bluuebunny/crossref_metadata_2025 huggingface dataset:
The selective vulnerability of nerve cells in Huntington's disease
Authors: Sieradzan K. A. , Mann D. M. A.
Published: March 2003

It is now more than 7 years since the genetic mutation causing Huntington's disease (HD) was first identified. Unstable CAG expansion in theIT15gene, responsible for disease, is translated into an abnormally long polyglutamine (polyQ) tract near the N‐terminus of the huntingtin protein. The presence of expanded polyQ in the mutant protein leads to its abnormal proteolytic cleavage with liberation of toxic N‐terminal fragments that tend to aggregate, probably first in the cytoplasm. Subsequent nuclear translocation of the cleaved mutant huntingtin is associated with formation of intranuclear protein aggregates and neurotoxicity, probably involving apoptotic cascades. These processes, which can be experimentally modelled in cultured neuronal and non‐neuronal cells, seem to underlie neurodegeneration in HD, and also other polyQ disorders, such as dentatorubro‐pallidoluysian degeneration, spinal and bulbar muscular atrophy and the spinocerebellar ataxias. They do not, however, explain why within the corpus striatum and cerebral cortex certain nerve cells are susceptible to disease and others are not. In the human HD brain, vulnerable pyramidal neurones within the deeper layers of the cerebral cortex frequently contain large intranuclear inclusions composed of N‐terminal fragments of huntingtin. Such inclusions are, however, rare within neurones of the striatum, even in the medium spiny neurones preferentially lost from this region. While inclusionsper sedo not seem to be neurotoxic, they may provide a surrogate marker of molecular pathology. Recent studies indicate that the nuclear accumulation of mutant huntingtin interferes with transcriptional events. Of particular importance may be the effect on the genes encoding neurotransmitter receptor proteins, especially those involved with glutamatergic neurotransmission. Such changes may trigger or facilitate a low‐grade, chronic excitotoxicity of the glutamatergic cortical projection neurones on their target cells in the striatum, already partly compromised by the toxic effects of the HD mutation. This combination of insults, for anatomical reasons experienced predominantly by striatal projection neurones, would eventually cause their selective demise.
The development of necrosis and apoptosis in glioma: experimental findings using spheroid culture systems*
Authors: Bell H. S. , Whittle I. R. , Walker M. , Leaver H. A. , Wharton S. B.
Published: March 2003

Cell death in gliomas may occur either by apoptosis, or, in the case of high grade tumours, by necrosis, but questions remain as to the pathogenesis and relationship between these processes. The development of cell death was investigated in multicellular glioma spheroid cultures. Spheroids model the development of cell death due to diffusion gradients in a three‐dimensional system without confounding influences of immune response, pressure gradients, etc. Spheroid cultures were established from four malignant glioma cell lines: U87, U373, MOG‐G‐CCM and A172; harvested from culture at weekly intervals and stained with Haematoxylin and Eosin (H&E), TdT‐mediated dUTP‐X nick end labelling (TUNEL) and by immunohistochemistry for vimentin, Glial Fibrillary Acidic Protein (GFAP) and Ki67. Annexin V flow cytometry and counts of apoptotic cells on H & E stained sections were performed to assess levels of apoptosis. Modes of cell death were also characterized by electron microscopy. Spatially separate zones of proliferation, differentiation and central cell death developed with increasing spheroid diameter. Central cell death developed at a predictable radius (300–400 µm) for each cell line. Ultrastructural examination showed this to be necrotic in type. Apoptosis was most reliably assayed by morphological counts using H & E. Basal levels of apoptosis were low (< 0.5%), but increased with increasing spheroid diameter (> 2% in U87). In particular, levels of apoptosis rose following development of central necrosis and apoptoses were most abundant in the peri‐necrotic zone. There were quantitative differences in the levels of apoptosis and necrosis between glioma cell lines. The predictable onset of necrosis in the spheroids will allow us to investigate the pathogenesis of necrosis and events in prenecrotic cells. There is a relationship between the development of necrosis and apoptosis in this model and these processes can be separately assayed. Further in vitro and genetic studies will enable us to study these events and interactions in greater detail than is possible using other cell culture and in vivo systems.
Mobilizing the Community to Address the Prenatal Health Needs of Immigrant Punjabi Women
Authors: Bhagat Radhika , Johnson Joy , Grewal Sukhdev , Pandher Preet , Quong Elizabeth , Triolet Kathy
Published: March 2003

In Canada, although prenatal education is available to all women, there are groups who do not access these services. One such group is Immigrant Punjabi women residing in the Lower Mainland of British Columbia. It was apparent that structured prenatal education, even when translation was available, would not meet the needs of this group. Efforts were required to help bring this issue into the community so that the community would endorse women's participation in prenatal preparation. The purpose of the project described in this article was to explore how community mobilization strategies could be used to improve the health of pregnant women in the Punjabi community. A collaborative approach was used with representatives from a variety of service agencies and the community. The mobilization strategy involved creating a platform to communicate with the community about prenatal health and health care, creating “buy‐in” from the physicians serving the women of the community, and providing prenatal sessions that built on the existing knowledge of the women. We describe the mobilization process and discuss the insights gained.
Bacteroides forsythus hemagglutinin is inhibited by N‐acetylneuraminyllactose
Authors: Murakami Y. , Higuchi N. , Nakamura H. , Yoshimura F. , Oppenheim F. G.
Published: March 2003

Bacteroides forsythus, which has been recognized as a pathogen associated with periodontitis, produces a hemagglutinin. The hemagglutinin was localized in the envelope of B. forsythus. The hemagglutinating activity was inhibited by lactose at concentrations as low as 1 mM, and by l‐arginine and l‐lysine at concentrations of 100 mM. N‐Acetylneuraminyllactose (NeuAc‐lactose) was at least 100 times more potent an inhibitor than lactose, as it completely inhibited the hemagglutination at concentrations below 10 µM. This is similar to the Helicobacter pylorl hemagglutinin. The hemagglutinin was heat‐labile, and resistant to treatment with proteases such as trypsin. A specific antibody raised against one of the S‐layer proteins that are major species‐specific proteins had no inhibitory effect on the hemmaglutination. These results suggest that the NeuAc‐lactose‐sensitive adhesin of B. forsythus may play an important role in colonization in the oral cavity.
Epidermal dysplasia andMalasseziainfection in two West Highland White Terrier siblings: an inherited skin disorder or reaction to severeMalasseziainfection?
Authors: Nett Claudia S. , Reichler Iris , Grest Paula , Hauser Beat , Reusch Claudia E.
Published: March 2003

Two 9‐month‐old West Highland White Terrier siblings were referred to our clinic with pruritus, alopecia and lichenification. Cytological examination of Scotch™ tape strippings revealedMalasseziaorganisms and cocci. Skin biopsy specimens showed epidermal dysplasia. Treatment included bathing with a 2% miconazole/chlorhexidine‐containing shampoo, orally administered ketoconazole (5 mg kg−1, every 12 h) and cloxacillin (25 mg kg−1every 8 h). Six weeks later, the dermal infection had resolved and there was hair regrowth. However, the dogs were still moderately pruritic. Intradermal allergy testing was positive for house dust mites, storage mites andMalassezia. Immunotherapy was initiated, and treatment with ketoconazole and cloxacillin was stopped. Skin biopsies, which were performed in both dogs 4 months after the first presentation, revealed mild superficial perivascular dermatitis. The remaining mild facial pruritus was easily controlled with topical treatment. These two cases indicate that epidermal dysplasia might be an inflammatory or hypersensitivity reaction to theMalasseziainfection or a result of excessive self‐trauma, rather than a congenital keratinization disorder.
A case of feline phaeohyphomycosis due to Fonsecaea pedrosoi
Authors: Fondati Alessandra , Gallo Maria Grazia , Romano Erica , Fondevila Dolores
Published: March 2003

The first report of a case of feline phaeohyphomycosis due to Fonsecaea pedrosoi is presented. Fonsecaea pedrosoi is an aetiologic agent of both human phaeohyphomycosis and chromoblastomycosis. In our cat, the lesion was confined to the skin and appeared as a firm swelling on the bridge of the nose. Diagnosis was based on histological examination of a cutaneous biopsy and fungal culture of a tissue sample on Sabouraud’s dextrose agar. Further diagnostic tests failed to reveal an underlying immunosuppression. Two treatment cycles with itraconazole, at the oral dose of 5 mg kg−1 given twice daily, induced complete clinical remission, but relapses occurred.
Efficacy of itraconazole as a combined continuous/pulse therapy in feline dermatophytosis: preliminary results in nine cases
Authors: Colombo S. , Cornegliani L. , Vercelli A.
Published: March 2003

This study evaluated the efficacy of itraconazole as a combined continuous/pulse therapy for feline dermatophytosis. Nine cats with dermatophytosis caused byMicrosporum caniswere treated with itraconazole at 10 mg kg−1orally once daily for 28 days and then on an alternate week regimen (1 week off, 1 week on) at the same dosage. Cats were re‐evaluated by physical examination and fungal culture at days 28, 42, 56 and 70 if necessary. Treatment was stopped when two consecutive negative fungal cultures were obtained. Eight cats were cured after 56 days, with two negative cultures obtained at days 28 and 42. In one case, a positive culture was obtained at day 28, but negative cultures were achieved at days 42 and 56. This protocol appears to be effective in the treatment of feline dermatophytosis, although these preliminary results should be confirmed by a controlled study.
Photosynthesis nuclear genes generally lack TATA‐boxes: a tobacco photosystem I gene responds to light through an initiator
Authors: Nakamura Masayuki , Tsunoda Tatsuhiko , Obokata Junichi
Published: March 2003

The promoter architecture of the nuclear‐encoded photosystem I genes was studied using a tobacco gene, psaDb, as a model case. Linker scanning mutations revealed that the psaDb promoter does not have a TATA box. Instead, pyrimidine‐rich Initiator (Inr) elements that overlap the transcription start sites are essential for light‐responsive transcription of this gene. When the psaDb promoter was mutated to have a TATA‐box but no Inr, light‐responsive transcription was impaired, indicating that the regulatory system of this gene prefers Inr to a TATA box. As very little is known about plant TATA‐less promoters, we subsequently examined whether this promoter architecture is unique to psaDb. Computer analysis of 232 plant promoters revealed surprising features; the majority of photosynthesis nuclear genes lacked TATA boxes, although the frequency of the TATA‐less promoters in non‐photosynthesis genes was less than 10%. These results strongly suggest that TATA‐independent transcription mechanisms play important roles in the regulated expression of photosynthesis nuclear genes.
Selenate‐resistant mutants of Arabidopsis thaliana identify Sultr1;2, a sulfate transporter required for efficient transport of sulfate into roots
Authors: Shibagaki Nakako , Rose Alan , McDermott Jeffrey P. , Fujiwara Toru , Hayashi Hiroaki , Yoneyama Tadakatsu , Davies John P.
Published: March 2003

To investigate how plants acquire and assimilate sulfur from their environment, we isolated and characterized two mutants of Arabidopsis thaliana deficient in sulfate transport. The mutants are resistant to selenate, a toxic analogue of sulfate. They are allelic to each other and to the previously isolated sel1 (selenate‐resistant) mutants, and have been designated sel1‐8 and sel1‐9. Root elongation in these mutants is less sensitive to selenate than in wild‐type plants. Sulfate uptake into the roots is impaired in the mutants under both sulfur‐sufficient and sulfur‐deficient conditions, but transport of sulfate to the shoot is not affected. The sel1 mutants contain lesions in the sulfate transporter gene Sultr1;2 located on the lower arm of chromosome 1. The sel1‐1, sel1‐3 and sel1‐8 mutants contain point mutations in the coding sequences of Sultr1;2, while the sel1‐9 mutant has a T‐DNA insertion in the Sultr1;2 promoter. The Sultr1;2 cDNA derived from wild‐type plants is able to complement Saccharomyces cerevisiae mutants defective in sulfate transport, but the Sultr1;2 cDNA from sel1‐8 is not. The Sultr1;2 gene is expressed mainly in roots, and accumulation of transcripts increases during sulfate deprivation. Examination of transgenic plants containing the Sultr1;2 promoter fused to the GUS‐reporter gene indicates that Sultr1;2 is expressed mainly in the root cortex, the root tip and lateral roots. Weaker expression of the reporter gene was observed in hydathodes, guard cells and auxiliary buds of leaves, and in anthers and the basal parts of flowers. The results indicate that Sultr1;2 is primarily involved in importing sulfate from the environment into the root.
Detailed three‐dimensional fetal echocardiography facilitated by an Internet link
Authors: Michailidis G. D. , Simpson J. M. , Karidas C. , Economides D. L.
Published: March 2003

Objectives

To assess whether a complete virtual cardiological examination can be achieved in stored three‐dimensional volumes of the fetal heart, transmitted to a tertiary fetal cardiology center via the Internet.

Methods

Thirty sequential normal singleton pregnancies were included in the study. Four cardiac volumes were acquired using a three‐dimensional ultrasound system. The volumes were sent via the Internet to a tertiary fetal cardiology center, where a detailed fetal cardiac examination was attempted using the three‐dimensional volumetric dataset.

Results

The median gestational age was 24 (range, 22–28) weeks. A complete heart examination was accomplished in 23 of 30 cases (76.7%; 95% confidence interval, 58–90%). The four‐chamber view and the cardiac situs were seen in all cases. The right ventricular outflow tract was seen in 29 (96.7%) cases and the left ventricular outflow tract in 25 (83.3%) cases. The long‐axis view of the aortic arch, superior vena cava, inferior vena cava and pulmonary veins were visualized in more than 80% of cases. The mean time of volume acquisition was 9.5 (standard deviation, 2.3) min and the mean examination time by the fetal cardiologist was 17 (standard deviation, 4.8) min.

Conclusions

These preliminary results demonstrate that a three‐dimensional virtual examination of the fetal heart is possible. There are limitations such as the lack of flow and functional information but complete ascertainment of the main cardiac connections was possible in the majority of cases. The use of an Internet link has major implications, particularly for situations in which the scanning center is geographically remote from the tertiary referral center. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Early prenatal sonographic diagnosis and follow‐up of Jeune syndrome
Authors: Den Hollander N. S. , Robben S. G. F. , Hoogeboom A. J. M. , Niermeijer M. F. , Wladimiroff J. W.
Published: March 2003

Jeune syndrome or asphyxiating thoracic dysplasia is an autosomal recessive osteochondrodysplasia. It is one of the six short‐rib (polydactyly) syndromes. The disease has a wide spectrum of manifestations, ranging from a latent to a mild or lethal condition. We describe the prenatal sonographic diagnosis of Jeune syndrome at 14 weeks of gestation in a fetus at risk for this condition, and the development of the syndrome throughout the pregnancy. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Multicenter screening for pre‐eclampsia and fetal growth restriction by transvaginal uterine artery Doppler at 23 weeks of gestation
Authors: Papageorghiou A. T. , Yu C. K. H. , Bindra R. , Pandis G. , Nicolaides K. H.
Published: March 2003

Objective

To determine the value of transvaginal color Doppler assessment of the uterine arteries at 23 weeks of gestation in predicting the subsequent development of pre‐eclampsia and fetal growth restriction.

Patients and methods

Women with singleton pregnancies attending for routine ultrasound examination at 23 weeks in any one of seven hospitals underwent Doppler assessment of the uterine arteries. The presence of an early diastolic notch in the waveform was noted, and the mean pulsatility index of the two arteries was calculated. Screening characteristics in the prediction of pre‐eclampsia and the delivery of a low birth‐weight infant were calculated.

Results

Doppler examination of the uterine arteries was attempted in 8335 consecutive singleton pregnancies, satisfactory waveforms were obtained from both vessels in 8202 (98.4%) cases and complete outcome data were available in 7851 (95.7%) of these. The mean gestational age was 23 (range, 22–24) weeks. The mean uterine artery pulsatility index did not change significantly with gestation (r = –0.0078; P = 0.483); the median value was 1.04 and the 95th centile was 1.63. In 9.3% of cases early diastolic notches in the waveform from both uterine arteries were present and in an additional 11.1% of cases there were notches unilaterally. Pre‐eclampsia with fetal growth restriction occurred in 42 (0.5%) cases, pre‐eclampsia without fetal growth restriction in 71 (0.9%) and fetal growth restriction without pre‐eclampsia in 698 (8.9%). The sensitivity of increased pulsatility index above the 95th centile (1.63) for pre‐eclampsia with fetal growth restriction was 69%, for pre‐eclampsia without fetal growth restriction was 24%, for fetal growth restriction without pre‐eclampsia was 13%, for pre‐eclampsia irrespective of fetal growth restriction was 41% and for fetal growth restriction irrespective of pre‐eclampsia was 16%. The sensitivity of fetal growth restriction defined by the 5th rather than the 10th centile was higher (19% vs. 16%). The sensitivity for both pre‐eclampsia and fetal growth restriction was inversely related to the gestational age at delivery; when delivery occurred before 32 weeks, the sensitivity for all cases of pre‐eclampsia with fetal growth restriction, pre‐eclampsia without fetal growth restriction and fetal growth restriction without pre‐eclampsia increased to 93%, 80% and 56%, respectively. The sensitivity of bilateral notches in predicting pre‐eclampsia and/or fetal growth restriction was similar to that of increased pulsatility index but the screen‐positive rate with notches (9.3%) was much higher than that with increased pulsatility index (5.1%).

Conclusions

A one‐stage color Doppler screening program at 23 weeks identifies most women who subsequently develop severe pre‐eclampsia and/or fetal growth restriction. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Incidence of major structural cardiac defects associated with increased nuchal translucency but normal karyotype
Authors: Ghi T. , Huggon I. C. , Zosmer N. , Nicolaides K. H.
Published: March 2003

Objective

To examine the association between increased nuchal translucency thickness and major cardiac defects in chromosomally normal fetuses.

Setting

Tertiary referral unit for fetal medicine and fetal cardiology.

Methods

During a 4‐year period (January 1997 to January 2001), detailed echocardiography was performed in 1319 chromosomally normal fetuses with increased nuchal translucency thickness at 10–14 weeks of gestation. The incidence of major cardiac defects was examined in relation to the fetal NT at the 10–14‐week scan.

Results

Major cardiac defects were diagnosed in 60 (4.5%) of the 1319 fetuses. In fetuses with a nuchal translucency thickness in the range of 2.5–3.4 mm, the incidence of major cardiac defects was 2.5% (18/722; 95% confidence interval, 1.5–3.9) and in those with a nuchal translucency thickness ≥ 3.5 mm, it was 7% (42/597; 95% confidence interval, 5.1–9.4).

Conclusion

Specialist echocardiography is indicated in all fetuses with increased nuchal translucency thickness because, in such fetuses, the incidence of major cardiac defects is substantially higher than in pregnancies with maternal diabetes, family history and exposure to drugs, where fetal echocardiography is widely considered to be necessary.Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Absence of the ductus venosus: report of 10 new cases and review of the literature
Authors: Contratti G. , Banzi C. , Ghi T. , Perolo A. , Pilu G. , Visentin A.
Published: March 2003

Objective

To assess the clinical significance of the absence of the ductus venosus.

Design

A retrospective study with a review of the literature.

Methods

The archives of our ultrasound laboratory and the English literature were searched for cases with a prenatal diagnosis of absence of the fetal ductus venosus.

Results

Between 1985 and 2000, 10 fetuses were diagnosed in our center as having absence of the ductus venosus. The review of the literature revealed 23 cases. Three main patterns of abnormal venous circulation were documented: (1) umbilical vein bypassing the liver and connecting directly to the right atrium (46%); (2) umbilical vein bypassing the liver and connecting to the inferior vena cava mostly through one of the iliac veins (25%); (3) umbilical vein connecting to the portal circulation without giving rise to the ductus venosus (21%). Major anomalies, including chromosomal aberrations, were found in 8/33 (24%) cases. Hydrops developed in 11/33 (33%) cases. Twenty fetuses with isolated absence of the ductus venosus were delivered, and 5 (20%) died. The portal vein was found to be absent in half of the infants examined after birth.

Conclusions

Our results and the review of literature suggest that absence of the ductus venosus is associated with a high incidence of fetal anomalies and adverse outcomes, including associated malformations, chromosomal aberrations, in utero heart failure and absence of the portal vein. Heart failure and absence of the portal vein seem particularly frequent when absence of the ductus venosus is associated with a connection of the umbilical vein to either the inferior vena cava or the right atrium.Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Value of sonomorphological criteria of the endometrium in women with postmenopausal bleeding: a multivariate analysis
Authors: Randelzhofer B. , Prömpeler H. J. , Sauerbrei W. , Madjar H. , Emons G.
Published: March 2003

Objective

This study was performed to examine whether an improvement in the transvaginal sonographic evaluation of the endometrium is possible by the addition of sonomorphological criteria to the measurement of endometrial thickness in women with postmenopausal bleeding.

Methods

Various sonomorphological criteria were analyzed prospectively in 321 patients with postmenopausal bleeding. In a logistic regression model relevant criteria were selected and a diagnostic formula for differentiation of endometrial sonographic findings was derived.

Results

The criteria of endometrial structure, endometrial–myometrial border and endometrial thickness were significant for the differentiation of malignancy. These results allowed an estimation of the probability of malignancy for each sonographic endometrial finding. Using the cut‐off point of 0.1 for the probability of malignancy, the sensitivity and specificity were 96.8% and 61.9%, respectively, with an accuracy of 72.3%. In contrast, the differentiation by endometrial thickness as the sole criterion (cut‐off point ≥5 mm) achieved a sensitivity of 97.9% and a specificity of 33.2%, with an accuracy of 52.3%.

Conclusion

A useful diagnostic formula based on sonomorphological and metric criteria for endometrial differentiation was obtained. The specificity and accuracy increased with a minimal loss of sensitivity. However, estimates for sensitivity, specificity, and accuracy may be overoptimistic because they were derived from the same data used for development of the model. Copyright © 2002 ISUOG
Molecular characterization of three gut genes from Glossina morsitans morsitans: cathepsin B, zinc‐metalloprotease and zinc‐carboxypeptidase
Authors: Yan J. , Cheng Q. , Li C.‐B. , Aksoy S.
Published: March 2003

Insect gut enzymes are involved in digestion of dietary proteins. Additionally, these enzymes have been implicated in the process of pathogen establishment in several insects including the tsetse fly (Diptera:Glossinidae), which is the vector for African trypanosomes. Both the male and female tsetse can transmit trypanosomes and are strict blood feeders during all stages of their development. Here, we describe the molecular characterization of three gut genes: cathepsin B (GmCatB), zinc‐metalloprotease (GmZmp) and zinc‐carboxypeptidase (GmZcp). The cDNA for GmCatB encodes a protein for 340 amino acids with a predicted molecular mass of 38.2 kDa, while the 854 bp GmZmp cDNA encodes a protein of 254 amino acids with a molecular mass of 29 kDa. The GmZcp cDNA is 1319 bp in length and has a 354 amino acids open reading frame for coding a 40 kDa protein. All three cDNAs have signal peptide sequences associated with their N‐terminal domains and structure analysis indicates that GmCatB and GmZmp are expressed as zymogens with pro‐domains proteolytically removed for activity. The activation domain associated with the carboxypeptidase sequences is lacking in GmZcp. While GmCatB transcription is constitutive, teneral flies express very low levels of transcripts for GmZmp and GmZcp prior to the first bloodmeal. Transcription of all genes is induced and remains high throughout the digestion cycle within a few hours following the first bloodmeal ingestion. Both GmCatB and GmZcp are parasite responsive, with the expression of both genes being higher in trypanosome infected flies.
A high affinity serotonin‐ and histamine‐binding lipocalin from tick saliva
Authors: Sangamnatdej S. , Paesen G. C. , Slovak M. , Nuttall P. A.
Published: March 2003

To overcome the inflammatory response in its host, the cattle‐feeding, brown ear tick secretes histamine‐binding proteins into the feeding site. These proteins are β‐barrels with two internal binding sites: a high‐affinity (H) site for histamine and a site (L) for which the natural ligand is unknown. Here we report a related protein (SHBP), secreted by a rodent‐ and cattle‐feeding tick, that traps both histamine and serotonin. The histamine‐binding H site is well conserved in SHBP, whereas residue changes in the L‐like site are consistent with binding of the bulkier serotonin molecule. As histamine is a key inflammatory mediator in cattle, while serotonin takes on this role in rodents, the diversification of these tick proteins may reflect host adaptation.
Seed dispersal by animals: exact identification of source trees with endocarp DNA microsatellites
Authors: Godoy José A. , Jordano Pedro
Published: March 2003

A long‐standing challenge in studies of seed dispersal by animal frugivores has been the characterization of the spatial relationships between dispersed seeds and the maternal plants, i.e. the seed shadow. The difficulties to track unambiguously the origin of frugivore‐dispersed seeds in natural communities has been considered an unavoidable limitation of the research field and precluded a robust analysis of the direct consequences of zoochory. Here we report that the multilocus genotype at simple sequence repeat (SSR; microsatellite) loci of the woody endocarp, a tissue of maternal origin, provides an unequivocal genetic fingerprint of the source tree. By comparing the endocarp genotype against the complete set of genotypes of reproductive trees in the population, we could unambiguously identify the source tree for 82.1% of the seeds collected in seed traps and hypothesize that the remaining 17.9% of sampled seeds come from other populations. Identification of the source tree for Prunus mahaleb seeds dispersed by frugivores revealed a marked heterogeneity in the genetic composition of the seed rain in different microhabitats, with a range of 1–5 distinct maternal trees contributing seeds to a particular landscape patch. Within‐population dispersal distances ranged between 0 and 316 m, with up to 62% of the seeds delivered within 15 m of the source trees. Long distance dispersal events, detected by the exclusion of all reproductive trees in the population, accounted for up to 17.9% of the seeds sampled. Our results indicate strong distance limitation of seed delivery combined with infrequent long‐distance dispersal events, extreme heterogeneity in the landscape pattern of genetic makeup, and a marked mosaic of multiple parentage for the seeds delivered to a particular patch.
Statistical power when testing for genetic differentiation
Authors: Ryman N. , Jorde P. E.
Published: March 2003

A variety of statistical procedures are commonly employed when testing for genetic differentiation. In a typical situation two or more samples of individuals have been genotyped at several gene loci by molecular or biochemical means, and in a first step a statistical test for allele frequency homogeneity is performed at each locus separately, using, e.g. the contingency chi‐square test, Fisher’s exact test, or some modification thereof. In a second step the results from the separate tests are combined for evaluation of the joint null hypothesis that there is no allele frequency difference at any locus, corresponding to the important case where the samples would be regarded as drawn from the same statistical and, hence, biological population. Presently, there are two conceptually different strategies in use for testing the joint null hypothesis of no difference at any locus. One approach is based on the summation of chi‐square statistics over loci. Another method is employed by investigators applying the Bonferroni technique (adjusting the P‐value required for rejection to account for the elevated alpha errors when performing multiple tests simultaneously) to test if the heterogeneity observed at any particular locus can be regarded significant when considered separately. Under this approach the joint null hypothesis is rejected if one or more of the component single locus tests is considered significant under the Bonferroni criterion. We used computer simulations to evaluate the statistical power and realized alpha errors of these strategies when evaluating the joint hypothesis after scoring multiple loci. We find that the ‘extended’ Bonferroni approach generally is associated with low statistical power and should not be applied in the current setting. Further, and contrary to what might be expected, we find that ‘exact’ tests typically behave poorly when combined in existing procedures for joint hypothesis testing. Thus, while exact tests are generally to be preferred over approximate ones when testing each particular locus, approximate tests such as the traditional chi‐square seem preferable when addressing the joint hypothesis.
Secondary predation: quantification of food chain errors in an aphid–spider–carabid system using monoclonal antibodies
Authors: Harwood J. D. , Phillips S. W. , Sunderland K. D. , Symondson W. O. C.
Published: March 2003

‘Secondary predation’ occurs when one predator feeds on a second predator, which has in turn eaten a target prey. Detection of prey remains within predators using monoclonal antibodies cannot distinguish between primary and secondary predation, potentially leading to quantitative and qualitative food chain errors. We report the first fully replicated experiments to measure secondary predation effects, using an aphid–spider–carabid system. Aphids, Sitobion avenae, were fed to spiders, Lepthyphantes tenuis, which were allowed to digest their prey for a range of time intervals. The spiders were then fed to carabids, Poecilus (=Pterostichus) cupreus, which were again allowed to digest their prey for set periods. The anti‐aphid monoclonal antibody used to identify S. avenae remains in P. cupreus was one that detected an epitope that increased in availability over the first few hours of digestion, amplifying the signal, extending detection periods and thus increasing the chances of detecting secondary predation. Despite this, and the fact that spiders are known to digest their prey more slowly than many other predators, detection of secondary predation was only possible if the carabids were killed immediately after consuming at least two spiders which were, in turn, eaten immediately after consuming aphids. As this scenario is unlikely to occur frequently in the field it was concluded that secondary predation is unlikely to be a serious source of error during field studies.
Phenotypic evolution and hidden speciation in Candidula unifasciata ssp. (Helicellinae, Gastropoda) inferred by 16S variation and quantitative shell traits
Authors: Pfenninger Markus , Magnin Frédéric
Published: March 2003

In an effort to link quantitative morphometric information with molecular data on the population level, we have analysed 19 populations of the conchologically variable land snail Candidula unifasciata from across the species range for variation in quantitative shell traits and at the mitochondrial 16S ribosomal (r)DNA locus. In genetic analysis, including 21 additional populations, we observed two fundamental haplotype clades with an average pairwise sequence divergence of 0.209 ± 0.009 between clades compared to 0.017 ± 0.012 within clades, suggesting the presence of two different evolutionary lineages. Integrating additional shell material from the Senckenberg Malacological Collection, a highly significant discriminant analysis on the morphological shell traits with fundamental haplotype clades as grouping variable suggested that the less frequent haplotype corresponds to the described subspecies C. u. rugosiuscula, which we propose to regard as a distinct species. Both taxa were highly subdivided genetically (FST = 0.648 and 0.777 P < 0.001). This was contrasted by the partition of morphological variance, where only 29.6% and 21.9% of the variance were distributed among populations, respectively. In C. unifasciata, no significant association between population pairwise FST estimates and corresponding morphological fixation indices could be detected, indicating independent evolution of the two character sets. Partial least square analysis of environmental factors against shell trait variables in C. u. unifasciata revealed significant correlations between environmental factors and certain quantitative shell traits, whose potential adaptational values are discussed.
Strategies for microsatellite isolation: a review
Authors: Zane L , Bargelloni L , Patarnello T
Published: March 2003

In the last few years microsatellites have become one of the most popular molecular markers used with applications in many different fields. High polymorphism and the relative ease of scoring represent the two major features that make microsatellites of large interest for many genetic studies. The major drawback of microsatellites is that they need to be isolated de novo from species that are being examined for the first time. The aim of the present paper is to review the various methods of microsatellite isolation described in the literature with the purpose of providing useful guidelines in making appropriate choices among the large number of currently available options. In addition, we propose a fast and easy protocol which is a combination of different published methods.
Population fragmentation in the southern rock agama, Agama atra: more evidence for vicariance in Southern Africa
Authors: Matthee Conrad A. , Flemming Alexander F.
Published: March 2003

Mitochondrial DNA sequence data derived from two genes were used to infer phylogeographical relationships between 13 Agama atra populations. Three distinct geographical assemblages were found among the lizard populations. The first occurs in southern Namibia, the second is restricted to the western dry arid regions of South Africa, whereas the third is distributed throughout the more mesic southern and eastern parts of the subcontinent. Geographically structured differences among populations within Agama clades are probably the result of dispersal and historic isolations among populations. At the broader scale, there were marked congruences between the Agama genetic discontinuities and those described previously in other rock‐dwelling vertebrates such as Pronolagus rupestris and Pachydactylus rugosus. This suggests vicariance, probably as a response to natural climatic changes during the past three million years.
Genetic diversity in Arabidopsis thaliana L. Heynh. investigated by cleaved amplified polymorphic sequence (CAPS) and inter‐simple sequence repeat (ISSR) markers
Authors: Barth S. , Melchinger A. E. , Lübberstedt TH.
Published: March 2003

In this study, we investigated genetic diversity among 37 accessions in Arabidopsis thaliana from Eurasia, North Africa and North America using morphological traits and two polymerase chain reaction (PCR)‐based marker systems: cleaved amplified polymorphic sequences (CAPS) and inter‐simple sequence repeats (ISSR). Cluster analysis based on genetic similarities calculated from CAPS data grouped the accessions roughly according to their geographical origin: one large group contained accessions from Western, Northern and Southern Europe as well as North Africa, a second group consisted of Eastern European and Asian continental accessions. North American accessions were interspersed into these groups. Contrary to the CAPS analysis, the dendrogram obtained from the ISSR data did not reflect the geographical origin of the accessions, and the calculated genetic distances did not match the CAPS results. This could be attributable to an uneven genomic distribution of ISSR markers as substantiated by a database search for ISSR binding sites in A. thaliana genomic DNA sequence files, or to the ISSR’s different mode of evolution. We recommend CAPS markers for diversity analysis in A. thaliana because a careful selection of markers can ascertain an even representation of the entire genome.
Gonad development and evidence of protogyny in the red‐throat emperor on the Great Barrier Reef
Authors: Bean K. , Mapstone B. D. , Davies C. R. , Murchie C. D. , Williams A. J.
Published: March 2003

The gonad development in the red‐throat emperor Lethrinus miniatus is described and the first detailed evidence for protogyny in this species provided. The identification of transitional individuals, bimodal sex‐specific size‐frequency distributions and female biased sex ratios suggest that L. miniatus is most likely a protogynous hermaphrodite. Transitional L. miniatus gonads were characterized by the concurrent degeneration of all oocytes and the proliferation of spermatocysts near the edge of the lamellae, an increase in blood vessels along strands of stromal tissue within the lamellae and the formation of multiple sperm sinuses. The sites of oocyte degeneration and proliferation of spermatocysts were spatially segregated. An increase in blood vessels along strands of stromal tissue within the lamellae of transitional phase gonads is likely to assist in the breakdown of oocytes and the proliferation of spermatocysts. Most mature resting females containing spermatocysts occurred within the transitional size‐frequency distribution, suggesting that the presence of spermatocysts in these females may be an early sign of sex change. Oocytes within female gonads were interrupted by filamentous strands of stromal tissue within the lamellae. The testis contained a remanent ovarian lumen but no residual oocytes. Three characteristics of transitional L. miniatus gonads were found to be unusual and described for few other species of coral reef fishes. These included the absence of oocytes within testes, increased numbers of blood vessels, and the presence of strands of stromal tissue within the lamellae.
Effect of adult pheromones on the avoidance of suspended sediment by migratory banded kokopu juveniles
Authors: Baker C. F.
Published: March 2003

Migratory banded kokopu Galaxias fasciatus juveniles exhibited an attraction to adult odours and an avoidance towards suspended sediment with a turbidity of 25 nephelometric turbidity units (NTU) in a two‐choice chamber apparatus. When the adult odours were mixed with suspended sediment at a turbidity of 25 or 35 NTU, an attraction towards the odour and suspended sediment chamber resulted. When adult odours were paired with turbid water at 50 NTU, juveniles would avoid the odour and suspended sediment chamber. These results demonstrate adult pheromones can increase the threshold for an avoidance response to suspended sediment in banded kokopu juveniles. This provides supporting evidence that odours released by adult conspecifics may provide an important migratory cue for juveniles in stream and habitat selection.
Enhanced phylogeographic information about Austrian brown trout populations derived from complete mitochondrial control region sequences
Authors: Duftner N. , Weiss S. , Medgyesy N. , Sturmbauer C.
Published: March 2003

Complete DNA sequences of the control region revealed a more fine‐scale genetic structuring within and among Austrian brown troutSalmo truttapopulations providing the opportunity for gene frequency analyses in the phylogeographic context. Ninety‐two individuals (75%) were assigned to nine Danubian haplotypes and 31 individuals (25%) comprised seven Atlantic haplotypes of northern European origin. Three of the Atlantic haplotypes were also found in an Austrian hatchery breeding stock.
Bodyfat percentage in girls increased steadily with age and percentile rank of body mass index
Authors: Yoshinaga Masao , Shimago Atsushi , Noikura Yoshihide , Kinou Sanae , Ohara Tsuruo , Miyta Koichiro
Published: March 2003

Background
: The purpose of the present study was to determine the body composition of elementary school children by bioelectrical impedance analysis (BIA) method with a subject in a standing position. The method is frequently used in Japan. The other aim was to evaluate the relationship between the body composition and percentile rank of the body mass index (BMI) in Japanese children.

Methods
: The number of subjects were 1042 children (530 boys and 512 girls aged from 6‐ to 12‐years‐old) from an elementary school. The bioelectrical impedance (BI) in the standing position was measured late in the morning before lunch. The fat percentage was derived from the body density according to the formula of Brozek et al. Each percentile value of BMI for each age and sex was determined from the frequency table of height and weight published by the Ministry of Education in Japan.

Results
: The fat percentage in both boys and girls was significantly correlated with the BMI, however, girls showed a closer linear relation than boys. The fat percentage in girls increased steadily with age and percent rank of the BMI. The fat percentage in boys was scattered in a wide range at each percentile rank of the BMI.

Conclusions
: The fat percentage measured by the BIA in the standing position is closely associated with the percentile rank of the BMI in elementary school girls. For boys, it will be necessary to compare data among different types of BI measurement methods.
Venous thromboembolic diseases associated with uterine myomas diagnosed before hysterectomy: A report of two cases
Authors: Tanaka Hirohiko , Umekawa Takashi , Kikukawa Toyo , Nakamura Mashio , Toyoda Nagayasu
Published: March 2003

Large uterine myomas (compressed veins in the pelvis), and the resulting impaired blood flow have been associated with deep vein thrombosis and pulmonary embolism. Careful detection of the preoperatively formed thrombi and strict perioperative management, such as in the following cases we report, may reduce lethal pulmonary embolism and may positively affect patient prognosis.
Critical incident stress debriefing following traumatic life experiences
Authors: Irving P. , Long A.
Published: March 2003

This study was designed to explore the use of critical incident stress debriefing as a therapeutic intervention following traumatic life events. A case study approach was used to allow the researchers to adopt a more flexible and overtly involved stance. Initial contact took place 24 h following the traumatic life experiences of three women. Critical incident stress debriefing was provided and data were collected and recorded within an ethical framework. Six months following the traumatic life experiences the women were interviewed again to explore their perceptions of the intervention that was provided. The results demonstrated positive outcomes. The women concluded that the debriefing intervention provided a safe forum for them to explore their needs, process their experiences and create constructive narratives. A carefully constructed critical incident stress debriefing intervention was used within the context of its objectives and acknowledged limitations. The study was small and generalizations cannot be made to other individuals who experience similar tragedies. Nevertheless, evidence from previous research coupled with the findings from this study suggests that mental health nurses might benefit from being educated and trained in critical incident stress debriefing. Further research needs to be carried out to explore the use of different models of stress debriefing applied to special circumstances. The goal of such interventions should be to alleviate symptoms and to prevent the development of a full‐blown post‐traumatic stress disorder.
Cell‐to‐cell movement of tobacco mosaic virus: enigmas and explanations
Authors: Rhee Yoon , Tzfira Tzvi , Chen Min‐Huei , Waigmann Elisabeth , Citovsky Vitaly
Published: March 2003

Tobacco mosaic virus (TMV) spreads between cells through plant intercellular connections, the plasmodesmata. This transport process is mediated by a specialized virus‐encoded movement protein, TMV MP. Recent advances in two major aspects of TMV MP function highlight the limits of our current knowledge and promise exciting future developments. First, findings that TMV MP interacts with cytoskeletal elements and cell wall proteins suggest potential mechanisms for TMV MP targeting from the cell cytoplasm to plasmodesmal channels. Second, indications that TMV MP phosphorylation plays a regulatory role in several activities of TMV MP begin to unravel molecular pathways that control TMV cell‐to‐cell transport. TMV systemic movement that follows its initial cell‐to‐cell spread, on the other hand, may be controlled through two different pathways used for viral entry into and exit from the host plant vascular tissue.