Immunogenicity of a recombinant Rift Valley fever MP-12-NSm deletion vaccine candidate in calves

The safety and immunogenicity of an authentic recombinant (ar) of the live, attenuated MP-12 Rift Valley fever (RVF) vaccine virus with a large deletion of the NSm gene in the pre-Gn region of the M RNA segment (arMP-12ΔNSm21/384) was tested in 4–6 month old Bos taurus calves. Phase I of this study evaluated the neutralizing antibody response, measured by 80% plaque reduction neutralization (PRNT₈₀), and clinical response of calves to doses of 1 × 10¹ through 1 × 10⁷ plaque forming units (PFU) administered subcutaneously (s.c.). Phase II evaluated the clinical and neutralizing antibody response of calves inoculated s.c. or intramuscularly (i.m.) with 1 × 10³, 1 × 10⁴ or 1 × 10⁵ PFU of arMP-12ΔNSm21/384. No significant adverse clinical events were observed in the animals in these studies. Of all specimens tested, only one vaccine viral isolate was recovered and that virus retained the introduced deletion. In the Phase I study, there was no statistically significant difference in the PRNT₈₀ response between the dosage groups though the difference in IgG response between the 1 × 10¹ PFU group and the 1 × 10⁵ PFU group was statistically significant (p < 0.05). The PRNT₈₀ response of the respective dosage groups corresponded to dose of vaccine with the 1 × 10¹ PFU dose group showing the least response. The Phase II study also showed no statistically significant difference in PRNT₈₀ response between the dosage groups though the difference in RVFV-specific IgG values was significantly increased (p < 0.001) in animals inoculated i.m. with 1 × 10⁴ or 1 × 10⁵ PFU versus those inoculated s.c. with 1 × 10³ or 1 × 10⁵ PFU. Although the study groups were small, these data suggest that 1 × 10⁴ or 1 × 10⁵ PFU of arMP-12ΔNSm21/384 administered i.m. to calves will consistently stimulate a presumably protective PRNT₈₀ response for at least 91 days post inoculation. Further studies of arMP-12ΔNSm21/384 are warranted to explore its suitability as an efficacious livestock vaccine.     

Locating the binding sites of anticancer tamoxifen and its metabolites 4-hydroxytamoxifen and endoxifen on bovine serum albumin

The breast anticancer drug tamoxifen and its metabolites bind serum albumins. We located the binding sites of tamoxifen, 4-hydroxytamoxifen and endoxifen on bovine serum albumin (BSA). FTIR, CD and fluorescence spectroscopic methods as well as molecular modeling were used to characterize the drug binding mode, binding constant and the effect of drug binding on BSA stability and conformation. Structural analysis showed that tamoxifen and its metabolites bind BSA via hydrophobic and hydrophilic interactions with overall binding constants of K_tam-BSA = 1.96 (±0.2) × 10⁴ M⁻¹, K_{4-hydroxytam-BSA} = 1.80 (±0.4) × 10⁴ M⁻¹ and K_endox-BSA = 8.01 (±0.8) × 10³ M⁻¹. The number of bound drug molecules per protein is 1.7 (tamoxifen), 1.4 (4-hydroxitamoxifen) and 1.13 (endoxifen). The participation of several amino acid residues in drug-protein complexes is stabilized by extended hydrogen bonding network with the free binding energy of −13.47 (tamoxifen), −13.79 (4-hydroxtamoxifen) and −12.72 kcal/mol (endoxifen). The order of binding is 4-hydroxy-tamoxen > tamoxifen > endoxifen. BSA conformation was altered by a major reduction of α-helix from 63% (free BSA) to 41% with tamoxifen, to 39% with 4-hydroxytamoxifen, and to 47% with endoxifen. In addition, an increase in turn and random coil structures was found, suggesting partial protein unfolding. These results suggest that serum albumins might act as carrier proteins for tamoxifen and its metabolites in delivering them to target tissues.     

Effect of vaccine dose on the safety and immunogenicity of a candidate TB vaccine, MVA85A, in BCG vaccinated UK adults

Purpose

A non-randomised, open-label, Phase I safety and immunogenicity dose-finding study to assess the safety and immunogenicity of the candidate TB vaccine Modified Vaccinia virus Ankara expressing Antigen 85A (MVA85A) from Mycobacterium tuberculosis (MTB) in healthy adult volunteers previously vaccinated with BCG.

Methods

Healthy BCG-vaccinated volunteers were vaccinated with either 1 × 10⁷ or 1 × 10⁸ PFU of MVA85A. All adverse events were documented and antigen specific T cell responses were measured using an ex vivo IFN-γ ELISPOT assay. Safety and immunogenicity were compared between the 2 dose groups and with a previous trial in which a dose of 5 × 10⁷ PFU MVA85A had been administered.

Results

There were no serious adverse events recorded following administration of either 1 × 10⁷ or 1 × 10⁸ PFU of MVA85A. Systemic adverse events were more frequently reported following administration of 1 × 10⁸ PFU of MVA85A when compared to either 5 × 10⁷ or 1 × 10⁷ PFU of MVA85A but were mild or moderate in severity and resolved completely within 7 days of immunisation. Antigen specific T cell responses as measured by the IFN-γ ELISPOT were significantly higher following immunisation in adults receiving 1 × 10⁸ PFU compared to the 5 × 10⁷ and 1 × 10⁷ doses. Additionally, a broader range of Ag85A epitopes are detected following 1 × 10⁸ PFU of MVA85A.

Conclusion

A higher dose of 1 × 10⁸ PFU of MVA85A is well-tolerated, increases the frequency of IFN-γ secreting T cells detected following immunisation and broadens the range of Ag85A epitopes detected.     

The live attenuated chimeric vaccine rWN/DEN4Δ30 is well-tolerated and immunogenic in healthy flavivirus-naïve adult volunteers

WNV has become the leading vector-borne cause of meningoencephalitis in the United States. Although the majority of WNV infections result in asymptomatic illness, approximately 20% of infections result in West Nile fever and 1% in West Nile neuroinvasive disease (WNND), which causes encephalitis, meningitis, or flaccid paralysis. The elderly are at particular risk for WNND, with more than half the cases occurring in persons older than sixty years of age. There is no licensed treatment for WNND, nor is there any licensed vaccine for humans for the prevention of WNV infection. The Laboratory of Infectious Diseases at the National Institutes of Health has developed a recombinant live attenuated WNV vaccine based on chimerization of the wild-type WNV NY99 genome with that of the live attenuated DENV-4 candidate vaccine rDEN4Δ30. The genes encoding the prM and envelope proteins of DENV-4 were replaced with those of WNV NY99 and the resultant virus was designated rWN/DEN4Δ30. The vaccine was evaluated in healthy flavivirus-naïve adult volunteers age 18–50 years in two separate studies, both of which are reported here. The first study evaluated 10³ or 10⁴ PFU of the vaccine given as a single dose; the second study evaluated 10⁵ PFU of the vaccine given as two doses 6 months apart. The vaccine was well-tolerated and immunogenic at all three doses, inducing seroconversion to WNV NY99 in 74% (10³ PFU), 75% (10⁴ PFU), and 55% (10⁵ PFU) of subjects after a single dose. A second 10⁵ PFU dose of rWN/DEN4Δ30 given 6 months after the first dose increased the seroconversion rate 89%. Based on the encouraging results from these studies, further evaluation of the candidate vaccine in adults older than 50 years of age is planned.     

Construction and immunogenicity of pseudotype baculovirus expressing Toxoplasma gondii SAG1 protein in BALB/c mice model

Toxoplasma gondii is a protozoan parasite causing toxoplasmosis to almost one-third of population all over the world. One of the most efficient ways to control this disease is immunization. However, so far, there is no effective vaccine available against this pathogen. Recently, a baculovirus pseudotype with vesicular stomatitis virus G protein (Bac-VSV–G) was found to efficiently transduce and express transgenes on mammalian cells, so it was considered as an excellent expressing vector. In this study, the value of Bac-VSV–G in delivering T. gondii antigen was investigated. T. gondii SAG1 gene was cloned into Bac-VSV–G, and recombinant baculovirus BV-G-SAG1 was obtained. Indirect immunofluorescence test showed BV-G-SAG1 was efficiently transduced and expressed in pig kidney cells. Then BALB/c mice were immunized with BV-G-SAG1 at different doses (1 × 10⁸, 1 × 10⁹, and 1 × 10¹⁰ PFU/mouse) and challenged with T. gondii RH strain tachyzoites after immunization. The levels of specific T. gondii antibody, interferon (IFN)-γ, IL-4, IL-10 expression and release, and the survival rate of treated mice were evaluated. Compared with the mice immunized with DNA vaccine (pcDNA/SAG1) encoding the same gene, BV-G-SAG1 induced higher levels of specific T. gondii antibody and (IFN)-γ expression with dose-dependent manner and the survival rate of mice with BV-G-SAG1 was significantly improved. These results indicated that pseudotype baculovirus-mediated gene delivery can be utilized as an alternative strategy to develop new generation of vaccines against T. gondii infection.     

Risk reduction assessment of waterborne Salmonella and Vibrio by a chlorine contact disinfectant point-of-use device

Unsafe drinking water continues to burden developing countries despite improvements in clean water delivery and sanitation, in response to Millennium Development Goal 7. Salmonella serotype Typhi and Vibrio cholerae bacteria can contaminate drinking water, causing waterborne typhoid fever and cholera, respectively. Household water treatment (HWT) systems are widely promoted to consumers in developing countries but it is difficult to establish their benefits to the population for specific disease reduction. This research uses a laboratory assessment of halogenated chlorine beads treating contaminated water to inform a quantitative microbial risk assessment (QMRA) of S. Typhi and V. cholerae disease in a developing country community of 1000 people. Laboratory challenges using seeded well water resulted in log₁₀ reductions of 5.44 (±0.98 standard error (SE)) and 6.07 (±0.09 SE) for Salmonella serotype Typhimurium and V. cholerae, respectively. In well water with 10% sewage and seeded bacteria, the log₁₀ reductions were 6.06 (±0.62 SE) and 7.78 (±0.11 SE) for S. Typhimurium and V. cholerae, respectively. When one infected individual was contributing to the water contamination through fecal material leaking into the water source, the risk of disease associated with drinking untreated water was high according to a Monte Carlo analysis: a median of 0.20 (interquartile range [IQR] 0.017–0.54) for typhoid fever and a median of 0.11 (IQR 0.039–0.20) for cholera. If water was treated, risk greatly decreased, to a median of 4.1 × 10⁻⁷ (IQR 1.6 × 10⁻⁸ to 1.1 × 10⁻⁵) for typhoid fever and a median of 3.5 × 10⁻⁹ (IQR 8.0 × 10⁻¹⁰ to 1.3 × 10⁻⁸) for cholera. Insights on risk management policies and strategies for public health workers were gained using a simple QMRA scenario informed by laboratory assessment of HWT.     

Development and efficacy of a novobiocin-resistant Streptococcus iniae as a novel vaccine in Nile tilapia (Oreochromis niloticus)

A novel attenuated Streptococcus iniae vaccine was developed from a virulent strain of Streptococcus iniae (ISET0901) through selection for novobiocin resistance (named ISNO). The safety of ISNO was then evaluated in Nile tilapia (Oreochromis niloticus) through intraperitoneal (IP) injection. When male tilapia (average weight 10 g) were IP injected with 2 × 10⁷ colony-forming units (CFU) of the attenuated S. iniae vaccine strain, no fish died. However, when the same age and size matched tilapia were IP injected with 2 × 10⁷ and 1 × 10⁵ CFU of the virulent parent strain of S. iniae, 100 and 90% fish died, respectively. Backpassage safety studies revealed that ISNO was unable to revert back to a virulent state. When IP vaccinated fish were challenged by the virulent ISET0901 strain of S. iniae, relative percent survival (RPS) values of vaccinated fish at 14, 28, 60, 90, and 180 days post ISNO vaccination (dpv) were 100, 100, 100, 89, and 75%, respectively, The RPS values of ISNO vaccinated fish (IP vaccination) against infections by five heterologous virulent strains of S. iniae (F3CB, 102F1K, 405F1K, IF6, and ARS60) at 60 dpv were 78, 90, 100, 100, and 100%, respectively. When tilapia were IP vaccinated by ISNO at dose of 1 × 10², 1 × 10³, 1 × 10⁴, 1 × 10⁵, 1 × 10⁶, and 1 × 10⁷ CFU/fish, RPS values at 28 dpv were 81, 94, 100, 100, 100, and 100%, respectively. At 28 dpv, RPS of vaccinated fish by ISNO through bath immersion (1 × 10⁷ CFU/ml) was 88%. ELISA results revealed that protection elicited by ISNO was due to antibody- as well as cell- mediated immunity. Our results suggest that ISNO could be used as a novel safe and efficacious vaccine to protect Nile tilapia from S. iniae infections.     

Evidence for differing evolutionary dynamics of A/H5N1 viruses among countries applying or not applying avian influenza vaccination in poultry

Highly pathogenic avian influenza (HPAI) H5N1 (clade 2.2) was introduced into Egypt in early 2006. Despite the control measures taken, including mass vaccination of poultry, the virus rapidly spread among commercial and backyard flocks. Since the initial outbreaks, the virus in Egypt has evolved into a third order clade (clade 2.2.1) and diverged into antigenically and genetically distinct subclades. To better understand the dynamics of HPAI H5N1 evolution in countries that differ in vaccination policy, we undertook an in-depth analysis of those virus strains circulating in Egypt between 2006 and 2010, and compared countries where vaccination was adopted (Egypt and Indonesia) to those where it was not (Nigeria, Turkey and Thailand). This study incorporated 751 sequences (Egypt n = 309, Indonesia n = 149, Nigeria n = 106, Turkey n = 87, Thailand n = 100) of the complete haemagglutinin (HA) open reading frame, the major antigenic determinant of influenza A virus. Our analysis revealed that two main Egyptian subclades (termed A and B) have co-circulated in domestic poultry since late 2007 and exhibit different profiles of positively selected codons and rates of nucleotide substitution. The mean evolutionary rate of subclade A H5N1 viruses was 4.07 × 10⁻³ nucleotide substitutions per site, per year (HPD 95%, 3.23-4.91), whereas subclade B possessed a markedly higher substitution rate (8.87 × 10⁻³; 95% HPD 7.0-10.72 × 10⁻³) and a stronger signature of positive selection. Although the direct association between H5N1 vaccination and virus evolution is difficult to establish, we found evidence for a difference in the evolutionary dynamics of H5N1 viruses among countries where vaccination was or was not adopted. In particular, both evolutionary rates and the number of positively selected sites were higher in virus populations circulating in countries applying avian influenza vaccination for H5N1, compared to viruses circulating in countries which had never used vaccination. We therefore urge a greater consideration of the potential consequences of inadequate vaccination on viral evolution.     

Discovery of a potent peptidic cyclophilin A inhibitor Trp-Gly-Pro

Through virtual screening of a rationally built database consisting of 40 peptides, we identified three short peptides. After testing these three synthetic peptides, we found that the peptide Trp-Gly-Pro (WGP) showed comparable inhibitory ability as positive control cyclosporine A (CsA) on CypA-mediated PPIase activity with IC₅₀ values of 33.11 nM and 10.25 nM, respectively. The peptide WGP had same order of CypA-binding affinity as CsA with dissociation equilibrium constant K_D of 3.41 × 10⁻⁶ and 6.42 × 10⁻⁶ M, respectively. This peptide could also inhibit HIV-1_IIIB infection. This study provides a novel strategy for rational design and development of peptidic drugs.     

Mercury and lead: Assessing the toxic effects on growth and metal accumulation by Lemna minor

Lemna minor L. was used to investigate the toxic effects of Pb and Hg either alone or in various binary mixtures under the static test conditions. A full-strength Jacob culture medium was used for the long-term cultivation of duckweeds and the experiments. Tests were run for 4 and 7 days. The EC₅₀ values for Pb was estimated as 6.8±0.2 mg L⁻¹ and 5.5±0.1 mg L⁻¹ for a 4 and a 7-day test periods, respectively. Hg was much more toxic than Pb with the EC₅₀ of 0.64±0.03 mg L⁻¹ (4 days) and 0.48±0.02 mg L⁻¹ (7 days). The amounts of Pb uptake by the plants were determined by atomic absorption spectrometer (AAS). The cold vapor AAS-technique (CV-AAS) was used for Hg determination. The interactive effect between Pb and Hg on growth was evaluated as additive on the basis of statistical data analysis. However, an antagonistic interaction was observed on the metal accumulation efficiency.     

Immunogenicity and protective efficacy of a psoralen-inactivated dengue-1 virus vaccine candidate in Aotus nancymaae monkeys

Psoralens are photoreactive compounds that cross-link pyrimidines after exposure to UVA radiation. In this experiment, we tested the protective efficacy of a psoralen-inactivated dengue vaccine candidate in non-human primates. Two groups of 7 Aotus nancymaae monkeys received either 10 ng per dose of inactivated DENV1 plus alum adjuvant or alum alone (controls). Doses were injected intradermally on days 0, 14, and 28. Monkeys then received a challenge inoculation of 1.1 × 10⁴ PFUs of WestPac 74 DENV-1 on day 132. At 62 days, only 1/7 vaccinated monkeys had detectable IgM, but IgG and neutralizing antibody remained detectable in 7/7. No IgM, IgG, or neutralizing antibody was detectable in control monkeys. DENV-1 viremia was detected after challenge in 3/7 vaccinated monkeys and 5/6 control monkeys (with one removed due to pregnancy) (p = 0.27), but days of viremia were reduced from 3.67 days/animal among controls to 0.71 days/animal among vaccinated monkeys (p = 0.051). Psoralen-inactivated DENV1 is immunogenic in Aotus nancymaae with a trend towards a reduction in days of viremia following experimental challenge.     

Vaccination of volunteers with low-dose,live-attenuated,dengue viruses leads to serotype-specific immunologic and virologic profiles

There are currently no vaccines or therapeutics to prevent dengue disease which ranges in severity from asymptomatic infections to life-threatening illness. The National Institute of Allergy and Infectious Diseases (NIAID) Division of Intramural Research has developed live, attenuated vaccines to each of the four dengue serotypes (DENV-1–DENV-4). Two doses (10 PFU and 1000 PFU) of three monovalent vaccines were tested in human clinical trials to compare safety and immunogenicity profiles. DEN4Δ30 had been tested previously at multiple doses. The three dengue vaccine candidates tested (DEN1Δ30, DEN2/4Δ30, and DEN3Δ30/31) were very infectious, each with a human infectious dose 50% ≤ 10 PFU. Further, infectivity rates ranged from 90 to 100% regardless of dose, excepting DEN2/4Δ30 which dropped from 100% at the 1000 PFU dose to 60% at the 10 PFU dose. Mean geometric peak antibody titers did not differ significantly between doses for DEN1Δ30 (92 ± 19 vs. 214 ± 97, p = 0.08); however, significant differences were observed between the 10 PFU and 1000 PFU doses for DEN2/4Δ30, 19 ± 9 vs. 102 ± 25 (p = 0.001), and DEN3Δ30/31, 119 ± 135 vs. 50 ± 50 (p = 0.046). No differences in the incidences of rash, neutropenia, or viremia were observed between doses for any vaccines, though the mean peak titer of viremia for DEN1Δ30 was higher at the 1000 PFU dose (0.5 ± 0 vs. 1.1 ± 0.1, p = 0.007). These data demonstrate that a target dose of 1000 PFU for inclusion of each dengue serotype into a tetravalent vaccine is likely to be safe and generate a balanced immune response for all serotypes.     

Anaerobic degradation of chlorothalonil in four paddy soils

Degradation of Chlorothalonil (CTN) was investigated in four different paddy soils under anaerobic conditions. The CTN biodegradation is strongly affected by the properties of the paddy soils. Soils associating with rich total carbon (TC), repeated CTN application, and neutral pH have shown the high capacity to biodegrade CTN. Additionally, anaerobic CTN biodegradation was accompanied by the methane generation and a drop of oxidation-reduction potential (ORP). The initial CTN concentration had a significant effect on CTN removal efficiency, and increase in the initial CTN concentration resulted in the decreasing of CTN removal percentage. However, it is believed that the inhibitory effect on anaerobic biodegradation of CTN is negligible in natural environment due to the much lower concentration of CTN in natural environment (at ng g⁻¹ or pg g⁻¹ level) than the one (10 μg g⁻¹) investigated in this study. The 4-hydroxy-2,5,6- trichloroisophthalonitrile (HTI), one of the major metabolites of CTN degradation, has shown the significant inhibitation to the anaerobic CTN biodegradation when its residual level is over 0.1 μg g⁻¹.     

Phase II,dose ranging study of the safety and immunogenicity of single dose West Nile vaccine in healthy adults ≥50 years of age

Introduction

ChimeriVax-WN02 is a live, attenuated chimeric vaccine for protection against West Nile virus (WNV) produced by insertion of the genes encoding the pre-membrane (prM) and envelope (E) proteins of WNV (strain NY99) into the yellow fever 7D vaccine virus. This Phase II, randomized, double-blind, placebo-controlled, multi-center study in the US assessed the immunogenicity, viremia, and safety of the ChimeriVax-WN02 vaccine.

Methods

The study included adults in general good health. Subjects aged ≥50 years were randomized to one of four treatment groups: ChimeriVax-WN02 4 × 10³ plaque-forming units (pfu) (n = 122), 4 × 10⁴ pfu (n = 124), 4 × 10⁵ pfu (n = 113), or placebo (n = 120). A subset of subjects was randomized to assess viremia after vaccination at three different dose levels. Subjects were followed for safety up to 6 months after vaccination.

Results

A total of 121subjects for WN024 × 10³, 122 for WN02 4 × 10⁴, 110 for WN02 4 × 10⁵, and 120 for the placebo group completed the study up to the 6-month safety follow-up. Seroconversion, as measured by plaque reduction neutralization test (PRNT), was achieved at Day 28 by 92.1%, 93.2%, and 95.4% of subjects in the WN02 4 × 10³, the WN02 4 × 10⁴, and the WN02 4 × 10⁵ groups, respectively. Viremia was transient, detected between Days 2 and 14 but not at Day 28, and in most cases did not reach the quantification threshold. The percentage of subjects reporting at least one event of reactogenicity was similar in the placebo and active vaccine groups and showed no dose relationship.

Conclusions

The ChimeriVax-WN02 vaccine was highly immunogenic and well tolerated among subjects ≥50 years old at all dose levels.     

A protective chimeric antibody to tick-borne encephalitis virus

The efficiency of several mouse monoclonal antibodies (mAbs) specific to the tick-borne encephalitis virus (TBEV) glycoprotein E in post-exposure prophylaxis was assessed, and mAb14D5 was shown to be the most active of all those studied. It was proven that the hybridoma cell line 14D5 produced one immunoglobulin H chain and two L chains. They were used to construct chimeric antibodies ch14D5a and ch14D5b, the affinity constants of which were 2.6 × 10¹⁰ M⁻¹ and 1.0 × 10⁷ M⁻¹, respectively, according to the SPR-based ProteOn biosensor assay. The neutralization index (IC₅₀) of ch14D5a was 0.04 μg/ml in the focus reduction neutralization test. In in vivo experiments, ch14D5a at a dose of 10 μg/mouse resulted in a 100% survival of the mice infected with 240 LD₅₀ of TBEV. This chimeric antibody is promising for further development of prevention and therapeutic drugs against TBEV.     

Influence of 17β-estradiol binding by dissolved organic matter isolated from wastewater effluent on estrogenic activity

The aims of this study were to determine the sorption coefficient (Log K_DOC) of 17β-estradiol (E2), according to the size and composition of dissolved organic matter (DOM) isolated from wastewater effluent using a fluorescence quenching (FQ) method, and to measure the estrogenic changes due to the extent of E2 sorption onto effluent DOM (EfOM) by using an E-screen bioassay. The highest log K_DOC of E2 for a DOM size fraction less than 0.2 μm was observed by 4.87±1.87 L kg⁻¹_DOC, and its estrogenicity was the lowest among all the size fractions at 1.2 ng-EEQ L⁻¹. However, E2 estrogenicity for a DOM size fraction less than 5 kDa was as high as that for the positive control due to the absence of fulvic acid- and protein-like DOM to bind with E2. The estrogenic activity for the hydrophobic fraction bound with E2 was significantly reduced to 1.6 ng-EEQ L⁻¹, while that for the hydrophilic fraction having no binding with E2 was 2.6 ng-EEQ L⁻¹, which was similar to that of the positive control (i.e., 2.8 ng-EEQ L⁻¹). The results support a conclusion that the change in estrogenicity was due to the strong sorption affinity of E2 onto DOM.     

Dose-response relationship between walking and the attenuation of inherited weight

Objective

Genetic factors account for 40%-70% of the variation in body mass index (BMI). We sought to test whether moderate intensity physical activity affected parent-offspring relationships for body mass index and regional adiposity in 26,587 female and 6428 male walkers surveyed in the United States in 2000.

Methods

Survey questionnaires provided self-reported usual walking distance, height, weight, and waist circumference, and mother's and father's adiposity (1 = lean, 2 = normal, 3 = overweight, and 4 = very overweight). Regression analyses were used to test whether the contribution of parental adiposities to the walkers' body mass indexes and waist circumferences diminished with walking.

Results

In the most sedentary group (walking < 1.5 km/d), average parental adiposity was a significant determinant of the walkers' body mass indexes and waist circumferences (female: P < 10⁻¹⁵; male: P < 10⁻¹³). Greater walking distance significantly diminished the effect of average parents' adiposity on the walkers' body mass indexes (female: P < 10⁻¹⁰; male P = 0.003) and waist circumferences (female: P < 10⁻⁶; male P = 0.01). Compared to the most sedentary female walkers, the effect of parental adiposity was reduced 36% for body mass indexes and 41% for waist circumferences (corresponding reductions in men were 36% and 46%, respectively).

Conclusion

These results suggest that moderate intensity physical activity attenuates inheritance of both total and regional adiposity in a dose-dependent manner.     

Heavy metal induced physiological alterations in Salvinia natans

Salvinia possess inherent capacity to accumulate high levels of various heavy metals. Accumulation of Cr, Fe, Ni, Cu, Pb and Cd ranged between 6 and 9 mg g⁻¹ dry wt., while accumulation of Co, Zn and Mn was ∼4 mg g⁻¹ dry wt. Heavy metal accumulation affected the physiological status of plants. Photosystem II activity noted to decline in Ni, Co, Cd, Pb, Zn and Cu exposed plants, while Photosystem I activity showed enhancement under heavy metal stress in comparison to control. The increase in PS I activity supported build up of transthylakoidal proton gradient (ΔpH), which subsequently helped in maintaining the photophosphorylation potential. Ribulose 1,5 dicarboxylase/oxygenase (Rubisco) activity noted a decline. Alterations in photosynthetic potential of Salvinia result primarily from changes in carbon assimilation efficiency with slight variations in primary photochemical activities and photophosphorylation potential. Studies suggest that Salvinia possess efficient photosynthetic machinery to withstand heavy metal stress.     

Safety and immunogenicity of recombinant Rift Valley fever MP-12 vaccine candidates in sheep

The safety and immunogenicity of two authentic recombinant (ar) Rift Valley fever (RVF) viruses, one with a deletion in the NSs region of the S RNA segment (arMP-12ΔNSs16/198) and the other with a large deletion of the NSm gene in the pre Gn region of the M RNA segment (arMP-12ΔNSm21/384) of the RVF MP-12 vaccine virus were tested in crossbred ewes at 30–50 days of gestation. First, we evaluated the neutralizing antibody response, measured by plaque reduction neutralization (PRNT₈₀), and clinical response of the two viruses in groups of four ewes each. The virus dose was 1 × 10⁵ plaque forming units (PFU). Control groups of four ewes each were also inoculated with a similar dose of RVF MP-12 or the parent recombinant virus (arMP-12). Neutralizing antibody was first detected in 3 of 4 animals inoculated with arMP-12ΔNSm21/384 on Day 5 post inoculation and all four animals had PRNT₈₀ titers of ≥1:20 on Day 6. Neutralizing antibody was first detected in 2 of 4 ewes inoculated with arMP-12ΔNSs16/198 on Day 7 and all had PRNT₈₀ titers of ≥1:20 on Day 10. We found the mean PRNT₈₀ response to arMP-12ΔNSs16/198 to be 16- to 25-fold lower than that of ewes inoculated with arMP-12ΔNSm21/384, arMP-12 or RVF MP-12. No abortions occurred though a single fetal death in each of the arMP-12 and RVF MP-12 groups was found at necropsy. The poor PRNT₈₀ response to arMP-12ΔNSs16/198 caused us to discontinue further testing of this candidate and focus on arMP-12ΔNSm21/384. A dose escalation study of arMP-12ΔNSm21/384 showed that 1 × 10³ plaque forming units (PFU) stimulate a PRNT₈₀ response comparable to doses of up to 1 × 10⁵ PFU of this virus. With further study, the arMP-12ΔNSm21/384 virus may prove to be a safe and efficacious candidate for a livestock vaccine. The large deletion in the NSm gene may also provide a negative marker that will allow serologic differentiation of naturally infected animals from vaccinated animals.