First isolation of West Nile virus in Zambia from mosquitoes

Mosquito surveillance studies to identify mosquito-borne flaviviruses have identified West Nile Virus (WNV) for the first time in Zambia. The Zambian WNV isolate from Culex quinquefasciatus mosquitoes collected in the Western Province was closely related genetically to WNV lineage 2 South African strains which have been previously shown to be highly neuroinvasive. These data provide the first evidence of the circulation of WNV in Zambia and suggest there should be an increased awareness of possible associated human and animal diseases in that country.

Co-circulation of multiple genotypes of African swine fever viruses among domestic pigs in Zambia (2013-2015)

During 2013-2015, several and severe outbreaks of African swine fever (ASF) affected domestic pigs in six provinces of Zambia. Genetic characterization of ASF viruses (ASFVs) using standardized genotyping procedures revealed that genotypes I, II and XIV were associated with these outbreaks. Molecular and epidemiological data suggest that genotype II ASFV (Georgia 2007/1-like) detected in Northern Province of Zambia may have been introduced from neighbouring Tanzania. Also, a genotype II virus detected in Eastern Province of Zambia showed a p54 phylogenetic relationship that was inconsistent with that of p72, underscoring the genetic variability of ASFVs. While it appears genotype II viruses detected in Zambia arose from a domestic pig cycle, genotypes I and XIV possibly emerged from a sylvatic cycle. Overall, this study demonstrates the co-circulation of multiple genotypes of ASFVs, involvement of both the sylvatic and domestic pig cycle in ASF outbreaks in Zambia and possible trans-boundary spread of the disease in south-eastern Africa. Indeed, while there is need for regional or international concerted efforts in the control of ASF, understanding pig marketing practices, pig population dynamics, pig housing and rearing systems and community engagement will be important considerations when designing future prevention and control strategies of this disease in Zambia.

GENERALISATION OF RADIATOR DESIGN TECHNIQUES FOR PERSONAL NEUTRON DOSEMETERS BY UNFOLDING METHOD

A novel technique for designing a radiator suitable for personal neutron dosemeter based on plastic track detector was discussed. A multi-layer structure has been proposed in the previous report, where the thicknesses of plural polyethylene (PE) layers and insensitive ones were determined by iterative calculations of double integral. In order to arrange this procedure and make it more systematic, unfolding calculation has been employed to estimate an ideal radiator containing an arbitrary hydrogen concentration. In the second step, realistic materials replaced it with consideration of minimisation of the layer number and commercial availability. A radiator consisting of three layers of PE, Upilex and Kapton sheets was finally designed, for which a deviation in the energy dependence between 0.1 and 20 MeV could be controlled within 18 %. An applicability of fluorescent nuclear track detector element has also been discussed.

Prognostic implications of CEBPA mutations in pediatric acute myeloid leukemia: a report from the Japanese Pediatric Leukemia/Lymphoma Study Group

CCAAT/enhancer-binding protein alpha (CEBPA) mutations are a favorable prognostic factor in adult acute myeloid leukemia (AML) patients; however, few studies have examined their significance in pediatric AML patients. Here we examined the CEBPA mutation status and clinical outcomes of pediatric AML patients treated in the AML-05 study. We found that 47 (14.9%) of the 315 evaluable patients harbored mutations in CEBPA; 26 cases (8.3%) harbored a single mutation (CEBPA-single) and 21 (6.7%) harbored double or triple mutations (CEBPA-double). After excluding core-binding factor-AML cases, patients harboring CEBPA mutations showed better overall survival (OS; P=0.048), but not event-free survival (EFS; P=0.051), than wild-type patients. Multivariate analysis identified CEBPA-single and CEBPA-double as independent favorable prognostic factors for EFS in the total cohort (hazard ratio (HR): 0.47 and 0.33; P=0.02 and 0.01, respectively). CEBPA-double was also an independent favorable prognostic factor for OS (HR: 0.30; P=0.04). CEBPA-double remained an independent favorable factor for EFS (HR: 0.28; P=0.04) in the normal karyotype cohort. These results suggest that CEBPA mutations, particularly CEBPA-double, are an independent favorable prognostic factor in pediatric AML patients, which will have important implications for risk-stratified therapy.

Novel method to control release of lipophilic drugs with high potency from silicone

Silicone has been utilized as a carrier material for sustained release system of lipophilic drugs. Extensive studies revealed that drug release rate is influenced by factors such as physicochemical properties of the drug and additives.(1-5)) When a lipophilic drug is highly potent at low concentrations, the drug release rate should be strictly controlled so as to avoid side effects. In this study, using vitamin D(3) (VD(3)) as an example of such drugs, we investigated novel method to suppress initial burst and to modify drug release rate from silicone matrix. As a result, it was found that (a). addition of human serum albumin (HSA) suppressed initial burst and enhanced release rate in the later stage, resulting constant release of VD(3), (b). covering a matrix formulation with a membrane of low diffusivity (core-rod formulation) suppressed initial burst and released drug in a constant rate, and (3) using materials for which the drug has high affinity as dissolution solvent (reservoir formulation), the drug release rate was reduced.

Novel drug delivery device using silicone: controlled release of insoluble drugs or two kinds of water-soluble drugs

Drug release mechanism from silicone carrier differs depending on physicochemical properties of the drug. So far, there have been few reports on controlled release of insoluble drug and on simultaneous release of two kinds of water-soluble drugs. The purposes of this study are to establish methods for (1). continuous release of insoluble drug, and (2). release of two kinds of water-soluble drugs from silicone carrier. Polystyrene beads (PSTB) and proteins such as interferon (IFN) and human serum albumin (HSA) were used as model drugs. PSTB was released from silicone only when citric acid (CA) and sodium bicarbonate (SB) existed as additives. The release patterns of IFN and HSA were almost same in the case of matrix and covered-rod formulations, but double-layered formulation released them in different patterns. As far as we are aware, this is the first report on the release of insoluble drug from silicone and the controlled release of two kinds of water-soluble drugs.

Injectable silicone implants as vaccine delivery vehicles

Injectable silicone implants were assessed as vaccine delivery vehicles in sheep, using either the model antigen avidin or Clostridium tetani and Clostridium novyi toxoids. Two types of implant were compared, the matrix type, that has been shown to deliver antigen in vitro in a first-order profile over approximately 1 month, and the covered rod type, that delivers antigen for several months in a zero-order profile. The implants were prepared using lyophilized antigen and adjuvant (in this case, recombinant ovine interleukin-1beta; rovIL-1beta) and manufactured in the absence of extremes of temperature or pH or the use of organic solvents. Use of the matrix type implant was capable of inducing antibody responses equivalent to those induced by conventional vaccination with aluminium hydroxide adjuvant ("alum"). The use of the covered rod implants, that release very low levels of antigen over a long period, induced responses that were markedly enhanced over the alum control groups. The covered rod implant also favoured production of both IgG1 and IgG2 isotypes in contrast to responses of matrix-vaccinated sheep and conventionally vaccinated control sheep in which IgG1 predominated. Prolonged duration of the antibody response was also observed following vaccination with covered rod implants. Dose-response analysis using the matrix implant demonstrated a trend towards improved responses for lower antigen doses. Clostridial vaccination of sheep showed that protective antibody titres up to 4-fold higher than for alum-adjuvanted groups could be induced by administering the antigen in the covered rod implant. Responses elicited by all implant groups were dependent on the inclusion of adjuvant into the implant formulation.

Continuous antigen delivery from controlled release implants induces significant and anamnestic immune responses

Two continuous delivery injectable silicone implants were tested to determine if they were capable of delivering vaccines in a single shot. The Type A implant delivers antigen in vitro over a 1-month-period and the Type B over several months. Vaccination studies in sheep were designed to compare the responses induced by the Type A and B implants, Alzet mini-osmotic pumps and conventional antigen delivery. A model antigen, avidin, was used along with IL-1beta or alum as adjuvants. Sheep were immunised with various formulations and the titre and isotype of the antigen specific antibodies monitored. The Type B implant induced antibody (Ab) titres of greater magnitude and duration than soluble vaccines or the Type A implant with adjuvant, but only if IL-1beta was included in the formulation. Both implants induced antibodies of IgG1 and IgG2 isotype. A memory response to soluble antigen challenge was induced by the Type B+IL-1beta implant, which was predominantly of an IgG1 isotype.

Sustained release of human growth hormone (hGH) from collagen film and evaluation of effect on wound healing in db/db mice

Collagen films containing human growth hormone (hGH) were prepared and the release of hGH from these films and their effect on healing of full-thickness wounds in db/db mice were evaluated. The release profiles of hGH from the collagen films varied with composition and preparation conditions. The film prepared by air-drying of the mixture of hGH and collagen solution released hGH continuously over 3 days both in vitro and in vivo. By application of collagen film containing 3 mg of hGH twice at an interval of 6 days to wounds, area of wounds on day 21 was significantly reduced compared with that of non-treated wounds. Application of hGH alone at the same dose had no significant effect on wound healing. The maximum serum hGH concentration after single administration of the hGH collagen film was lower than that with hGH alone, and hGH persisted in serum over 3 days. These results suggest that hGH collagen film may be a useful topical formulation for the treatment of wounds.

A Japanese herbal medicine, Sho-saiko-to, prevents gut ischemia/reperfusion-induced hepatic microvascular dysfunction in rats

BACKGROUND AND AIM

We have reported that gut ischemia/reperfusion (I/R) causes hepatic microvascular dysfunction. Nitric oxide (NO) has been found to be a modulator of the adhesive interactions between leukocytes, platelets, and endothelial cells. Sho-saiko-to (TJ-9), a Japanese herbal medicine, is reported to have protective effects against liver injury and to regulate NO production. The objective of this study was to determine whether TJ-9 affects hepatic microvascular dysfunction elicited by gut I/R, and to investigate the role of NO.

METHODS

Male Wistar rats were exposed to 30 min of gut ischemia followed by 60 min of reperfusion. Intravital microscopy was used to monitor leukocyte recruitment and the number of non-perfused sinusoids (NPS). Plasma tumor necrosis factor (TNF)-alpha and alanine aminotransferase (ALT) activities were measured. In another set of experiments, TJ-9 (1 g/kg per day intragastrically) was administered to rats for 7 days. In some experiments, dexamethasone (ST) (2 mg/kg per day intravenously) was administered.

RESULTS

In control rats, gut I/R elicited increases in the number of stationary leukocytes, NPS, and plasma TNF-alpha and ALT activities, and these changes were mitigated by the pretreatment with TJ-9. Pretreatment with an NO synthase inhibitor diminished the protective effects of TJ-9 on the increase in leukostasis in the pericentral region, NPS, and plasma TNF-alpha levels, but not its effect on the increase in leukostasis in the midzonal region, total number of stationary leukocytes, or plasma ALT activities. Pretreatment with TJ-9 increased plasma nitrite/nitrate levels. The responses caused by gut I/R were attenuated by the pretreatment with ST. Pretreatment with an NO synthase inhibitor did not affect the effect of ST.

CONCLUSIONS

These results suggest that TJ-9 attenuates the gut I/R-induced hepatic microvascular dysfunction and inflammatory responses such as TNF-alpha production in the early phase via enhancement of NO production, and sequential hepatocellular damage via its anti-inflammatory effect like corticosteroid effect.

Development of a new drug delivery system for protein drugs using silicone (II)

In order to achieve a zero-order release of protein drugs, we have developed a new drug delivery system using silicone, which is named the covered-rod-type formulation. Preparation of the covered-rod-type formulation was conducted under mild conditions without heat treatment or the use of organic solvents. The covered-rod-type formulation released human serum albumin (HSA) or interferon (IFN) at a constant rate for 30-100 days in vitro without significant initial burst. When the IFN covered-rod-type formulation was implanted in nude mice, the serum IFN concentration was maintained at a constant level during the period of observation, i.e., 28 days. The covered-rod-type formulation enabled precise control of the release of the protein drugs and would be expected to increase the duration of the drug effect and to reduce the frequency of administration and side effects.

Isolation, characterization, and expression analysis of zebrafish large Mafs

Large Maf proteins, which are members of the basic leucine zipper (b-Zip) superfamily, are involved in the determination and control of cellular differentiation. The expression patterns of various vertebrate large Maf mRNAs were described previously. Here, we report the cloning of a novel zebrafish large Maf cDNA, SMaf1 (Somite Maf1), and other zebrafish large Mafs, the N-terminus domains of which possess transactivational activity. We also analyzed the expression patterns of SMaf1 and SMaf2 (Somite Maf2)/Krml2 as well as MafB/Val and c-Maf during zebrafish embryogenesis. In particular, the robust expression of the novel SMaf1 mRNA, which overlapped that of MyoD, in somitic cells during somitogenesis was noteworthy. In addition, the expression patterns of SMaf2 and MafB in the blood-forming regions, and those of c-Maf and MafB in the lens cells showed spatial redundancy, although the temporal appearance of these genes at these sites differed. These data indicate that SMafs may play important roles in somitogenesis, and that Maf proteins may have overlapping and yet specific functions as to the determination and differentiation of cell lineages.

Myositis and interstitial lung disease associated with autoantibody to a transfer RNA-related protein Wa

We describe 2 patients with myositis and interstitial lung disease with the autoantibody to Wa antigen, a 48-kDa transfer RNA-related protein. In contrast to the previous description of anti-Wa antibody, our patients lacked systemic sclerosis-related features, but had clinical features consistent with those associated with antibodies to aminoacyl-transfer RNA synthetases. The difference in clinical presentation between our patients and patients with systemic sclerosis may be explained by recognition of different epitopes on the Wa antigen.

Development of new drug delivery system for protein drugs using silicone (I)

A novel technique, by which protein drugs effective in small doses can be released over a long period, was developed using silicone and a water-soluble substance. In this study, interferon (IFN) was used as a model of the protein drugs. The IFN-silicone formulation released IFN over long periods of time in vitro and suppressed tumor growth in nude mice for about 100 days after a single administration. This indicates that physiologically active IFN is released over a prolonged period of time from the IFN-silicone formulation in vivo. Silicone formulations are expected to be a practically feasible sustained-release formulation.

A 718-kb DNA sequence of the Escherichia coli K-12 genome corresponding to the 12.7-28.0 min region on the linkage map

The 718,122 base pair sequence of the Escherichia coli K-12 genome corresponding to the region from 12.7 to 28.0 minutes on the genetic map is described. This region contains at least 681 potential open reading frames, of which 277 (41%) have been previously identified, 147 (22%) are homologous to other known genes, 139 (20%) are identical or similar to the hypothetical genes registered in databases, and the remaining 118 (17%) do not show a significant similarity to any other gene. In this region, we assigned a cluster of cit genes encoding multienzyme citrate lyase, two clusters of fimbrial genes and a set of lysogenic phage genes encoding integrase, excisionase and repressor in the e14 genetic element. In addition, a new valine tRNA gene, designated valZ, and a family of long directly repeated sequences, LDR-A, -B and -C, were found.

Materials for enhancing cell adhesion by immobilization of cell-adhesive peptide

Materials to enhance cell adhesion were synthesized by surface integration of peptide, Arg-Gly-Asp-Ser(RGDS), which is an active-site sequence of cell-adhesive proteins. Polystyrene film was glow-discharged and graft-copolymerized with acrylic acid. Then the peptide was immobilized to the poly(acrylic acid) grafts by using water-soluble carbodiimide. The cell-adhesive activity of the RGDS-immobilized film increased with increasing amount of immobilized peptide, and approached the activity of fibronectin(FN)-immobilized film. The RGDS-immobilized film was more stable against heat treatment and pH variation than the FN-immobilized film. In addition, the RGDS-immobilized film enhanced cell growth more strongly than the FN-immobilized film.