bluuebunny/crossref_metadata_2025 huggingface dataset:
Bond strength of fibre‐reinforced composite to the metal surface
Authors: Vallittu P. K. , Kurunmäki H.
Published: August 2003

Summary  The aim of this study was to measure push‐out bond strength of gold alloy and pure titanium bars to dimethacrylate polymer‐glass fibre composite. Metal bars were either left untreated, or sandblasted with 110 μm grain size aluminium oxide, pyrolytically silica‐coated (Silicoater, Heraeus Kulzer) and silanized, tribochemically silica‐coated, silanized (Rocatec, 3M‐ESPE) and heat treated (100 °C/10 min), or tribochemically silica‐coated and left unsilanized. Light‐polymerizable opaque was applied on the metal surface and unidirectional glass fibres with Bis‐GMA–PMMA monomer–polymer gel matrix was placed in contact to the bars and polymerized. Push‐out test was performed for dry specimens and for those thermocycled (12·000 ×55–5 °C). For titanium and gold alloy silica‐coatings with the silane treatments resulted in the highest bond strengths. Values for titanium were somewhat higher than those for gold alloy. Silica‐coating without silane treatment gave lower bond strengths but higher than that obtained with aluminium oxide sandblasting. The control specimens showed the lowest bond strength values. anova showed differences between the groups (P < 0·0001) whereas no significant differences between dry and thermocycled specimens were found. The results suggest that pyrolytical silica‐coating with silane application resulted in highest bond strengths of dimethacrylate based fibre‐reinforced composite to pure titanium and gold alloy.
The effect of the addition of poly (methyl methacrylate) fibres on the transverse strength of repaired heat‐cured acrylic resin
Authors: Jagger D. C. , Alshumailin Y. R. , Harrison A. , Rees J. S.
Published: August 2003

Summary The aim of the present study was to investigate the effect of addition of an experimental poly (methyl methacrylate) (PMMA) fibre in linear form, 0·75 mm in diameter on the transverse strength of repaired heat‐cured poly (methyl methacrylate) denture base material. Specimens of heat‐cured PMMA were repaired with an autopolymerizing acrylic resin and an autopolymerizing acrylic resin together with the addition of untreated and surface‐treated PMMA fibres in different arrangements. The transverse bend test was carried out using a LIoyd's Instrument Material Testing Machine. From the results, it can be concluded that the box incorporated into the repair joint produced a significant decrease in the moduli of elasticity and rupture which may be due to stress concentration effects. The addition of one layer of untreated PMMA fibres significantly decreased the modulus of rupture. The addition of two layers of untreated fibres produced a slight but statistically non‐significant increase in the modulus of rupture. The addition of surface‐treated (with butadiene styrene latex emulsion) fibres into the repair complex gave no improvement compared with the addition of untreated fibres in terms of transverse strength. There was an insignificant decrease in the modulus of rupture compared with the untreated fibres.
A simplified sieve method for determining masticatory performance using hydrocolloid material
Authors: Ohara A. , Tsukiyama Y. , Ogawa T. , Koyano K.
Published: August 2003

Summary  The purpose of this study was to develop a simplified technique for measuring masticatory performance by measuring the particle size distribution of masticated hydrocolloid impression material using a sieve method. Masticatory performance was defined as the rate of increase in the number of particles of masticated material on specific sieves with the increment in the number of chewing strokes. The number and weight of masticated hydrocolloid impression material on 10 sieves were compared with results for peanuts. The reproducibility of this method to determine masticatory performance was then examined. In seven sieves, there was a linear relationship between the number of particles and the number of chewing strokes for the hydrocolloid impression material; Pearson's correlation coefficient was higher for the hydrocolloid impression material than for peanuts. Measuring masticatory performance three times a day and three times every week revealed there were no differences in intra‐individual variation in masticatory performance in six sieves. There was no significant difference between the masticatory performance calculated from two mastication tasks using the specific sieves and that calculated from seven tasks. These results suggest that this simplified sieve method using hydrocolloid materials can be reliably used for research purposes and in clinical situations.
Evaluation of penetration and adaptation of three different sealers: a SEM study
Authors: Sevimay S. , Dalat D.
Published: August 2003

Summary  In this study, dentinal penetration and adaptation of three endodontic sealers were evaluated by using scanning electron microscope (SEM). Seventeen recently extracted, human maxillary anterior teeth were used. After the crowns were removed from the cementoenamel junction, the root canals were instrumented. The teeth were then randomly divided into three groups of five roots each and two teeth were used as controls. The smear layer was removed with EDTA and NaOCl. The canals were obturated with AH 26, CRCS, RSA sealers and gutta‐percha using lateral condensation technique. Each root was sectioned longitudinally and then prepared for SEM evaluation. The SEM results showed that AH 26 was the best sealer penetrating into dentinal tubules and adapted to dentinal walls when compared with the CRCS and RSA. The CRCS and RSA occluded the orificies of dentinal tubules. The RSA showed that the penetration was less than AH 26 and more than CRCS.
Stress analysis of an upper central incisor restored with different posts
Authors: De Castro Albuquerque R. , De Abreu Polleto L. T. , Fontana R. H. B. T. S. , Cimini C. A.
Published: August 2003

Summary  The effect of different anatomic shapes and materials of posts in the stress distribution on an endodontically treated incisor was evaluated in this work. This study compared three post shapes (tapered, cylindrical and two‐stage cylindrical) made of three different materials (stainless steel, titanium and carbon fibre on Bisphenol A‐Glycidyl Methacrylate (Bis‐GMA) matrix). Two‐dimensional stress analysis was performed using the Finite Element Method. A static load of 100N was applied at 45° inclination with respect to the incisor's edge. The stress concentrations did not significantly affect the region adjacent to the alveolar bone crest at the palatine portion of the tooth, regardless of the post shape or material. However, stress concentrations on the post/dentin interface on the palatine side of the tooth root presented significant variations for different post shapes and materials. Post shapes had relatively small impact on the stress concentrations while post materials introduced higher variations on them. Stainless steel posts presented the highest level of stress concentration, followed by titanium and carbon/Bis‐GMA posts.
Salivary flow rate and pH during prolonged gum chewing in humans
Authors: Polland K. E. , Higgins F. , Orchardson R.
Published: August 2003

Summary  Gum chewing for 20 min causes an increase in salivary flow rate and salivary pH. Most people chew gum for longer than 20 min, and our aim was to determine how whole mouth salivary flow rate and pH might adapt during prolonged gum chewing. Resting saliva was collected over 5 min; gum‐stimulated saliva was collected at intervals during 90 min, chewing a single pellet (1·5 g) of mint‐flavoured, sugar‐free gum (n = 19). Subjects chewed at their own preferred rate and style. Both salivary flow rate and pH were increased above resting levels for the entire 90 min. The salivary flow was significantly greater (anovaP < 0·05) than resting flows up to 55‐min chewing. The saliva pH remained significantly higher (P < 0·0001) than the resting pH even after 90‐min chewing. When the experiment was repeated with the gum pellets replaced at 30 and 60 min (n = 9), similar increases in salivary flow rate and pH were found. In the latter experiment, there was no evidence of any cumulative effects on flow or pH. The persistent increase in salivary pH in particular could be beneficial to oral and dental health.
Spatial and temporal partitioning of behaviour by adult dacines: direct evidence for methyl eugenol as a mate rendezvous cue for Bactrocera cacuminata
Authors: Raghu S. , Clarke A. R.
Published: August 2003

Abstract.  Resource use in adult Dacinae (Diptera: Tephritidae) is believed to be restricted to the host plant (i.e. the plant that provides fruit for oviposition and larval development). However, studies on Bactrocera cacuminata did not support this hypothesis. Thus, it was hypothesized that adult flies partition their diurnal activities between spatially separated resources (host plant, sugar, protein and methyl eugenol) as a function of the physiological status of the fly (immature, mature–unmated, mature–mated). In accordance with a priori predictions, the results of a field‐cage study show that there are significant diurnal patterns in abundance and behaviour, and that flies of different physiological status use resources differently. Immature flies spend most of their time foraging for sugar and protein to facilitate development. Sexually mature flies forage for sugars during the day, and at dusk, responded strongly to methyl eugenol and mate. The fact that polygynous males wait at methyl eugenol at dusk whereas the mated, monandrous females spend their time ovipositing in fruit and are nonresponsive to methyl eugenol, supports Metcalf's hypothesis that such phenylpropanoids serve as mate rendezvous cues.
Biological effects of alkaloïds extracted from three plants of Moroccan arid areas on the desert locust
Authors: Abbassi Khadija , Atay‐Kadiri Zineb , Ghaout Said
Published: August 2003

Abstract. The effects of three plant species, Calotropis procera, Zygophyllum gaetulum and Peganum harmala on survival, feeding behaviour and reproduction in the desert locust (Schistocerca gregaria) were studied under laboratory conditions. The species originate in Moroccan arid areas and were seen to be avoided by locusts during the 1995 upsurge in Morocco. Alkaloids were extracted from leaves of the plants and applied topically to lettuce for leaves which were then offered with no other food to young adults of the desert locust for 3 days. The locust were then fed on untreated lettuce for 15 days. Controls were fed with lettuce leaves treated with ethanol. The results indicate that the alkaloids extracted from each of the three plant species cause a significant mortality compared to untreated controls and reduced food intake, as well as causing weight loss. Alkaloids extracted from C. procera and Z. gaetulum prevent sexual maturity both in males and females. However, alkaloids extracted from P. harmala merely delay sexual maturity by at least 8 days and engender a reduction in female fecundity and hatching rate compared to untreated controls. The presence and the concentration of alkaloids and other secondary substances in the investigated plants may explain the avoidance behaviour manifested by locusts under natural conditions.
The effect of temperature on the behaviour and development of Triatoma brasiliensis
Authors: Guarneri Alessandra A. , Lazzari Claudio , Xavier Ana Amélia P. , Diotaiuti Liléia , Lorenzo Marcelo G.
Published: August 2003

Abstract.  The effects of temperature on the development of early stages and the thermopreference of nymphs and adults were analysed in the haematophagous bug Triatoma brasiliensis Neiva, 1911 (Hemiptera, Reduviidae). Egg hatching, mortality of nymphs, feeding and moulting success of the early stages of T. brasiliensis were all affected by temperature. While high rates of egg hatching were observed between 25 and 27 °C, no hatching occurred at 12, 19 and 38 °C. The mortality of first‐instar nymphs was highest at 38 °C, at which no insects survived after 10 days of exposure. Feeding success was only affected at the lowest temperature (12 °C). No ecdysis was observed in the groups exposed to 12, 19 and 21 °C. Recently fed fourth‐instar nymphs preferred to stay at a temperature of approximately 30 °C. The preferred temperature began to decline gradually to approximately 27 °C during ecdysis, reaching 26 °C at 30 days after ecdysis. After a second blood meal, the insects' preferred temperature was again approximately 30 °C. The thermopreference pattern of females was similar to that of nymphs. Nymphs and females showed a daily fluctuation in their preferred temperature, moving towards higher values at the beginning of the dark phase, and choosing lower ones after this time interval, at which they remained until the end of the light phase. The females laid their eggs in all sectors of the arena, although the largest numbers of eggs were found between 28 and 32 °C.
Pheromone trail decay rates on different substrates in the Pharaoh's ant, Monomorium pharaonis
Authors: Jeanson Raphaël , Ratnieks Francis L. W. , Deneubourg Jean‐Louis
Published: August 2003

Abstract.  Many ants use pheromone trails to organize collective foraging. This study investigated the rate at which a well‐established Pharaoh's ant, Monomorium pharaonis (L.), trail breaks down on two substrates (polycarbonate plastic, newspaper). Workers were allowed to feed on sucrose solution from a feeder 30 cm from the nest. Between the nest and the feeder, the trail had a Y‐shaped bifurcation. Initially, while recruiting to and exploiting the feeder, workers could only deposit pheromone on the branch leading to the feeder. Once the trail was established (by approximately 60 ants per min for 20 min), the ants were not allowed to reinforce the trail and were given a choice between the marked and unmarked branches. The numbers of ants choosing each branch were counted for 30 min. Initially, most went to the side on which pheromone had been deposited (80% and 70% on the plastic and paper substrates, respectively). However, this decayed to 50% within 25 min for plastic and 8 min for paper. From these data, the half‐life times of the pheromone are estimated as approximately 9 min and 3 min on plastic and paper, respectively. The results show that, for M. pharaonis, trail decay is rapid and is affected strongly by trail substrate.
Motivation models fail to explain oviposition behaviour in the diamondback moth
Authors: Monks Adrian , Kelly Dave
Published: August 2003

Abstract.  It is widely accepted that previous experience and internal physiological factors (such as egg‐load) affect host‐plant discrimination during oviposition by phytophagous insects. However, there is some debate as to how these factors interact in a mechanistic sense to control acceptance. The role of learning and host deprivation in host acceptance by adult diamondback moths (Plutella xylostella L.) was investigated. In the first experiment, we tested whether experience of a lower ranked host cabbage increased acceptance of a higher ranked host as predicted by a hierarchy threshold model. Moths trained on cabbage were over three times more likely to accept cabbage during testing than untrained moths. There was no effect of cabbage training on acceptance of cress, indicating that the effect of training was species‐specific. In a second experiment, designed to test the prediction of motivation models that insects become less discriminating when deprived of oviposition opportunities, depriving females of host plants for 2 nights significantly increased female egg‐load (×2.3). Host deprivation did not decrease discrimination between the preferred host cress and cabbage. Cabbage and cress plants were equally likely to have been accepted by nondeprived moths after 1 night of exposure, yet moths deprived of hosts for 2 nights strongly preferred cress when tested during the first 20 min of the scotophase. During this 20‐min period, previous host deprivation increased acceptance of host plants generally but did not decrease discrimination between hosts. These data contradict the expectation that there is an inverse relationship between host species discrimination and the failure of an insect to find hosts as found in existing oviposition acceptance models. As an alternative, the Incremental Acceptance Model of host acceptance behaviour is presented, in which responsiveness to a host is a function of the recent encounter rate with host‐specific stimuli, and the oviposition reflex is regulated by nonspecific cues such as egg‐load.
Searching by visual and acoustic cues among bushcrickets (Orthoptera: Tettigoniidae): will females remain faithful to a male who stops calling?
Authors: Bailey W. J. , Ager E. I. , O'Brien E. K. , Watson D. L.
Published: August 2003

Abstract. Female nocturnal bushcrickets (Requena verticalis: Listroscelidinae: Tettigoniidae: Orthoptera) orientate towards and approach a conspecific male by tracking the direction of its call. If a male stops calling during this approach, the female may remain faithful and continue on the same track or change direction and pursue another calling male. Factors that might influence this decision were examined experimentally. When presented with a male call in conjunction with a visual cue, females maintained orientation towards the visual cue following cessation of the call. Furthermore, when a visual cue was presented with an acoustic cue, females were more likely to be faithful, regardless of call intensity.
Electroantennogram responses of aphid nymphs to plant volatiles
Authors: Chung Park Kye , Hardie Jim
Published: August 2003

Abstract.  Electroantennogram (EAG) responses of immature aphids were investigated for 30 plant volatile compounds in third‐ and fourth‐stadium nymphs of the black bean aphid, Aphis fabae. The nymphs were destined to develop into adult alate (winged) virginoparae. The EAG response profiles were similar to those previously reported in the adults. Among the compounds tested, hexanonitrile elicited the largest EAG responses in both nymphal stadia, corresponding to previously reported results with adults. Six‐carbon aliphatic compounds showed relatively higher EAG activities in the nymphs but, in contrast, (E)‐2‐hexenal, benzaldehyde, α‐pinene and β‐pinene, and citronellal elicited relatively smaller EAG responses in nymphs than adults. Although overall EAG response profiles were similar between the third and the fourth stadia for the majority of the volatiles, four aldehyde compounds, hexanal (E)‐2‐heptenal, 2‐hydroxybenzaldehyde and citronellal, showed relatively higher EAG activities in the third than in the fourth stadium. The present study indicates that aphid nymphs possess a functional olfactory receptor system before the antennae are fully developed morphologically and physiologically.
Determinants of oviposition inAcanthoscelides obtectus: a nonconformist bruchid
Authors: Parsons Deborah M. J. , Credland Peter F.
Published: August 2003

Abstract.Acanthoscelides obtectusis atypical of bruchids found in stored seeds because females do not attach eggs individually to host seeds but scatter them irregularly among potential hosts. In other respects, its life history resembles that of other species and comparison provides evidence for the adaptive nature of their behaviour. Individual females differ dramatically in the temporal pattern of their oviposition. The hypothesis is proposed that this is an adaptation to life in heterogeneous habitats. Oviposition is not regulated by host availability to the same extent as in other bruchids, providing evidence that regulation of the number of eggs laid by species which stick eggs to host seeds is an adaptation to the abundance of hosts. The continued presence of males and opportunity for multiple matings does not affect fecundity or egg viability. Females preferentially lay on clean seeds when provided with a choice between them and seeds previously exposed to other adult beetles. However, they do not appear to be deterred by, or cannot detect, the presence of larvae infesting seeds. Other bruchid species avoid such seeds that they can identify by the occurrence of egg cases and pheromones. The number of eggs laid is influenced by the host cultivar available for oviposition. Oviposition byA. obtectusappears to be an adaptation to both storage environments and the heterogeneous environment of a growing crop or uncultivated land. Its behaviour suggests an ancestral condition in bruchids and the changes which might have occurred in the ecology of other bruchid species as they have adapted to become pests of human seed stores.
Insect duets: underlying mechanisms and their evolution
Authors: Bailey Winston J.
Published: August 2003

Abstract. Duetting between the sexes in insects involves the use of airborne acoustic signals, substrate vibration and bioluminescence. Unlike avian duets, in which females may initiate the interaction, among insects the duet starts with the male, and the female usually provides a brief reply. Insect duets are characterized by low variance in the reply latency of the female (the time between a key element in the male call and the onset of the female's response). Duetting is reviewed principally in Orthoptera but also in Plecoptera, Hemiptera, Neuroptera and bioluminescence in the Coleoptera. The mechanisms of the duet are examined first, followed by evolution and the associated change in searching strategies of each sex. As defined, the duet has distinct temporal characteristics and these are compared with acoustic interactions among males in those species that exhibit male–male synchrony and alternation. For insects, the key element of a duet for species' recognition is low variance in the reply latency of females. In cases in which the male's initiating signal is extremely short, reply latencies become indicators of species' recognition. However, in those species in which the initiating male call is under selection through female choice, the male call is predictably longer and occasionally more complex. Under these circumstances, reply latencies often increase, creating an opportunity for alternative male tactics. When alternative tactics exist in nature, males may decrease the intensity of their call, insert a trigger pulse that signals to the female the end of its complex call, or males may even add a masking signal that obscures the competing signal.
Role of placental alkaline phosphatase in the internalization of trypomatigotes ofTrypanosoma cruziinto HEp2 cells
Authors: Sartori M. J. , Mezzano L. , Lin S. , Muñoz S. , de Fabro S. P.
Published: August 2003

SummaryBackgroundIn vitro, Trypanosoma cruziinvades a wide variety of mammalian cells by an unique process that is still poorly understood. Trypomastigotes adhere to specific receptors on the outer membrane of host cells before intracellular invasion, causing calcium ion mobilization and rearrangement of host cell microfilaments.

ObjectiveTo test if placental alkaline phosphatase (PLAP), a trophoblast plasma membrane protein anchored by a glycosylphosphatidylinositol molecule, is involved in the transplacental transmission of this parasite.

MethodWe cultured HEp2 cells with the parasite and studied PLAP and actin microfilaments. The results were correlated with invasion rate.

ResultsHuman HEp2 tumour cells express PLAP. HEp2 cells infected with trypomastigotes showed alteration in their alkaline phosphatase activity and a different pattern of actin organization, compared to control cells. Perturbation of PLAP from HEp2 cells before infection withT. cruzitrypomastigotes decreased the invasion rate.

ConclusionPlacental alkaline phosphatase could be involved in the internalization ofT. cruziinto HEp2 cells, via activation of tyrosine kinase and rearrangement of actin microfilaments.
Variation in incidence of serious adverse events after onchocerciasis treatment with ivermectin in areas of Cameroon co‐endemic for loiasis
Authors: Twum‐Danso Nana A. Y. , Meredith Stefanie E. O.
Published: August 2003

Summary Objective To determine the incidence of serious adverse events (SAEs) after mass treatment with ivermectin in areas co‐endemic for loiasis and onchocerciasis, and to identify potential risk factors associated with the development of these SAEs, in particular encephalopathic SAEs.

Methods We retrospectively analysed SAEs reported to have occurred between 1 December 1998 and 30 November 1999 in central‐southern Cameroon by chart review, interview and examination of a subset of patients.

Results The overall incidence of SAEs for the three provinces studied was 6 per 100 000. However, for Central Province alone the incidence of SAEs was 2.7 per 10 000 overall, and 1.9 per 10 000 for encephalopathic SAEs associated with Loa loa microfilaremia (PLERM). The corresponding rates for the most severely affected district within Central Province (Okola) were 10.5 per 10 000 and 9.2 per 10 000 respectively. Symptoms began within the first 24–48 h of ivermectin administration but there was a delay of approximately 48–84 h in seeking help after the onset of symptoms. First‐time exposure to ivermectin was associated with development of PLERM.

Conclusion In Cameroon, the incidence of SAEs following ivermectin administration in general, and PLERM cases in particular, varies substantially by district within the areas co‐endemic for loiasis and onchocerciasis. More intense surveillance and monitoring in the first 2 days after mass distribution in ivermectin‐naïve populations would assist in early recognition, referral and management of these cases. The increased reporting of SAEs from Okola is unexpected and warrants further investigation. Research is urgently needed to find a reliable screening tool to exclude individuals (rather than communities) at risk of PLERM from the mass treatment program.
Seasonal profiles of malaria infection, anaemia, and bednet use among age groups and communities in northern Ghana
Authors: Koram Kwadwo A. , Owusu‐Agyei Seth , Fryauff David J. , Anto Francis , Atuguba Frank , Hodgson Abraham , Hoffman Stephen L. , Nkrumah Francis K.
Published: August 2003

Summary We conducted all‐age point prevalence surveys to profile the severity and seasonality of malaria and anaemia in Kassena‐Nankana District of northern Ghana. Random cross‐sectional surveys were timed to coincide with the end of low (May 2001) and high (November 2001) malaria transmission seasons and to yield information as to the potential value of haemoglobin (Hb) levels and parasitaemia as markers of malaria morbidity and/or malaria vaccine effect. Parasitaemia was found in 22% (515 of 2286) screened in May (dry‐low transmission), and in 61% of the general population (1026 of 1676) screened in November (wet‐high transmission). Malaria prevalence in May ranged from 4% (infants <6 months and adults 50–60 years) to 54% (children 5–10 years). Age‐specific malaria prevalence in November ranged from 38% (adults 50–60 years) to 82% (children 5–10 years). Differences between low‐ and high‐transmission periods in the prevalence of severe anaemia (SA) among young children (6–24 months) were unexpectedly comparable (low, 3.9%vs. high, 5.4%; P = 0.52) and greatly reduced from levels measured in this same community and age group in November 2000 (12.5%) and November 1996 (22.0%). Despite the lower frequency of anaemia/SA in young children surveyed in 2001, it was still clear that this condition was strongly associated with parasitaemia and that children under 5 years of age experienced a significant drop in their mean Hb levels by the end of the high transmission season. Prevalence of parasitaemia was significantly lower (P < 0.01) among infants and young children (<2 years) whose parents reported the use of bednets. There was a significantly lower risk of parasitaemia among infants [odds ratio (OR) 6–8] and young children (OR 3–4) living in the central, more urbanized sector of the study area.
Plasmodium falciparum gametocytaemia in Nigerian children: before, during and after treatment with antimalarial drugs
Authors: Sowunmi A. , Fateye B. A.
Published: August 2003

Summary We evaluated gametocyte carriage and intensities of gametocytaemia in 710 children presenting with acute, symptomatic, uncomplicated Plasmodium falciparum malaria who were treated with various antimalarial drug regimens: chloroquine (CQ); chloroquine plus chlorpheniramine, a histamine H1 receptor antagonist that reverses CQ resistance in P. falciparum in vitro and in vivo (CQCP); chloroquine plus ketotifen, a histamine H1 receptor antagonist that reverses CQ resistance in P. falciparum in vitro but not in vivo in the present study (CQK); chloroquine plus pyrimethamine–sulphadoxine (CQPS); amodiaquine (AQ); amodiaquine plus pyrimethamine–sulphadoxine (AQPS); and pyrimethamine–sulphadoxine (PS). On presentation, gametocyte carriage was significantly higher in CQ‐resistant (CQ‐R) than in CQ‐sensitive (CQ‐S) infections. Following CQ treatment, gametocyte carriage was significantly higher at all times after treatment and gametocyte density significantly higher on day 7 of follow‐up in children with CQ‐R than CQ‐S infections. CQ treatment of CQ‐R infections resulted in significantly higher density of gametocytaemia on day 7 compared with pre‐treatment (day 0), but similar treatment of CQ‐S infections resulted in significantly lower density of gametocytaemia on day 14 compared with day 0. Among children with CQ‐R infections, those with mild (RI) resistance carried gametocytes significantly more often than those with moderate (RII) resistance on days 5 and 7 of follow‐up (P = 0.04 and 0.01, respectively). Disposition kinetics of gametocytaemia using a non‐compartmental method showed that the half life of gametocytaemia was longer and the clearance slower in children with CQ‐R than in those with CQ‐S infections. PS treatment was associated with significantly higher gametocyte carriage at all times between days 1 and 14, and significantly higher gametocytaemias on days 7 and 14 than in the other treatment regimens. Combination of AQ with PS significantly decreased gametocyte carriage at all times between days 1 and 14 of follow‐up. Continuing use of CQ in CQ‐R infections may encourage transmission of CQ‐R infections; SP monotherapy is associated with significant gametocyte carriage and gametocytaemia and may encourage transmission of SP resistant infections as resistance to the drug increases.
Plasmodium falciparum: correlation of in vivo resistance to chloroquine and antifolates with genetic polymorphisms in isolates from the south of Lao PDR
Authors: Berens Nicole , Schwoebel Babett , Jordan Sabine , Vanisaveth Viengxay , Phetsouvanh Rattanaxay , Christophel Eva‐Maria , Phompida Samlane , Jelinek Tomas
Published: August 2003

Levels of drug resistance of Plasmodium falciparum strains against antimalarials have increased in Laos. In several studies, chloroquine (CQ) resistance has been associated with point mutations in the Pfcrt and pfmdr genes, and sulphadoxine/pyrimethamine (S/P) resistance with point mutations in the genes of dihydrofolate reductase (DHFR) and dihydropteroate synthetase (DHPS). We combined a study of these molecular markers with an in vivo antimalarial drug sensitivity study in Attapeu province in the south of Lao PDR. We treated 100 patients with either CQ, S/P or a combination of both. In the CQ group, Pfcrt mutations showed a very high sensitivity (100%) but a low specificity (12.5%) to predict resistance. The combination of mutations in the Pfcrt and pfmdr genes was highly specific and had a positive predictive value of 100%. Mutations in the DHPS gene showed a high correlation with the development of resistance. The prevalence of mutations in the DHFR gene, especially codon 108 Asn, was predictive with high sensitivity (100%) but low specificity. Isolates derived from patients treated with a combination of both drugs showed a high correlation between the mutation in codon 437 of DHPS gene and in vivo‐resistance (odds ratio 16.00, CI). The study provides evidence for the existence of antimalarial drug resistance in the south of Lao PDR, and offers a molecular method to predict resistance.
An estimation of the entomological inoculation rate for Ifakara: a semi‐urban area in a region of intense malaria transmission in Tanzania
Authors: Drakeley C. , Schellenberg D. , Kihonda J. , Sousa C. A. , Arez A. P. , Lopes D. , Lines J. , Mshinda H. , Lengeler C. , Schellenberg J. Armstrong , Tanner M. , Alonso P.
Published: August 2003

Summary An entomological study on vectors of malaria and their relative contribution to Plasmodium falciparum transmission in the semi‐urban area of Ifakara, south‐eastern Tanzania, was conducted. A total of 32 houses were randomly sampled from the area and light trap catches (LTC) performed in one room in each house every 2 weeks for 1 year. A total of 147 448 mosquitoes were caught from 789 LTC; 26 134 Anopheles gambiae s.l., 615 A. funestus, 718 other anophelines and 119 981 culicines. More than 60% of the total A. gambiae s.l. were found in five (0.6%) LTCs, with a maximum of 5889 caught in a single trap. Of 505 A. gambiae s.l. speciated by polymerase chain reaction, 91.5% were found to be A. arabiensis. Plasmodium falciparum sporozoite enzyme‐linked immunosorbent assay tests were performed on 10 108 anopheles mosquitoes and 39 (0.38%) were positive. Entomological inoculation rate (EIR) estimates were generated using a standard method and an alternative method that allows the calculation of confidence intervals based on a negative binomial distribution of sporozoite positive mosquitoes. Overall EIR estimates were similar; 31 vs. 29 [95% confidence interval (CI): 19, 44] infectious bites per annum, respectively. The EIR ranged from 4 (95% CI: 1, 17) in the cool season to 108 (95% CI: 69, 170) in the wet season and from 54 (95% CI: 30, 97) in the east of the town to 15 (95% CI: 8, 30) in the town centre. These estimates show large variations over short distances in time and space. They are all markedly lower than those reported from nearby rural areas and for other parts of Tanzania.
Influence of socio‐economic background and antenatal care programmes on maternal mortality in Surabaya, Indonesia
Authors: Taguchi N. , Kawabata M. , Maekawa M. , Maruo T. , Aditiawarman  , Dewata L.
Published: August 2003

Summary Objective To determine the risk factors, such as socio‐economic background, quality of antenatal care and availability of family planning, responsible for high maternal mortality in Surabaya, Indonesia.

Methods The study used a case‐control design. Descriptive, bivariate and multivariate analyses were carried out, comparing 59 maternal deaths and 177 women survivors in the referral hospital, from 1996 to 1999.

Results The risk factors for maternal mortality were: living outside of Surabaya [odds ratio (OR) = 11.7, 95% confidence interval (CI) = 5.0–29.2], unemployment (OR = 4.4, 95% CI = 1.7–13.8), unavailability of toilet facilities (OR = 2.9, 95% CI = 1.0–7.7), <4 antenatal visits (OR = 2.5, 95% CI = 1.1–5.5) and initial visit to antenatal care facilities after the fourth month of pregnancy (OR = 3.0, 95% CI = 1.3–7.0). There was no significant association between maternal mortality and the availability of family planning.

Conclusion Low socio‐economic background and the availability of antenatal care have a significant influence on maternal mortality in Surabaya, Indonesia.
Emerging rickettsial infections in Sri Lanka: the pattern in the hilly Central Province
Authors: Kularatne S. A. M. , Edirisingha J. S. , Gawarammana I. B. , Urakami H. , Chenchittikul M. , Kaiho I.
Published: August 2003

Summary Objectives To identify different rickettsial infections using a specific immunofluorescent technique in patients clinically diagnosed as ‘typhus fever’ in the Central Province of Sri Lanka, and to define the clinical picture, assess the severity of infection and to determine the pattern of geographical distribution of the infections of the hospital‐based patients.

Methods A specific indirect immunofluorescent antibody technique was used on the sera of two groups of patients in laboratories in Japan and Thailand.

Results We serodiagnosed infections with Orientia tsutsugamushi, Rickettsia typhi and spotted fever group in 56 of 118 clinically investigated patients. There were eight infections with O. tsutsugamushi, two with R. typhi and 10 spotted fever group patients with IgM antibodies suggestive of acute infection. Nineteen patients had antibodies against these three rickettsial species, suggestive of past exposure, co‐infection or cross‐reactivity of antigens. Discrete, erythematous maculopapular rash was common to all three types of infection except for five patients who had no rash. Five patients positive for spotted fever antibodies developed fern‐leaf type skin necrosis with severe illness. Duration of the febrile period ranged from 4 to 23 days with defervescence occurring after specific antibiotic treatment.

Conclusions The study has shown the presence of different types of rickettsial infections in the Central Province of Sri Lanka. The characterization of the clinical picture and the severity of infection provide useful information for the proper management of the patients in the future.
Transmission intensity index to monitor filariasis infection pressure in vectors for the evaluation of filariasis elimination programmes
Authors: Sunish I. P. , Rajendran R. , Mani T. R. , Munirathinam A. , Tewari S. C. , Hiriyan J. , Gajanana A. , Reuben R. , Satyanarayana K.
Published: August 2003

We conducted longitudinal studies on filariasis control in Villupuram district of Tamil Nadu, south India, between 1995 and 2000. Overall, 23 entomological (yearly) data sets were available from seven villages, on indoor resting collections [per man hour (PMH) density and transmission intensity index (TII)] and landing collections on human volunteers [PMH and annual transmission potential (ATP)]. All four indices decreased or increased hand‐in‐hand with interventions or withdrawal of inputs and remained at high levels without interventions under varied circumstances of experimental design. The correlation coefficients between parameters [PMH: resting vs. landing (r = 0.77); and TII vs. ATP (r = 0.81)] were highly significant (P < 0.001). The former indices from resting collections stand a chance of replacing the latter from landing collections in the evaluation of global filariasis elimination efforts. The TII would appear to serve the purpose of a parameter that can measure infection pressure per unit time in the immediate household surroundings of human beings and can reflect the success or otherwise of control/elimination efforts along with human infection parameters. Moreover, it will not pose any additional risk of new infection(s) and avoids infringement of human rights concerns by the experimental procedures of investigators, unlike ATP that poses such a risk to volunteers.
Enzyme Immunoassays for the Determination of Ovine LH and FSH
Authors: Peclaris GM , Pappa A , Deligiannis K , Koutsotolis K
Published: August 2003

Contents

The development of competitive enzyme immunoassays for ovine plasma LH (oLH) and FSH (oFSH) is described. Standards and plasma samples were preincubated with diluted antiserum to oLH or oFSH and the reacted solution (100 μl per well) was transferred to plates previously coated with oLH or oFSH, respectively. The second antibody used was anti‐rabbit IgG horseradish peroxidase. The measuring range was 0.39–50 ng/ml for each hormone and the 50% relative binding sensitivity was 9 ng/ml for oLH. The respective value for oFSH was 3.5 or 34 ng/ml with different hormone and antibody preparations used for the assay. The enzyme immunoassays were used to determine oLH and oFSH levels in plasma from ewes of two breeds during the oestrous cycle. The assays detected the first FSH surge coincident with the LH surge, the second FSH surge about 24 h later and the periodic fluctuations of FSH concentrations during the luteal phase of the oestrous cycle. These enzyme immunoassays are an efficient and economic alternative to the established radioimmunoassays (RIA) for oLH and oFSH.
The Effect of Post‐Ovulatory Artificial Insemination on Sow Reproductive Performance
Authors: Castagna CD , Peixoto CH , Bortolozzo FP , Wentz I , Ruschel F , Neto GB
Published: August 2003

Contents

In order to increase reproductive performance, sows are usually inseminated several times during oestrus. In practice, this results in a significant number of sows receiving one or more post‐ovulatory inseminations. This study was carried out to determine the percentage of sows that receive one or more post‐ovulatory inseminations and the effect of such treatment on reproductive performance. The results were analysed from a total of 1298 sows on two farms. It was observed that more than 70% of the sows received at least one post‐ovulatory insemination and approximately 20% received two or more. There was no observed effect on the rate of return to oestrus, farrowing rate or litter size (p > 0.05).
Detection of Water Buffalo Sex Chromosomes in Spermatozoa by Fluorescence in situ Hybridization
Authors: Révay T , Kovács A , Presicce GA , Rens W , Gustavsson I
Published: August 2003

Contents

In order to identify X‐ and Y‐bearing spermatozoa in water buffalo by fluorescence in situ hybridization (FISH), some available probes of closely related species were examined. An X‐ and Y‐specific probe set, made from flow sorted yak chromosomes, labelled in somatic metaphases of water buffalo the whole X and Y, respectively, except their centromere regions. A cattle Y‐chromosome repeat sequence (BC1.2) showed strong signal on the telomere region of the buffalo Y‐chromosome, demonstrating the evolutionary conservation of this locus in water buffalo. In hybridization experiments with spermatozoa from five buffaloes, the yak X‐Y paint set demonstrated clear signals in more than 92% (46.8% X and 45.8% Y) of the cells. Using the cattle Y‐chromosome specific BC1.2 probe, clear hybridization signal was detected in more than 48% of the cells. Statistical analysis showed that there was no significant difference between bulls or from the expected 50 : 50 ratio of X‐ and Y‐bearing cells. The probes presented here are reliable to assess separation of X‐ and Y‐bearing spermatozoa.
Successful Non‐Surgical Transfer of Horse Embryos to Mule Recipients
Authors: Camillo F , Vannozzi I , Rota A , Di Luzio B , Romagnoli S , Aria G , Allen WR
Published: August 2003

Contents

Mules, hybrids resulting from the mating of a horse mare (Equus caballus, 2n = 64) to a Jack donkey (E. asinus, 2n = 62), are generally infertile. Five horse embryos were transferred non‐surgically to two cyclic and one acyclic recipient mules. In the mares and cycling mules, oestrus and ovulation were induced with, respectively,d‐cloprostenol and human chorionic gonadotrophin (hCG). The acyclic mule, on the other hand, received oestradiol benzoate when the embryo donor was showing oestrus and progesterone after the donor had ovulated and until pregnancy diagnosis. Non‐surgical embryo collections were attempted on day 7 after ovulation and recovered embryos were transferred transcervically into the mules’ uteri. Mules that became pregnant were blood sampled serially for equine chorion gonadotrophin (eCG), progestagen and total conjugated oestrogen concentrations until around 6 months of gestation. The three embryos transferred to the acyclic mule did not produce any pregnancies whereas both embryos transferred to the cycling mules resulted in the birth of live foals. The peak concentration and duration of secretion of eCG differed markedly between the two pregnant mules, although both animals appeared to develop secondary corpora lutea beyond day 40 of gestation, as in normal intraspecies horse pregnancy. Moreover, the rise in serum oestrogen concentrations from around day 90 was also similar to that seen in normal pregnant mares. Parturition occurred spontaneously on day 348 of gestation in both mules and the resulting colt foals developed normally to weaning. Thus, cycling mules can carry a horse conceptus after non‐surgical embryo transfer and give birth to a normal mature foal.
Effect of Anticoagulants and Sampling Time on Results of Progesterone Determination in Canine Blood Samples
Authors: Thuróczy J , Wölfling A , Tibold A , Balogh L , Jánoki GA , Solti L
Published: August 2003

Contents

The concentration of plasma progesterone was measured by ELISA, in serum and samples prepared with three different anticoagulant agents – namely ethylenediaminetetraacetic acid (EDTA), heparine and sodium fluoride oxalate potassium(NaFK). Forty clinically healthy bitches were selected based on the signs of pro‐oestrus or oestrus. Values of progesterone concentration were significantly higher in serum than in EDTA‐plasma (p < 0.0005); heparin‐plasma (p < 0.05) and NaFK‐plasma (p < 0.005). During pro‐oestrus and oestrus until the time of ovulation, progesterone exhibited a conspicuous and statistically verified diurnal pattern (p < 0.05), its serum concentration being higher during 6.00–7.00 p.m. than 8.00–9.00 a.m. By the time of ovulation tendency of higher p.m. progesterone level reverses and from this point on the a.m. progesterone concentration is higher. The results of these experiments indicate that the concentration of canine progesterone assayed with ELISA may be affected by the time of collection and the method of preservation used.
Poly(ADP‐Ribose) Polymerase in Bovine Retained and Not Retained Placenta
Authors: Kankofer Marta , Guz Leszek
Published: August 2003

Contents Poly(ADP‐ribose) polymerase (PARP) synthesizes poly(ADP‐ribose) in response to DNA strand breaks using NAD+ as a substrate. It leads to consequences for metabolism not only on a cellular level, but also on a tissue level, among others: NAD+ and ATP depletion. Retention of foetal membranes (RF) in cows is supposed to be connected with the imbalance between production and neutralization of reactive oxygen species, leading to oxidative damage to DNA, lipids and proteins. The aim of this preliminary study was to detect the presence of PARP in bovine placenta and to describe the enzyme with respect to type of placental tissue, time and mode of delivery. Placentomes, collected after spontaneous delivery or caesarian section, were divided into maternal and foetal parts of placenta, homogenized, and subjected to electrophoresis. Cows were divided into six groups as follows: (A) caesarian section before term with RF, (B) caesarian section before term without RF, (C) spontaneous delivery at term with RF, (D) spontaneous delivery at term without RF, (E) caesarian section at term with RF, (F) caesarian section at term without RF. PARP was detected by Western blotting using commercially available bovine anti PARP antibody. Bands referred to as bovine PARP standard were present in all examined tissues as well as the products of its cleavage. However, the patterns of bands were different with respect to type of tissue, time, and mode of delivery. Further experiments on detailed relationship between PARP activity and the process of releasing and retaining of bovine placenta are necessary.
Reinke's Crystals in an Interstitial Cell Tumour of a Rabbit (Oryctolagus cuniculus)
Authors: Marino F , Ferrara G , Rapisarda G , Galofaro V
Published: August 2003

Contents One case of interstitial cell tumour in the testicle of a New Zealand White rabbit was reported. The rabbit was 9‐years old and had monolateral testicular lesion. There was enlargement of left testis and the lesion were seen on the cut surface. Light microscopy revealed intracytoplasmic crystals of Reinke that resembled to the features observed for this tumour in human. Immunohistochemically, this tumour was positive for vimentin.