Global prevalence and gender inequalities in at least 60 min of self-reported moderate-to-vigorous physical activity 1 or more days per week: An analysis with 707,616 adolescents

BACKGROUND

Guidelines recommend that adolescents should accumulate an average of 60 min per day of moderate-to-vigorous physical activity (MVPA). However, using only this cut-off could hide important information. For instance, from a population-level point of view, increasing physical activity for those with no or low physical activity could provide more health benefits than increasing physical activity for those with intermediate levels. Also, including a more sensitive cut-point of ≥1 day per week could be an additional strategy for identifying those with low access/opportunities for physical activity practice. Thus, the current study aims to estimate the prevalence of ≥60 min of MVPA ≥1 days per week among adolescents globally, and to describe any relevant gender inequalities.

METHODS

We used representative datasets from 146 countries/territories collected between 2003 and 2019. MVPA was self-reported. Participants were grouped into younger (≤14 years old) and older (>14 years old) adolescents. Crude Poisson regression models were used to identify the relative differences in ≥60 min of MVPA ≥1 days per week between boys and girls, and random-effects meta-analysis models were used to identify the pooled estimates. Analyses were stratified by country and region.

RESULTS

Approximately 80% of both younger and older adolescents reported ≥60 min of MVPA ≥1 days per week. This prevalence was ≥94% in Europe and Central Asia and North America, while the estimates for the other regions were <77%. The prevalence of ≥60 min of MVPA ≥1 days per week was higher among boys than girls, with the largest differences occurring among the oldest adolescents (PR≤14y: 1.04 (95% confidence interval (95%CI): 1.03‒1.04) vs. PR>14y: 1.09 (95%CI: 1.08‒1.10)).

CONCLUSION

Approximately 8 out of 10 adolescents reported accumulating ≥60 min of MVPA ≥1 day per week, with notable differences between regions. Gender differences were observed in several countries, especially among the oldest adolescents. Priorities for physical activity promotion among adolescents should include increasing access/opportunities for physical activity among those who do not achieve ≥60 min of MVPA ≥1 days per week and reducing gender inequalities.

Short-term testicular warming under anesthesia causes similar increases in testicular blood flow in Bos taurus versus Bos indicus bulls, but no apparent hypoxia

Bull testes must be 4-5 °C below body temperature, with testicular warming more likely to cause poor-quality sperm in Bos taurus (European/British) versus Bos indicus (Indian/zebu) bulls. Despite a long-standing dogma that testicular hyperthermia causes hypoxia, we reported that increasing testicular temperature in bulls and rams enhanced testicular blood flow and O₂ delivery/uptake, without hypoxia. Our objective was to determine effects of short-term testicular hyperthermia on testicular blood flow, O₂ delivery and uptake and evidence of testicular hypoxia in pubertal Angus (B. taurus) and Nelore (B. indicus) bulls (nine per breed) under isoflurane anesthesia. As testes were warmed from 34 to 40 °C, there were increases (P < 0.0001, but no breed effects) in testicular blood flow (mean ± SEM, 9.59 ± 0.10 vs 17.67 ± 0.29 mL/min/100 g, respectively), O₂ delivery (1.79 ± 0.06 vs 3.44 ± 0.11 mL O₂/min/100 g) and O₂ consumption (0.69 ± 0.07 vs 1.25 ± 0.54 mL O₂/min/100 g), but no indications of testicular hypoxia. Hypotheses that: 1) both breeds increase testicular blood flow in response to testicular warming; and 2) neither breed has testicular hypoxia, were supported; however, the hypothesis that the relative increase in blood flow is greater in Angus versus Nelore was not supported. Although these were short-term increases in testicular temperature in anesthetized bulls, results did not support the long-standing dogma that increased testicular temperature does not increase testicular blood flow and an ensuing hypoxia is responsible for decreases in motile, morphologically normal and fertile sperm.

Effects of restricted vs. step up dietary adaptation for 6 or 9 days on feedlot performance, feeding behaviour, ruminal and blood variables of Nellore cattle

This study was designed to determine effects of quantitatively restricted intake of the final finishing diet as a means of dietary adaptation compared with diets increasing in concentrate (step up) over periods of 6 and 9 days on feedlot performance, carcass characteristics, feeding behaviour, blood gas profile and rumen morphometrics of Nellore cattle. One hundred twenty 22-month-old Nellore bulls (352 ± 20 kg) were randomly allocated in 24 pens and fed for 84 days. The experimental design was a completely randomized block with 2 × 2 factorial arrangement of treatments: adaptation using either step up protocol for 6 days or 9 days or restriction protocol for 6 days or 9 days, where the pen (five bullocks/pen; six pens/treatment) was considered the experimental unit. Cattle adapted by step up protocol had significantly greater average daily gain throughout the study when compared to those adapted by restriction protocol, regardless of adaptation length. During the adaptation period, a greater dry matter intake fluctuation was observed for animals maintained on restriction programme when compared to those adapted to the finishing diets using step up protocol. In addition, a protocol × length interaction for rumenitis scores was observed, where the level of injuries to the ruminal wall was significantly higher for the cattle adapted by restriction protocol for 9 days and lower for animals submitted for 9 days to the step up programme. Likewise, a protocol × length interaction for mitotic index was observed, in which cattle adapted by step up protocol for 9 days had lower numbers of cells in mitosis. Thus, the step up protocol led to better feedlot performance, and based on this fact, the length of 9 days promoted better rumen epithelium adaptation of Nellore cattle to high-concentrate diets.

The effect of early measles vaccination at 4.5 months of age on growth at 9 and 24 months of age in a randomized trial in Guinea-Bissau

Background

Providing an early, additional measles vaccine (MV) at 4.5 months of age has been shown to reduce child mortality in low-income countries. We studied the effects on growth at 9 and 24 months of age.

Methods

A randomized controlled trial was conducted in Guinea-Bissau from 2003–2007 including 6,648 children. Children were randomized 1:1:1 to receive Edmonston-Zagreb measles vaccine at 4.5 and 9 months of age (group A), no vaccine at 4.5 months and Edmonston-Zagreb measles vaccine at 9 months (group B), or no vaccine at 4.5 months and Schwarz measles vaccine at 9 months (group C) Data on anthropometrics were obtained at enrolment at 4.5 months of age and again at 9 and 24 months of age. Analyses were stratified by sex, season of enrolment, and neonatal vitamin A supplementation (NVAS) status, as all these factors have been shown to modify the effect of early MV on mortality.

Results

Overall there was no effect of early MV on anthropometry at 9 months. At 24 months children who had received early MV had a significantly larger mid-upper-arm-circumference (MUAC/in cm) (Difference = 0.08; 95% CI (0.02;0.14)) compared with children in the control group; this effect was most pronounced among girls (0.12 (0.03;0.20)). The effect of early MV on MUAC remained significant in the dry season and in girls who received placebo rather than NVAS.

Conclusion

Early MV was associated with a larger MUAC particularly in girls. These results indicate that a two-dose measles vaccination schedule might not only reduce child mortality but also improve growth.

Trial registration

ClinicalTrials.gov NCT00168558. Registered September 9, 2005, retrospectively registered

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-016-0738-z) contains supplementary material, which is available to authorized users.

Different effects of BCG strains - A natural experiment evaluating the impact of the Danish and the Russian BCG strains on morbidity and scar formation in Guinea-Bissau

BACKGROUND

Different Bacillus Calmette-Guerin (BCG) vaccine strains may have different non-specific effects. We assessed the effect of two BCG strains (Danish and Russian) on childhood morbidity and BCG scarification in Guinea-Bissau.

METHODS

During 2011-2013, infants in the Bandim Health Project's urban study area received the Danish or Russian BCG in a natural experiment. Health center consultations were registered at point of care and scar status and size at age 4½ months. We assessed the effect of strain on consultation rates between vaccination and age 45days in Cox proportional hazards models. Scar prevalence and size were compared using binomial regression and ranksum tests.

RESULTS

Among 1206 children, 18% received Danish BCG (n=215) and 82% Russian BCG (n=991). The adjusted hazard ratio (aHR) for consultations was 0.94 (95% CI 0.60-1.46) for Danish BCG compared with Russian BCG. Girls vaccinated with Danish BCG tended to have lower consultation rates compared with girls vaccinated with Russian BCG (aHR 0.56 (0.25-1.24)), whereas the effect was opposite for boys (aHR 1.24 (0.74-2.11)), p=0.09. Children vaccinated with Danish BCG were more likely to develop a scar (97%) than children vaccinated with Russian BCG (87%), the relative risk (RR) being 1.11 (1.06-1.16). The effect was stronger in girls, and BCG scar size was larger among infants vaccinated with the Danish strain.

CONCLUSION

BCG strain influences scar prevalence and scar size, and may have sex differential effects on morbidity. BCG strains are currently used interchangeably, but BCG scarring has been linked to subsequent survival. Hence, more research into the health effects of different BCG strains is warranted. Small adjustments of BCG production could potentially lower childhood morbidity and mortality at low cost.

Effects of feeding a spray-dried multivalent polyclonal antibody preparation on feedlot performance, feeding behavior, carcass characteristics, rumenitis, and blood gas profile of Brangus and Nellore yearling bulls

The objective of this study was to evaluate the effects of replacing monensin (MON) with a spray-dried multivalent polyclonal antibody preparation (PAP) against several ruminal microorganisms on feedlot performance, carcass characteristics, feeding behavior, blood gas profile, and the rumenitis incidence of Brangus and Nellore yearling bulls. The study was designed as a completely randomized design with a 2 × 2 factorial arrangement, replicated 6 times (4 bulls per pen and a total of 24 pens), in which bulls ( = 48) of each biotype were fed diets containing either MON fed at 300 mg/d or PAP fed at 3 g/d. No significant feed additive main effects were observed for ADG ( = 0.27), G:F ( = 0.28), HCW ( = 0.99), or dressing percentage ( = 0.80). However, bulls receiving PAP had greater DMI ( = 0.02) and larger ( = 0.02) final LM area as well as greater ( < 0.01) blood concentrations of bicarbonate and base excess in the extracellular fluid than bulls receiving MON. Brangus bulls had greater ( < 0.01) ADG and DMI expressed in kilograms, final BW, heavier HCW, and larger initial and final LM area than Nellore bulls. However, Nellore bulls had greater daily DMI fluctuation ( < 0.01), expressed as a percentage, and greater incidence of rumenitis ( = 0.05) than Brangus bulls. In addition, Brangus bulls had greater ( < 0.01) DMI per meal and also presented lower ( < 0.01) DM and NDF rumination rates when compared with Nellore bulls. Significant interactions ( < 0.05) between biotype and feed additive were observed for SFA, unsaturated fatty acids (UFA), MUFA, and PUFA concentrations in adipose tissues. When Nellore bulls were fed PAP, fat had greater ( < 0.05) SFA and PUFA contents but less ( < 0.01) UFA and MUFA than Nellore bulls receiving MON. For Brangus bulls, MON led to greater ( < 0.05) SFA and PUFA and less ( < 0.05) UFA and MUFA than Brangus bulls fed PAP. Feeding a spray-dried PAP led to similar feedlot performance compared with that when feeding MON. Spray-dried PAP might provide a new technology alternative to ionophores.

Valuation of OSA process and folic acid addition as excess sludge minimization alternatives applied in the activated sludge process

The aim of this study was to investigate the ability of the oxic-settling-anaerobic (OSA)-process and the folic acid addition applied in the activated sludge process to reduce the excess sludge production. The study was monitored during two distinct periods: activated sludge system with OSA-process, and activated sludge system with folic acid addition. The observed sludge yields (Yobs) were 0.30 and 0.08 kgTSS kg(-1) chemical oxygen demand (COD), control phase and OSA-process (period 1); 0.33 and 0.18 kgTSS kg(-1) COD, control phase and folic acid addition (period 2). The Yobs decreased by 73 and 45% in phases with the OSA-process and folic acid addition, respectively, compared with the control phases. The sludge minimization alternatives result in a decrease in excess sludge production, without negatively affecting the performance of the effluent treatment.

Consortia of microalgae and bacteria in the performance of a stabilization pond system treating landfill leachate

This study treated sanitary landfill leachate and was conducted in a pilot-scale system composed of three serial ponds (P1, P2 and P3), followed by a rock filter, in order to evaluate the microbial consortium influence on system performance and to investigate microorganism dynamics in the process. The system was broken into three stages, with a continuous flow rate (Q = 200 L d⁻¹) for 43 weeks. The stages were as follows: conventional operation (stage I), 12 h aeration in P2 (stage II), and 18 h aeration in P2 (stage III). The results showed the possibilities for treating landfill leachate, presenting an average efficiency of 75% for both filtered biochemical oxygen demand and ammonium. At the end of stage III, the ammonium concentration was 6 mg L⁻¹, which is lower than that established by Brazilian regulations for wastewater discharge (CONAMA 430/2011). The aeration applied in P2 led to a change in the microbial consortia during the second and third stage, which influenced the quality of the final effluent. The best performance was seen in stage III, where the system showed high microbial diversity, including the presence of nitrifying bacteria.

A comparison of ex vivo cytokine production in venous and capillary blood

We performed a randomized study of the immunological effects of an early measles vaccine given at 4.5 months of age and aimed to obtain venous samples from the infants at baseline and 6 weeks later. If this was not feasible, a capillary sample was obtained. We analysed baseline samples from the first 50 children enrolled in the study to investigate the potential differences in ex vivo cytokine production between venous blood and capillary blood. We also obtained paired venous and capillary blood samples from 11 adult volunteers. Whole blood was stimulated with lipopolysaccharide (LPS) [a Toll-like receptor (TLR)-4 ligand], (S)-(2, 3-bis (palmitoyloxy)-(2-RS)-propyl)-N-palmitoyl-(R)-Cys-(S)-Ser-(S)-Lys4-OH, trihydrochloride (PAM3Cys) (a TLR-2 ligand), phytohaemagglutinin (PHA) or purified protein derivative (PPD). Cytokine concentrations in the supernatants were assessed by a multiplexed assay and were compared between venous and capillary samples in both infants and adults. The production of both the pro- and the anti-inflammatory cytokines, tumour necrosis factor (TNF)-alpha and interleukin (IL)-10, was higher in cultures of capillary blood compared with venous blood. This was found in non-stimulated control samples as well as in blood stimulated with PAM3Cys and PPD. Adults produced more IL-5 in venous blood than in capillary blood upon PHA stimulation. We found no other difference in the levels of IL-5 or IFN-gamma between venous and capillary blood. In capillary blood we found sex differences in response to PHA but this was not the case in venous blood. We found significant differences in the production of cytokines between venous and capillary blood. Such differences should be taken into account when setting up immuno-epidemiological studies.

BCG vaccination among West African infants is associated with less anergy to tuberculin and diphtheria-tetanus antigens

To examine risk factors for anergy, delayed-type hypersensitivity was assessed among 884 infants participating in a vaccine trial in Guinea-Bissau. The infants were skin-tested at 7.5 months of age with a panel of seven intradermal antigens. Risk factors for anergy to tuberculin or anergy to both the diphtheria and tetanus antigens were determined in relation to Bacillus Calmette-Guérin (BCG) vaccination, diphtheria-tetanus-pertussis (DTP) vaccination, and measles vaccination. We found sick children to be more anergic to tuberculin and diphtheria-tetanus antigens than healthy children (OR=2.49 (95% confidence interval 1.40-4.55)). There was a higher prevalence of anergy to tuberculin in the rainy season than in the dry season (OR=1.67 (1.25-2.23)). Children who had taken antimalarials within the last week had a higher prevalence of anergy to tuberculin (OR=1.41 (1.02-1.92)). BCG vaccination was significantly associated with less anergy to tuberculin and diphtheria-tetanus antigens (OR=0.42 (0.28-0.63), OR=0.77 (0.60-0.99), respectively). Children vaccinated with BCG before 1 month of age were more anergic to tuberculin than children vaccinated after 1 month (OR=1.61 (1.19-2.19)). DTP vaccination was associated with less anergy to diphtheria-tetanus antigens (OR=0.40 (0.32-0.49)), but not to tuberculin. Children with a positive reaction to tuberculin were less likely to be anergic to diphtheria-tetanus antigens (OR=0.36 (0.26-0.49)) than children with a negative tuberculin reaction. Children who were vaccinated with BCG before they received their last DTP vaccine were less anergic to diphtheria-tetanus antigens (OR=0.40 (0.16-0.88)) than other DTP-vaccinated children. In conclusion, current disease, rainy season, age below 1 month of age at the time of BCG vaccination, and administration of chloroquine or quinimax within the last 7 days were risk factors for anergy to tuberculin among 7.5-month-old infants. BCG vaccination and a positive tuberculin reaction were associated with a lower prevalence of anergy to both tuberculin and diphtheria-tetanus. Thus, BCG vaccination may contribute to better cell-mediated immune responses among infants.

Measles antibody responses after early two dose trials in Guinea-Bissau with Edmonston-Zagreb and Schwarz standard-titre measles vaccine: better antibody increase from booster dose of the Edmonston-Zagreb vaccine

In Guinea-Bissau, children were randomised at 6 months of age to receive either two doses of standard-titre measles vaccine at 6 and 9 months of age or an inactivated polio vaccine at 6 months and standard-titre measles vaccine at 9 months of age. During the first 5 months, children received Edmonston-Zagreb (EZ) vaccine and during the following 11 months, the Schwarz (SW) vaccine. Five percent of the mothers, 74% of children at 6 months of age, and 92% of unvaccinated children at 9 months of age had unprotective levels (<125 mIU/ml) of measles antibodies. Among children receiving EZ vaccine, 1% were unprotected at 18 months of age after either two (3/240) or one (3/211) doses of vaccine, the geometric mean measles antibody titre (GMT) being approximately 1550 mIU/ml in both groups. Among those receiving SW vaccine 9% (34/365) and 3% (9/310) were unprotected at 18 months of age in the two-dose and the one-dose groups (RR = 3.21 (95% confidence interval (CI) 1.56-6.58)), respectively. The GMT was higher after one dose of SW vaccine at 9 months of age (2491 mIU/ml) than after two doses of SW vaccine (1125 mIU) (P < 0.001). In the EZ vaccine group, there was no significant difference in antibody level for children vaccinated in the presence of high or low levels of maternal antibodies, whereas there was a marked difference in the SW group. The second EZ vaccine induced a significant antibody increase between 9 months of age (1191 mIU) and 18 months of age (1602 mIU, P=0.011), whereas antibody levels tended to decline from 9 months (1243 mIU) to 18 months of age (998 mIU, P = 0.124) after the second dose of SW vaccine. Conclusively, after two doses of EZ measles vaccine more children were protected at 18 months of age than after two doses of SW. One dose of SW provided the highest antibody response, but a higher proportion of unprotected than one or two doses of EZ. The EZ vaccine was less sensitive to maternal antibodies, and able to increase the antibody response by revaccination, while the second SW vaccine resulted in an unchanged or lower antibody response.

Bacterial lipoprotein based expression vectors as tools for the characterisation of African swine fever virus (ASFV) antigens

African swine fever virus (ASFV) is the causative agent of an important pig disease for which protective mechanisms are still poorly understood. The present work was aimed at the characterisation of ASFV antigens using previously reported vectors that allow their expression as fusion proteins with the bacterial lipoprotein OprI. Several recombinant clones induced SLA-restricted, ASFV-specific lymphoproliferation and one (A2) was demonstrated to stimulate ASFV-specific CTL activity in vitro, in opposition to the effect of UV inactivated virus. The nucleotide sequence of the fragment cloned in A2 showed 99% identity with a portion of the G1340L ORF of the BA71V isolate, and the expressed fusion lipoprotein induced specific antibodies in vivo. Blood mononuclear leukocytes from a pig immunised with outer membrane preparations from A2 showed to reduce strongly (99.6%) the ASFV yield in cultures of autologous macrophages. However, after inoculation with virulent virus the pig developed acute fatal ASF. Overall our results show that OprI based expression vectors are valuable tools to screen viral antigens in terms of their capacity to trigger immune competent cells.

Early two-dose measles vaccination schedule in Guinea-Bissau: good protection and coverage in infancy

BACKGROUND

Previous studies from Africa have suggested that there is little benefit to be gained from early two-dose measles vaccination schedules. Two-dose schedules have been associated with no improvement in coverage due to immunization of the same individuals on both occasions, low return rate, high refusal rate, low vaccine efficacy, and fear of blunting of the antibody response. Because of the poor results achieved previously with two-dose measles vaccination schedules, we studied patterns of participation, reasons for non-participation, vaccination coverage and relative efficacy of a one-dose versus a two-dose schedule in connection with the implementation of an early two-dose trial in Guinea-Bissau.

METHODS

Children born from September 1994 to January 1996 were randomized into two groups receiving either two doses of measles vaccine at 6 and 9 months or one dose of inactivated polio vaccine (IPV) at 6 months and measles vaccine at 9 months.

RESULTS

At 6 months of age 86% (1869/2181) of the children participated, and at 9 months of age participation was 87% (1775/2035). The return rate for obtaining a second dose of vaccine was 93% (1647/1773). The main reason for not participating was travelling (78%). Around 50% of those who did not take part in one vaccination took part in the other. When only children participating the first time they were called for a measles vaccination were included, the measles vaccination coverage in the one-dose group was 59% versus 80% in the two-dose group, i.e. a 50% reduction in the risk of not being vaccinated (relative risk [RR] 0.50; confidence interval [CI]: 0.43-0.57). Few measles cases have occurred in the study area since the implementation of the trial making precise estimation of the relative efficacy of the two vaccine strategies difficult, but all seven clinically diagnosed measles cases occurred in the one-dose group making the relative efficacy for the two-dose group compared with the one-dose group 100% (95% CI: 35%-100%; two-tailed P = 0.016). When including maternal reports, the relative efficacy was 90% (95% exact confidence interval; two-tailed P = 25%-97%, P = 0.022).

CONCLUSION

In this study of a two-dose measles immunization schedule at 6 and 9 months of age there was no sign of low participation or poor return rates. The risk of not being vaccinated was lower in the two-dose group than in the one-dose group, and the relative efficacy of a two-dose versus a one-dose schedule was high. Although our results were obtained within a trial where dedicated personnel informed every participant personally about the study, we believe our results indicate that with thorough information about the population it may be possible to achieve a higher coverage with a two-dose measles vaccination schedule than a one-dose schedule. A two-dose schedule may be a feasible way to resolve the problems of low coverage and severe measles infection among infants.

Identification of a 25-aminoacid sequence from the major African swine fever virus structural protein VP72 recognised by porcine cytotoxic T lymphocytes using a lipoprotein based expression system

Identification of African swine fever virus (ASFV) proteins recognised by cytotoxic T lymphocytes (CTL) from swine surviving ASFV/NH/P68 infection was assessed using expression vectors based on the Pseudomonas aeruginosa outer membrane lipoprotein I gene (oprI). Viral antigens expressed as fusion lipoproteins were shown to be taken efficiently by porcine blood-derived macrophages incubated with outer membrane protein preparations from transformed E. coli. To assess recognition by CTL the fusion lipoprotein-treated macrophages were used as targets in 51Cr release microcytotoxicity assays. Using this approach it was shown that the aminoacid sequence HKPHQSKPILTDENDTQRTCSHTNP from the major structural ASFV protein (VP72), encoded by a recombinant clone (pVUB72) is presented by macrophages, which are lysed under restriction of SLA class I antigens. Overall, the results demonstrate that the oprI based vectors are valuable tools to study ASFV-specific CTL activity.

Porcine immune responses to African swine fever virus (ASFV) infection

Immune responses mediating protection against ASFV are poorly understood. Anti-ASFV antibodies may influence the course of the clinical disease but they have never been found to neutralize the virus. Recent developments on cellular defense mechanisms, using swine protection models, and on the induction and role of some cytokines warrant further investigation on these areas.

African swine fever virus specific porcine cytotoxic T cell activity

African swine fever virus (ASFV) specific, cytotoxic T lymphocyte (CTL) activity has been studied in a protection model in which SLA inbred miniature swine are experimentally inoculated with a naturally occurring, non-fatal ASFV isolate (NHV). Peripheral blood mononuclear cells (PBMC) from such infected swine show significant activity in CTL assays, using cultured ASFV-infected porcine blood derived macrophages as target cells. This CTL activity is elicited from PBMC by in vitro restimulation of effector cells with low doses (multiplicity of infection = 0.1) of the homologous virus isolate for 48 to 72 h. For SLAc/c effectors, this CTL activity appears to be SLA class I restricted because (1) blocking target cell antigens with monoclonal antibodies (mAb) against SLA class I antigens causes a major reduction in CTL activity; (2) there is preferential lysis of SLA class I matched, ASFV infected targets; and (3) depletion of effector cells with CD8 specific mAb and complement causes a reduction in CTL activity. The CTL activity is ASFV specific for all pigs tested in that infected macrophages are preferentially lysed as compared to normal (non-infected) cultured macrophages or macrophages infected with hog cholera virus (HCV). Lysis of macrophages infected with different ASFV isolates revealed that there is marked lysis of macrophages infected with the virulent L60 isolate but less lysis of macrophages infected with the DR-II and Tengani isolates. In summary, our data show that ASFV specific CTL activity is triggered in swine infected with the NHV ASFV isolate.

In vitro induction of swine peripheral blood monocyte proliferation by the fibroblast-derived murine hematopoietic growth factor CSF-1

The addition of conditioned medium from murine L929 fibroblasts (MGF) to cultures of swine peripheral blood mononuclear cells (MNL) resulted in growth of cells of macrophage/monocyte lineage (MO). Glass-adherent swine MNL, shown to be greater than 95% phagocytic MO, grew in the presence of MGF, whereas swine blood granulocytes and lymphocytes were not MGF-responsive. Primary and secondary MO growth were directly dependent on MGF presence and concentration. MGF-stimulated MO synthesized DNA, as measured by cellular incorporation of tritium-labeled thymidine (3H-TdR). This mitogenic response was maximal by 5 to 6 days in primary MO cultures and declined thereafter to a lower magnitude in secondary MO cultures. In the presence of MGF, viable MO numbers increased with an approximate population doubling time of 5 to 7 days in primary culture. This growth rate was prolonged, to about 10 to 12 days, for MGF-stimulated MO in secondary cultures. MGF removal from primary and secondary MO cultures resulted in rapid growth cessation and cell death. MGF-stimulated MO could not be sustained in secondary culture beyond 7 weeks. MGF-cultured MO were positive for latex phagocytosis, non-specific esterase, Fc-receptor expression, and could mediate antibody-dependent cell-mediated cytotoxicity. The MO-mitogenic principle of MGF was identified as the murine, macrophage-specific colony-stimulating factor, CSF-1 (M-CSF). The swine MO-proliferative response to MGF was inhibited by addition of monospecific goat antisera to M-CSF. Purified M-CSF stimulated the growth of swine MO from cultures of MNL and primary glass-adherent MO.

Virus-specific cellular blastogenesis and interleukin-2 production in swine after recovery from African swine fever

Animals recovered from viral diseases represent an important model to study the host cellular and humoral immune responses to the etiologic agents. This is particularly important for African swine fever virus (ASFV) infections in which antibodies have little or no virus-neutralizing effect. Pigs surviving experimental infection with the naturally occurring low-virulent, nonhemadsorbing ASFV/NH/P68 (NHV) isolate did, however, exhibit virus-specific T-cell activities, as measured by a variety of assays. A strong virus-induced, antigen-specific blastogenic response was observed only with blood mononuclear cells (BMC) from ASF-recovered swine, whereas cells from recovered and naive swine responded similarly to the mitogens concanavalin A and phytohemagglutinin. The ASFV-induced blastogenesis was dependent on virus dose and on the presence of adherent cells. Blood mononuclear cells cultured with antigenically related hemadsorbing ASFV isolates of different virulence characteristics, the highly virulent L60 isolate and moderately virulent DRII isolate, exhibited a similar magnitude of blastogenesis to cells infected with the low-virulent NHV isolate. Virus-infected cells proved to be an efficient inducer of interleukin-2 (IL-2) activity to cells from recovered swine, but not from naive swine, whereas T-cell-specific lectins induced production of similar amounts of IL-2 activity from cells of naive and recovered swine. Correlated with the appearance of virus-induced IL-2 activity in the culture supernatant was the induction of promiscuous killing in cells exposed to prolonged (7 days) virus stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

A family survey of lupus erythematosus. 1. Heritability

First degree relatives and spouses of 36 patients with systemic lupus erythematosus (SLE) and 37 with discoid lupus erythematosus (LE) were assessed using the ARA criteria. They were compared with relatives and spouses of patients with other rheumatic and related complaints. Definite SLE was present in 3.9% of relatives of SLE probands, 2.6% of discoid relatives and 0.3% of controls. Discoid LE was diagnosed in 0.6% of SLE and 3.5% of discoid families compared with 0.5% of controls. None of the spouses of LE probands had SLE or discoid LE. The data gave the best fit for a polygenic inheritance with a heritability of 66 +/- 11% for SLE and 44 +/- 10% for discoid LE. Genetic factors are thus less important in SLE and discoid LE than in generalized osteoarthritis, spondylitis or gout with heritabilities of 90, 72 and 90%, respectively.

Modulation of porcine peripheral blood-derived macrophage functions by in vitro infection with African swine fever virus (ASFV) isolates of different virulence

Macrophages play an important role in defense against invading pathogens and neoplastic diseases. Their ability to maintain their functional characteristics is also important in the survival of the host. Loss of macrophage function during infection may be important in determining resistance or susceptibility of a host species. In this communication, we describe the effect of ASFV replication, in macrophages in vitro, on the functional characteristics of these cells. Infection with ASFV did not alter the expression of Fc receptors nor their ability to mediate ADCC. However, African swine fever virus was shown to modulate antibody mediated phagocytosis, chemiluminescence and chemotaxis. Similar modulation of certain macrophage functions was observed with ASFV isolates that differed in their virulence. We were therefore, unable to correlate the virulence of ASFV with the ability to alter macrophage function.