bluuebunny/crossref_metadata_2025 huggingface dataset:
A DNA marker to identify predation of Plutella xylostella (Lep., Plutellidae) by Nabis kinbergii (Hem., Nabidae) and Lycosa sp. (Aranaea, Lycosidae)
Authors: Ma J. , Li D. , Keller M. , Schmidt O. , Feng X.
Published: July 2005

Abstract:  Predators are important biotic factors in the population dynamics of the diamondback moth, Plutella xylostella. A specific DNA marker was developed to detect P. xylostella in the gut contents of two polyphagous predators, Nabis kinbergii and Lycosa sp. A distinct 275‐bp product was amplified by polymerase chain reaction (PCR) from the internal transcribed spacer (ITS‐1) of the ribosomal gene of P. xylostella, but not from 11 other arthropod species collected from Brassica fields in South Australia. Fortuitously, the primer set could also amplify DNA products from two species and three varieties of Brassica plants, with the fragment size about 600 bp. When N. kinbergii was analysed after feeding a single fourth instar P. xylostella, 67% of individuals were positive with the 275‐bp PCR product up to 16 h after feeding. Likewise, the PCR product was detected in 80% individuals of Lycosa sp. up to 72 h after feeding on a single fourth instar P. xylostella larva. Initial tests of samples collected from the field showed that the predation incidences for both N. kinbergii and Lycosa sp. determined by the 275‐bp fragment corresponded to the density of P. xylostella in the field.
Portable ophthalmic microscopes in the Philippines: an overview
Authors: Tan Anna , Fraser Clay , Staples Brian , Mesurier Richard L , Newland Henry
Published: July 2005

Abstract

Background:  Demonstrations were held all over the Philippines to teach local microscope operators basic maintenance skills and troubleshooting for their portable microscopes.

Methods:  Fifteen microscopes were examined and feedback was obtained from 16 microscope operators. The different parameters of the microscope were evaluated as follows: (i) user‐friendliness, (ii) demand and availability of technical services and spare parts, (iii) portability and (iv) frequent problems encountered. Some suggestions for improvement are proposed.

Results:  There was a general satisfaction among the operators with their microscopes; however, there was a lack of technical support services. Most microscopes were portable and the original casing was adequate for transport. Even though most microscopes were functioning, their quality could be improved with maintenance. The three most common problems identified were: mouldy/dirty lenses, expired mould pellets and poor alignment.

Conclusions:  The portable operating ophthalmic microscope has an important role in the prevention of international blindness. The archaic attitude of sending microscopes to professional technicians for simple maintenance and repair should be abandoned. Instead demonstrations aimed at teaching these skills to local operators and surgeons should be held, in order to improve the technical support available. Different microscope operators can help provide microscope designers with feedback for future improvements. Similar demonstrations could be considered for other countries with a similar scarcity of technical support services.
The role of anterior cingulate cortex and precuneus in the coordination of motor behaviour
Authors: Wenderoth Nicole , Debaere Filiep , Sunaert Stefan , Swinnen Stephan P.
Published: July 2005

Behavioral studies in humans have shown that bimanual coordination imposes specific demands on the central nervous system that exceed unimanual task control. In the present study we used functional magnetic resonance imaging to investigate the neural correlate of this additional coordination effort, i.e. regions responding more strongly to bimanual movements than inferred from summing up the responses to the unimanual subtasks. Subjects were scanned while performing movements along different directions, either uni‐ or bimanually. During the bimanual condition, trajectories of movement of the left and right hand were spatially incompatible, such that additional effort was required to break away from intrinsically favored mirror‐movements and to integrate movements of both limbs into a new spatial pattern. Our main finding was that the execution of spatially complex bimanual coordination as compared with the unimanual subtasks activated the anterior cingulate cortex (posterior part) as well as the dorso‐anterior precuneus. We hypothesize that the anterior cingulate exerts its modulatory effect on other motor areas, such as the primary motor cortex and the supplementary motor area, in order to suppress intrinsically favored coordination tendencies. Conversely, the precuneus is likely to be involved in shifting attention between different locations in space, which was necessary for monitoring the trajectories of the left and right wrist when both limbs moved in parallel. Our findings suggest that the coordination effort during bimanual and perhaps other modes of coordinated behavior is mediated by regions contributing to higher order functions, which form an interface between cognition and action.
Effects of attention and arousal on early responses in striate cortex
Authors: Poghosyan Vahe , Shibata Tadahiko , Ioannides Andreas A.
Published: July 2005

Humans employ attention to facilitate perception of relevant stimuli. Visual attention can bias the selection of a location in the visual field, a whole visual object or any visual feature of an object. Attention draws on both current behavioral goals and/or the saliency of physical attributes of a stimulus, and it influences activity of different brain regions at different latencies. Attentional effect in the striate and extrastriate cortices has been the subject of intense research interest in many recent studies. The consensus emerging from them places the first attentional effects in extrastriate areas, which in turn modulate activity of V1 at later latencies. In this view attention influences activity in striate cortex some 150 ms after stimulus onset. Here we use magnetoencephalography to compare brain responses to foveally presented identical stimuli under the conditions of passive viewing, when the stimuli are irrelevant to the subject and under an active GO/NOGO task, when the stimuli are cues instructing the subject to make or inhibit movement of his/her left or right index finger. The earliest striate activity was identified 40–45 ms after stimulus onset, and it was identical in passive and active conditions. Later striate response starting at about 70 ms and reaching a peak at about 100 ms showed a strong attentional modulation. Even before the striate cortex, activity of the right inferior parietal lobule was modulated by attention, suggesting this region as a candidate for mediating attentional signals to the striate cortex.
Evaluation of glossy appearance of facial make‐up using CG images
Authors: Minami K. , Kaneko T. , Nabeshima H. , Iwamoto H. , Ojima N. , Nagatani N. , Hori K.
Published: July 2005

A new method for optimizing the glossy appearance of facial make‐up is proposed. Reflections from skin make‐up comprise two components, specular and diffuse. Glossiness of the skin can be optimized by controlling the magnitude of the specular component in applied cosmetic foundation. To determine optimal appearance of glossiness, a series of images of a woman's face with make‐up varying in the magnitude of specular reflection were synthesized using computer‐graphics techniques, and 15 female volunteers selected the most beautiful skin from among those simulated faces. For calculating the specular component of the facial images, six bidirectional reflectance distribution functions (BRDFs) were generated from the goniophotometric spectra of two foundation membranes that differed in reflectivity from each other. Results of the image evaluations on dark, normal or bright skin are shown. In addition, evaluation of images in which the specular component was shifted to blue caused by blue pearl pigments is shown.
Nursing and nursing education in Iraq: challenges and opportunities
Authors: Garfield R. , McCarthy C. F.
Published: July 2005

Background:  There has been extensive damage to nursing education and training in Iraq over the last two decades through three international wars, counterinsurgency struggles in the north and south, 13 years of economic sanctions, dictatorship and foreign occupation. Fortunately, there is wide agreement that nursing is a key area for further attention. Many nursing leaders have emigrated and the numbers of nurses working in professional roles in Iraq declined sharply after 1990.

Issues:  The number of nurses per population has always been low in Iraq, and fell off precipitously after foreign workers left. There is less than one nursing staff of any kind for physician today. Few of the nursing staff are qualified to what would be minimal standards of professional practice in many countries. There is a strong educational base for nursing education in three Iraqi universities, but it relates little to other schools or hospitals. Military nurses, now being integrated into the public system of hospital care, are considered to have far more technical skill levels than non‐military nurses.

Actions:  Iraq needs a new generation of well trained nurses to develop primary care and health education activities. Programmes in nursing administration and community health nursing need to be developed. The World Health Organization has supported the development of training centres and short courses for nursing leaders. The former six levels of entry to nursing practice have been streamlined to three. Nursing salaries since the 2003 invasion have been greatly increased. These are good beginnings, and much more remains to be done to restore nursing in Iraq.
Clinical and instrumental evaluation of a food supplement in improving skin hydration
Authors: Primavera G , Berardesca E
Published: July 2005

Synopsis

Topically applied cosmetic products can be helpful in improving skin hydration. The study shows how oral supplementation could be helpful in improving and preventing the skin dehydration. A total of 32 healthy female volunteers entered the study. Of which, 16 were treated with a food supplement based on vegetable ceramides, amino acids, fish cartilage, antioxidants and essential fatty acids for 40 days and 16 with placebo. The results of the clinical and instrumental evaluations carried out in this study, have highlighted how the active treatment is effective in improving skin hydration and in reducing the cutaneous smoothness and roughness and the depth of furrows, in comparison to the placebo. In fact, concerning several important parameters, as stratum corneum hydration and skin roughness, the improvement measured exceeded 25%. We therefore suggest that a combination of treatments (oral and topical) can be more effective in improving skin hydration.
Elastic vesicles as topical/transdermal drug delivery systems
Authors: Choi M. J. , Maibach H. I.
Published: July 2005

Synopsis

Skin acts a major target as well as a principle barrier for topical/transdermal drug delivery. Despite the many advantages of this system, the major obstacle is the low diffusion rate of drugs across the stratum corneum. Several methods have been assessed to increase the permeation rate of drugs temporarily. One simple and convenient approach is application of drugs in formulation with elastic vesicles or skin enhancers. Elastic vesicles are classified with phospholipid (Transfersomes® and ethosomes) and detergent‐based types. Elastic vesicles were more efficient at delivering a low and high molecular weight drug to the skin in terms of quantity and depth. Their effectiveness strongly depends on their physicochemical properties: composition, duration and application volume, and entrapment efficiency and application methods. This review focuses on the effect of elastic liposomes for enhancing the drug penetration and defines the action mechanism of penetration into deeper skin.
A Multistate Approach for Estimating the Incidence of Human Immunodeficiency Virus by Using Data from a Prevalent Cohort Study
Authors: Alioum Ahmadou , Commenges Daniel , Thiébaut Rodolphe , Dabis François ,   Groupe d’Epidémiologie Clinique du Syndrome d’Immunodéficience Acquise en Aquitaine
Published: July 2005

Cohort studies of individuals infected with the human immunodeficiency virus (HIV) provide useful information on the past pattern of HIV diagnoses, progression of the disease and use of antiretroviral therapy. We propose a new method for using individual data from an open prevalent cohort study to estimate the incidence of HIV, by jointly modelling the HIV diagnosis, the inclusion in the cohort and the progression of the disease in a Markov model framework. The estimation procedure involves the construction of a likelihood function which takes into account the probability of observing the total number of subjects who are enrolled in the cohort and the probabilities of passage through the stages of disease for each observed subject conditionally on being included in the cohort. The estimator of the HIV infection rate is defined as the function which maximizes a penalized likelihood, and the solution of this maximization problem is approximated on a basis of cubic M-splines. The method is illustrated by using cohort data from a hospital-based surveillance system of HIV infection in Aquitaine, a region of south-western France. A simulation study is performed to study the ability of the model to reconstruct the incidence of HIV from prevalent cohort data.
Differentiating Noisy Radiocommunications Signals: Wavelet Estimation of a Derivative in the Presence of Heteroscedastic Noise
Authors: Baxter Paul D. , Upton Graham J. G.
Published: July 2005

Radio scientists require estimates of the rate of change in rain-induced signals. Unfortunately, these signals are observed in the presence of atmospheric noise, which has a variance that is dependent on temperature, pressure and other climatic variables. We develop a systematic approach to the problem, using wavelet differentiation combined with coefficient-dependent thresholding, and illustrate the considerable benefits that this provides over more conventional techniques.
Efficiency of combined methotrexate/chloroquine therapy in adjuvant‐induced arthritis
Authors: Silva M.A.R.C.P. , Ishii‐Iwamoto E.L. , Bracht A. , Caparroz‐Assef S.M. , Kimura E. , Cuman R.K.N. , Bersani‐Amado C.A.
Published: July 2005

The present study evaluates the effects of methotrexate (MTX) and chloroquine (CQ), and of combined MTX + CQ treatment, on the inflammatory response and on plasma and liver phosphatase and transaminase activities, employing an adjuvant‐induced arthritis model in rats. Arthritis was induced by the intradermal injection of a suspension of Mycobacterium tuberculosis in mineral oil into the plantar surface of the hind paws. Development of the inflammatory response was assessed over a 21‐day period. Animal groups received either: (i) MTX, administered i.p., weekly, in 0.15, 1.5, 3, 6 or 12 mg/kg doses; (ii) CQ, given intragastrically, in daily 25 or 50 mg/kg doses; or (iii) MTX + CQ, administered in two combinations (MTX1.5 mg/kg + CQ50 mg/kg, or MTX6 mg/kg + CQ50 mg/kg). At the end of the experimental period, the animals were anesthetized and killed, blood and liver samples were collected and prepared for measurement of acid and alkaline phosphatase (AP, ALP), and aspartate (AST) and alanine aminotransferase (ALT) activities. MTX at 6 and 12 mg/kg reduced the inflammatory response while CQ had no effect. MTX6 mg/kg + CQ50 mg/kg reduced the inflammatory response similar to MTX12 mg/kg, without affecting the bone marrow. Plasma AP and liver ALP activities were very elevated in the arthritic rats. While MTX treatment partially reduced both plasma AP and liver ALP activities at all doses used in the arthritic rats, CQ treatment reduced plasma AP, but increased liver AP activity. MTX + CQ treatment decreased plasma AP and liver ALP activities in the arthritic rats to control values. Plasma and liver AST activities were unaltered in the arthritic rats, and were unaffected by treatment. However, plasma and liver ALT activities were significantly reduced in the arthritic rats. While MTX or CQ treatment did not alter plasma transaminase activity in the arthritic rats, after MTX + CQ treatment, plasma ALT activity returned to normal values. In conclusion, the present data suggest that MTX + CQ treatment provides more effective anti‐inflammatory protection against adjuvant‐induced arthritis than does MTX alone, reverting the alterations in enzyme activities induced by this inflammatory disease in rats.
Minor abnormalities of renal function: a situation requiring integrated management of cardiovascular risk
Authors: Segura Julian , Ruilope Luis M.
Published: July 2005

Changes in renal function related with essential hypertension are associated with an elevated cardiovascular morbidity and mortality. Indices of altered renal function (e.g. microalbuminuria, increased serum creatinine concentrations, decrease in estimated creatinine clearance or overt proteinuria) are independent predictors of cardiovascular morbidity and mortality. The Framingham Heart Study documented the relevance of proteinuria for cardiovascular prognosis in the community. The Intervention as a Goal in Hypertension Treatment (INSIGHT) Study assessed the role of proteinuria as a very powerful risk factor. It has also been shown that microalbuminuria along with primary hypertension poses a high risk for cardiovascular diseases. Recent data indicate that even minor derangements of renal function are associated with the clustering of cardiovascular risk factors observed in metabolic syndrome, that promote progression of atherosclerosis. All these parameters should be routinely evaluated in clinical practice, and considered in any stratification of cardiovascular risk in hypertensive patients. The high prevalence of chronic kidney disease in the general and in the hypertensive populations implies the need for an integrative therapeutic approach to fully protect renal and cardiovascular systems simultaneously.
Use of the Atad catheter for the induction of labour in women who have had a previous Caesarean section – a case series
Authors: MILLER Trent David , DAVIS Gregory
Published: July 2005

The induction of labour of women with an unfavourable cervix who have had a previous Caesarean section, is challenging. Eight women who had a Caesarean section in a previous pregnancy had labour induced with an Atad catheter. Six out of eight women achieved labour, and two out of these six women had a vaginal delivery. An Atad catheter is an option for women needing induction of labour with an unfavourable cervix who have had a Caesarean section previously and are motivated to have a vaginal delivery.
Management of recurrent epithelial ovarian carcinoma
Authors: VASEY Paul A.
Published: July 2005

Despite the standardisation of surgical techniques and significant progress in chemotherapeutics over the last 30 years, advanced epithelial ovarian cancer remains the most lethal gynaecological malignancy in the western world. Although the majority of women achieve a remission following primary therapy, most patients with advanced stage disease will eventually relapse and become candidates for ‘salvage’ therapy. The chances of a further remission depend on factors such as the ‘treatment‐free interval’, and there are now a large number of chemotherapy agents with activity in ovarian cancer available to the oncologist. Recent randomised studies have reported on survival benefits for chemotherapy in recurrent disease, and therefore careful and appropriate selection of treatments has assumed a greater importance. This article reviews the most current data, and discusses the factors involved in making individualised treatment decisions.
Recent Advances in the Molecular Genetics of Paramecium1
Authors: KUNG CHING , SAIMI YOSHIRO , HAYNES W. JOHN , LING KIT‐YIN , KISSMEHL ROLAND
Published: July 2005

ABSTRACT. Paramecium continues to be used to study motility, behavior, exocytosis, and the relationship between the germ and the somatic nuclei. Recent progress in molecular genetics is described. Toward cloning genes that correspond to mutant phenotypes, a method combining complementation with microinjected DNA and library sorting has been used successfully in cloning several novel genes crucial in membrane excitation and in trichocyst discharge. Paramecium transformation en masse has now been shown by using electroporation or bioballistics. Gene silencing has also been discovered in Paramecium, recently. Some 200 Paramecium genes, full length or partial, have already been cloned largely by homology. Generalizing the use of gene silencing and related reverse‐genetic techniques would allow us to correlate these genes with their function in vivo.
Clinical Presentation and Significance of Emerging Opportunistic Infections1
Authors: MILLER ROBERT F.
Published: July 2005

ABSTRACT. In recent years the clinical face of the Acquired Immune Deficiency Syndrome has changed significantly as a consequence of use of prophylaxis against Pneumocystis carinii pneumonia and combination antiretroviral therapy. In this context several opportunistic pathogens have emerged as causes of clinically important disease. Many of these infective agents have previously been defined by specific geographical locations. Their clinical presentation frequently mimics other (non) opportunistic infections with which they may co‐exist. The diagnosis is frequently delayed as the diagnostic possibility may not be in the clinician's differential diagnosis. Invasive procedures are frequently required in order to secure a diagnosis. Despite treatment, prognosis is often poor. Clinicians should be aware of these opportunistic pathogens in order that a timely diagnosis may be made and appropriate therapy given.
Analysis of the 5.8S rRNA Gene and the Internal Transcribed Spacers in Naegleria spp. and in N. fowleri
Authors: PÉLANDAKIS MICHEL , SERRE STÉPHANIE , PERNIN PIERRE
Published: July 2005

ABSTRACT. Internal transcribed spacers (ITS) and the 5.8S ribosomal gene of 21 Naegleria fowleri strains and eight other species including Naegleria gruberi were sequenced. The results showed that this region can help differentiate between and within species. The phylogeny of Naegleria spp. deduced from the ITS and the 5.8S gene produced four major lineages, fowleri‐lovaniensis, galeacystisitalica‐clarki‐gruheri‐australiensis, andersoni‐jamiesoni, and pussardi, that fit perfectly with those inferred from the 18S rRNA gene analysis. The N. gruberi isolate, NG260, was closely related to Naegleria pussardi. The other N. gruberi isolates branched together with Naegleria australiensis in another lineage. The ITS and 5.8S results for N. fowleri were congruent with those previously deduced by RAPD analysis. The phylogenetic analysis inferred from ITS and RAPD data revealed two major groups. The French Cattenom and Chooz and South Pacific strains constituted the first group. The second group encompassed the strains corresponding to the EuroAmerican and Widespread RAPD variants and shared the same substitution in the 5.8S gene. In addition, it was possible to define species specific primers in ITS regions to rapidly identify N. fowleri.
The Behavior of the Doublet of Oxytricha bifaria (Ciliata, Hypotrichida): A Contribution to the Understanding of This Enigmatic Form
Authors: RICCI NICOLA , ERRA FABRIZIO , BANCHETTI ROSALBA
Published: July 2005

ABSTRACT. The tracks of normal organisms of Oxytricha bifaria and of stage IA, IB, II, III, IV and V doublets were studied to test the hypothesis that the doublet might function as a dispersal form. Stage IA, the only stage to swim, swims straight with only rare interruptions; its rate of mobility (Rmo= 443 μ/s) is roughly twice that of singlets (Rmo= 218 μ/s). Stage IA doublets swim in three‐dimensional movement which enables them to be carried away by water currents. The other stages seem to represent passage back towards the normal singlet form. The ethological evidence reported here together with other results already published supports the working hypothesis that the doublet of O. bifaria is a dispersal form suggests that the doublet might well represent a special fourth differentiation state of this species in addition to pairs, giants, and cysts.
Molecular Mechanisms of Microtubular Organelle Assembly in Tetrahymena
Authors: GAERTIG JACEK
Published: July 2005

Thanks to recent technological advances, the ciliate Tetrahymena thermophila has emerged as an attractive model organism for studies on the assembly of microtubular organelles in a single cell. Tetrahymena assembles 17 types of distinct microtubules, which are localix.ed in cilia, cell cortex, nuclei, and the endoplasm. These diverse microtubules have distinct morphologies, stabilities, and associations with specific Microtubule‐Assoeiated Proteins. For example, kinesin‐111, a microtubular motor protein, is required for assembly of cilia and is preferentially targeted to microtubules of actively assembled, immature cilia. It is unlikely that the unique properties of individual microtubules are derived from the utilization of diverse tubulin genes, because Tetrahymena expresses only a single isotype of α‐and two isotypes of β‐tubulin. However, Tetrahymena tubulins are modified secondarily by a host of post‐translational mechanisms. Each microtubule organelle type displays a unique set of secondary tubulin modifications. The results of systematic in vivo mutational analyses of modification sites indicate a divergence in significance among post‐translational mechanisms affecting either α‐or β‐tubulin. Both acetylation and polyglycylation of α‐tubulin are not essential and their complete elimination does not change the cell's phenotype in an appreciable way. However, the multiple polyglycylation sites on β‐tubulin are essential for survival, and their partial elimination dramatically affects cell motility, growth and morphology. Thus, both high‐precision targeting of molecular motors to individual organelles as well as organelle‐specific tubulin modifications contribute to the creation of diverse microtubules in a single cytoplasm of Tetrahymena.
The Effects of Elevated Temperatures and Various Time‐Temperature Combinations on the Development of Brachiola (Nosema) algerae N. Comb. in Mammalian Cell Culture
Authors: LOWMAN PAUL M. , TAKVORIAN PETER M. , CALI ANN
Published: July 2005

ABSTRACT. Nosema algerae Vávra and Undeen 1970, a microsporidian known to cause infection in mosquitoes, develops in mammalian cell cultures at 24–35°C and in the tails and footpads of athymic mice. More recently it has been reported to grow at 38°C in human cell culture. The present study is a two‐part temperature/development examination. The first part examines the development of N. algerae in rabbit kidney cell culture at 29°C, which permits the formation of functional spores within 72 h, and compares the effect of elevated temperatures (36.0, 36.5, 37°C) on parasite development. At these elevated temperatures, N. algerae infects but undergoes only one or two proliferative divisions, with no evidence of sporogony by 72 h post‐inoculation. During this time, however, the host cells continue to divide resulting in fewer infected cells over time and giving the appearance of a diminished parasitemia. Additionally, at 37°C some organisms degenerate/hibernate by 72 h while others remain viable/active. It is not until 96 h that the parasites appear in large clusters of proliferative stages in the few host cells that are infected. By 120 h post‐inoculation, proliferative cells, sporoblasts, and early spores are observed. These results suggest that elevated temperatures impede proliferation rates and the onset of sporogony. The second part of this study evaluates developmental changes in N. algerae when incubation temperatures and times are varied during parasite growth, resulting in abnormal parasite morphology. These abnormalities were not present when parasites were grown at constant temperature (29–37°C). This report demonstrates that N. algerae can successfully develop at high temperatures (37°C), justifying its taxonomic relocation to the genus Brachiola.
Characterization of Sarcocystis falcatula Isolates from the Argentinian Opossum, Didelphis albiventris
Authors: DUBEY J. P. , LINDSAY D. S. , VENTURINI L. , VENTURINI C.
Published: July 2005

ABSTRACT. Two isolates of Sarcocystis falcatula were obtained from the lungs of budgerigars (Melopsittacus undulatus) fed sporocysts from two naturally‐infected South American opossums (Didelphis albiventris). The two isolates were designated SF‐1A and SF‐2A. Both isolates induced fatal infections in budgerigars. Both isolates underwent schizogony in African green monkey kidney cells. The structure of schizonts in the lungs of budgerigars was more variable than that observed in cell culture. The two isolates were identified as 5. falcatula by the two species‐specific Hinf 1 restriction fragments dervied from digestion of a PCR amplification using primers JNB33/JNB54. Thus, the South American opossum, D. albiventris, is a definitive host for S. falcatula.
Phylogenetic Analysis of the Small Subunit Ribosomal RNA of Marteilia.refringens Validates the Existence of Phylum Paramyxea (Desportes and Perkins, 1990)1
Authors: BERTHE FRANCK C. J. , LE ROUX FRÉDÉRIQUE , PEYRETAILLADE ERIC , PEYRET PIERRE , RODRIGUEZ DAVID , GOUY MANOLO , VIVARÈS CHRISTIAN P.
Published: July 2005

ABSTRACT. Marteilia refringens is recognized as one of the most significant pathogens of bivalve molluscs. The nucleotide sequence of the small subunit ribosomal RNA gene of Marteilia refringens is used to elucidate the phylogenetic position of the phylum Paramyxea. Genomic DNA was extracted from sporangia of Marteilia, purified from infected blue mussels, Mytilus edulis, and flat oysters, Ostrea edulis. The sequences obtained from Marteilia species purified from both oysters and mussels were identical. The sequence identity was confirmed by in situ hybridization using a DNA probe targeted to a variable region of the ribosomal DNA. The small subunit ribosomal RNA gene sequence of M. refringens is very different from all known sequences of eukaryotic organisms, including those of myxosporeans and haplosporeans. Therefore, the phylum Paramyxea should continue to be recognized as an independent eukaryotic phylum.
Descriptions and Phylogenetic Systematics of Myxobolus spp. from Cyprinids in Algonquin Park, Ontario
Authors: SALIM KOWTHAR Y. , DESSER SHERWIN S.
Published: July 2005

ABSTRACT. Eight species of Myxobolus were collected from four species of cyprinids in Algonquin Park, Ontario. On the basis of spore morphology, five of these species are described as new and two are redescribed. The evolutionary relationships among these eight species were studied using partial small subunit ribosomal DNA (ssu‐rDNA) sequence data. The resulting cladograms, which were highly resolved and with strongly supported relationships, allowed for the evaluation of spore morphology, host specificity, and tissue tropism, criteria traditionally used in species identification. These criteria, recently criticized for creating artificial rather than natural taxonomic groupings, were evaluated for their reliability in the systematics of the species examined. The data showed that distantly related species often infect the same host and tissue, and that closely related species often occur in different hosts. Morphologically similar species are more closely related to each other and the taxonomy based on spore morphology is consistent with the relationships depicted in the phylogenies. These results suggest that spore morphology is better than host specificity and tissue tropism as a species character, as well as tor determining evolutionary relationships among the species of Myxobolus examined.
Characterisation and Sequence Analysis of a Carbamate Kinase Gene from the Diplomonad Hexamita inflata1
Authors: DIMOPOULOS MARY , BAGNARA ALDO S. , EDWARDS MICHAEL R.
Published: July 2005

ABSTRACT. Hexamita inflata can derive energy from the degradation of arginine via the arginine dihydrolase pathway. Carbamate kinase catalyses the third enzymatic step of the pathway synthesising ATP from the catabolism of carbamyl phosphate. This study reports the identification and characterisation of a carbamate kinase gene from this free‐living diplomonad, together with measurements of carbamate kinase enzyme activity in cell‐free extracts and a preliminary analysis of the carbamate kinase mRNA by reverse‐ transcription polymerase chain reaction. Analysis of the carbamate kinase gene revealed the use of non‐canonical codons for glutamine. Phylogenetic studies showed a consistent close relationship between carbamate kinase sequences of H. inflata and Giardia intestinalis.
Characterization of the Gene Encoding a Histidine and Aspartic Acid‐Rich Protein from Pneumocystis carinii1
Authors: LEE CHAO‐HUNG , LASBURY MARK E. , PAULSRUD JOHN R. , BAUER NANCY L. , BRADY STEPHEN L. , WEINBERG GEOFFREY A. , DURANT PAMELA J. , BARTLETT MARILYN S. , SMITH JAMES W.
Published: July 2005

ABSTRACT. A cDNA clone derived from Pneumocystis carinii contained an unusual sequence (GTGATG)2(ATGGTG)4(ATG)4 and many GAT repeats. It was found to encode a histidine and aspartic acid‐rich protein (HARP). The complete cDNA contained an 888–bp open reading frame encoding a putative protein of 32.6 kDa. The deduced HARP protein contained 39 aspartic acid and 22 histidine residues. The genomic copy of the HARP gene (1203 bp in length) was found to contain 3 small introns of 46, 44, and 38 bp, respectively. HARP was predicted by computer programs to be a plasma membrane protein with nickel‐binding activity.
Purification of GVBD‐Inducing Protein from the Ciliate Tetrahymenathermophila
Authors: SUGII MANABU , FUJISHIMA MASAHIRO
Published: July 2005

ABSTRACT. Germinal‐vesicle‐breakdown (GVBD) was induced if a 132,000‐g supernatant of Tetrahymena thermophila homogenates was injected into Xenopus oocytes. Using this induction of GVBD as a bioassay system, a GVBD‐inducing substance was purified from the Tetrahymena by ultra‐filtration, liquid chromatography, and electroelution from a band on native‐PAGE gel. Proteins eluted from the single band on the native‐PAGE gel induced GVBD in the absence of oocyte protein synthesis. This band resolved into two bands on SDS‐PAGE: 60 and 1 12 kDa. The 60 kDa protein was the active fraction inducing GVBD. Immunoprecipitation of the 60 kDa protein prevented the GVBD‐inducing activity, supporting the conclusion that the 60 kDa protein is the GVBD‐inducing substance. An immunoblot with anti‐60 kDa monoclonal antibody and PSTAIR antibody showed that p 13sue1 ‐beads could remove cdc2 homologues from T. thermophila supernatant but could not remove the GVBD‐inducing activity. The 60‐kDa protein appeared at the same time as micronuclear division and disappeared at the beginning of the macronuclear division during synchronous cell division. The cyclic appearance of the 60‐kDa protein in the T. thermophila cell cycle suggests that this protein has a cell cycle function. Key Words. cdc2 homologue, cell cycle, M‐phase promoting factor, PSTAIR antibody, p13sue1‐beads, Xenopus oocytes.
In Vivo and In Vitro Development of the Protist Helicosporidium sp.
Authors: BOUCIAS DRION G. , BECNEL JAMES J. , WHITE SUSAN E. , BOTT MICHEAL
Published: July 2005

ABSTRACT. We describe the discovery and developmental features of a Helicosporidium sp. isolated from the black fly Simulium jonesi. Morphologically, the helicosporidia are characterized by a distinct cyst stage that encloses three ovoid cells and a single elongate filamentous cell. Bioassays have demonstrated that the cysts of this isolate infect various insect species, including the lepidopterans, Helicoverpa zea, Galleria mellonella, and Manduca sexta, and the dipterans, Musca domestica, Aedes taeniorhynchus, Anopheles albimanus, and An. quadrimaculatus. The cysts attach to the insect peritrophic matrix prior to dehiscence, which releases the filamentous cell and the three ovoid cells. The ovoid cells are short‐lived in the insect gut with infection mediated by the penetration of the filamentous cell into the host. Furthermore, these filamentous cells are covered with projections that anchor them to the midgut lining. Unlike most entomopathogenic protozoa, this Helicosporidium sp. can be propagated in simple nutritional media under defined in vitro conditions, providing a system to conduct detailed analysis of the developmental biology of this poorly known taxon. The morphology and development of the in vitro produced cells are similar to that reported for the achorophyllic algae belonging to the genus Prototheca.
Genetic Diversity in the Microsporidian Encephalitozoon hellem Demonstrated by Pulsed‐Field Gel Electrophoresis
Authors: DELARBRE SEBASTIEN , GATTI SIMONETTA , SCAGLIA MASSIMO , DRANCOURT MICHEL
Published: July 2005

ABSTRACT. Encephalitozoon hellem is a microsporidian species responsible for opportunistic infections in AIDS patients. Use of a novel chitinase‐based method allowed unsheared chromosomal DNA to be recovered from eleven E. hellem isolates derived from three geographic regions. All isolates were typed by 18S rDNA sequencing, which showed that they belonged to internal transcribed spacer type 1. After ethidium bromide staining, pulsed‐field gel electrophoresis (PFGE) analysis discriminated two new karyotypes comprising 7 and 8 chromosomal bands respectively, ranging in size from 205‐ to 272‐kb pairs. Genomic size was estimated to be 2.39 Mb. Our data indicate PFGE is useful for typing E. hellem and confirms genetic diversity among E. hellem genotypes.
Seasonal Variability in Abundance and Diversity of Soil Gymnamoebae Along a Short Transect in Southeastern USA
Authors: BASS POLLY , BISCHOFF PAUL J.
Published: July 2005

ABSTRACT. The abundance and diversity of gymnamoebae in three subsoils varying in compaction and water retention along a 1.2 m transect were documented as the local climatic conditions changed from late summer 1999 through mid‐summer 2000. The mean density of gymnamoebae for the loose soil (i,655/g) was greater than either the most compact (1,468/g) or moderately compact soil (851/g). Minimum densities occurred in middle and late summer for all soils while significant (F = 38.803, ≤ 0.0002) density peaks at 3,212/g occurred in early summer in the most compact soil, 2,928/g in the least compact, and 2,209/g in the moderately compact soil, Limax non‐eruptive gymnamoebae (mt 2) correlated (r = 0.49, p≤ 0.016) with moisture while eruptive limax gymnamoebae (mt 3) correlated with temperature (r = 0.07, p≤ 0.024), moisture (r = 0.58, p≤ 0.001) and precipitation (r = 0.46, p≤ 0.029). Flattened or discoid amoebae (mt 4) dominated throughout most of the survey, and the two limax groups showed inverse relationships, Chisquare analyses showed significant differences in the numbers of limax eruptive gymnamoebae compared to all other morphotypes on all but one sampling period.
Four New Species of Macropodinium (Ciliophora: Litostomatea) from Australian Wallabies and Pademelons
Authors: CAMERON STEPHEN L. , O'DONOGHUE PETER J. , ADLARD ROBERT D.
Published: July 2005

ABSTRACT. Samples of Macropodinium spp. were collected from 3 new macropodid species: from 21 of 28 (75%) black‐striped wallabies (Macropus dorsalis); 10 of 11 (91%) swamp wallabies (Wallabia bicolor); and 22 of 43 (51%) Tasmanian pademelons (Thylogale billardierii). The examination of ciliate morphology by silver impregnation and scanning electron microscopy led to the redescription of the genus Macropodinium and the description of 4 new species: Ma. tricresta sp. nov. and Ma. spinosus sp. nov. from M. dorsalis; Ma. maira sp. nov. from T. billardierii; and M. bicolor sp. nov. from W. bicolor, each species was strictly host specific. Cellular orientation was reinterpreted on the basis of vestibular morphology and it is concluded that Macropodinium spp. are laterally rather than dorso‐ventrally compressed. The striated groove is thus dorso‐ventral rather than lateral. Oral ciliation consisted of up to three bands: an adoral band composed of oblique kineties; a vestibular band of longitudinal kineties; and a preoral band of longitudinal kineties. Somatic ciliation occurred in two longitudinal bands: a dense band composed of several parallel kineties on the left side of the dorso‐ventral groove; and a sparse band composed of a single kinety on the right internal side of the dorso‐ventral groove. Few structures were homologous to those of other litostome ciliates, and thus the relationship of Macropodinium to other litostomes cannot yet be clearly defined.
Differential Antibody Recognition of Four Allelic Variants of the Merozoite Surface Protein‐2 (MSP‐2) of Plasmodium falciparum
Authors: TONHOSOLO RENATA , WUNDERLICH GERHARD , FERREIRA MARCELO U.
Published: July 2005

ABSTRACT. The merozoite surface protein‐2 (MSP‐2) is a major vaccine candidate for the asexual blood stage of Plasmodium falciparum. MSP‐2 is essentially dimorphic, and allelic families are named after the representative isolates FC27 and IC1. The polymorphic central region contains immunodominant repeats, which vary in number, length, and sequence within and between allelic families. We have examined the antibody recognition of repeat regions from both MSP‐2 allelic families expressed as recombinant fusion peptides. The results are summarized as follows. (1) Immunization of mice with the fusion peptides elicited IgG antibodies that cross‐reacted with the native MSP‐2 molecule in an allelic family‐specific manner. (2) These mouse antibodies recognized the recombinant proteins in both a variant‐specific and a family‐specific manner, as shown in inhibition immunoassays. Antibodies raised against the peptide FC27 seemed to be essentially variant‐specific, since the soluble form of the S20 antigen (a member of FC27 family) had relatively little inhibitory effect on them. (3) The overall pattern of human IgG antibody responses to MSP‐2 in Karitiana Indians, a population continuously exposed to hypoendemic malaria in the Brazilian Amazon Region, differs from that described in hyperendemic areas in Africa and Papua New Guinea in two important features: there was no clear age‐dependent increase in the prevalence and mean concentration of specific IgG antibodies, and there was no skewing towards the IgG, subclass in antibody responses. (4) The relatively poor correlation between concentrations of IgG antibodies that are specific for members of the same allelic family suggests that recognition of MSP‐2 peptides by naturally acquired antibodies was largely variant‐specific in this population. The potential role of naturally acquired variant‐specific antibodies in immune evasion, by selecting mutant parasites carrying insertions or deletions of repeat sequences, is briefly discussed.
Quantitation of Cryptosporidium parvum Infection in Cell Culture Using a Colorimetric In Situ Hybridization Assay
Authors: ROCHELLE PAUL A. , FERGUSON DONNA M. , JOHNSON ANNE M. , DE LEON RICARDO
Published: July 2005

ABSTRACT. A quantitative colorimetric in situ hybridization assay was developed for detecting Cryptosporidium parvum infection in cell cultures using a digoxigenin‐labeled probe targeting 18S rRNA. Intra‐cellular developmental stages of C. parvum such as trophozoites and meronts were clearly discerned by light microscopy as localized areas of dark purple/black precipitate against a colorless background. Infections developed focally and the term infectious focus was applied to each cluster of developmental stages. There were no significant differences in the number of infectious foci following 24 h or 48 h incubation. However, 24 h and 48 h dose response curves were significantly different when infectivity was measured as the number of developmental stages per monolayer, with an average of 5.3‐fold more stages following 48 h incubation. When infectivity was expressed as the number of infectious foci per inoculum oocyst converted to a percentage, it was demonstrated that the rate of infection decreased with increasing oocyst age. Oocysts of the Iowa isolate that were 7–10 days old demonstrated 7.8 ± 2.4% infectivity (mean ± standard deviation) compared to 4.2 ± 0.8% for 21–28 day‐old oocysts and 1.4 ± 1.3% for 42–70 day‐old oocysts. The assay also detected infection with other genotype 2 oocysts and a genoptye 1 isolate. This assay provides a direct quantitative approach for measuring C. parvum infectivity in cell culture.
Correlation Between In Vitro and In Vivo Infectivity of Leishmania infantum Clones
Authors: MÉNDEZ SUSANA , FERNÁNDEZPÉREZ FRANCISCO JOSÉ , SANTÍN MÓNICA , DE LA FUENTE CONCEPCIÓN , CUQUERELLA MONTSERRAT , GÓMEZMUÑOZ MARÍA TERESA , ALUNDA JOSÉ MARÍA
Published: July 2005

ABSTRACT. Eleven clones of a single strain of Leishmania infantum (MCAN/ES/88/ISS441, Doba) were analyzed for biological behavior in vivo and in vitro. Different clones showed differences in growth dependent upon the two culture media employed. All clones displayed only slight differences in H2O2 and NaNO2 sensitivity compared to the original strain, whereas in vitro infectivity for mouse peritoneal macrophages differed significantly among the clones. In vivo infections in hamsters correlated strongly with in vitro infectivity. The phenotypic differences found suggest a polyclonal structure for the Leishmania infantum strain studied.
Nuclear and Cortical Regulation in Doublets of Paramecium: II. When and How do Two Cortical Domains Reorganize to One?
Authors: IFTODE FRANCINE , PRAJER MALGORZATA , FRANKEL JOSEPH
Published: July 2005

ABSTRACT. Homopolar doublets with twofold rotational symmetry were generated in Paramecium tetraurelia and in P. undecaurelia by electrofusion or by arrested conjugation. These doublets underwent a complex cortical reorganization over time, which led to their reversion to singlets. This reorganization involved a reduction in number of ciliary rows, a progressive inactivation and loss of one oral meridian, and a reduction and eventual disappearance of one cortical surface (semicell) situated between the two oral meridians. The intermediate steps of this reorganization included some processes that resemble those previously described in regulating doublets of other ciliates, and others that are peculiar to members of the “P. aurelia” species‐group and some of its close relatives. The former included a disappearance of one cortical landmark (a contractile vacuole meridian) and transient appearance of another (a third cytoproct) within the narrower semicell. The latter included a reorganization of the paratene zone and the associated invariant (non‐duplicating) region to occupy the entire narrower semicell and a redistribution of zones of most active basal‐body proliferation within the opposite, wider semicell. The final steps of reorganization involved anterior displacement, invagination, and resorption of one of the two oral apparatuses and eventual disappearance of the associated oral meridian. An oral meridian deprived of its oral apparatus, either by spontaneous resorption or microsurgical removal, could persist for some time in “incomplete doublets” before regulating to the singlet condition. The phylogenetically widespread events encountered in the regulation of doublets to singlets suggest that Paramecium shares some of the global regulatory properties that are likely to be ancestral in ciliates. The more specific events are probably associated with the complex cytoskeletal architecture of this organism and with the frequent occurrence of autogamy that was described in the preceding study (Prajer et al. 1999).