bluuebunny/crossref_metadata_2025 huggingface dataset:
Human duodenal phase III migrating motor complex activity is predominantly antegrade, as revealed by high‐resolution manometry and colour pressure plots
Authors: Andrews J. M. , O'donovan D. G. , Hebbard G. S. , Malbert C. H. , Doran S. M. , Dent J.
Published: March 2003

Abstract
 Late phase III migrating motor complex activity has been said to be primarily retroperistaltic but has not been assessed with high resolution manometry or three‐dimensional colour pressure plots (pressure/time/distance). Duodenal phase III was examined in healthy young volunteers (seven male, two female) with a 20‐lumen assembly. With the most proximal sidehole in the distal antrum, after a 4.5‐cm interval 18 sideholes at 1.5‐cm intervals spanned the duodenum with a final sidehole 3 cm beyond. Fasting pressures were recorded until phase III occurred. Comparisons were made between proximal (P) and distal (D) duodenum during early (E) (first 0.5–1 min) and late (L) (last 0.5–1 min) phase III. With colour pressure analysis, 121 of 180 pressure wave (PW) sequences were purely antegrade, two purely retrograde and 57 bidirectional. Ten of fifty‐seven bidirectional PW sequences were complex, branching to become two separate sequences. Bidirectional sequences occurred more frequently in late than early phase III (L 43 vs. E 14 of 57), but their occurrence did not differ between proximal and distal duodenum (P31 vs. D 24 of 57). Antegrade propagation velocity was faster in late compared with early phase III (L 28.50 vs. E 17.05 mm s−1; P = 0.006), but did not differ between proximal and distal duodenum. Colour pressure analysis also indicated an intermittent segmental pattern to phase III, with each subject exhibiting a change in velocity or direction, or a relative failure of peristalsis somewhere along the duodenum during part of phase III. Duodenal phase III is not homogenous and, in contrast with previous studies, does not primarily constitute a retroperistaltic pump. Colour pressure analysis is useful in interpreting intraluminal pressure profiles and may improve the sensitivity and specificity of clinical studies.
Neural integrity is essential for the propagation of colonic migrating motor complexes in the mouse
Authors: Powell A. K. , O'brien S. D. , Fida R. , Bywater R. A. R.
Published: March 2003

Abstract
 The mechanisms that underlie the propagation of contractions along the colon are uncertain. We have examined whether spontaneous colonic migrating motor complexes (CMMCs) migrate through a region of muscle paralysis, or through a region where neural transmission was disrupted in the isolated mouse colon. Mouse colon was mounted in a separately perfused three‐compartment organ bath and recordings of circular muscle tension were made. Drug application was restricted to the middle compartment. Application of nifedipine (1 µmol L−1), an l‐type calcium channel antagonist, reduced the contraction amplitude by ∼94%, without affecting the form of contractions in the proximal and distal compartments. Moreover, CMMCs appeared to remain temporally related in all compartments. In contrast, interruption of neural transmission in the middle compartment by either tetrodotoxin (1.6 µmol L−1), hexamethonium (500 µmol L−1) or a low‐calcium, high‐magnesium solution abolished CMMCs in this compartment; contractions recorded in the proximal and distal compartments became slower in frequency and were no longer synchronized. The experiments suggest that there may be more than one ‘pacemaker’ generating spontaneous CMMCs and that CMMCs can migrate through a region where there is minimal tension generation, but not through a region where neural integrity has been compromised.
Idiopathic slow transit constipation and megacolon are not associated with neurturin mutations
Authors: Chen B. , Knowles C. H. , Scott M. , Anand P. , Williams N. S. , Milbrandt J. , Tam P. K. H.
Published: March 2003

Abstract
 Chronic idiopathic slow‐transit constipation (ISTC) and idiopathic megacolon (IMC) are early‐onset gastrointestinal motility disorders of unknown aetiology. The gene encoding the neurotrophic factor neurturin may be a candidate for these disorders, as neurturin‐deficient mice have a similar enteric phenotype. In the present study, we tested this hypothesis. Genomic DNA from 26 cases of chronic idiopathic STC [with a family history of constipation in 15 (58%) and Hirschsprung's disease in two (8%)], and five cases of IMC [two familial (40%)] was screened by direct DNA sequencing using the fluorescent dideoxy terminator method. Results were compared with published sequence data and 24 control DNAs. Our results revealed several previously unreported common sequence polymorphisms, but overall frequencies were comparable between patients and controls. We conclude that mutation of neurturin is not a frequent cause of ISTC or IMC.
Acid challenge delays gastric pressure adaptation, blocks gastric emptying and stimulates gastric fluid secretion in the rat
Authors: Holzer P. , Painsipp E. , Jocic M. , Heinemann A.
Published: March 2003

Abstract Functional dyspepsia can be associated with impaired gastric relaxation in response to food intake and delayed gastric emptying. In this study, we investigated whether luminal hydrochloric acid (HCl) may reproduce these motor alterations in phenobarbital‐anaesthetized rats via activation of extrinsic neural pathways. Intragastric pressure (IGP) changes induced by a 2‐mL fluid bolus were recorded with an oesophageal catheter, and gastric emptying was determined via the fluid volume recovered from the stomach 30‐min post‐bolus. Experiments involving acute nerve transections or pharmacological blockade of nitric oxide synthesis revealed that the initial increase of IGP after a 0.35 mol L−1 HCl bolus is dampened by duodenogastric and gastrogastric relaxation reflexes depending on vagal and splanchnic pathways as well as nitric oxide. Compared with saline, HCl (0.15–0.5 mol L−1) delayed the subsequent decrease (adaptation) of IGP, inhibited gastric emptying and stimulated gastric fluid secretion as seen in stomachs with ligated pylorus. The acid‐evoked delay in IGP adaptation and inhibition of gastric emptying involved duodenogastric and duodenopyloric extrinsic nerve reflexes, whereas the gastric fluid secretion was independent of the extrinsic innervation. It is proposed that the gastropyloric motor changes induced by luminal acid challenge have a bearing on the motor disturbances underlying functional dyspepsia.
Middle cerebral artery occlusion in the rat: consistent protocol for a model of stroke
Authors: Aspey  , Cohen  , Patel  , Terruli  , Harrison
Published: March 2003

Variability in the effects of the intraluminal suture method of middle cerebral artery occlusion (MCAO) in the rat has been a common and disadvantageous finding. Therefore, we systematically investigated the effects of suture type and rat strain on outcome. First, the clinical and neuropathological effects of permanent MCAO with either an uncoated or a silicone‐coated nylon suture were studied over 7 days in Sprague–Dawley rats (n=36 for each type of suture). Outcome was less severe with the uncoated compared with the silicone‐coated suture (e.g. total cerebral infarct volume at 24 h before any fatalities was 119.9±79.8 mm3 , cf. 183.0±36.5 mm3 , n=12 for each, P<0.05; and overall mortality rate was 12.5% cf. 33%, respectively), but much more variable (coefficient of variation was 66.6% cf. 19.9%, respectively). Second, being more consistent in its effects, the silicone‐coated suture was further studied in Wistar and Fischer‐344 rats (n=12 for each). Seventy‐five per cent of the Wistar’s died prematurely from gross hemispheric oedema. Motor deficit and extent of infarction in the Fischer‐344 rats were both significantly greater compared with Sprague‐Dawley rats (e.g. total cerebral infarct volume at 24 h in the former was 253.6±25.4 mm3 , n=11, P<0.05), and more consistent (coefficient of variation was only 10.0%). It was concluded that the silicone‐coated suture and the Fischer‐344 rats strain produced the most consistent results and their novel combination provides a reliable acute stroke model.
Neuronal apoptosis does not correlate with dementia in HIV infection but is related to microglial activation and axonal damage
Authors: Adle‐Biassette  , Chrétien  , Wingertsmann  , Héry  , Ereau  , Scaravilli  , Tardieu  , Gray
Published: March 2003

To characterize the distribution of apoptotic neurons and their relationships with the stage of disease, a history of HIV‐dementia, and the degree of productive HIV infection, microglial activation and axonal damage, we examined the brains of 40 patients. Samples of frontal and temporal cortex, basal ganglia and brain stem were taken post‐mortem from 20 patients with AIDS (including three with HIV‐dementia, and eight with cognitive disorders that did not fulfil the criteria for HIV‐dementia), 10 HIV‐positive asymptomatic cases and 10 seronegative controls. Neuronal apoptosis was demonstrated by in situ end labelling in 18 AIDS cases and two pre‐AIDS cases; a single apoptotic neuron was present in the temporal cortex of a control. Semiquantitative evaluation showed that the severity of neuronal apoptosis in the cerebral cortex correlated with the presence of cerebral atrophy, but not with a history of HIV dementia. There was no global quantitative correlation between neuronal apoptosis and HIV encephalitis or microglial activation. However, there was some topographical correlation between these changes. In the basal ganglia, apoptotic neurons were much more abundant in the vicinity of multinucleated giant cells and/or p24 expressing cells. Microglial activation was constantly present in these areas. Axonal damage was identified using β‐amyloid‐precursor protein (βAPP) immunostaining in 17 AIDS and eight pre‐AIDS brains. Although no global quantitative correlation could be established between axonal damage and neuronal apoptosis there was an obvious topographic correlation supporting the view that axonal damage, either secondary to local microglial activation or due to the intervention of systemic factors, may also contribute to neuronal apoptosis.
Calcium homeostasis and ultrastructural studies in a patient with limb girdle muscular dystrophy type 2C
Authors: Hassoni  , Cullen
Published: March 2003

There is increasing evidence that γ‐sarcoglycan is absent and other sarcoglycans are reduced in patients with the limb‐girdle muscular dystrophy type 2C (LGMD2C) form of severe childhood autosomal recessive muscular dystrophy. In the present investigation, we combined microspectrofluorimetry and electron microscopy techniques to investigate the physiological function and the ultrastructure of control and LGMD2C myotubes. Results obtained from Ca2+ measurements showed that the resting level of the cytosolic free calcium ([Ca2+ ]i ) in control myotubes was 73±3.4 nmol/l (mean±se, n=35) and in LGMD2C myotubes was 69±4 nmol/l (n=44). Carbachol (CCh, 10μmol/l ) induced a 335±10 nmol/l (n=8) rise in [Ca2+ ]i in control myotubes and 531.9±32 nmol/l (n=23) in LGMD2C myotubes. Similarly, elevations of [Ca2+ ]i by 35 mmol/l K+ were 324±32 nmol/l (n=8) in control myotubes and 442.8±24 nmol/l (n=22) in LGMD2C myotubes. Caffeine (10 mmol/l) activated similar [Ca2+ ]i peaks in control and LGMD2C myotubes but induced a biphasic response in LGMD2C in four out of 12 myotubes and only a monophasic response in control myotubes. The ultrastructural results showed that the plasma membrane was abnormally indented and convoluted in both the LGMD2C biopsy and the LGMD2C cultured myotubes. It is suggested that the reduction in components of the dystrophin–glycoprotein complex results in the instability and an increase in the surface area of the plasma membrane, which may result in a higher population of Ca2+ channels in the LGMD2C myotubes.
Ultrastructural changes in peripheral nerve in hereditary motor and sensory neuropathy‐Lom
Authors: King  , Tournev  , Colomer  , Merlini  , Kalaydjieva  , Thomas
Published: March 2003

Ultrastructural observations have been made on nerve biopsy specimens from five cases of hereditary motor and sensory neuropathy‐Lom (HMSNL). A number of features that distinguish it from other hereditary demyelinating neuropathies were identified. Teased fibre studies were not feasible but examination of longitudinal sections by electron microscopy demonstrated demyelination/remyelination. Severe progressive axonal loss was a conspicuous feature. There was no indication of axonal atrophy. Hypertrophic onion bulb changes were present in the younger patients which later regressed, probably secondary to axonal loss. Myelin thickness was generally reduced in relation to axon diameter, indicating hypomyelination, and partial ensheathment of axons by Schwann cells was observed. The Schmidt–Lanterman incisures were atypical in extending for long lengths along the internode. Uncompacted myelin with a periodicity greater than that observed in other neuropathies in which it occurs was a feature, as was the accumulation of pleomorphic material in the adaxonal Schwann cell cytoplasm. An unusual finding was the presence of intra‐axonal accumulations of irregularly arranged curvilinear profiles. These resemble those that have been described in experimental vitamin E deficiency. The amount of endoneurial collagen was markedly increased and some endoneurial blood vessels showed a non‐specific basal laminal reduplication.
Widespread occurrence of α‐synuclein/NACP‐immunoreactive neuronal inclusions in juvenileand adult‐onset Hallervorden–Spatz diseasewith Lewy bodies
Authors: Wakabayashi  , Yoshimoto  , Fukushima  , Koide  , Horikawa  , Morita  , Takahashi
Published: March 2003

α‐Synuclein (originally called precursor of the non‐Aβ component of Alzheimer’s disease amyloid‐NACP) is a presynaptic nerve terminal protein and is now known to be a major component of Lewy bodies (LBs) in Parkinson’s disease. Previous studies have shown that LBs are occasionally found in patients with Hallervorden–Spatz disease (HSD), a hereditary or sporadic neuroaxonal dystrophy. Therefore, an immunocytochemical examination of the brain tissues from two patients with HSD for α‐synuclein/NACP was performed. In both cases, LBs were observed in the substantia nigra, locus ceruleus and other subcortical nuclei. These LBs were strongly immunolabelled with anti‐α‐synuclein/NACP. Moreover, abnormal α‐synuclein/NACP‐immunoreactive structures in the neuronal somata and processes were found in the cerebral neocortex, hippocampus, basal ganglia, thalamus, pontine and inferior olivary nuclei, spinal grey matter, and peripheral sympathetic ganglia. Although numerous dystrophic axons (spheroids) were found throughout the brain, either none or only a few were positive for α‐synuclein/NACP. These findings suggest that widespread accumulation of α‐synuclein/NACP is a pathological feature in patients suffering from HSD with LBs, and that this phenomenon is unrelated to axonal spheroid formation.
Differential expression of S100 calcium‐binding proteins characterizes distinct clinical entities in both WHO grade II and III astrocytic tumours
Authors: Camby I. , LeFranc F. , Titeca G. , Neuci S. , Fastrez M. , Dedecken L. , Schäfer B.W. , Brotchi J. , Heizmann C.W. , Pochet R. , Salmon I. , Kiss R. , Decaestecker C.
Published: March 2003

The computer‐assisted microscopic analysis of Feulgen‐stained nuclei enabled us to identify two subgroups of astrocytomas (WHO grade II) and two subgroups of anaplastic astrocytomas (WHO grade III) with significantly distinct clinical outcomes (Decaestecker et?al. Brain Pathol 1998; 8: 29–38). The astrocytomas labelled in the present study as typical (TYP‐ASTs) behaved clinically like real astrocytomas while atypical astrocytomas (ATYP‐ASTs) behaved similarly to anaplastic astrocytomas. The anaplastic astrocytomas that we labelled as typical (TYP‐ANAs) behaved clinically like anaplastic astrocytomas while atypical ones (ATYP‐ANAs) behaved like glioblastomas. In the present study, we investigate whether some biological characteristics could be evidenced across these four groups of TYP‐ and ATYP‐ASTs and TYP‐ and ATYP‐ANAs. The data show that the levels of expression (immunohistochemically assayed and quantitatively determined by means of computer‐assisted microscopy) of vimentin, the glial fibrillary acidic protein and the platelet‐derived growth factor‐α did not differ significantly across these four groups of astrocytic tumours. The level of cell proliferation (determined by means of both the anti‐proliferating cell nuclear antigen and the anti‐MIB‐1 antibodies; P < 0.001 to P < 0.0001) differed very significantly between the astrocytomas and anaplastic astrocytomas, but not between the typical and atypical variants identified in each group. In sharp contrast, the levels of expression of the S100A3 and S100A5 proteins differed markedly in the solid tumour tissue in relation to the astrocytic tumour types and grades. In addition, while the levels of expression of S100A6 did not change in the astrocytic tumour tissue in relation to histopathological grade, the levels of expression of this S100 protein (but not those of S100A3 and S100A5) differed markedly in the blood vessel walls according to whether these vessels originated from low‐ or high‐grade astrocytic tumours.
Fas and Fas‐L expression in Huntington's disease and Parkinson's disease
Authors: Ferrer I. , Blanco R. , Cutillas B. , Ambrosio S.
Published: March 2003

The Fas/Fas‐L signalling system plays a role in the control of cell death and the survival of lymphocytes, in the regulation of the immune system, and in the progression of autoimmune diseases. Studies in the nervous system have shown Fas/Fas‐L activation in multiple sclerosis and in various paradigms leading to neuronal death. Enhanced Fas and Fas‐L expression has also been documented in astrocytomas and glioma cell lines. However, little is known about the possible implication of Fas/Fas‐L signals in primary human neurodegenerative diseases. In an attempt to gain understanding of the mechanisms commanding cell death and neurone loss in Huntington's disease (HD) and Parkinson's disease (PD), Fas and Fas‐L expression has been examined in the brains of patients with HD and PD with Western blotting and immunohistochemistry. Fas and Fas‐L expression levels are reduced in the caudate and putamen, but not in the parietal cortex, in HD, as revealed in Western blots. Moreover, Fas and Fas‐L immunoreactivity is reduced in striatal neurones in HD. Fas and Fas‐L immunoreactivity is also decreased in neurones of the substantia nigra pars compacta in PD. Reduced Fas and Fas‐L expression is observed equally in Lewy body‐bearing and non‐Lewy body‐bearing neurones. Yet increased Fas and Fas‐L immunoreactivity occurs in normal astrocytes in control brains and in reactive astrocytes in diseased brains. The meaning of increased Fas and Fas‐L expression in astrocytes is still unclear. However, the present results suggest that Fas/Fas‐L signals are minimized in sensitive neurones in HD and PD.
Multiple malformations and maternal smoking
Authors: Källén K.
Published: March 2003

The Swedish health registries were used to investigate a possible effect of maternal smoking on the incidence of multiple malformations. Among 1 413 811 infants born in 1983–96 and with known smoking exposure in early pregnancy, 26 619 with isolated malformations and 1409 with two or more malformations were selected. After controlling for year of birth, maternal age, parity and educational level, a statistically significant association between maternal smoking and multiple malformations was found (OR 1.15; 95% CI 1.02, 1.29). Among isolated malformations, the estimated OR for maternal smoking was close to unity (OR 1.02; 95% CI 0.99,1.05), but a strong heterogeneity of the magnitude of the association between maternal smoking and the different malformations was found. Among multimalformed, no such heterogeneity was indicated. The ORs for maternal smoking were calculated for all possible pairwise combinations of 44 selected malformations, but no association between maternal smoking and any specific combination could be detected. The ORs for maternal smoking among probable cases of VATER, CHARGE or OEIS non‐random associations, respectively, were estimated, but no association was indicated between maternal smoking and any of the malformation complexes. The results of the present study indicate that maternal smoking is associated with a non‐specific increased risk of multiple malformations, but further research is needed before such an inference can be made.
Effect of sucking characteristics on breast milk creamatocrit
Authors: Aksit Sadik , Ozkayin Nese , Caglayan Suat
Published: March 2003

One of the problems in the care of healthy children is that mothers often give infant formulae to their normally growing infants in the first 4 months of life because they believe that they are unable to satisfy them. However, the association of fat content in breast milk with the sucking pattern of the infant is not clearly known. In order to determine whether the fat concentration of human milk was associated with sucking characteristics of the infants, 80 healthy 2‐month‐old babies and their mothers were included in the study. Milk creamatocrit was assessed at the beginning, at the first, fifth and 10th minutes and at the end of breast feeding. The creamatocrit values increased as the time elapsed from the beginning of breast feeding. There was an inverse relationship between milk volume and creamatocrit at both the beginning and the end of breast feeding (P < 0.05). The mean milk volume was higher and the mean creamatocrit at the end of breast feeding was lower in the infants whose 2‐month weight gain was higher than the 75th percentile (75P) compared with those whose 2‐month weight gain was lower than the 25th percentile (25P) (for milk volume 105 ± 36 mL vs. 76 ± 30 mL, respectively, P < 0.05; and for creamatocrit value 11.4 ± 4.0 vs. 14.3 ± 3.8, respectively, P < 0.05). Milk volume is the most important factor affecting weight gain of exclusively breast‐fed babies, and fat concentration of human milk is not a primary determining factor in individual differences in weight gain of the infants and appears to be secondary to factors such as number of feeds per day, duration of breast feeding and the volume of milk sucked.
Indices of birthweight‐specific perinatal mortality in Germany from 1985 to 1999
Authors: Rettwitz‐Volk Werner
Published: March 2003

A study of the trends in German perinatal data over the 15 years from 1985 to 1999 is complicated by the fact that the numbers from 1991 onwards represent the data for reunified Germany, whereas the numbers before 1991 give the data for former West Germany. The latest figure for the number of livebirths in Germany was 770 744 in 1999 with a rate of low birthweight of 6.5% and a perinatal mortality rate of 0.62%. A constant increase in numbers of low‐birthweight infants was observed, rising from 33 531 in 1985 to 41 145 in 1990 and from 47 863 in 1991 to 50 294 in 1999. This rise in low‐weight births concerned mainly infants of <1500 g. In parallel, there was a decrease in early neonatal and infant mortality rates in all subgroups of low‐birthweight infants except for the extremely small infants of <500 g where no clear tendency was observed over 15 years.
DNA immunization by intramuscular injection or gene gun induces specific IgG antibodies against a Schistosoma japonicum 22 kDa antigen, Sj22, when fused to the murine Ig K‐chain secretory leader sequence
Authors: WAINE  , MAZZER  , MCMANUS
Published: March 2003

The 22 kDa tegumental surface membrane‐associated antigen of Schistosoma japonica, Sj22, is of recognized interest in schistosomiasis vaccine research. However, previous attempts to induce antibody responses against Sj22 by DNA immunization have been unsuccessful. In this report we demonstrate that fusing the Sj22 cDNA to the murine immunoglobulin Ig κ‐chain secretory leader sequence results in the generation of antigen‐specific IgG antibodies following DNA immunization. Mice were immunized into the skin with DNA‐coated gold microspheres using a gene‐gun, or into the quadriceps muscle by intramuscular injection. Both methods of delivery generated antigen‐specific IgG antibodies against the 22 kDa schistosome antigen. The use of a secretory leader sequence, such as the murine Ig‐kappa chain used in this study, may facilitate the induction of host antibody responses following DNA immunization with other parasite cDNAs.
Malaria parasite‐specific Th1‐like T cells simultaneously reduce parasitemia and promote disease
Authors: HIRUNPETCHARAT CHAKRIT , FINKELMAN FRED , CLARK IAN A. , GOOD MICHAEL F.
Published: March 2003

CD4+ T cells have been implicated in immunity to the blood stages of malaria and cytokines associated with both monocyte and T cell activation have been implicated in disease. To determine whether specific T cells capable of inhibiting parasite growth can also mediate pathology we have transfused populations of Plasmodium berghei‐specific T cells into normal and immunodeficient naive mice. We observed that they could inhibit parasite growth but were unable to save the animals which exhibited significantly greater anaemia and weight loss than control infected animals receiving either no T cells or T cells specific for ovalbumin. T cell‐dependent tomour necrosis factor (TNF)α was a critical component in both parasite killing and disease promotion. Experiments with blocking antibodies demonstrated that all T‐cell mediated antiparasitic immunity and all T‐cell mediated weight loss was TNF‐dependent. Blocking TNF‐α in mice that received parasite‐specific T cells prolonged the survival of the mice. Nitic oxide demonstrated no antiparasite effect, but was involved in the regulation of T‐cell mediated weight loss. The data thus show that while parasite‐specific CD4+ T cells can significantly limit parasite growth, such an effect need not be beneficial to the host, and that TNF‐α and nitric oxide are critical effector molecules operating downstream of parasite‐specific T cells in both immunity and disease.
Hemozoin is a key factor in the induction of malaria‐associated immunosuppression
Authors: Scorza Tatiana , Magez Stefan , Brys Lea , De Baetselier Patrick
Published: March 2003

Infection‐associated immunoincompetence during malaria might result from macrophage dysfunction. In the present study, we investigated the role of macrophages as target for immunosuppression during infection, using the murine Plasmodium c. chabaudi model. Special attention has been paid to the analysis of processing/presentation of protein antigens and presentation of peptides, using cocultures of peritoneal exudate cells (PECs) from infected mice and antigen‐specific T‐cell hybridomas. The results obtained indicate a defective processing of protein antigens that becomes maximal at acute parasitemias. In addition, macrophages from acutely infected mice suppress the interleukin‐2 production by the antigen‐activated T‐cell hybridomas. This effect was independent of prostaglandin and nitric oxide production by the macrophage. The possible role of parasite components in the impaired accessory cell function of PECs was investigated and hemozoin, the end‐product of the hemoglobin catabolism by intraerythrocytic malaria parasites, was found to induce similar infection‐associated deficiencies in vitro. Moreover, hemozoin, was shown to mimic the immunosuppressive effects induced in PECs during in‐vivo infections with P. chabaudi. In conclusion, we propose that hemozoin is a key factor in the malaria‐associated immunosuppression, affecting both the antigen processing and immunomodulatory functions of macrophages.
Relative protective properties of three membrane glycoprotein fractions from Haemonchus contortus
Authors: Smith  , Smith  , Pettit  , Newlands  , Skuce
Published: March 2003

Jacalin lectin was used as a ligand to isolate a fraction containing two distinct protective antigens from detergent extracts of membranes from Haemonchus contortus. The first antigen was identified as a complex which appeared very similar to Haemonchus galactose‐containing glycoprotein (H‐gal‐GP), which is a previously described protective protease complex, except that it was substantially depleted of one of the main H‐gal‐GP components, a 230 kDa metallopeptidase‐containing band. The new complex was termed Haemonchus sialylated galactose‐containing glycoprotein (H‐sialgal‐GP), because it bound to jacalin but not to peanut lectin and only jacalin will bind the sialylated form of galactosyl (β‐1,3) N‐acetylgalactosamine. Two protection trials with sheep showed that H‐sialgal‐GP and H‐gal‐GP were equally efficacious, reducing numbers of Haemonchus eggs by between 86% and 93% and worms by between 52% and 75%, respectively. The second jacalin‐binding protective antigen fraction was separated from H‐sialgal‐GP by ion exchange and gel filtration chromatography. It was greatly enriched for two proteins termed p46 and p52 according to their apparent molecular weights. Immunization of sheep with these proteins gave protection values of 78% for eggs and 33% for worms, which are significantly lower than those obtained with either H‐gal‐GP or H‐sialgal‐GP. N‐terminal amino acid sequence data from p46 and p52 showed that both proteins were closely related to a previously described 45 kDa Haemonchus membrane protein, which had conferred protection against Haemonchus in guinea‐pigs.
A heart‐specific CD4+ T‐cell line obtained from a chronic chagasic mouse induces carditis in heart‐immunized mice and rejection of normal heart transplants in the absence of Trypanosoma cruzi
Authors: Ribeiro‐Dos‐Santos R. , Mengel J.O. , Postol E. , Soares R.A.O. , Ferreira‐Fernandez E. , Soares M.B.P. , Pontes‐De‐Carvalho L.C.
Published: March 2003

To study the role of autoreactive T cells in the pathogenesis of cardiomyopathy in Chagas' disease, we generated a cell line by repeated in vitro antigenic stimulation of purified splenic CD4+ T lymphocytes from a chronically Trypanosoma cruzi‐infected mouse. Cells from this line were confirmed to be CD4+ CD8− and proliferated upon stimulation with soluble heart antigens from different animal species, as well as with T. cruzi antigen, in the presence of syngeneic feeder cells. In vitro antigen stimulation of the cell line produced a Th1 cytokine profile, with high levels of IFNγ and IL‐2 and absence of IL‐4, IL‐5 and IL‐10. The cell line also terminated the beating of fetal heart clusters in vitro when cocultured with irradiated syngeneic normal spleen cells. In situ injection of the cell line into well established heart transplants also induced the cessation of heart beating. Finally, adoptive transfer of the cell line to heart‐immunized or T. cruzi‐infected BALB/c nude mice caused intense heart inflammation.
Type 2‐biased expression of cytokine genes in lung granulomatous lesions induced by Nippostrongylus brasiliensis infection
Authors: Matsuda Shinji , Tani Yoichi , Yamada Minoru , Yoshimura Kentaro , Arizono Naoki
Published: March 2003

Infections with helminthic parasites occasionally induce pulmonary diseases with possible involvement of immunological mechanisms. In rats infected with the nematode Nippostrongylus brasiliensis, pulmonary granulomatous lesions develop and persist after the larvae have migrated through the lungs. To determine the pathogenesis of this lesion, we examined cytokine gene expression in the lungs using RT‐PCR and in situ hybridization. Two weeks after infection, when fully developed lesions appeared, levels of IL‐3 and of type2 cytokines IL‐4, IL‐5, IL‐6 and IL‐13 gene expression were markedly enhanced in whole lung homogenates. Those of IL‐2 and IFN‐γ were also slightly increased 2 weeks postinfection. IL‐12 mRNA level did not change after 2 weeks but was slightly increased after 4 weeks. Levels of IL‐10 and proinflammatory cytokine TNF gene expression did not show significant changes, although a slight increase was observed in IL‐1β message after 2 weeks. In situ hybridization studies showed that lung granulomatous lesions were composed mainly of lymphoid cells expressing IL‐3, IL‐4 and IL‐13 mRNA, but not IFN‐γ mRNA. IL‐5 mRNA‐expressing cells were fewer in number than these cells. RMCP II immunohistochemistry revealed that mast cells increased in number in the lung granulomas. From these results, it was concluded that the nematode infection‐associated lung granuloma was a type 2 lesion.
A comparison of local and peripheral parasite‐specific antibody production in different strains of mice infected with Trichuris muris
Authors: Blackwell Nathan M. , Else Kathryn J.
Published: March 2003

The serum parasite‐specific antibody responses of different mouse strains infected with Trichuris muris reflect the nature of the T‐helper response mounted by the host, in that resistant Th2‐responding strains, such as BALB/K, produce immunoglobulin (Ig)G1 and susceptible predominantly Th1‐responding strains, such as AKR, produce IgG2a and IgG1. However, the kinetics of antibody production in the sera, as determined by enzyme‐linked immunosorbent assay, do not reflect infection status in that resistant strains can expel their worm burdens before antibodies are detectable in the sera. Here, we show that parasite‐specific antibody production by in vitro lipopolysaccharide‐stimulated mesenteric lymph node cells (MLN) not only correlate with serum antibody isotypes, but also follow expulsion kinetics. Additionally, the antibody levels seen locally match changes in absolute B220+ cell numbers in the MLN (determined by flow cytometry) and changes in MLN parasite‐specific plasma cells in the MLN (determined by ELISPOT). These results show that B cell responses are tightly regulated locally in both resistant and susceptible strains of mice infected with T. muris.
Toxoplasma gondii infection can regulate the expression of tumour necorsis factor‐α receptors on human cell in vitro
Authors: Derouich‐Guergour Dorra , Aldebert Delphine , Vigan Ines , Jouvin‐Marche Evelyne , Marche Patrice N. , Aubert Dominique , Ambroise‐Thomas Pierre , Pelloux Hervé
Published: March 2003

The in vitro regulation of tumour necrosis factor (TNF)‐α receptors during Toxoplasma gondii infection of human MRC5 fibroblasts and human myelomonocytic THP‐1 cells was investigated. Cells were infected with the virulent RH of T. gondii. TNFR membrane receptors were analysed by flow cytometry with biotinylated TNF‐α. Shedding of the soluble form of TNFR1 and TNFR2 in cell culture supernatants was measured by enzyme‐linked immunosorbent assay, and expression of mRNA production of TNFR1 and TNFR2 was analysed by quantitative real‐time ploymerase chain reaction, 1 h after infection. In the MRC5 cell line, T. gondii infection did not induce any up‐ or down‐regulation of membrane TNFRs, soluble TNFRs or mRNA of TNFRs. However, THP‐1 cell infection with living parasites induced a significant soluble TNFR1 release by THP‐1 cells after 1 h. We detected an approximately 50% up‐regulation (P < 0·01) of soluble TNFR1 in infected THP‐1 cells compared to controls. No change in soluble TNFR2 levels was observed in the same conditions. Moreover, infection decreased the level of TNF membrane receptors, but had no effect on TNFR1 and TNFR2 mRNA levels. TNFR modulation by T. gondii infection, in vitro, depends on the cell type. Furthermore, our data suggest that living parasites control the shedding of the soluble form of TNFR1. This mechanism may influence the role of TNF‐α in toxoplasmosis.
Attempts to immunize sheep against the scab mite, Psoroptes ovis
Authors: Smith W. D. , Bates P. , Pettit D. M. , Van Den Broek A. , Taylor M. A.
Published: March 2003

Adult Psoroptes ovis were successively extracted in saline, 1% Tween, 1% Triton and 8 m urea +0·1% CHAPS. The Triton extract was separated into fractions which did or did not bind to ConA lectin. Using QuilA as adjuvant, both Triton fractions and the saline, Tween and urea extracts were tested separately as candidate protective antigens against a P. ovis challenge infestation in sheep. All induced circulating antibody responses, but the saline and Tween extracts also stimulated significant protective effects in those sheep which developed active disease. Compared to control sheep injected with adjuvant only, these immunized animals had more than two and seven‐fold reductions in mean lesion areas and mite numbers, respectively.
A model for blood meal digestion and fat metabolism in male tsetse flies (Glossinidae)
Authors: LODER PHILIP M. J. , HARGROVE JOHN W. , RANDOLPH SARAH E.
Published: March 2003

Abstract. Fat and haematin levels of mature male Glossina morsitans morsitans Westwood were estimated at different times after feeding at temperatures between 15 and 30°C. Flies were kept (largely inactive) in 7.5 × 2.5 cm tubes, or in actograph cages, where flight activity increased with time after feeding. Haematin excretion was modelled as a series of three first order reactions, all with the same rate parameter. The model accounted for > 98% of the variance in mean haematin in each of seven experiments; the rate parameter increased linearly with temperature and activity level. A similar approach was adopted for modelling fat metabolism. The rate coefficients of lipogenesis increased with temperature, and that for lipolysis with temperature, activity level and their interaction. All experiments were analysed simultaneously to provide equations predicting haematin or fat levels for all times, for active or inactive flies, and for temperatures between 15 and 30°C. Haematin exhibited large variations between individuals, but for active flies the expected haematin content at a given time varied little between flies kept at 25 and at 30°C. In inactive flies kept at 25°C, lipogenesis peaked at ≈ 24 h and lipolysis at ≈ 48 h. For active flies the times were 12 and 24 h, respectively; both rates were about twice as high as in inactive flies. Active flies produced (up to 1 mg) more fat out of a given size of blood meal than inactive flies. Curves of fat content against logarithm of haematin content differed little with temperature, and can therefore be useful for comparative studies of field populations of tsetse.
Trap‐jaws revisited: the mandible mechanism of the ant Acanthognathus
Authors: GRONENBERG WULFILA , BRANDÃO C. ROBERTO F. , DIETZ BODO H. , JUST STEFAN
Published: March 2003

Abstract.Ants of the genus Acanthognathus stalk small insects and catch their prey by a strike with their long, thin mandibles. The mandibles close in less than 2.5 ms and this movement is controlled by a specialized closer muscle. In Acanthognathus, unlike other insects, the mandible closer muscle is subdivided into two distinct parts: as in a catapult, a large slow closer muscle contracts in advance and provides the power for the strike while the mandibles are locked open. When the prey touches specialized trigger hairs, a small fast closer muscle rapidly unlocks the mandibles and thus releases the strike. The fast movement is steadied by large specialized surfaces in the mandible joint and the sensory‐motor reflex is controlled by neurones with particularly large, and thus fast‐conducting, axons.
Mate finding in the forest cockchafer, Melolontha hippocastani, mediated by volatiles from plants and females
Authors: Ruther J. , Reinecke A. , Thiemann K. , Tolasch T. , Francke W. , Hilker M.
Published: March 2003

The response of the forest cockchafer, Melolontha hippocastani F. (Coleoptera, Scarabaeidae), towards volatiles emitted by different host plants and conspecifics was tested in field experiments during the flight period at dusk. Funnel traps containing artificially damaged leaves from the host plants Carpinus betulus L. and Quercus rubra L., as well as from the non‐host plant Prunus serotina Ehrh. caught significantly more beetles than empty control traps. On the other hand, traps baited with undamaged leaves from Q. rubra did not catch significantly more beetles than empty controls. Leaves from C. betulus damaged by beetle feeding did not attract more beetles than artificially damaged leaves. By use of gas chromatography coupled with electroantennographic detection (GC‐EAD) electrophysiological responses of males and females were shown for 18 typical plant volatiles. A synthetic mixture of selected typical green plant volatiles was also highly attractive in the field. A total of 9982 beetles was caught during the field experiments, among them only 33 females. This suggests that attraction to damaged foliage during flight period at dusk is male‐specific. Field experiments testing the attractiveness of female M. hippocastani towards conspecific males by employing caged beetles and beetle extracts indicated that males of M. hippocastani use a female‐derived sex pheromone for mate location. On wired cages containing either unmated feeding females, or unmated females without access to foliage, or feeding males in combination with extracts from unmated females, significantly more males landed during the flight period than on comparable control cages containing feeding males or male extracts. A possible scenario of mate location in M. hippocastani involving feeding‐induced plant volatiles and a female‐derived sex pheromone is discussed.
Topical application of Pya‐AKH stimulates lipid mobilization and locomotion in the flightless bug, Pyrrhocoris apterus (L.) (Heteroptera)
Authors: Kodrík Dalibor , Socha Radomír , Zemek Rostislav
Published: March 2003

Abstract Two different methods of applying Pya‐AKH to long‐winged (macropterous) females of the firebug, Pyrrhocoris apterus (Linnaeus) (Heteroptera) were compared: both injection and topical application increased the levels of lipids in the haemolymph and stimulated locomotor activity. Lipid mobilization was maximal when 10 pmol was applied by injection or 40–100 pmol by topical application, with the first significant responses occurring 1.5 h after injection and 2 h after topical application. The highest elevations of lipid concentration in the haemolymph were comparable between the treatments, i.e. 14.36 ± 3.59 mg/mL for injection and 14.43 ± 4.07 mg/mL for topical application. However, these maximal elevations were achieved at different times: 3 h after the injection and 7 h after the topical application.

Injection of 10 and 40 pmol of Pya‐AKH stimulated locomotor activity with maximal activity 3 h later but, surprisingly, injection of 80 pmol showed no effect initially and than a slight inhibitory effect after 6–8 h.

Increased locomotor activity was found after topical application of Pya‐AKH, but the response was lower than after injection and appeared later, 5–9 h after the hormone application. In addition, the greatest increase in walking activity required topical application of 300 pmol and was still less dramatic than the response to injection. The stimulatory effect of Pya‐AKH on locomotion was positively correlated with its effect on lipid mobilization only for injection of the hormone. It is argued that a stress caused by injection could play a role in the appearance of the complex response to adipokinetic hormone.
Olfactory responses of the vine weevil, Otiorhynchus sulcatus, to tree odours
Authors: Van Tol R. W. H. M. , Visser J. H. , Sabelis M. W.
Published: March 2003

Abstract A Y‐tube olfactometer and a still‐air olfactometer were developed to determine the attractiveness of several host plants for the vine weevil (Otiorhynchus sulcatus (F.); Coleoptera: Curculionidae). Odours of weevil‐damaged yew (Taxus baccata) and spindle trees (Euonymus fortunei) are attractive to the vine weevil, but Rhododendron and strawberry (Fragaria × ananassa) are not. Undamaged Euonymus is attractive to the weevils in springtime but not in late summer. When clean air or undamaged Euonymus is the alternative, weevils strongly prefer weevil‐damaged Euonymus foliage, and this preference is retained throughout the year. Hence, plant damage plays a role in attraction of the vine weevil. In contrast to the permanent attractiveness of weevil‐damaged Euonymus, mechanically damaged plants gradually lose the attractiveness that they have early in the growing season. This suggests that emission of volatiles, produced by the plants in response to weevil damage, is important for attraction of the weevils because the weevils may use these plant odours to find suitable food plants throughout the season. Apart from weevil‐damage‐related plant volatiles, green leaf volatiles must also play a significant role, as indicated by the fact that weevils prefer: early season, undamaged Euonymus over clean air; early season, mechanically damaged Euonymus over undamaged Euonymus; and, throughout the season, had no preference when mechanically damaged Euonymus is tested against weevil‐damaged Euonymus. Thus, monitoring traps may be developed by the use of green leaf volatiles and/or herbivore‐induced volatiles, as attractants.
The chilling sensitivity of root ammonium influx in a cultivated and wild tomato
Authors: Bloom A. J. , Randall L. B. , Meyerhof P. A. , St Clair D. A.
Published: March 2003

A chilling episode of a few hours damaged root ammonium absorption in a cultivated tomato (Lycopersicon esculentum cv. T‐5), but not in a wild congener from high altitudes (Lycopersicon hirsutum LA1778). In the cultivar, ammonium influx was strongly temperature dependent and showed the residual effects of chilling, whereas ammonium efflux was nearly temperature invariant and showed no persistent effects. A 2 h exposure to 5 °C significantly depressed subsequent ammonium absorption at 20 °C, and about 12 h at 20 °C was required for recovery. For both the cultivated and wild species, rerooted cuttings were slightly less sensitive to chilling than seedlings. The relative inhibition (mean ± SE) of ammonium absorption before and after chilling was 58·4 ± 2·5% for the cultivated species and 29·0 ± 9·1% for the wild species. The F1 hybrid between the species showed a relative inhibition of 52·4 ± 3·6%, suggesting that chilling sensitivity may be dominant. In a backcross of the hybrid to L. esculentum, the phenotypic distribution of the relative inhibition of ammonium absorption indicated that this trait is segregating.
Light and temperature dependence of the emission of cyclic and acyclic monoterpenes from holm oak (Quercus ilex L.) leaves
Authors: Staudt M. , Bertin N.
Published: March 2003

In a laboratory study, we investigated the monoterpene emissions from Quercus ilex, an evergreen sclerophyllous Mediterranean oak species whose emissions are light dependent. We examined the light and temperature responses of individual monoterpenes emitted from leaves under various conditions, the effect of heat stress on emissions, and the emission‐onset during leaf development. Emission rate increased 10‐fold during leaf growth, with slight changes in the composition. At 30 °C and saturating light, the monoterpene emission rate from mature leaves averaged 4·1 nmol m–2 s–1, of which α‐pinene, sabinene and β‐pinene accounted for 85%. The light dependence of emission was similar for all monoterpenes: it resembled the light saturation curve of CO2 assimilation, although monoterpene emission continued in the dark. Temperature dependence differed among emitted compounds: most of them exhibited an exponential increase up to 35 °C, a maximum at 42 °C, and a slight decline at higher temperatures. However, the two acyclic isomers cis‐β‐ocimene and trans‐β‐ocimene were hardly detected below 35 °C, but their emission rates increased above this temperature as the emission rates of other compounds fell, so that total emission of monoterpenes exponentially increased from 5 to 45 °C. The ratio between ocimene isomers and other compounds increased with both absolute temperature and time of heat exposure. The light dependence of emission was insensitive to the temperature at which it was measured, and vice versa the temperature dependence was insensitive to the light regime. The results demonstrated that none of the models currently applied to simulate isoprene or monoterpene emissions correctly predicts the short‐term effects of light and temperature on Q. ilex emissions. The percentage of fixed carbon lost immediately as monoterpenes ranged between 0·1 and 6·0% depending on temperature, but rose up to 20% when leaves were continuously exposed to temperatures between 40 and 45 °C.