby showing that genetic information can be transferred from the fragment of plus strand to progeny plus strands. We propose that both uptake of a third strand by superhelical DNA and the action of nucleases on the resulting complex may simulate early steps in genetic recombination.