bluuebunny/crossref_metadata_2025 huggingface dataset:
Maternal pre‐eclampsia/eclampsia and the risk of sudden infant death syndrome in offspring
Authors: Li De‐Kun , Wi Soora
Published: March 2003

To determine whether maternal exposure to pre‐eclampsia/eclampsia during pregnancy increases the risk of sudden infant death syndrome (SIDS) in offspring, we conducted a population‐based case–control study using the California linked birth and death certificate data. All infants who died of SIDS (ICD‐9 code 798.0) during 1989–91 were identified as cases. More than 96% of the identified SIDS cases were diagnosed through autopsy. Ten controls who did not die from SIDS were randomly selected for each case from the birth certificate matched to the case on the year of birth. Among 2029 cases and 21 037 controls included in the final analysis, mothers of 49 cases (2.4%) and 406 controls (1.9%) had a diagnosis of either pre‐eclampsia or eclampsia noted on the birth certificate. After adjustment for maternal age, prenatal smoking, race/ethnicity, parity, maternal education, gestational age at the initial visit for prenatal care, infant year of birth and infant sex, maternal pre‐eclampsia/eclampsia during pregnancy was associated with a 50% increased risk of SIDS in the offspring (odds ratio = 1.5, 95% confidence interval 1.1, 2.0). Potential under‐reporting of pre‐eclampsia/eclampsia on the birth certificates was likely to be non‐differential and is unlikely to explain the finding. Fetal hypoxia resulting from pre‐eclampsia/eclampsia or immunological aetiology affecting the risk of both pre‐eclampsia/eclampsia and SIDS may explain the finding.
The changing prevalence of neural tube defects: a population‐based study in the North of England, 1984–96
Authors: Rankin Judith , Glinianaia Svetlana , Brown Robert , Renwick Marjorie
Published: March 2003

Using data from the Northern Congenital Abnormality Survey, we describe trends in the prevalence of neural tube defects (NTDs), maternal age‐specific prevalence, outcome of pregnancy and the sensitivity of antenatal diagnosis of NTD‐affected pregnancies in the Northern Region during 1984–96. This population‐based sample consisted of 934 NTDs: there were 403 (43.1%) with anencephaly, 472 (50.5%) with spina bifida and 59 (6.3%) with encephalocele. The total prevalence at birth was 17.9 per 10 000 births and terminations (95% confidence interval [CI] = 16.7, 19.0) with a significant reduction over time (χ2for trend = 7.2;P = 0.007). The overall birth prevalence was 5.6 per 10 000 births [95% CI = 5.0, 6.3]; there was also a significant reduction in birth prevalence with time (χ2for trend = 68.3;P< 0.0001). Maternal age‐specific prevalence rates decreased with increasing age. The proportion of NTD pregnancies terminated increased from 60.3% (325 cases) during 1984–90 to 78.6% (293 cases) during 1991–96, whereas the proportion of livebirths declined from 31.7% (171 cases) to 15.0% (56 cases) (P< 0.001). The sensitivity of antenatal diagnosis was consistently high for anencephaly (98%) and increased significantly for spina bifida from 60% during 1984–90 to 85% during 1991–96 (P< 0.05). Ascertainment of all cases of NTD in the Northern Region revealed a twofold reduction in birth prevalence between 1984–90 and 1991–96. This has resulted from improvements in the accuracy of antenatal detection of NTD‐affected pregnancies with an increase in terminations of pregnancy.
Review of risk factors for Sudden Infant Death Syndrome
Authors: Sullivan  , Barlow
Published: March 2003

Abstract here
Maternal age, anthropometrics and pregnancy oestriol
Authors: Kaijser Magnus , Jacobsen Geir , Granath Fredrik , Cnattingius Sven , Ekbom Anders
Published: March 2003

It has been hypothesised that oestrogen exposure in utero influences the risk for breast cancer in adult life. Although several studies report associations between breast cancer and maternal factors associated with birthweight of the offspring – a marker for antenatal oestriol exposure – little is known about the relations between maternal oestrogen levels and these factors per se. We therefore analysed the association between oestriol levels in 188 women in the 17th, 25th, 33rd and 37th weeks of pregnancy, and maternal age, prepregnancy weight, height and pregnancy weight gain.

Both maternal prepregnancy body mass index and maternal height were, after controlling for infant birthweight, independently and inversely associated with oestriol levels (P = 0.0021 and P = 0.0006 respectively). We found no association between maternal age or pregnancy weight gain and pregnancy oestriol levels. These findings suggest that the previously reported associations between maternal age and maternal pregnancy weight gain and the offspring’s risk of breast cancer are due to factors other than antenatal exposure to oestriol.
West Coast study of childhood brain tumours and maternal use of hair‐colouring products
Authors: Holly Elizabeth A , Bracci Paige M , Hong Mi‐Kyung , Mueller Beth A , Preston‐Martin Susan
Published: March 2003

The immature nervous system of the fetus is characterised by rapid cell growth and division and is particularly vulnerable to carcinogens and mutagens. Several epidemiological studies have reported an increased risk for childhood brain tumours (CBT) associated with exposure to N‐nitroso compounds (NOC). Hair‐colouring products (hair ‘dyes’) that contain NOC‐related aromatic amines have shown mutagenicity in vitro and carcinogenic properties in vivo. The potential public health impact of the relationship between hair dye use and carcinogenesis has prompted epidemiological research, given that a large proportion of American women have used hair dyes.

A large population‐based case–control study was conducted on the west coast of the USA to investigate risk factors for CBT including exposure to NOC. Eligible CBT patients (<20 years of age and diagnosed between 1984 and 1991) were identified from cancer registries in Los Angeles County, the San Francisco Bay Area in California and the Seattle area in Washington state. A total of 540 biological mothers of these children were interviewed, and 801 control subjects who were frequency matched to the CBT patients on birth year and sex were obtained using random digit dialling. Mothers were asked details about personal use of hair dyes during the index pregnancy including frequency of use, trimester of use and type of dye used.

Results from age‐ and sex‐adjusted unconditional logistic regression analyses showed no association between risk for CBT and use of hair dyes 1 month before and/or during pregnancy nor during specific trimesters. A nearly twofold increased risk for CBT was associated with single‐interval use during the 1 month before pregnancy, but the confidence interval (CI) was imprecise and the estimate was not different from unity (OR = 1.9, 95% CI [0.5, 7.0]). Exclusive use of permanent dye, temporary dye or hair darkeners was not associated with risk for CBT. A twofold increased risk (OR = 2.0, 95% CI [0.83, 4.7]) was observed with exclusive use of semi‐permanent dye during the month before or during pregnancy. Exclusive use of semi‐permanent dye during the month before pregnancy and/or first trimester also was associated with an elevated risk for CBT, again not different from unity and with an imprecise CI (OR = 2.5, 95% CI = [0.58, 10.3]). There was no evidence of an association between risk for CBT by histological subtypes and use of hair dyes during the index pregnancy or the month before conception. Together with results from previous studies, these results provide no consistent evidence of an association between risk for CBT and use of hair dyes during pregnancy.
The autopsy: experience of a regional neonatal intensive care unit
Authors: Okah Felix A.
Published: March 2003

Autopsy rates have declined steadily throughout the 1970s and 1980s. This trend, if not reversed, could negatively affect information provided to families as well as the training of physicians. In the 1980s, low autopsy rates among neonatal deaths, 50–72%, were attributed to limited parental understanding and to physicians’ attitudes. In the early 1990s, alternatives to the routine autopsy, such as limited endoscopic/needle autopsies, were widely popularised, and the physician's education about autopsy vigorously addressed. The effects of these efforts on autopsy rates in the latter part of the 1990s have not been well studied.

The study population consisted of 643 infants who died at an Ohio, USA, neonatal intensive care unit (NICU) between 1 January 1986 and 31 December 1998. Neonatologists obtained consent for autopsy. Information obtained from the computer database included birth hospital, gestational age, age at death, birth and death weight, race, sex, death year and maternal age, religion, gravidity and parity. The overall autopsy rate during the 13‐year study period was 54% [95% CI 44.1%, 63.1%]. There was a trend towards progressive decrease in autopsy rates, 59% in 1986–89, 52% in 1990–94 and 47% in 1995–98 (P = 0.078). Autopsy was associated with increasing gestational age (P < 0.001) and decreasing parity [OR = 0.53 for >2 compared with ≤2, 95% CI 0.36, 0.99], but not with other variables. Autopsy rates remain suboptimum and may be declining despite efforts at educating the medical and general community about its benefits. Among infants who die in the NICU, autopsy is more likely the more mature the infant at birth and the fewer children the mother has. Physicians need to seek autopsy more conscientiously, with consideration for the emotional well‐being of the family, and for its potential diagnostic and research value to science.
Non‐response bias as a likely cause of the association between young maternal age at the time of delivery and the risk of cancer in the offspring
Authors: Schüz Joachim
Published: March 2003

Some epidemiological studies have shown an association between young maternal age at the time of delivery and risk of cancer in the offspring. In a recent German case–control study, there was a twofold increase in the leukaemia risk for children whose mothers were aged < 20 years at the time of delivery. As the prevalence of younger mothers among control families was particularly low, data on maternal age distributions for the general population of Germany were obtained in order to examine the representativeness of the control sample. Despite the excellent sampling frame based on data from complete and up‐to‐date population registries and a satisfactory response rate among controls (≈71%), there seemed to be a material deficit of young mothers in the control sample. The prevalence of young mothers in the control group was 1.4%[95% CI 0.8%, 2.0%] compared with 2.9% in the general population and 3.3%[1.8%, 4.8%] among leukaemia cases. The most likely cause of this deficit was non‐participation. Non‐participation bias is hard to identify if no information is available on non‐responders and if it results from only small subgroups among the total control sample. Maternal age and childhood leukaemia are an example where differential non‐participation creates a spurious moderate association for a relatively rare exposure situation. But nowadays, many epidemiological studies target the detection of small to moderate risk increases for rare exposures. Therefore, the choice of a representative control group as well as the achievement of an excellent response rate are of prime importance.
Down's syndrome: occurrence and outcome in the north of England, 1985–99
Authors: Bell Ruth , Rankin Judith , Donaldson Liam J.
Published: March 2003

This study reports changes in the prevalence and outcome of Down's syndrome pregnancies within a 15‐year period in a defined geographical population in the north of England. Cases of Down's syndrome in births and terminations of pregnancy occurring between 1985 and 1999, were identified from the Northern Congenital Abnormality Survey. The total prevalence for the 15 years was 15.2 per 10 000 births and terminations of pregnancy [95% CI 14.2, 16.2]. Total prevalence showed an upward trend over time, due largely to increasing maternal age. Sixty‐seven per cent of cases resulted in live births, and the overall live birth prevalence was 10.3 per 10 000 live births [95% CI 9.4, 11.1]. The proportion of cases resulting in termination of pregnancy rose from 15% in 1985–89 to 38% in 1995–99; the rate of increase was greater in women aged < 35 years. Forty‐five per cent of live born infants had an additional anomaly recorded. Survival at 1 year was 78% for those with an additional anomaly recorded, and 96% for those without. There was a non‐significant trend towards improved survival in all infants with Down's syndrome, from 87% in 1985–94 to 92% in 1995–99. Despite increasing termination of Down's syndrome pregnancies resulting from the greater availability of antenatal screening and diagnosis, there has been no significant reduction in live birth prevalence. These infants have high rates of co‐existing structural anomalies and are at high risk of death in the first year of life. There is a continuing need to address the reasons for poor survival for Down's syndrome infants, and to plan for their complex health and social care needs. These findings are useful for parents deciding on prenatal screening, as well as for clinicians and health service managers.
The effect of nematode infection upon intestinal smooth muscle function
Authors: VALLANCE  , COLLINS
Published: March 2003

Nematode infections are useful in studying both host defence and inflammation induced changes in intestinal physiology, including increased contraction by intestinal muscle. Our initial studies of the heightened muscle function found during T. spiralis infection led to investigations of the role of immune and inflammatory cells and mediators in the immunodulation of intestinal muscle function. By infecting various immunodeficient mouse strains, as well as gene transfer to the intestine, T lymphocytes, and in particular the CD4+ve subset were found to be responsible for altering smooth muscle function. However, eosinophils as well as the cytokine interleukin‐4 may also be involved. Investigations also indicate a potential role for increased muscle function and propulsive activity in expelling nematode parasites. Mutant mice which suffer aberrant intestinal propulsion, or based upon an immunodeficiency, undergo reduced changes in muscle function during infection, undergo prolonged infections. While increased muscle function may be an adaptive host response, the changes in muscle function may persist long after the resolution of the infection. Thus understanding the mechanisms behind the immunomodulation of intestinal muscle function may also impact upon clinical gastroenterology, since motility disturbances in man often occur following enteric infections, or other inflammatory conditions of the bowel.
The Th1 to Th2 shift induced by Schistosoma mansoni does not exacerbate murine aids (MAIDS)
Authors: LACROIX CLAIRE , AKARID KHADIJA , CHAU FRANC¸OISE , SINET MARTINE , VEROLA OLIVIER , CARBON CLAUDE , DEROUIN FRANCIS
Published: March 2003

Schistosoma mansoni infection in mice is associated with a switch from a Th1 to a Th2‐type cytokine response. The role of Th1 and Th2 responses in immune dysregulations associated with AIDS and murine AIDS (MAIDS) is controversial, but a Th2 bias could be associated with disease progression, raising the hypothesis that helminth infections might accelerate the retroviral disease progression. Here, we used the murine model of AIDS to evaluate the course of the viral disease during co‐infection with S. mansoni. C57BL/6 mice were infected with S. mansoni cercariae 8 weeks before intravenous challenge with the LP‐BM5 retroviral complex. MAIDS did not progress faster in co‐infected mice, in terms of spleen and inguinal lymphadenopathy size, ecotropic virus titres in the spleen, or in vitro proliferative responses to mitogen. Th2 cytokine production was not enhanced in co‐infected animals, except for an isolated increase in IL‐4 production 21 weeks after LP‐BM5 infection. Co‐infected animals had significantly lower lymph node and spleen weights than mice infected with LP‐BM5 only. MAIDS did not influence the granulomatous response to S. mansoni in the liver of co‐infected mice. Finally, infection with S. mansoni neither enhanced Th2 cytokine production nor accelerated MAIDS progression in animals subsequently challenged with LP‐BM5.
Secretion of IL‐12 by murine macrophages activated by immunoglobulin receptor‐mediated internalization of the surface coat of Trichinella spiralis larvae
Authors: Modha  , Piedrafita  , Roberts  , Kusel  , Kennedy
Published: March 2003

Trichinella spiralis larvae incubated with a rabbit antiserum raised against the larval surface coat bound murine macrophages to the parasite surface. Cell binding was not observed without the antisurface coat serum, or with incubation of larvae in normal rabbit serum, or with antibodies to keyhole limpet haemocyanin which identify a cryptic T. spiralis larval antigen. Cell adherence to the larval surface was lost by treatment of the cells with the lysosomotropic drug primaquine, implicating a receptor‐mediated mechanism. Cells adhering to the parasite surface internalized parasite surface coat material, which was subsequently concentrated into endosomes. Culture supernatants from these cells contained enhanced levels of IL‐12. Thus, the initial Th1 response to T. spiralis infection may be explained by these data.
Fasciola hepatica infection downregulates Th1 responses in mice
Authors: O'neill Sandra M. , Brady Miriam T. , Callanan John J. , Mulcahy Grace , Joyce Patrick , Mills Kingston H.G. , Dalton John P.
Published: March 2003

Immune responses induced with helminth parasites have been extensively studied, but there is limited information on those to Fasciola hepatica, especially on the subtype of T cell induced with this parasite. We investigated the local and systemic T cell responses of different strains of mice following oral infection with doses of metacercariae from F. hepatica. Spleen cells from BALB/c and 129Sv/Ev mice given a low‐dose (5 metacercariae) infection exhibited a Th2 response, producing high levels of the cytokines IL‐4 and IL‐5, and low levels of IFN‐γ and IL‐2. In contrast, C57BL/6 mice showed a mixed Th1/Th2 response. A more marked polarization to a Th2 response was observed in BALB/c, 129Sv/Ev exposed to a high‐dose (15 metacercariae) infection and the C57BL/6 mice also exhibited a clear Th2 response. IL‐4 defective (IL‐4−/−) C57BL/6 mice infected with 5 metacercariae produced less IFN‐γ and more IL‐5 compared to their wild‐type C57BL/6 counterparts, suggesting that IL‐4 is important in establishing the Th2 type response in murine fasciolosis. However, the secretion of IFN‐γ and IL‐2 was completely suppressed in the high‐dose infection and this was also observed in IL‐4−/− mice. Thus, liver flukes may secrete molecules that downregulate Th1 responses. T cell responses in the mesenteric (MLN) and hepatic lymph nodes (HLN) were also examined since newly excysted juveniles infect through the intestinal wall of their host before migrating to the hepatic tissue. Cells from both MLN and HLN secreted higher levels of IL‐4 and IL‐5 compared to spleen cells. We also observed a difference in cytokine profiles secreted by the MLN and HLN, which may reflect responses to antigens liberated by newly excysted juveniles and hepatic stage parasites, respectively.
Evidence for genomic imprinting of the major QTL controlling susceptibility to trypanosomiasis in mice
Authors: Clapcott Steven J. , Teale Alan J. , Kemp Stephen J.
Published: March 2003

Inbred strains of laboratory mice exhibit marked differences in survival time following infection with Trypanosoma congolense, the principal cause of trypanosomiasis in African livestock. The difference in survival time between the relatively resistant C57BL/6 J and more susceptible BALB/c inbred strains has been attributed to three quantitative trait loci (QTLs), Tir1, Tir2 and Tir3. In order to determine whether there was a parent‐of‐origin effect on this trait, four backcross populations derived from the C57BL/6 J and BALB/c parental strains were bred and inoculated with T. congolense. The two populations with F1 fathers and BALB/c mothers had a significantly greater overall survival rate than the two populations with BALB/c fathers and F1 mothers. This pattern of inheritance suggested the involvement of imprinted genes. Genotyping with markers at the three QTLs controlling susceptibility revealed that the difference in survival time was consistent with genomic imprinting of the QTL of largest effect, Tir1.
Schistosomamansoni gene GP22 encodes the tegumental antigen Sm25: (1) antibodies to a predicted B‐cell epitope of Sm25 cross‐react with other candidate vaccine worm antigens; (2) characterization of a recombinant product containing tandem‐repeats of this peptide as a vaccine
Authors: Petzke Mary M. , Suri Parmjeet K. , Bungiro Richard , Goldberg Miriam , Taylor Sarah F. , Ranji Sumant , Taylor Harry , McCray Joseph W. , Knopf Paul M.
Published: March 2003

Monospecific antibodies against two putative epitopes of schistosome protein encoded by gene GP22 (182 codons, no introns) were used to probe worm extracts fractionated by lentil‐lectin affinity chromatography or by electrophoresis. Anti‐peptide‐α (codons 70–84) exclusively identifies the N‐glycanase‐sensitive, 25 kDa tegumental glycoprotein Sm25 in the lectin‐bound fraction of detergent‐solubilized adult worm extract S3. In contrast, antipeptide‐δ (codons 151–162) does not react with Sm25 but cross‐reacts with other schistosome proteins, including candidate vaccine antigens paramyosin (Sm97) and glutathione‐S‐transferases (Sm26, Sm28, Sj26). Recombinant protein r4 × 47, constructed to express multiple copies of codon sequence 117–163 (containing δ), reacts with anti‐δ and is uniquely recognized by protective Fischer twice‐infected (F‐2x) rat antiserum. Immunization with r4 × 47 induces antibodies with cross reactivities similar to anti‐δ, but which also recognize Sm25. Despite these cross‐reactivities with protective antigens, rodents vaccinated with r4 × 47 were not protected against cercarial infection. On the basis of these data, two hypotheses are proposed: (1) antigenic epitopes other than δ are present within the r4 × 47 sequence which induce antibodies reactive with Sm25 and/or (2) peptide‐δ assumes alternative antigenic conformations, dependent upon the context of neighbouring sequences, some of which mimic epitopes of proteins encoded by other schistosome genes. These mimotopes are not targets of protective antibodies.
Immunoglobulin E and mast cell responses are related to worm biomass but not expulsion of Hymenolepis diminuta during low dose infection in rats
Authors: Ishih Akira , Uchikawa Ryuichi
Published: March 2003

It is well known that the destrobilation and later expulsion are characteristics of multiple Hymenolepis diminuta infections in rats. This process is suggested to be mediated by a variety of host cellular responses. It has also been suggested that immunoglobulin (Ig) E may have a beneficial role for some cestodes including H. diminuta. We examined the intestinal mast cell and serum IgE responses to a 10‐H. diminuta infection in three different rat strains. Tapeworm infection induced no increased mast cell and IgE responses in F344 rats in which neither worm biomass nor worm burden decreased during 6 weeks of observation. The number of mast cells and amounts of serum rat mast cell protease (RMCP) II and IgE markedly increased from 3 weeks postinfection (p.i.) in BN rats. The worm biomass in BN rats was significantly lower than that in F344 rats, but worm burden was not different from that in F344 rats at 3 or 6 weeks p.i. In DA rats, the number of mast cells and levels of serum RMCP II and IgE increased at 6 weeks but not at 3 weeks p.i. Although numbers of mast cells and serum RMCP II and IgE levels were lower in DA rats than in BN rats, smaller and fewer worms were recovered in DA rats than in F344 and BN rats at from 3 and 6 weeks p.i. Worms were recovered from all of F344 and BN rats, while only 40% of DA rats harboured worms at 6 weeks p.i. These results suggested that the worm biomass was related to mast cell and IgE responses, but these responses were not required for worm expulsion during low dose H. diminuta infection in rats.
A previous infection withToxoplasma gondiidoes not protect against a challenge withNeospora caninumin pregnant sheep
Authors: Innes E.A. , Lundén A. , Esteban I. , Marks J. , Maley S. , Wright S. , Rae A. , Harkins D. , Vermeulen A. , McKendrick I.J. , Buxton D.
Published: March 2003

Sheep immunized with Toxoplasma gondii (Toxovax®) prior to pregnancy were tested for their ability to withstand a challenge at 90 days gestation with 107Neospora caninum (NC1) tachyzoites. The antibody responses in sheep following immunization with T. gondi were specific for T. gondii whereas peripheral blood mononuclear cells responded to both T. gondii and caninumantigen in vitro.This suggested that there was induction of crossreactive immune recognition in the sheep, at least at the cellular level. Following challenge of sheep at mid‐gestation with N caninum, no febrile responses were recorded in the group of sheep which had previously received Toxovax® while significant febrile responses were recorded in the group of sheep which received N  challenge alone. Antibody responses to N  developed in all sheep following challenge and antibody responses to T,gondii were boosted in the group of sheep which had previously been immunized with Toxovax®. No antibodies to were observed in the sheep which received the challenge alone. Peripheral blood mononuclear cells from both groups of sheep responded to T.gondii N.caninum antigen invitro and interferon gamma was present in the cell‐free supernatant from activated cells. However despite evidence of the induction of crossreactive immunity between T.gondii N.caninum this was not sufficient to prevent foetal death. The group of sheep which had received Toxovax® prior to pregnancy and the group of sheep which only received the N.caninum challenge experienced 100% foetal death compared with 0% in the unchallenged control group. Vaccination prior to pregnancy with Toxovax® did protect against foetal death following oral challenge at 90 days with 2000  oocysts which caused 100% foetal death in a control challenge group.
Immune‐mediated damage is not essential for the expulsion of Nippostrongylus brasiliensis adult worms from the small intestine of mice
Authors: Ishiwata Kenji , Nakao Hiroshi , Nakamura‐Uchiyama Fukumi , Nawa Yukifumi
Published: March 2003

Nippostrongylus brasiliensis adult worms are expelled from the rat small intestine during a primary infection by two steps. First, host immune responses cause damage to the worms, and then a nonspecific inflammatory response initiates expulsion. We have tested the two‐step expulsion hypothesis in mice infected with N. brasiliensis. After a primary infection in C57BL/6 mice, adult worms started to lay eggs on day 5 postinfection (p.i.) and were expelled around day 9–10 p.i. According to the rat system, 5 day‐ and 8‐day‐old worms were assumed to be ‘normal’ and ‘damaged’, respectively. When 5 day‐ and 8 day‐old worms obtained from C57BL/6 mice were transferred surgically into the small intestine of naive C57BL/6 mice, both 5 day‐ and 8 day‐old worms were almost simultaneously expelled by day 6 postworm implantation (p.w.i.). In contrast, when 5 day‐ and 8 day‐old worms of mouse origin were implanted into naive Wistar rats, 8 day‐old worms were expelled by day 5 p.w.i., while 5 day‐old worms were expelled by day 8 p.w.i. Similar results were obtained when BALB/c mice were used. Therefore, mice can expel N. brasiliensis adult worms as rapidly as rats expel ‘damaged’ worms, regardless of the status of the worms (‘normal’ or ‘damaged’). Stat6‐deficient mice were unable to expel implanted 5 day‐old worms up to day 10 p.w.i., suggesting that cellular mechanisms depending on Stat6‐signalling system are necessary for the expulsion. When N. brasiliensis adult worms obtained from Stat6‐deficient mice 5 and 15 days after a primary infection were implanted into Wistar rats, the former established in the recipient rats for approximately 1 week and were then expelled by day 10 p.w.i., whereas the latter were expelled by day 4 p.w.i. These results suggest that immune‐mediated damage of N. brasiliensis adult worms (first step) is not a prerequisite for expulsion from the small intestine of mice, although adult worms are actually damaged by Stat6‐independent immune mechanisms.
Early response of guinea‐pig lungs toTrichinella spiralisinfection
Authors: Dzik Jolanta M. , Gołos Barbara , Jagielska ELżbieta , Kapała Agnieszka , Wałajtys‐Rode ELżbieta
Published: March 2003

In order to assess immunological response, induced in guinea‐pig lungs byTrichinella spiralis,cellular infiltration into pulmonary alveolar space and production ofand NO in alveolar macrophages obtained from bronchoalveolar lavage fluid (BALF), as well as accumulation of nitric oxide (NO) metabolites in BALF and serum, were evaluated during the early period of primaryT. spiralisinfection (from 4th to 8th and on 14th day after oral administration of larvae) and on 6th day after secondary infection. Primary infection caused increased infiltration of lymphocytes, macrophages, neutrophils and eosinophils, while secondary infection resulted in raised lymphocyte and eosinophil numbers. In spite of marked cellular infiltration of alveolar space, only very limited activation of effector cells, pointing to a suppressed innate response, was apparent, as (i) BALF supernatant phospholipid/protein concentration ratio, and lung levels of phospholipid peroxidation markers, conjugated dienes and malondialdehyde, did not change during 7 days following infection; (ii) primary, but not secondary, infection caused only a transient increase of superoxide anion production by alveolar macrophages; (iii) despite expression of inducible nitric oxide synthase in macrophages of control, infected and BCG‐treated animals, and of interferon (IFN)‐γ‐like activity in sera of infected animals, macrophage nitric oxide production was not affected by infection, even after additional stimulationin vitro(lipopolisaccharide + hrIFN‐γ) or in vivo (BCG or secondaryT. spiralisinfection); and (iv) increased nitrate concentrations were found in BALF supernatant and serum, but not in lung homogenates, of infected animals.
Venom induces alarm behaviour in the social wasp Polybioides raphigastra (Hymenoptera: Vespidae): an investigation of alarm behaviour, venom volatiles and sting autotomy
Authors: Sledge M. F. , Dani F. R. , Fortunato A. , Maschwitz U. , Clarke S. R. , Francescato E. , Hashim R. , Morgan E. D. , Jones G. R. , Turillazzi S.
Published: March 2003

Chemicals from the venom gland elicited alarm behaviour and attack in the Asian polistine wasp Polybioides raphigastra. When presented with crushed venom glands workers of this wasp respond with a mass stinging attack. Gas chromatography–mass spectrometry analyses show that the major volatiles in the venom gland are alkanes, monounsaturated alkenes and 2‐alcohols. Several pyrazines, a spiroacetal and aromatics were also identified as trace compounds. The anatomy and morphology of the sting apparatus are reported, and we describe sting autotomy in this wasp. This is the first such report for the Ropalidiinae. The structures responsible for autotomy are likely to be large barbs present on the sting lancets, and a conspicuous tooth present on the medial side of the left lancet. Sting autotomy in P. raphigastra probably plays an important role in the localization of sites of attack by wasps defending the nest.
Behavioural and electrophysiological responses of the phlebotomine sandfly Lutzomyia longipalpis (Diptera: Psychodidae) when exposed to canid host odour kairomones
Authors: Dougherty M. J. , Guerin P. M. , Ward R. D. , Hamilton J. G. C.
Published: March 2003

Compounds from the odour‐producing glands of the fox Vulpes vulpes were collected. This complex mixture of compounds was used to stimulate the ‘ascoid’ olfactory organs of female sandflies in single sensillum and gas chromatography‐linked single sensillum recordings. Sixteen of these compounds were identified using gas chromatography‐linked mass spectrometry and amounts present were determined. The compounds fell into four organic classes: ketones, carboxylic acids, alcohols and aldehydes. Specific neurones present in the ascoid sensillum that responded to each of these classes of compound were characterized.

A bioassay chamber was developed that gave female sandflies the choice of two odour sources. Female sandflies were attracted upwind by fox odour and were trapped in closer proximity to the fox odour port than the control port. Synthetic compounds were recombined in appropriate quantities to mimic the fox odour. In this bioassay, the synthetic blend attracted sandflies upwind, and again they were caught closer to the test port than the control port. Furthermore, the synthetic fox odour induced an electrophysiological response from neurones in the ascoid sensillum that was very similar to that induced by natural fox odour. No synthetic compound alone induced the same behavioural response from sandflies as did whole fox odour. However, benzaldehyde, 4‐hydroxy‐4‐methyl‐2‐pentanone and 4‐methyl‐2‐pentanone alone did cause sandflies to fly upwind and to be caught closer to the test port than the control.
Diel patterns of reproductive activities in the tomato fruit fly, Neoceratitis cyanescens
Authors: Brevault T. , Quilici S.
Published: March 2003

We describe the diurnal temporal and spatial patterns of reproductive activities (mating and ovipositing) of adult tomato fruit flies, Neoceratitis cyanescens (Bezzi) (Diptera: Tephritidae), under laboratory, field‐cage and field conditions. The distribution pattern of flies in the different habitats (host and non‐host plants) showed temporal, physiological and sexual differences. Mature females were observed to frequent host plants preferentially, particularly in the late afternoon. By contrast, immature females preferred to rest on non‐host plants throughout the day. Males frequented mainly non‐host plants but some were observed on host fruits in the morning. Mating activity took place preferentially on non‐host plants, in the morning. In laboratory cages, females showed a strong daily propensity to engage in mating behaviour; the mean percentage of mating females was 88 ± 5%. Time allotted to this activity (4 h 52 min ± 1 h 23 min in laboratory cages and at least 3 h for the mating pairs observed in the field) appeared considerable compared to the time required to satisfy feeding or oviposition activities. Except for a few ovipositing females observed in the morning, oviposition activities occurred mainly in the late afternoon.
Anthocorid predators learn to associate herbivore‐induced plant volatiles with presence or absence of prey
Authors: Drukker Bas , Bruin Jan , Sabelis Maurice W.
Published: March 2003

We investigated how the plant‐inhabiting, anthocorid predator, Anthocoris nemoralis, copes with variation in prey, host plant and associated herbivore‐induced plant volatiles and in particular whether the preference for these plant odours is innate or acquired. We found a marked difference between the olfactory response of orchard‐caught predators and that of their first generation reared on flour moth eggs in the laboratory, i.e. under conditions free of herbivory‐induced volatiles. Whereas the orchard‐caught predators preferred odour from psyllid‐infested pear leaves, when offered against clean air in a Y‐tube olfactometer, the laboratory‐reared first generation of (naive) predators did not. The same difference was found when a single component (methyl salicylate) of the herbivore‐induced plant volatiles was offered against clean air. After experiencing methyl salicylate with prey, however, the laboratory‐reared predators showed a pronounced preference for this volatile. This acquired preference did not depend on whether the volatile had been experienced in the juvenile period or in the adult phase, but it did depend on whether it had been offered in presence or absence of prey. In the first case, they were attracted to the plant volatile in subsequent olfactometer experiments, but when the volatile had been offered during a period of prey deprivation, the predators were not attracted. We conclude that associative learning is the most likely mechanism underlying acquired odour preference.
Food availability controls the onset of metamorphosis in the dung beetle Onthophagus taurus (Coleoptera: Scarabaeidae)
Authors: Shafiei Majid , Moczek Armin P. , Nijhout H. Frederik
Published: March 2003

In nature, larvae of the dung beetle Onthophagus taurus (Schreber 1759) are confronted with significant variation in the availability of food without the option of locating new resources. Here we explore how variation in feeding conditions during the final larval instar affects larval growth and the timing of pupation. We found that larvae respond to food deprivation with a reduction in the length of the instar and premature pupation, leading to the early eclosion of a small adult. To achieve pupation, larvae required access to food for at least the first 5 days of the final instar (= 30% of mean third‐instar duration in control individuals), and had to exceed a weight of 0.08 g (= 58% of mean peak weight in control individuals). Larvae that were allowed to feed longer exhibited higher pupation success, but increased larval weight at the time of food deprivation did not result in increased pupation success except for larvae weighing > 0.14 g. Larvae responded to food deprivation by initiating and undergoing the same sequence of developmental events, requiring the same amount of time, as ad libitum‐fed larvae once those had reached their natural peak weight. Our results reveal a striking degree of flexibility in the dynamics and timing of larval development in O. taurus. They also suggest that premature exhaustion of a larva's food supply can serve as a cue for the initiation of metamorphosis. Premature metamorphosis in response to food deprivation has been documented in amphibians, but this is, to the best of our knowledge, the first time such a behaviour has been documented for a holometabolous insect. We discuss our findings in the context of the natural history and behavioural ecology of onthophagine beetles.
The effects of acclimation to sunlight on the xylem vulnerability to embolism in Fagus sylvatica L.
Authors: COCHARD H. , LEMOINE D. , DREYER E.
Published: March 2003

We assessed the effects of irradiance received during growth on the vulnerability of Fagus sylvatica L. xylem vessels to water‐stress‐induced embolism. The measurements were conducted on (1) potted saplings acclimated for 2 years under 100% and 12% incident global radiation and (2) branches collected from sun‐exposed and shaded sides of adult trees. Both experiments yielded similar results. Light‐acclimated shoots were less vulnerable to embolism. Xylem water potential levels producing 50% loss of hydraulic conductivity were lower in sun‐exposed branches and seedlings than in shade‐grown ones (–3·0 versus –2·3 MPa on average). The differences in vulnerability were not correlated with differences in xylem hydraulic conductivity nor vessel diameter. Resistance to cavitation was correlated with transpiration rates, midday xylem and leaf water potentials in adult trees. We concluded that vulnerability to cavitation in Fagus sylvatica may acclimate to contrasting ambient light conditions.
Measurements of electrical leaf surface conductance reveal re‐condensation of transpired water vapour on leaf surfaces
Authors: BURKHARDT J. , KAISER H. , GOLDBACH H. , KAPPEN LUDGER
Published: March 2003

Electrical conductance (λ) was measured continuously and in vivo on leaf surfaces of Vicia faba and Aegopodium podagraria. λ increased with rise and decreased with fall in humidity, exhibiting a hysteresis during an applied humidity cycle [90–20–‐90% relative humidity (r.h.)]. After treatment with NaNO3 aerosols, a sudden increase in λ was observed at 73% r.h., which is close to the deliquescence point of the salt. Transpiration and electrical conductance of untreated leaves were measured simultaneously under conditions of constant r.h., while the photosynthetic photon flux density and CO2 concentration of the air were varied to induce changes of stomatal aperture. At 35% r.h., changes of light and CO2 level revealed a strong correlation between stomatal conductance (gS) and λ for Vicia faba leaves. This was also found at 90, 75, 60, 45 and 25% r.h. on the lower but not on the astomatous, upper surface of Aegopodium podagraria. The correlation between gS and λ for stomata‐bearing leaf surfaces indicates that an equilibrium exists between the ambient water vapour phase and the liquid water phase on and within the cuticle. This is modified by transpired water vapour influencing the air humidity inside the boundary layer. Our results imply re‐condensation of transpired water vapour to salts on the leaf surface and its sorption to the cuticle.
δ13C of CO2 respired in the dark in relation to δ13C of leaf carbohydrates in Phaseolus vulgaris L. under progressive drought
Authors: DURANCEAU M. , GHASHGHAIE J. , BADECK F. , DELEENS E. , CORNIC G.
Published: March 2003

A, leaf net CO2 assimilation a, fractionation against 13C for CO2 diffusion through air b, net fractionation against 13C during CO2 fixation by Rubisco and PEPc δ13C, carbon isotopic composition Δ, discrimination against 13C during CO2 assimilation d, the term including the fractionation due to CO2 dissolution, liquid phase diffusion and also discrimination during both respiration and photorespiration DW, leaf dry weight  dδ13C, the difference between CO2 respired in the dark and plant material in their carbon isotope composition  dΔ, variation in modelled discrimination at a given pi/pa relative to a reference value at pi/pa = 0·7  FW, leaf fresh weight gc, leaf conductance to CO2 diffusion  HPLC, high‐performance liquid chromatography  LMA, leaf mass per area pa, ambient partial pressure of CO2 pi, intercellular partial pressure of CO2  PEPc, phosphoenolpyruvate carboxylase  PPFD, photosynthetic photon flux density RPDB, 13C/12C ratio of standard PDB RS, 13C/12C ratio of sample  Rubisco, ribulose 1,5 bisphosphate carboxylase‐oxygenase  RWC, leaf relative water content  SW, leaf saturated weight  VPD, vapour pressure deficit   The variations in δ13C in both leaf carbohydrates (starch and sucrose) and CO2 respired in the dark from the cotyledonary leaves of Phaseolus vulgaris L. were investigated during a progressive drought. As expected, sucrose and starch became heavier (enriched in 13C) with decreasing stomatal conductance and decreasing pi/pa during the first half (15 d) of the dehydration cycle. Thereafter, when stomata remained closed and leaf net photosynthesis was near zero, the tendency was reversed: the carbohydrates became lighter (depleted in 13C). This may be explained by increased pi/pa but other possible explanations are also discussed. Interestingly, the variations in δ13C of CO2 respired in the dark were correlated with those of sucrose for both well‐watered and dehydrated plants. A linear relationship was obtained between δ13C of CO2 respired in the dark and sucrose, respired CO2 always being enriched in 13C compared with sucrose by ≈ 6‰. The whole leaf organic matter was depleted in 13C compared with leaf carbohydrates by at least 1‰. These results suggest that: (i) a discrimination by ≈ 6‰ occurs during dark respiration processes releasing 13C‐enriched CO2; and that (ii) this leads to 13C depletion in the remaining leaf material.
The biochemical and molecular basis for photosynthetic acclimation to elevated atmospheric CO2
Authors: MOORE B. D. , CHENG S.‐H. , SIMS D. , SEEMANN J. R.
Published: March 2003

A
max, maximum CO2 assimilation rate CAB, genes encoding chlorophyll a/b binding proteins Ci, intercellular CO2 concentration PGK, the gene encoding 3‐phosphoglycerate kinase PRK, the gene encoding phosphoribulokinase PSAB, the gene encoding the 83 kDa apoprotein of the PSI reaction centre PSBA, the gene encoding the D1 protein of photosystem II RBCS, genes encoding the Rubisco small subunit protein RBCL, the gene encoding the Rubisco large subunit protein Rubisco, ribulose‐1,5‐bisphosphate carboxylase/ oxygenase SBP, the gene encoding sedoheptulose‐1,5‐bisphosphatase  There have been many recent exciting advances in our understanding of the cellular processes that underlie photosynthetic acclimation to rising atmospheric CO2 concentration. Of particular interest have been the molecular processes that modulate photosynthetic gene expression in response to elevated CO2 and the biochemical processes that link changes in atmospheric CO2 concentration to the production of a metabolic signal. Central to this acclimation response is a reduction in ribulose‐1,5‐bisphosphate carboxylase/oxygenase (Rubisco) protein content. Studies indicate that this reduction results from species‐dependent variation in the differential use and temporal control of molecular processes. We present a model for the control of Rubisco protein accumulation that emphasizes the role of subunit message translation as well as the abundance of subunit messages as components of the acclimation response. Many studies indicate that photosynthetic acclimation to elevated CO2 results from adjustments in leaf carbohydrate signalling. The repression of photosynthetic gene expression is considered to occur primarily by hexokinase functioning as a hexose flux sensor that ultimately affects transcription. Leaf hexoses may be produced as potential sources of signals primarily by sucrose cycling and secondarily by starch hydrolysis. An increased rate of sucrose cycling is suggested to occur at elevated CO2 by enhanced provision of sucrose to leaf acid invertases. Additionally, sink limitations that accentuate photosynthetic acclimation may result from a relative decrease in the export of leaf sucrose and subsequent increase in cellular sucrose levels and sucrose cycling.
The light induction of maize phosphoenolpyruvate carboxylase kinase translatable mRNA requires transcription but not translation
Authors: Hartwell J. , Jenkins G. I. , Wilkins M. B. , Nimmo H. G.
Published: March 2003

We have previously demonstrated that the level of translatable mRNA for phosphoenolpyruvate carboxylase kinase in maize leaves is increased in response to light (Hartwell et al. 1996; Plant Journal10, 1071–1078). To identify the steps required for this increase, we have examined the effects of protein and RNA synthesis inhibitors. The RNA synthesis inhibitors actinomycin D and cordycepin (500 μM) strongly inhibited the light‐induced increases in kinase translatable mRNA and the apparent phosphorylation state of phosphoenolpyruvate carboxylase, as judged by its sensitivity to inhibition by L‐malate. The protein synthesis inhibitors cycloheximide and puromycin blocked the light‐induced increase in the apparent phosphorylation state of phosphoenolpyruvate carboxylase but not the increase in kinase translatable mRNA. Indeed, the amount of phosphoenolpyruvate carboxylase kinase translatable mRNA after 3 h of illumination of leaves treated with either 1 mM puromycin or 100 μM cycloheximide was double that in illuminated control leaves. Each inhibitor reduced the light‐induction of two control genes, malic enzyme and pyruvate, phosphate dikinase. Thus the light induction of phosphoenolpyruvate carboxylase kinase translatable mRNA requires RNA synthesis, but not protein synthesis.