bluuebunny/crossref_metadata_2025 huggingface dataset:
Self-reported medical history survey of humans as a measure of health risk to the chimpanzees (Pan troglodytes schweinfurthii) of Kibale National Park, Uganda
Authors: Adams Hayley Rebecca , Sleeman Jonathan M. , Rwego Innocent , New John C.
Published: March 2003

Kibale National Park (KNP), Uganda, has a number of chimpanzees habituated for tourism. The close genetic relationship between humans and chimpanzees means that there is the potential for disease transmission between the two. The aim of this study was to establish the diseases to which chimpanzees may be exposed by surveying the medical histories of humans in contact with the chimpanzees of KNP. Medical questionnaires were given to tourists visiting KNP and to the population of a village close to the park. The 62 tourist surveys returned indicated a high prevalence of disease symptoms, in particular diarrhoea, as well as ongoing infectious diseases and a lack of current vaccinations. The 50 local surveys returned also indicated a high prevalence of disease symptoms, in particular respiratory disease, along with a low rate of vaccination and a high frequency of visual contact with the chimpanzees both within and outside KNP. This study indicates that humans are a potential source of infection for chimpanzees. The results, which have been communicated to the appropriate authorities, will assist in the devising of proper tourist viewing regulations and provide local health authorities with the information necessary to improve both public health and chimpanzee health. Further recommendations include education of tourists regarding appropriate vaccinations, hand washing prior to the visit, the use of facemasks during the visit, and the provision of latrines. Chimpanzee ecotourism is becoming increasingly popular and protecting the chimpanzees' health will help to ensure that ecotourism is a sustainable activity.
Community attitudes towards wildlife management in the Bolivian Chaco
Authors: Noss Andrew J. , Cuéllar Rosa Leny
Published: March 2003

The process of community wildlife management in the Izozog area of the Bolivian Chaco began with participatory field research – self-monitoring of hunting activities and research on key game species. On-going discussions in community meetings have elicited seven wildlife management recommendations: (1) establishing hunting zones, (2) hunting only adults, (3) hunting only males during the reproductive season, (4) hunting only for the family's needs, (5) hunting only abundant animals, (6) protecting plants that are important to wildlife, and (7) prohibiting hunting by outsiders. We compare community attitudes towards these management measures. A majority of communities favour, in decreasing order, measures 7, 4, 6 and 1, communities are divided with respect to measures 2 and 3, and most communities oppose measure 5. Two socio-economic characteristics of communities – location and ethnicity – are associated with patterns of attitudes towards wild-life management among communities, whereas religion, economic activity and community size are not. Izoceño communities are currently reinterpreting traditional beliefs both to support and to oppose active wildlife management measures.
The extirpation of large mammals and implications for montane forest conservation: the case of the Kilum-Ijim Forest, North-west Province, Cameroon
Authors: Maisels F. , Keming E. , Kemei M. , Toh C.
Published: March 2003

A review was carried out of the mammalian fauna of the Kilum-Ijim forest in the mountains of northwest Cameroon. The purpose was to examine the loss of species, particularly of larger mammals, and the implications of this for forest ecology. Information was collected by direct observation, hunter interviews and a literature review. The forest is the largest remaining representative fragment of the West African montane forest habitat. Seventy-seven species of mammal have been recorded in the forest over the last 50 years. Most are small, especially rodents, bats and insectivores. Seven species are endemic to the Kilum-Ijim area. The process of species extirpation probably began over 100 years ago with the loss of the mega-fauna, possibly beginning with elephantLoxodonta africana(several generations ago), and certainly with buffaloSyncerus caffer(at least 20 years ago), and other large mammals. Remaining large mammal population densities are very low and many species are close to regional extinction. The long-term consequences of these extinctions is uncertain but, as many tree species are monkey- or ruminant-dispersed, severe ecosystem damage has probably already occurred. Human population density in the area is around 300 people per sq km, and no sustainable offtake of wild animals will ever be possible that would provide more than a few grams of meat per person per year from the forest. The protein requirements of the communities of the area will have to continue to be supplied from domesticated stock. Since 1987 the Kilum-Ijim Forest Project of BirdLife International has been working to conserve the remaining forest, using a community forestry approach in collaboration with traditional and local authorities and the government of Cameroon. The project is investigating ways to improve the production of domestic animals outside the forest boundary.
Sociodemographic determinants of low birthweight in Greece: a population study
Authors: Lekea‐Karanika  , Tzoumaka‐Bakoula  , Matsaniotis
Published: March 2003

A total population sample of 10 654 singleton births from the Greek National Perinatal Survey of April 1983 was analysed to identify factors independently associated with low birthweight (LBW). The sample was divided into two groups according to the gravidity of the mothers (3368 primigravidae and 7286 multigravidae). Data examined included regional characteristics, marital status, age at and duration of marriage, parental ages at delivery, crowding in the home, insurance status, parental occupational classification and parental education levels. Logistic regression was used to define the socio‐economic and demographic characteristics independently associated with the delivery of an LBW singleton baby. Significantly different LBW rates were found among the two groups: 4.3% in the primigravidae and 5.2% for multigravidae. For primigravidae significant associations were found with marital status, maternal occupation and father’s education, while for multigravidae significant features were mother’s education and place (region) of residence. The study showed little to assist in devising strategies of primary prevention of LBW in Greece.
Stillbirths in relation to the coastline of Cumbria, 1950–89
Authors: Dummer  , Pearce  , Dickinson  , Charlton  , Salotti  , Parker
Published: March 2003

The nuclear installation at Sellafield, in west Cumbria in the north of England, has discharged radioactive waste into the Irish Sea since 1952. The objective of this paper was to investigate whether women living near to the coast in Cumbria had an increased risk of having stillborn children. A retrospective cohort analysis was carried out using all 259 050 births (4017 stillbirths) to women normally resident in Cumbria during 1950–89, allowing for year of birth, social class and birth order using (i) comparison of observed and expected numbers of stillbirths in distance bands relative to the coast, (ii) comparison of cumulative observed and expected numbers of stillbirths by distance from the coast, and (iii) logistic regression analysis of stillbirth risk in relation to distance from the coast. Comparison of observed and expected numbers of stillbirths in distance bands within 10 km of the coast did not provide evidence of an excess risk of stillbirth closer to the coast. The comparison of the cumulative observed and expected numbers of stillbirths within 10 km of the coast supported this result. Logistic regression analysis of all births in Cumbria showed that distance from the coast did not significantly influence stillbirth risk (P > 0.05). There was no evidence to suggest an increased risk of stillbirth in mothers resident nearer to the coast.
Reliability of placental histology using archived specimens
Authors: Grether  , Eaton  , Redline  , Bendon  , Benirschke  , Nelson
Published: March 2003

Archived placental materials provide a resource for retrospective studies of perinatal outcomes. Using archived specimens, we evaluated inter‐rater reliability in the assessment of placental histological features possibly associated with neonatal illness and long‐term neurological outcome. Five expert placental pathologists independently reviewed archived placental specimens on 30 subjects born during 1983–85 in six different hospitals. Moderate to substantial agreement among the raters was observed for a variety of indicators of inflammation, presence of macrophages with pigment and indicators of villous maturity, increased syncytial knots and maternal vasculopathy. Existing pathology reports for these specimens from routine histology examinations conducted at the time of delivery were in substantial agreement with expert review for the presence of any subchorionitis/chorionitis/chorioamnionitis. In conclusion, considerable inter‐rater agreement was observed for several relatively common and potentially important placental findings. Archived placental materials and pathology reports may be useful in retrospective studies.
Maternal obesity and glucose intolerance during pregnancy among Mexican‐Americans
Authors: Kieffer Edith C.
Published: March 2003

Low birthweight is uncommon among Mexican‐American infants, despite the substantial proportion of mothers who live in poverty. This apparent paradox has generated studies of factors protecting fetal growth, but may have masked other important health problems in the Mexican‐American community. Obesity, impaired glucose tolerance and diabetes are common among Mexican‐American women of childbearing age and during pregnancy. Prevalence of these conditions is two to four times higher in Mexican‐American than in non‐Hispanic white women. As obesity and glucose intolerance during pregnancy are associated with fetal overgrowth and increased risk of subsequent obesity and type 2 diabetes in mother and child, the adequacy of birthweight as a measure of maternal and infant risk may be obscured in populations with a high prevalence of these conditions. Their possible contribution to the increasing incidence of obesity and type 2 diabetes in Mexican‐American children, adolescents and young adults has not been examined. Appropriate preconception, prenatal and follow‐up care may identify high‐risk women, improve weight and metabolic status and reduce the severity and impact of diabetes and its complications. However, late or no prenatal care is common among Mexican‐American women and the frequency of follow‐up care is unknown. As low birthweight is a major public health indicator of maternal and neonatal health, perceived ‘good birth outcomes’ have reduced health policy, programme and research attention to Mexican‐American mothers and infants. Studies of the impact of obesity and glucose intolerance during pregnancy on the birthweights of Mexican‐American infants should be undertaken, along with systematic assessment of the subsequent health status and preventive health‐care needs of women and children in this population.
Vitamin A deficiency in healthy children aged 6–59 months in İzmir Province of Turkey
Authors: Kurugöl  , Egemen  , Keskinogˇlu  , Darcan  , Akşit
Published: March 2003

Vitamin A deficiency even at subclinical levels is associated with increased childhood mortality. There have been few studies related to vitamin A status of children in Turkey. The aim of this study was to assess vitamin A status of children aged 6–59 months in İzmir, Turkey, and to evaluate the relationship of these levels with nutritional status. One hundred and sixty children were selected for the study using the cluster sampling method. Serum retinol levels were measured by high‐performance liquid chromatography (HPLC) and ranged from 9.8 to 59.2 μg/dL (mean 29.3 ± 9.5 μg/dL). Levels were below the lower limit of the normal range in 15.6% of the children. Deficient and marginal serum retinol among stunted children were observed in 16% and 42% respectively. There was a statistically significant relationship between low serum retinol and stunting (P < 0.05). Although xerophthalmia and other clinical signs of vitamin A deficiency are rarely seen, subclinical vitamin A deficiency is a public health problem in İzmir, Turkey.
Overheated news of a ‘medical breakthrough’
Authors: Silverman William A.
Published: March 2003

Medicine pays almost exclusive homage to the shock of the new. We place a constant emphasis on novelty. We trumpet the most recent discoveries and give far too little attention to the concepts underlying our accumulated knowledge. Ours is an era of the instantaneous and immediate fact, a time when traditions are dissolving and the perceived need for a dialogue with the past is all but invisible.

Richard Horton1
Methods to improve the reliability of histopathological diagnoses in the placenta
Authors: Beebe  , Cowan  , Hyde  , Altshuler
Published: March 2003

The interobserver reliability of histopathological features in the placenta was examined. Two pathologists independently reviewed slides from 250 placentas. The pathologists were given a morphological description of the placenta, but were blinded to clinical status, gestational age and original diagnoses. A protocol for diagnosis and grading of features was first developed and pilot‐tested. Definitions and criteria were refined and elaborated. A range of features was examined including inflammatory lesions, features indicative of reduced uterine blood flow and other miscellaneous histopathological changes. Weighted kappa coefficients were calculated. The effect of multiple features on reliability was examined by stratifying on the presence of a second feature and calculating stratum‐specific kappa coefficients. Results indicated good to excellent agreement for diagnoses of chorioamnionitis, cord vasculitis, funisitis and villitis (κw range 0.70–0.83). Agreement between observers was more variable for the diagnosis of reduced uterine blood flow states. Excellent agreement was observed for the diagnosis of meconium staining of the placenta (κw = 0.79). In general, lower levels of agreement were observed for features in the presence of a second feature. Reproducible measures are a prerequisite to using placental histopathology for diagnostic and prognostic information. This study demonstrated reliable placental diagnoses can be achieved through a standardised protocol.
Accuracy of self‐reported cigarette smoking among pregnant women in the 1990s
Authors: Klebanoff Mark A. , Levine Richard J. , Morris Cynthia D. , Hauth John C. , Sibai Baha M. , Ben Curetevine  , Catalano Patrick , Wilkins Diana G.
Published: March 2003

In large, prospective studies of pregnancy conducted in the 1960s, women reported very accurately whether or not they smoked. However, in the 1990s, pregnant women who smoke are often pressured to reduce or quit smoking, and the incentive to misreport may be greater than in the past. To assess the accuracy of reported smoking, the authors compared self‐reported smoking with cotinine in the serum and/or urine of 105 women who participated in the Calcium for Pre‐eclampsia Prevention pilot study in 1992. Cotinine confirmed the report of 84.6% of women who reported smoking and 94.5% of women who denied smoking. These fractions are virtually identical to those obtained in a pregnancy cohort from the 1960s. The authors conclude that in the setting of two obstetrical research studies not specifically focused on smoking, the accuracy of self‐reported cigarette smoking did not change substantially from the 1960s to the 1990s.
Birthweight, vitamin D receptor genotype and the programming of osteoporosis
Authors: Dennison Elaine M. , Arden Nigel K. , Keen Richard W. , Syddall Holly , Day Ian N. M. , Spector Timothy D. , Cooper Cyrus
Published: March 2003

Studies of the association between polymorphisms of the gene for the vitamin D receptor (VDR) and adult bone mass have been inconsistent, pointing to the possibility that gene–environment interactions may vary in different populations. We have demonstrated previously an association between weight in infancy (a marker of the intrauterine and early post‐natal environment) and each of adult bone mass and VDR genotype. We therefore sought to extend these observations in an elderly UK cohort and to investigate the possibility of an interaction between these genetic and early environmental markers of later osteoporosis risk. One hundred and sixty‐five men and 126 women aged 61–73 years for whom birth records were available underwent bone mass measurements at baseline and follow‐up 4 years later. Whole‐blood samples were obtained, DNA extracted using standard techniques and polymorphisms in the VDR and collagen type Iα1 (Col IA1) genes identified. In the cohort as a whole, there were no significant associations between either birthweight or VDR genotype and bone mineral density (BMD) or bone loss rate at either site. However, the relationship between lumbar spine BMD and VDR genotype varied according to birthweight. Among individuals in the lowest third of birthweight, spine BMD was higher (P = 0.01) in individuals of genotype ‘BB’ after adjustment for age, sex and weight at baseline. In contrast, spine BMD was reduced (P = 0.04) in individuals of the same genotype who were in the highest third of the birthweight distribution. A significant (P = 0.02) statistical interaction was also found between VDR genotype and birthweight as determinants of BMD. Similar but slightly weaker associations were seen between lumbar spine bone mineral content (BMC) and VDR genotype in the lowest birthweight tertile. When examining the relationship between Col1A1 genotype and bone mass, lumbar spine BMC was higher in individuals of genotype ‘Ss’ or ‘ss’ in the lowest birthweight tertile (P = 0.02) after adjustment for age, sex and weight at baseline. These results suggest that genetic influences on adult bone size and mineral density may be modified by undernutrition in utero.
Fetal growth and systolic blood pressure in young adulthood: the Swedish Young Male Twins Study
Authors: Johansson‐Kark Malin , Rasmussen Finn , Stavola Bianca De , Leon David A.
Published: March 2003

The objective was to test the fetal origins hypothesis by examining the association between fetal growth and systolic blood pressure in a large cohort of adult male twins of known zygosity. This cohort study is based on a record linkage of routinely collected data from the Swedish Medical Birth Registry, the Swedish Military Conscription Registry and a mailed questionnaire. It comprises 886 pairs of same‐sex male twins born in Sweden in 1973–79 for whom data were available on size at birth and systolic blood pressure, height and weight at age 17–19 years. Based on self‐reported similarity of appearance in childhood, 384 twin pairs were classified as monozygotic (MZ), 269 as dizygotic (DZ) and 233 as of uncertain zygosity (XZ). Differences in systolic blood pressure within and between twin pairs were analysed in relation to birthweight and birthweight‐for‐gestational‐age z‐score using random effects linear models.

Within twin pairs, a 1 kg difference in birthweight was associated with a difference of −1.30 mmHg in systolic blood pressure [95% confidence interval −4.15, +1.54] for MZ twins and +0.14 [−3.49, +3.76] for DZ twins; for all twins combined it was −0.21 [−2.13, +1.71]. Between twin pairs, a 1 kg difference in birthweight was associated with a difference of −2.68 mmHg in systolic blood pressure [−4.95, −0.42] for MZ twins and +0.28 [−2.35, +2.91] for DZ twins; for all twins combined −1.68 [−3.15, −0.22]. All these estimates included adjustment for age, year and conscription centre of examination, gestational age and height and weight at conscription. These results provide little support for the fetal origins hypothesis. The estimates of the within‐pair effect in MZ twins and their wide confidence intervals (including zero) cannot exclude the existence of common genetic mechanisms, but are also not inconsistent with an in utero programming effect. This study highlights some methodological problems with twin studies.
Maternal, paternal and environmental tobacco smoking and breast feeding
Authors: Leung Gabriel M. , Ho Lai‐Ming , Lam Tai‐Hing
Published: March 2003

The effects of environmental tobacco smoke (ETS) on breast‐feeding patterns are poorly understood, while those of parental smoking on breast‐feeding initiation vs. duration have not been clearly delineated. We conducted a prospective, population‐based birth cohort study to examine the independent effects of maternal, paternal and ETS on breast‐feeding initiation and duration. A total of 6747 Hong Kong Chinese infants were recruited and followed up in 1997–8. We obtained detailed household smoking history and recorded breast‐feeding patterns in three follow‐up interviews over 9 months. We found that both maternal and paternal smoking were associated with not initiating breast feeding (odds ratio [OR] for ever maternal smoking = 2.51, 95% confidence interval [CI] = 1.63, 3.86; OR for ever paternal smoking = 1.22, 95% CI = 1.08, 1.39). Exposure to ETS in utero and post partum were also related to not starting breast feeding (ORETS in utero = 1.10, 95% CI = 0.99,1.24; ORETS post partum = 1.21, 95% CI = 1.08, 1.36). These effects, however, did not persist for breast‐feeding duration of ≤ 4 months. Cox proportional hazards modelling confirmed the lack of association between any form of smoking and breast‐feeding duration. Our findings suggest that smoking of any kind, during or after pregnancy, is a strong risk indicator for not initiating breast feeding. Smoking as a risk indicator for underlying socio‐economic, demographic and psychosocial factors is probably responsible for most of the observed adverse effects, although we cannot rule out direct contributions from pathophysiological mechanisms. Public health strategies directed at these underlying factors should be vigorously pursued to reduce the adverse effects of tobacco on breast feeding and infant health in general.
Weight and weight gain at 4 months (The Netherlands 1998): influences of nutritional practices, socio‐economic and ethnic factors
Authors: Bulk‐Bunschoten Anneke M. W. , Bodegom Sylvia van , Reerink J. Dorothea , Jong Pieternel C. M. Pasker‐de , Groot Cornelis J. de
Published: March 2003

We describe the determinants of weight gain in the first 4 months of life in a cohort of 3256 infants. The study was designed as a survey with follow‐up. In the period 1 April to 1 July 1998, all infants, usually 4 weeks old but not older than 4 months, brought to a well‐baby clinic for the first time were included. Nutritional practices, demographic data on mother and child, birthweight and a second weight measured between days 118 and 147 were recorded. Simple and multiple linear regression analyses were performed. The average weight gain over 4 months was 27.7 g/day for boys and 24.5 g/day for girls. Weight gain was lower with high parity and if the mother was a native Dutch speaker. Nutritional practices affected weight gain only slightly: exclusive breast feeding for 4 months lowered the weight gain by 0.06 g/day. However, because of their higher birthweight, breast‐fed infants weighed a little more than formula‐fed infants at 4 months. In addition, we compared the median weight at the age of 4 months with the median weight at the same age in previous Dutch growth studies. The median weight, adjusted to day 133, was higher in 1998 than in 1965, 1980 and 1997 (boys 7.15 vs. 6.85, 6.77 and 6.95 kg; girls 6.59 vs. 6.49, 6.39 and 6.45 kg respectively).
Maternal factors associated with the duration of breast feeding in Jeddah, Saudi Arabia
Authors: Shawky Sherine , Abalkhail Bahaa A.
Published: March 2003

Recently, there has been increasing concern about the decline in breast‐feeding pattern in developing countries. The objectives of this study were to document the recent breast‐feeding trends in Jeddah during the first year of an infant's life and identify the probable maternal risk factors implicated in breast‐feeding cessation. Data were collected from six randomly selected primary health care centres in Jeddah City. All married women with an infant ≤ 12 completed months of age were interviewed, and information on socio‐demographic characteristics, breast feeding and contraceptive use were collected. Cox proportional hazard regression model was used to calculate the adjusted odds ratios for the various maternal risk factors related to breast‐feeding cessation.

A total of 400 women were enrolled in the study. Their mean age at delivery was 28.0 years (SD = 4.1 years). Approximately 40.0% had never attended school, 43.0% had at least five children and 13.8% were smokers. Deliveries by caesarean section were reported by 13.0% of women and contraceptive use by 44.7%, among whom oral contraceptives were the commonest method. Around 94.0% of women ever initially breast fed their infants, and this proportion dropped to 40.0% by the infant's 12th month. Women who delivered by caesarean section (OR = 1.9 [95% CI 1.3, 2.8]P = 0.001) and those who used oral contraceptives (OR = 1.5 [95% CI 1.1, 2.2]P = 0.031) were at higher risk of stopping breast feeding and lower probability of maintaining breast feeding to the 12th month post partum than those who delivered vaginally and did not use oral contraceptives.

Breast‐feeding practice seems to decline rapidly during the first year of the infant's life. Health care professionals should promote breast‐feeding practice as early as the antenatal period. They should also take into consideration the impact of caesarean section deliveries and early oral contraceptive use to avoid their negative impact on breast‐feeding practice.
Immune responses to Plasmodium falciparum antigens during a malaria vaccine trial in Tanzanian children
Authors: ALONSO  , LOPEZ  , BORDMANN  , SMITH  , APONTE  , WEISS  , URASSA  , ARMSTRONG‐SCHELLENBERG  , KITUA  , MASANJA  , THOMAS  , OETTLI  , HURT  , HAYES  , KILAMA  , TANNER
Published: March 2003

Among Tanzanian children living in an area of intense and perennial malaria transmission, prevalence of naturally acquired IgG antibodies that recognize SPf66, NANP, p190 and a 19 kDa fragment of the merozoite surface protein‐1 (MSP‐1) is high and increases with age. This possibly reflects the high level of natural exposure of the children to P. falciparum. The prevalences of IgG antibodies that recognize the three putative merozoite derived sequences contained in the malaria vaccine SPf66 (83.1, 55.1 and 35.1) is low but also show some age dependence. Three doses of the SPf66 vaccine induce a strong IgG antibody response against both the SPf66 construct, NANP and the three individual peptides. Vaccination with SPf66 did not result in an increase of anti19 kDa fragment antibodies. This reflects the specificity of the humoral immune response induced by the SPf66 construct. Among vaccinated children, antibody titres against SPf66 decreased over time following the third dose. However, 18 months after the third dose, SPf66 recipients still had significantly higher IgG titres and stimulation indices of peripheral blood mononuclear cells (PBMC) than placebo recipients. Within the vaccine group, there is a trend for increasing anti‐SPf66 IgG titre to be associated with decreasing risk of clinical malaria but this was not statistically significant. Results also show the difficulties of establishing whether antibody responses are related to protection in field trials in endemic areas.
In vivo treatment with recombinant IL‐12 protects C57BL/6J mice against secondary alveolar echinococcosis
Authors: EMERY ISABELLE , LECLERC CLAUDE , SENGPHOMMACHANH KAPPRASEUTH , VUITTON DOMINIQUE ANGÈLE , LIANCE MARTINE
Published: March 2003

Using an experimental model of hepatic Echinococcus multilocularis infection in C57BL/6J mice, intraperitoneal administration of 0.8 μg of recombinant IL‐12 to mice with an established infection was shown to reduce the parasite burden as soon as two weeks after the end of treatment. At that time, in vitro Echinococcus multilocularis‐induced spleen T cell proliferative responses as well as IFN‐γ and IL‐5 production were higher in IL‐12 treated mice than in untreated mice. Administration of 0.8 μg of IL‐12 at the time of infection was shown to be without effect on the parasite establishment. However, this treatment greatly inhibited the subsequent metacestode development. Indeed, ten weeks after infection, it induced a complete healing in 37.5% of mice. At that time, the development of metastases was inhibited in 68.75% of IL‐12‐treated mice. This reduction of parasite burden was mainly associated with a strong proliferation of spleen cells to E. multilocularis antigen and with a high IFN‐γ production. Altogether, our results show that IL‐12 is of crucial importance in inhibiting the larval growth after the metacestode establishment in the liver and suggest that this cytokine could be of potential value in the treatment of human alveolar echinococcosis.
Microbicidal activity of eosinophils is associated with activation of the arginine‐NO pathway
Authors: .OLIVEIRA  , FONSECA  , ROMÃO  , FIGUEIREDO  , FERREIRA  , CUNHA
Published: March 2003

In order to investigate the ability of rat peritoneal eosinophils to produce nitric oxide (NO) induced by cytokines in vitro, these cells were activated with several cytokines (IL‐5, IL‐8, Rantes, TNF‐α, IFN‐γ) in association or not with LPS. Under these conditions, we were able to detect nitrite in the incubation medium when the eosinophils were stimulated with IFN‐γ or IL‐8 in the presence of LPS. LPS alone also induced nitrite production. Significant levels of nitrite in the medium were already present after 12 h of stimulation and increased steadily within the next 48 h. Regarding NO synthase, its highest activity was achieved at 12 h after IFN‐γ/LPS stimulation. After this peak, the enzymatic activity reduced gradually to control levels 48 h after the stimulation. The simultaneous addition of the NO synthase inhibitor L‐NIO (100 μM) to the eosinophil suspension blocked nitrite production and NO synthase activity. On the other hand, neither IL‐5, Rantes nor TNF‐α were able to induce the release of nitrite in the presence or absence of LPS. To evaluate the microbicidal effect of these cells against the Leishmania parasite, eosinophils were infected with Leishmania major. It was observed that these cells were able to produce nitrite and to kill the parasite after activation with LPS/IFN‐γ. Moreover, L‐NIO blocked this leishmanicidal activity and the nitrite production. Our results suggest that activated eosinophils release NO which is involved in their microbicidal activity against Leishmania major.
IgE antibody during infection with the ovine abomasal nematode, Teladorsagia circumcincta: primary and secondary responses in serum and gastric lymph of sheep
Authors: Huntley J.F. , Schallig H.D.F.H. , Kooyman F.N.J. , Mackellar A. , Jackson F. , Smith W.D.
Published: March 2003

A monoclonal antibody to ovine IgE was employed in an ELISA to investigate the IgE antibody responses in serum and gastric lymph to a primary infection of Teladorsagia circumcincta, and following challenge in previously infected sheep. During a primary response, IgE antibody to antigens derived from the infective third stage (L3) and adult (L5) worms were negligable, with low levels of IgE antibody detected in serum and lymph. In contrast, there was a pronounced IgE antibody response in 2/4 sheep to L3 antigens during 2–8 days after challenge of previously infected animals but low levels of IgE antibody to L5 antigens. This response was confirmed in a second but similar experiment, where relatively high levels of IgE antibody was detected to antigens from L3. Antibody levels were higher in lymph than in serum from the same animals, and Western blots of L3 antigen following SDS‐PAGE under reducing conditions revealed several bands of MW26–96KD which reacted with the IgE antibody from gastric lymph. Immunohistochemical staining indicated that these IgE antibodies may be reacting with allergens associated with the surface cuticle of the worms.
The relationship between circulating and intestinal Heligmosomoides polygyrus‐specific IgG1 and IgA and resistance to primary infection
Authors: Ben‐Smith  , Wahid  , Lammas  , Behnke
Published: March 2003

Specific serum and intestinal immunoglobulin (Ig)G1 and IgA responses to Heligmosomoides polygyrus were measured in a panel of seven inbred mouse strains which exhibit ‘rapid’ (< 6 weeks (SWR × SJL)F1), ‘fast’ (< 8 weeks, SJL and SWR), ‘intermediate’ (10–20 weeks, NIH and BALB/c) or ‘slow’ (> 25 weeks, C57BL/10 and CBA) resolution of primary infections. Mice with ‘rapid’, ‘fast’ or ‘intermediate’ response phenotypes produced greater serum and intestinal antibody responses than those with ‘slow’ phenotypes. The F1 hybrids ((SWR × SJL)F1) of two ‘fast’ responder strains showed the earliest antibody response with maximum titres evident within 6 weeks of infection. There was a negative correlation between the serum IgG1 responses and worm burdens in individual mice within a number of mouse strains, and also between serum IgG1 and IgA responses and worm burdens in the ‘rapid’ ((SWR × SJL)F1) responder strain. The presence of IgG1 in the gut was found to be due to local secretion rather than plasma leakage. Using Western immunoblotting, serum IgG1 from ‘rapid’ and ‘fast’ responder but not ‘slow’ responder mice was found to react with low molecular weight antigens (16–18 kDa) in adult worm excretory/secretory products.
In‐vivo treatment with benznidazole enhances phagocytosis, parasite destruction and cytokine release by macrophages during infection with a drug‐susceptible but not with a derived drug‐resistant Trypanosoma cruzi population
Authors: Murta  , Ropert  , Alves  , Gazzinelli  , Romanha
Published: March 2003

To study the effect of chemotherapy on parasite–macrophage interaction we used the wild‐type Y strain (drug‐susceptible) of Trypanosoma cruzi and a drug‐resistant parasite population derived from the same strain. Trypomastigotes isolated from untreated infected mice, as well as, 3 h after treatment with BZ were incubated with inflammatory macrophages and used to study phagocytosis, parasite destruction, cytokine release and reactive nitrogen intermediates (RNI) synthesis. Phagocytosis and destruction of the drug‐susceptible parasites were significantly enhanced by drug treatment. These enhancements were accompanied by an increase in cytokines [interleukin (IL)‐12 and tumour necrosis factor (TNF)α] and RNI release by murine inflammatory macrophages primed with IFN‐γ. In contrast, BZ treatment of mice infected with drug‐resistant T. cruzi population showed no effect whatsoever. The synthesis of IFN‐γ and RNI by splenocytes of mice infected with either susceptible and drug‐resistant parasite populations, before and after treatment with BZ were also studied. Only the splenocytes from mice infected with the drug‐susceptible parasites treated with BZ produced high levels of IFN‐γ and RNI. Our findings indicate that BZ acts on the drug‐susceptible T. cruzi parasites by enhancing the phagocytosis and the production of cytokines and RNI, thus, favouring the destruction of the intracellular parasites by the cellular compartment of the immune system.
In vitro induction of nitric oxide synthase in astrocytes and microglia by Trypanosoma brucei brucei
Authors: Girard Murielle , Ayed Zoulikha , Preux Pierre‐Marie , Bouteille Bernard , Preud'homme Jean‐Louis , Dumas Michel , Jauberteau Marie‐Odile
Published: March 2003

In stage II human african trypanosomiasis (HAT), which is characterized by central nervous system (CNS) involvement, neurones and oligodendrocytes might be targets of dysimmune processes. Nitric oxide (NO) production by peripheral macrophages is documented in HAT. We studied the production of NO by murine astrocytes and microglia cocultured with Trypanosoma brucei(T. b.) brucei AnTat 1.9. Purified astrocytes or microglia from mouse brains were cocultured with T. b. brucei, and in some instances with interferon (IFN)‐γ, which is known to be released during the disease and also to be a growth factor for trypanosomes. Inducible NO synthase (iNOS) expression was studied by indirect immunofluorescence and reverse transcriptase‐polymerase chain reaction. NO production was determined by measuring nitrite generation in culture. Detection of iNOS in astrocytes and microglia in the presence of T. b. brucei, was closely associated with nitrite production and was strongly enhanced by the addition of IFN‐γ to the culture medium. The stimulation of iNOS activity required parasite–cell contact and likely occurred at the transcriptional level. This study demonstrates the induction of iNOS in CNS‐related macrophage cells in the presence of trypanosomes and its potentiation by IFN‐γ.
Vaccination against coccidiosis: host strain‐dependent evocation of protective and suppressive subsets of murine lymphocytes
Authors: Rose M.elaine , Hesketh Patricia , Grencis Richard K. , Bancroft Allison J.
Published: March 2003

BALB/c mice are normally more resistant than C57BL/6 (B6) mice to infection with Eimeria vermiformis, but these phenotypes can be reversed by oral or parenteral vaccination with a crude antigen prepared from the parasite. Treatment of mice with antibodies specific for CD4+ or CD8+ T cells showed that the increased susceptibility of vaccinated BALB/c mice was associated with the presence of CD4+ T cells. This finding was confirmed when the recipients of CD4+ T cells selected from the mesenteric lymph nodes (MLN) of vaccinated BALB/c mice produced more oocysts after challenge than the recipients of a similar population of cells from sham‐vaccinated mice. The residual population of cells (presumably enriched for CD8+ T cells, ‘CD8+’), on the other hand, conferred some protection and, in B6 mice, the findings were reversed. Thus, vaccination induced suppressive or protective CD4+ cells and protective or suppressive ‘CD8+’ cells, depending upon the normal resistance/susceptibility phenotype of the host. Examinations of the isotypes (IgG1, IgG2a) of specific serum antibodies, and of the levels of IFN‐γ and IL‐5 cytokines released by MLN cells stimulated ex vivo, did not allow any further characterization of the mechanisms involved.
DNA immunization with Onchocerca volvulus genes, Ov‐tmy‐1 and OvB20: serological and parasitological outcomes following intramuscular or GeneGun delivery in a mouse model of Onchocerciasis
Authors: Harrison  , Bianco
Published: March 2003

The objective of this study was to evaluate whether the distinct immune responses invoked by epidermal and intramuscular DNA immunization could be harnessed to improve upon the levels of protection to Onchocerca volvulus infective larvae achieved previously by recombinant protein immunization. Intramuscular (IM) and epidermal (GeneGun) routes of DNA immunization generally drive T helper1 and Th2 dominant responses, respectively. This dichotomy was used in an attempt to further define the nature of host‐protective immunity in a mouse model of onchocerciasis. Mice were immunized with DNA plasmids expressing the O. volvulus antigens, Ov‐TMY‐1 (tropomyosin) and OvB20 (a nematode specific gene product). While, IM and GeneGun immunization of mice with Ov‐tmy‐1 induced expected Th1/Th2‐associated IgG isotype profiles, mice responded to OvB20 immunization with a Th2 dominant response, irrespective of the delivery route. Despite inducing potent serological responses, neither DNA construct promoted statistically significant levels of protection to L3 challenge infection. We conclude that DNA immunization has good potential for induction of humoral responses against nematode infections and that serological responses alone do not predict vaccination efficacy under the conditions used here to measure host resistance to parasite challenge.
Apoptosis modulation in mononuclear cells recovered from individuals exposed to Plasmodium falciparum infection
Authors: Balde Aissatou Toure , Aribot Georgette , Tall Adama , Spiegel Andre , Roussilhon Christian
Published: March 2003

In endemic areas, asymptomatic infection by the malaria parasite Plasmodium falciparum was found associated with elevated percentages of human host's mononuclear cell spontaneous in‐vitro apoptosis. In Dielmo, a village where malaria is holoendemic, apoptosis was age‐and parasite‐dependent. In‐vitro exposure of peripheral blood mononuclear cells (PBMC) to the parasite extract induced a marked increase in the mononuclear cell membrane expression of functional CD95 antigen: a 3‐h exposure of the mononuclear cells to anti‐CD95 antibodies led to a detectable increase in the mean percentage of apoptotic nuclei found in the cultures carried out in the presence of P. falciparum extracts compared to control cultures. IL‐2, IL‐4, IL‐6 and IL‐10 promoted the viability of PBMC in cultures while IL‐1α or IFN‐γ had no obvious impact and TNFα gave conflicting results. IL‐2 was the most efficient cytokine at rescuing PBMC from cell death and this effect was associated with a strong increase in T cell activation. In contrast, IL‐4 and IL‐10 had no such effect on T cell activation, hence they acted as survival factors and not through their mitogenic activity. Taken together, these different observations suggested that the levels of in‐vitro apoptosis observed were not only associated with parasite infection, but also potentially modulated by the human host through different pathways.
Trypanosoma brucei brucei infection impairs MHC class II antigen presentation capacity of macrophages
Authors: Namangala  , Brys  , Magez  , De Baetselier  , Beschin
Published: March 2003

During African trypanosomiasis, macrophages play a central role in T cell hyporesponsiveness to parasite‐related and unrelated antigens. In this study, the ability of macrophages from Trypanosoma b. brucei‐infected mice to present exogenous antigens to a major histocompatibility complex (MHC) class II‐restricted CD4+ T cell hybridoma was analysed. We demonstrate that the antigen presentation capacity of macrophages from infected mice is markedly reduced as a result of a lower expression of [MHC class II‐peptide] complexes on their plasma membrane. This defect did not result from a decreased antigen uptake/catabolism, a reduced MHC class II and intercellular adhesion molecule 1 expression on the surface of macrophages, a decreased affinity of MHC class II molecules for antigenic peptides, a competition between exogenous and parasite antigens, or the generation of inhibitory peptides. Our data indicate that the step resulting in coexpression of processed antigens and MHC class II molecules is affected in T. b. brucei‐infected mice. Additionally, macrophages from infected mice secreted IL‐10 that in turn contributes to the impairment of T cell activation.
Humoral responses to a secretory Onchocerca volvulus protein: differences in the pattern of antibody isotypes to recombinant Ov20/OvS1 in generalized and hyperreactive onchocerciasis
Authors: Mpagi Joseph L. , Büttner Dietrich W. , Tischendorf Frank W. , Erttmann Klaus D. , Brattig Norbert W.
Published: March 2003

The Onchocerca volvulus secretory protein Ov20/OvS1 represents a dominant antigen expressed in the infective larvae, microfilariae and adult stages of the parasite. The humoral responses to this protein have not yet been analysed in the polar clinical and immunological forms of onchocerciasis. Analysis by ELISA of class and subclass antibodies to Ov20/OvS1 in persons with the generalized or the hyperreactive form of onchocerciasis revealed similar strong responses of IgG1, IgG4 and IgM antibody levels in both forms of onchocerciasis and significant differences were observed in the IgE and IgA antibody classes. Computation of the ratios of antibodies showed that persons with the generalized form exhibited significantly higher ratios of IgG4 to IgG1, IgG4 to IgE, and IgM to IgE than patients with the hyperreactive form. To investigate the isotype recognition of antigenic sites on Ov20/OvS1 protein, three recombinantly expressed fragments (F1–3) of Ov20/OvS1 were probed using sera which strongly reacted with intact recombinant Ov20/OvS1. Epitope(s) on F1 comprising amino acid residues 1–63 were significantly recognized by IgG1 and IgE, while IgM recognized epitopes on all three fragments. The strongest reaction of IgM occurred with epitope(s) formed by residues 108–171 (F3). In contrast, IgG4 type antibodies were not reactive with either of the three OvS1 fragments, but they reacted with intact Ov20/OvS1 protein. Generalized onchocerciasis, unable to eliminate microfilariae, and hyperreactive onchocerciasis, with a high potency to eliminate or to reduce parasite loads, can be distinguished by a distinct pattern of isotype responses to Ov20/OvS1.
Echinococcus granulosus: assays for hydatid immunoregulatory factors using established lymphoid cell lines
Authors: Macintyre Andrew R. , Dixon John B. , Bleakley Jill S. , Green Jack R.
Published: March 2003

Mitosis, mitochondrial metabolic rate and proliferation were measured in established lymphoid cell lines exposed to chromatographic fractions of equine Echinococcus granulosus hydatid fluid. In several cell lines, one or more of the three parameters were modified by the exposure. As an assay for potential immunoregulatory activity, the method was simple and repeatable. The following novel observations were made: (1) Mitotic reaction was found among lines of T‐cell, B‐cell and macrophage origin; (2) mitosis was accompanied by proliferation in the B‐cell lines, B9 and A20, and in the macrophage lines, HL‐60 and P388d. With mitotically responsive T‐cells, proliferation was slight in CTLL‐2 and absent in D10, implying cell‐cycle modification; (3) mitotic responsiveness tended to occur in cell lines with mature characteristics; (4) among cytokine‐dependent cell lines, hydatid fluid FPLC fraction 1 mimicked IL‐1 and several fractions mimicked IL‐2 and IL‐6 in the maintenance of mitosis; and (5) there was significant statistical interaction between the influences of mammalian cytokines and hydatid fluid fractions, implying that the propensity of antigenically unprimed lymphoid cells to be regulated by E. granulosus is conditioned by cytokine activity.
The roles of the glycosylphosphatidylinositol anchor on the production and immunogenicity of recombinant ookinete surface antigen Pbs21 of Plasmodium berghei when prepared in a baculovirus expression system
Authors: Martínez Andrés Páez , Margos Gabriele , Barker Guy , Sinden Robert E.
Published: March 2003

Malarial ookinetes express an immunodominant surface protein (P28) that is a priority candidate for the development of transmission‐blocking vaccines. The full length P28 gene from Plasmodium berghei [Pbs21(1–213)] and a deletion construct [Pbs21(1–188)] encoding a protein that lacks the 25 C‐terminal amino acids, including the glycosylphosphatidylinositol (GPI) anchor signal, were expressed in insect cells using baculovirus vectors. Pbs21(1–213) protein is strongly hydrophobic, found in the cytoplasm and on the surface of Spodoptera Sf21 cells, and in the culture medium. Pbs21(1–188) protein was largely found in the aqueous phase of the medium and in the cytoplasm of Sf21 cells, but was not detected on the cell surface. The presence of 25 C‐terminal amino acids is therefore critical to the attachment of recombinant Pbs21 to the parasite plasma membrane. Mice were immunized subcutaneously or intramuscularly with affinity purified recombinant Pbs21(1–213), Pbs21(1–188) or native Pbs21 proteins. Following two immunizations, native Pbs21 induces higher titres when administered by either route, than the recombinant protein bearing an insect GPI anchor, which in turn is markedly more immunogenic than the recombinant polypeptide lacking a GPI anchor. When specific anti Pbs21 antibody titres exceeded 1 mg/ml all three antigens were capable of inducing transmission blockade ≥ 90%, below 1 mg/ml blockade did not correlate with antibody concentration.