bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure of the mouse gene encoding peripherin: a neuronal intermediate filament protein
Authors: Karpov Vadim , Landon Françoise , Djabali Karima , Gros François , Portier Marie‐Madeleine
Published: September 2004

Summary— The gene encoding mouse peripherin, a neuronal intermediate filament protein, has been cloned. Its sequence, through 1021 nucleotides composing the 5′‐flanking region, nine exons, eight introns and 547 nucleotides of the 3′‐flanking region, as well as its transcription initiation site have been determined. The amino acid coding sequence differs from that of the rat peripherin gene. The mouse gene has an additional histidine near the N‐terminal end, and shows three conservative and two non‐conservation changes. The promoter sequence, containing the binding sites for transcription factors as well as other sequences is homologous to promoter regions of other type III intermediate filament protein genes and other neuronal‐specific genes.
Principal and intercalated cells in primary cultures of rabbit renal collecting tubules revelaed by monoclonal antibodies
Authors: Tauc Michel , Koechlin Noémie , Jamous Marc , El Ouaghi Mahjoub , Gastineau Monique , Le Moal Corinne , Poujeol Philippe
Published: September 2004

Summary— In this study we describe the production and characterization of two monoclonal antibodies (mAb 503 and mAb 703) raised against the apical membrane of rabbit cortical collecting tubule (CCT) cells. The specificity of the two monoclonal antibodies was studied by immunoelectron microscopy on kidney sections. These antibodies were used to identify principal and intercalated cells in primary cultures of CCT. To assess the maintenance of the basic characteristics of the cortical collecting cells during the growth process we determined the biochemical and electrophysiological properties of cultured CCT. Of the monoclonal antibodies produced mAb 503 was specifically directed against the luminal membrane of intercalated cells as shown by immunoelectron microscopy. mAb 703 bound specifically the apical membrane of the principal cells. In primary cultures of CCT mAb 503 and mAb 703 bound antigens present on the apical membrane of different cells and permitted the study of the distribution of the two cell types. Results showed the maintenance of the epithelial polarity of cultured CCT and the expression of specific antigens.
Ultrastructural, cytochemical and immunocytochemical investigation of the interphase nucleus in the unicellular green alga Chlamydomonas reinhardtii
Authors: Tremblay Stéphane D. , Gugg Siegfried , Lafontaine Jean G.
Published: September 2004

Summary— The ultrastructural organization of the interphase nucleus of the green alga Chlamydomonas reinhardtii was investigated and found to be largely dependent on the fixation conditions. In specimens stained with bismuth, densely contrasted granules ranging from 25 to 45 nm in diameter were localized throughout the interchromatin space and often formed clusters. These granules were labeled by RNase A‐gold complexes and may represent the counterparts of animal and higher plant cll interchromatin granules. Within the nucleolus the Ag‐NOR and pyroantimonate stains and, to a lesser extent, the bismuth stain reacted with the nucleolar dense fibrillar component (DFC). When cells were subjected to a heat shock at 42°C, the nucleolar DFC was found to progressively separate from the nucleolus and, after 3 h, appeared as a continuous meandering thread about 0.1 μm in width. Within the nucleolus, labeling on conventional preparations occurred as small clusters with antibodies to H3 histones or to DNA whereas RNase A‐gold complexes labeled most of it including fibrillar centers. Improved ultrastructural preservation in cryofixed, cryosubstituted specimens gently fixed in glutaraldehyde permitted to localize nucleolar DNA predominantly at the outer edge of fibrillar centers and to a lesser extent within the neighbouring DFC. Our results indicate that the structure and composition of Chlamydomonas interphase nuclei are comparable, despite particularities, to those of animal and higher plant nuclei.
Characterization and supramolecular architecture of the cellulose‐protein fibrils in the tunic of the sea peach (Halocynthia papillosa, Ascidiacea, Urochordata)
Authors: Van Daele Yves , Revol Jean‐François , Gaill Françoise , Goffinet Gerhard
Published: September 2004

Summary— The cellulose‐protein fibrils, which constitute by far the bulk of the fibrous fraction of the sea peach tunic (Halocynthia papillosa), were structurally and chemically characterized, either in situ or after extraction procedures, with the use of classical electron microscoy combined with diffraction contrast imaging and electron diffraction, histochemistry, affinity cytochemistry and chemical analysis. These fibrils exhibit a cross‐sectional shape close to a parallelogram. The cyrstallites forming their core, with lateral dimensions ranging from roughly 5 to 20 nm, are composed of native cellulose of higher crystallinity than that of plant cellulose. They are associated with acid mucopolysaccharidés (amps) and proteins which form a coating material appearing as a continuous sheath enveloping the axial crystallite in the cuticular layer or as patches more‐or‐less periodically distributed around and along the fibre axis in the fundamental layer. Tunicin, the alkali‐insoluble fibrous fraction, is not pure cellulose, yielding only 22–60% of its dry weight as glucose equivalents, depending on the tunical layer. It is suggested that in addition to the high degree of crystallinity of the tunical cellulose, the presence of a significant amount of coating material composed of amino acids and proteoglycans firmly linked to cellulose molecules contributes to tunicin's high resistance to hydrolysis.
Confocal scanning optical microscopy and three‐dimensional imaging
Authors: Laurent Michel , Johannin Georges , Le Guyader Hervé , Fleury Anne
Published: September 2004

Summary— Confocal scanning optical microscopy has significant advantages over conventional fluorescence microscopy: it rejects the out‐of‐locus light and provides a greater resolution than the wide‐field microscope. In laser scanning optical microscopy, the specimen is scanned by a diffraction‐limited spot of laser light and the fluorescence emission (or the reflected light) is focused onto a photodetector. The imaged point is then digitized, stored into the memory of a computer and displayed at the appropriate spatial position on a graphic device as a part of a two‐dimensional image. Thus, confocal scanning optical microscopy allows accurate non‐invasive optical sectioning and further three‐dimensional reconstruction of biological specimens. Here we review the recent technological aspects of the principles and uses of the confocal microscope, and we introduce the different methods of three‐dimensional imaging.
Synthesis and secretion by mouse 3T3 cells of a inhibitor of cell growth (mIGFBP‐3): Correlation with cell proliferation
Authors: Liu Li , Blat Christiane , Harel Louise
Published: September 2004

Summary— Our results show that stimulation by serum of dense cultures of 3T3 cells rapidly induced increased synthesis of a growth inhibitor (mIGFBP‐3) capable of binding IGF. mIGFBP‐3 was secreted by stimulated cells immediately after its synthesis, and accumulated in the medium. Accumulation of mIGFBP‐3 in the medium increased, as a function of growth factor (bFGF, PDGF, insulin) concentrations and time. bFGF was the best stimulatory factor for both DNA synthesis and accumulation of mIGFBP‐3 in the first 24 h of incubation. DNA synthesis was arrested after 48 h of incubation with bFGF when accumulation of mIGFBP‐3 was maximal. Since we showed that mIGFBP‐3 is able to inhibit bFGF stimulation of DNA synthesis in mouse fibroblasts, it is possible that the accumulation of mIGFBP‐3 induces a feedback regulation of cell growth.
Synthesis and secretion of lipids by long‐term cultures of female rat hepatocytes
Authors: Rincón‐Sánchez Ana Rosa , Hernández Ascención , de López Lourdes Ma , Mendoza‐Figueroa Tomás
Published: September 2004

Summary— The objective of this work was to characterize lipid metabolism in long‐term cultures of adult rat hepatocytes from female rats and explore the potential use of this culture system to study the effect of hormones, drugs and toxic chemicals on it. Hepatocytes, seeded on a feeder layer of 3T3 cells, maintained for 2 weeks their typical morphology. The cultures were able to take up [14C]acetic and [14C]oleic acid from the culture medium and incorporate them into lipids. The synthesis and secretion of lipids by [14C]acetic acid‐labeled cultures had a maximum value after 11 and 13 days in culture. Triacylglycerols were the main lipidic species synthesized and secreted by hepatocytes (up to 67% of the total lipids); they also synthesized and secreted phospholipids, cholesterol and cholesterol esters from [14C]acetic acid. Similarly, [14C]oleic acid‐labeled cultures synthesized and secreted mostly triacylglycerols (up to 60–70% of the total lipids), but they were also able to incorporate the labeled precursor into both cellular and secreted phospholipids and cholesterol esters. The activity of glycerol‐phosphate‐dehydrogenase, marker enzyme of glycerolipid synthesis, decreased slightly during the culture time whereas the activity of malic enzyme, marker of fatty acid synthesis, increased. Our results show that long‐term cultures of female rat hepatocytes are able to synthesize and secrete several lipids, specially triacylglycerols, from both [14C]acetic and [14C]oleic acid for at least 2 weeks and that they maintain enzyme activities related with the synthetic pathways of glycerolipids and fatty acids. They also suggest that these cultures could be a useful model system to study lipid metabolism and the effect of hormones, drugs and toxic chemicals on it.
Segregation of viral double‐stranded and single‐stranded DNA molecules in nucleo fo adenovirus infected cells as revealed by electron microscope in situ hybridization
Authors: Puvion‐Dutilleul Francine , Pichard Evelyne
Published: September 2004

Summary— Formation of progeny viruses in the nuclei of HeLa cells infected with adenovirus type 5 was studied at the ultrastructural level by in situ hybridization techniques allowing specific detection of either viral double‐stranded DNA (dsDNA) or single‐stranded DNA (ssDNA). Prior to the initiation of replication of viral genomes, infective DNA molecules which entered the nucleus of the target cell were randomly distributed among host chromatin fibers including nucleolus‐associated chromatin. They were double‐stranded, that is, without single‐strand breaks. Such association of viral DNA with host condensed chromatin also occurred in mitosis. The initiation of viral genome replication occufred simultaneously with the appearance in the nucleoplasm of small fibrillar regions containing intermingled viral dsDNA and ssDNA. Later, at the intermediate stage of nuclear transformation, viral dsDNA and ssDNA molecules were almost entirely separated into two contiguous substructures. At this stage, viruses were observed occasionally in the vicinity of viral ssDNA accumulation sites. Still later, an additional substructure developed in the centre of the nucleus which consisted of large quantities of viral dsDNA, traces of viral ssDNA and abundant viruses. Portions of viral ssDNA were attached to some viruses even at late stage of nuclear transformation, an association which strongly suggests the occurence of encapsidation of at least some of the viral genomes while they are still engaged in replication.
Drosophila C virus cycle during the development of two Dorosphila melanogaster strains (Charolles and Champetières) after larval contamination by food
Authors: Lautié‐Harivel Nicole
Published: September 2004

Summary— Dorosphila C virus (DCV) cycle during Drosophila melanogaster development was studied after feeding contamination at the first, most sensitive, instar (L1). Two Drosophila strains were examined and compared. Presence of DCVC in apparently healthy animals (L3 larvae bred on a contaminated rearing medium and adults coming from larvae which were grown on medium containing DCVC) was demonstrated by biological tests. Using the immunofluorescence technique, DCV was exhibited in the diseased Charolles larvae, in the lumen of the digestive tract and in the basal part of gut cells which is in contact with the haemolymph. On the contrary, in Charolles larvae which seemed ‘healthy’, DCV was exhibited only in the lumen of the digestive tract at the apical boundary of the gut cells. But DCV typical protein capsid was not shown in the tissue of Drosophila L3 and adults. However, C virus remained in Drosophila tissues even after host metamorphosis and would seem to interact with Drosophila cells. Hypotheses are proposed concerning the intracellular state of Drosophila C virus in this case.
Changes in the ribonucleoprotein constituents of the nucleus during the differentiation of muscle cells in the chick embryo
Authors: Zavala Guadalupe , Aguilar Xochtil , Jiménez Felipe Luis , Echeverría Olga M , Vázquez‐Nin Gerardo
Published: September 2004

Summary— The ribonucleoprotein components of the nucleus of chick embryo muscle cells in different stages of development were studied by electron microscopic quantitative stereology. The changes of the constituents were related with the appearance of the innervation by means of silver impregnation for light microscope. The numerical density of the perichromatin granules (PCG) is low in mononuclear cells and myotubes. It is noteworthy that the frequency of the PCG does not change during the transition of the cells in mitotic cycle to postmitotic myoblasts and during myofibril differentiation. However, there is an important increment in this parameter when the motor nerve fibers arrive at the muscle and the synaptic contacts are established. This change is correlated with appearance, or at least with a great increasé, of the importance of posttranscriptional controls of the expression of some genes. The augmentation in the frequency of PCG is not accompanied by alterations of the abundance of total RNP particles, in close resemblance with the phenomena occurring in neuroblast during the differentiation of synaptic endings. The variations of the nucleolar volume coincide with the changes in rRNA synthesis.
Properties of chicken cardiac dystrophin
Authors: Fabbrizio Eric , Harrican Marie‐Cécile , Pons Françoise , Leger Jocelyne , Mornet Dominique
Published: September 2004

Summary— We investigated the presence of dystrophin by immunoblot and immunofluorescence analyses, negative staining, rotatory shadowing and immunogold electron microscopy in chicken cardiac muscle. Saponin was found to be better than Triton X‐100 for providing a new ‘dystrophin‐enriched’ solution for use in biochemical studies of the molecule. By Western blot analysis, only a 400‐kDa band was revealed with polyclonal antibodies directed against a central region (residues 1178–1723) of the dystrophin molecule and no cross‐reactions with other proteins or degraded products were observed. Specific cleavage of the dystrophin molecule showed that the central rod‐shaped domain corresponded to a resistant ‘core’. This structure might rigidify the protein. By immonofluorescence, dystrophin was localized at the periphery of cardiac ventricular cells. The molecule was examined by electron microscopy and found to have variable lengths (140–160 nm for the monomeric from and about 260 ± 10 nm or more for oligomeric forms). These oligomeric structures are considered to be associated molecules which are only partially overlapped lengthwise. The precise distribution of dystrophin within the cardiac muscle was determined by visualisation of gold particles in immuno‐electron microscopy. Gold particles were found on the sarcolemma with no evidence of any association with cytoplasmic structures. The present data provide further details on the cardiac dystrophin molecule and suggest that its capacity of self‐association may elasticize the dystrophin dimer.
Developmental changes in the heterocellular epidermis of Pelobates syriacus integument
Authors: Gabbay Shoshna , Rosenberg Mira , Warburg Michael R , Rott Ruth , Katz Uri
Published: September 2004

Summary— Changes in characteristic components of the skin epidermis of the large tadpole of Pelobates syriacus were studied throughout its development. The fate of two specific cells in the skin epidermis was followed, from the young tadpole to the adult was studied. It was found that flask‐shaped type cells in the tadpole epidermis which are PAS‐positive, stain with peanut lectin (PNA). There is not detectable band 3 in the premetamorphosed stages, and mitochondria‐rich cells are very rare. This pattern of staining changes completely upon metamorphosis: the PAS‐positive cells, specific to the tadpole epidermis disappear, and the mitochondria‐rich (MR) cells in the adult skin epithelium react with polyclonal anti‐band 3 antibody. Western blot analysis showed the presence of a band 3‐like protein of about 95 kDa, only in the adult epithelial extract, coroborrating the immunocytochemical observations. The finding of the presence of band 3‐like protein in the MR cells of Pelobates, is similar to the observations made in the skin of other amphibian species. On the other hand, the binding of peanut lectin to MR Cells is species‐specific, since it does not react with the MR cells in the skin epithelium of Pelabotes syriacus.
Assembly and fate of basal bodies in the colourless phytoflagellate Polytoma papillatum
Authors: Wolf Klaus Werner
Published: September 2004

Summary— The morphogenesis of basal bodies is described in the phytoflagellate Polytoma papillatum. The observations are based on the analysis of ultrathin serial sections through the flagellar apparatus of interphase, mitotic, and postmitotic cells using transmission electron microscopy. Formation of new basal bodies starts in prometaphase. Individual A‐subfibres develop orthogonally to the long axis of mature basal bodies. The microtubules assemble at the surface of an annulus of amorphous material. By telophase, a complete cylinder of A‐subfibres with a length of approximately 300 nm has formed. Although the proximal ends of these new probasal bodies are detached from the mature basal bodies, prominent reorientation of the probasal bodies does not occur. They remain with their proximal ends in the vicinity of mature basal bodies. In daughter cells with probasal bodies around 400 nm long, the assembly of microtubular triplets is initiated. B‐ and C‐subfibres first show up distal from the mature basal bodies and may elongate towards them. Thus, A‐subfibres on the one side and B‐ and C‐subfibres on the other appear to growt with opposite polarity. If A‐subfibres grow at their plus ends, B‐ and C‐subfibres elongate at their minus ends. The latter is unusual in comparison with individual cytoplasmic and spindle microtubules. Possible the presence of a lateral template in the form of the A‐subfibres is responsible for the deviating growth characteristics of the incomplete B‐ and C‐subfibres. In interphase cells, the mature basal bodies extend into long flagella. The new basal bodies remain devoid of flagella and are less than 85 nm long. Thus, they have shortened relative to their precursors in mitotic and postmitotic cells. At the onset of a new division cycle, the flagellate basal badies shed their flagella. The breaking point is at the triplet‐doublet transition of the flagellum.
A cytoplasmic dynein heavy chain in sea urchin embryos*
Authors: Gibbons Ian R. , Asai David J. , Tang Wen‐Jing Y. , Gibbons Barbara H.
Published: September 2004

Summary— By making the hypothetis that the pattern of conserved sequence residues in the vicinity of the hydrolytic ATP‐binding site of dynein would resemble that in myosins from a broad variety of sources, we designed degenerate oligonucleotide primers capable of amplifying this region of multiple dynein isoforms from sea urchin embryo poly(A)+ RNA. Quantification of the expression of two of these dynein isoforms has shown that the level of mRNA encoding for the β‐heavy chain, like that of tubulin, increases 2–3‐fold after deciliation of the embryos, whereas the expression of the second dynein isoforms, like that of actin, is essentially unaffected. This second isoform is believed to be the cytoplasmic dynein of sea urchin embryos.
Dynein of sperm flagella of oyster beloning to protostomia also has a two‐headed structure
Authors: Wada Shigeo , Okuno Makoto , Nakamura Ken‐Ichi , Mohri Hideo
Published: September 2004

Summary— An axonemal dynein was purified from the sperm of Crassostrea gigas, an oyster belonging to Protostomia. The molecular masses of component polypeptides were almost equivalent to those of other dyneins. Biochemical and biophysical properties were also quite similar. For example, UV‐cleavage, inhibition of ATPase by vanadate and induction of microtubule gliding were observed with the axonemal dynein. The oyster dynein had a two‐headed structure as had the outer arm dynein of Deuterostomia such as sea urchin, rainbow trout and bull spermatozoa. On the other hand, dyneins of Protozoa are three‐headed particles. From the evolutional point of view, it is likely that the number of heads of dynein molecule decreased when Metazoa evolved from Protozoa.
The covalent oscillator: A paradigm accounting for the sliding/bending mechanism and wave propagation in cilia and flagella
Authors: Cosson Jacky
Published: September 2004

Summary— In most models of wave propagation in eucaryotic flagella and cilia, a clear distinction is made between the dynein dependent microtubule sliding which represents the oscillatory motor and the bending mechanism which regulates wave propagation. Little is known about the physical elements regulating the latter: in the present model, the bending propagation is postulated to be supported by an open/close cyclic mechanism protease/ligase dependent, which involves transient covalent links between adjacent microtubular doublets; this open/close cycle propagates in register with the powering action of the dynein motor along the exoneme. The implications of the model are discussed in relation to previous data which involve protease/ligase in the axonemal function as well as other data which can be integrated by the proposed model.
Chymotrypsin‐like protease activity associated with demembramated sperm of chum salmon
Authors: Inaba Kazuo , Morisawa Masaaki
Published: September 2004

Summary— Our previous study suggested that a chymotrypsin‐like protease was involved in the motility of chum salmon sperm (Inaba K, Morisawa M, Biomed Res (1991) 12, 435–437). In this study, we examined the peptidase activity of demembranated sperm of chum salmon using ten synthetic peptides. When spermatozoa were treated with 0.04% Triton X‐100 for extracting the plasma membrane and the suspension was separated into the Triton‐soluble and insoluble fractions by centrifugation, only the hydrolytic activity towards succinyl (Suc)‐Leu‐Leu‐Val‐Tyr‐4‐methylcoumaryl‐7‐amide (MCA), a typical substrate for chymotrypsin‐like protease, was mostly retained in the insoluble fraction. The bulk of the activities toward other substrates was detected in the soluble fraction. Flagellar axonemes isolated from demembranated sperm showed considerable hydrolytic activity toward Suc‐Leu‐Leu‐Val‐Try‐MCA and the activity was still retained in the axoneme even after further washing. The hydrolysis was activated by a low concentration of SDS, suggesting that the protease associated with the axonemes is a multicatalytic ATP‐dependent proteinase (proteasome). Motility of demembranated sperm was inhibited by Suc‐Leu‐Leu‐Val‐Tyr‐MCA in an ATP‐concentration‐dependent manner. These results suggest that proteasomes associated with flagellar axoneme regulate flagellar motility.
Higher plant microtubule‐associated proteins (MAPs): A survey
Authors: Schellenbaum Paul , Vantard Marylin , Lambert Anne‐Marie
Published: September 2004

Summary— Microtubule‐associated proteins (MAPs) are one of the factors which regulate the different properties of microtubules during cell cycle and differentiation. They have been characterized as proteins which promote tubulin assembly in a concentration‐dependent manner and bind to the outer surface of the polymers in vitro. Most of our knowledge comes from studies of neural microtubule‐associated proteins and recent results highlight their implication in neuronal morphogenesis. In contrast, until recently, few data are available about the proteins that associate with plant tubulins. This is due principally to the fact that plant microtubule‐associated proteins cannot be purified by the standard procedures used for neural microtubule‐associated proteins. First, we will describe methods which have been used to isolate these proteins in plant cells. We will then discuss the biochemical and immunological properties of the plant microtubule‐associated proteins which have been isolated. From these results, putative functions can be proposed for these proteins n the particular plant cytoskeleton activities.
Effects of calcium on the longituindal flagellum of Oxyrrhis marina
Authors: Godart Hélène , Huitorel Philippe
Published: September 2004

Summary— 2–4 nm filaments represent a new class of cytoskeletal components. They are found in ciliary and flagellar roots and centrosomes of all eucaryotes. They are also the major components of paraflagellar rods (PFR) in Euglena, trypanosomes and dinoflagellates. Oxyrrhis marina, a marine dinoflagellate, possesses a transverse and a longitudinal flagellum. Only the longitudinal flagellum carries the PFR along the proximal two‐thirds of its length. This flagellum is not only capable of the classic flagellar beat but is also able to retract and bend, a property mediated by external calcium. To determine if calcium has a direct role in the bending, experimental conditions were established to permeabilization and reactivation. Our conditions to reactivate the axoneme function (wave propagation) appear similar to those observed in the case of the sea urchin sperm. The results show that in vitro, an increase in calcium concentration induces a conformational change of the longitudinal flagellum in the absence of ATP with a half maximum effect at 0.1 μM. In the presence of ATP, this morphology modification causes a total inhibition of the wave propagation which is replaced by non‐propulsive contractions of low amplitude. As these properties are not shared by reactivated sea urchin sperm flagella or the transverse flagellum of O marina devoid of PFR, we propose that PFR are responsible for the bending phenomenon. A calcium shock also induces flagellar excision with a half maximum effect at 0.3 μM, and immunofluorescence results suggest that a centrin‐like protein is present in O marina and is responsible for this excision.
Intravenous opioid testing in patients with chronic non‐cancer pain
Authors: Gustorff Burkhard
Published: September 2004

The clinical use of an intravenous opioid testing can help to predict whether opioids will be beneficial. The determination of individual opioid responsiveness justifies subsequent long‐term opioid treatment and is generally recommended. An overview over current testing procedures is given with particular regard to choice of opioid, maximum dose, determination of endpoints and duration of testing and recovery.

Remifentanil testing is a new approch and is studied in a randomized placebo‐controlled cross‐over study in 24 patients suffering from severe non‐cancer pain. An ascending infusion of remifentanil and placebo respectively was titrated against endpoints. The testing allowed a disctinction between 11 opioid‐responders and 13 non‐responders. Complete recovery after end of infusion was rapid with a reach of baseline conditions after 25 min in all patients. Thus the complete remifentanil testing procedure required at utmost 1 h. In conclusion, remifentanil testing offers a more rapid procedure allowing the routine use in an ambulatory setting.
The effects of disease severity, use of corticosteroids and social factors on neuropsychiatric complaints in severe acute respiratory syndrome (SARS) patients at acute and convalescent phases
Authors: Sheng Bun , Wing Cheng Sammy Kin , Lau Kwok Kwong , Li Ho Lun , Yiu Chan Eric Lok
Published: September 2004

Objective

To evaluate the effects of disease severity, corticosteroids and social factors on neuropsychiatric complaints in severe acute respiratory syndrome (SARS) patients, both during acute and convalescent phases.

Methods

Self-administered mail questionnaires survey to 308 SARS patients after discharging from hospital. Both patients and their families were asked about symptoms related to various neuropsychiatric domains, and the questions covered both acute and convalescent phases.

Results

Among the 102 (33%) valid replies, 65% had strong symptoms in convalescent phase as indicated by GHQ28 score ≥ 5. In multiple linear regression analysis, use of pulse steroid and total dosages of pulse steroid during hospitalisation were predictive for anxiety-depression, psychosis and behavioural symptoms in acute phase, the effects persisted in convalescent phase. Disease severity had direct correlation with symptoms in all neuropsychiatric domains at acute phase and anxiety-depression and cognition at convalescent phase. Health care workers had more neuropsychiatric complaints in both phases. Severity of symptoms, corticosteroids and social factors explained about half of the variances (R2 = 52) in anxiety-depression at acute phase and 33% at convalescent phase.

Conclusions

Severe disease, high dose corticosteroids and being health care workers were independent predictors of neuropsychiatric complaints in both acute and convalescent phases.
Patellofemoral joint contact area increases with knee flexion and weight‐bearing
Authors: Besier Thor F. , Draper Christine E. , Gold Garry E. , Beaupré Gary S. , Delp Scott L.
Published: September 2004

Patellofemoral pain is a common and debilitating disorder. Elevated cartilage stress of the patellofemoral joint is hypothesized to play a role in the onset of pain. Estimating cartilage stress requires accurate measurements of contact area. The purpose of this study was to estimate patellofemoral joint contact areas in a group of healthy, pain‐free subjects during upright, weight‐bearing conditions. Sixteen subjects (8 female, 8 male) were scanned in a GE Signa SP open configuration MRI scanner, which allowed subjects to stand or squat while reclining 25° from vertical with the knee positioned at 0°, 30°, or 60° of flexion. A custom‐built backrest enabled subjects to be scanned without motion artifact in both weight‐bearing (0.45 body weight per leg) and reduced loading conditions (‘unloaded’ at 0.15 body weight) at each knee flexion posture. Male subjects displayed mean unloaded patellofemoral joint contact areas of 210, 414, and 520mm2 at 0°, 30° and 60° of knee flexion, respectively. Female subjects' unloaded contact areas were similar at full extension (0°), but significantly smaller at 30° and 60° (p < 0.01), with mean values of 269 and 396 mm2, respectively. When normalized by patellar dimensions (height × width), contact areas were not different between genders. Under weight‐bearing conditions, contact areas increased by an average of 24% (p < 0.05). This study highlights the differences in patellofemoral joint contact area between gender, knee flexion postures, and physiologic loading conditions. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Interlocus nonrandom association of polymorphisms in
Drosophila
chemoreceptor genes
Authors: Takano-Shimizu Toshiyuki , Kawabe Akira , Inomata Nobuyuki , Nanba Noriko , Kondo Rumi , Inoue Yutaka , Itoh Masanobu
Published: September 2004

Some forms of multilocus selection with epistasis, such as truncation selection, can effectively reduce the mutation load [Kondrashov, A. S. (1988)
Nature
336, 435–440]. Many quantitative characters, including complex genetic diseases, are likely to be subject to these types of selection. However, direct measurement of selection in natural populations is difficult and the effect of epistasis on within-species variations remains unclear. Epistatic interaction in the fitness effect can generate linkage disequilibrium (LD). Therefore, we may detect the action of natural selection from its amount and pattern. Here, we report a large number of interlocus nonrandom associations between polymorphisms in 98
Drosophila
chemoreceptor genes. LD was examined in two fly samples collected at the same location, but in different seasons. The amount of LD was much larger in the spring sample than in the autumn one. The between-sample difference was much more striking for the replacement polymorphisms than for the silent polymorphisms. This difference between the replacement and silent polymorphisms could not be attributed to differences in the mean marker distances. We also found a significant excess of associations between one frequent and one less common allele for the replacement polymorphisms, but not for the silent polymorphisms. It is unlikely that a simple seasonal bottleneck could explain all these differences in the scale of LD between the samples and between the replacement and silent polymorphisms. Natural selection is suggested to play a significant role in shaping the pattern of LD observed in this study.
Genomic plasticity of the causative agent of melioidosis,
Burkholderia pseudomallei
Authors: Holden Matthew T. G. , Titball Richard W. , Peacock Sharon J. , Cerdeño-Tárraga Ana M. , Atkins Timothy , Crossman Lisa C. , Pitt Tyrone , Churcher Carol , Mungall Karen , Bentley Stephen D. , Sebaihia Mohammed , Thomson Nicholas R. , Bason Nathalie , Beacham Ifor R. , Brooks Karen , Brown Katherine A. , Brown Nat F. , Challis Greg L. , Cherevach Inna , Chillingworth Tracy , Cronin Ann , Crossett Ben , Davis Paul , DeShazer David , Feltwell Theresa , Fraser Audrey , Hance Zahra , Hauser Heidi , Holroyd Simon , Jagels Kay , Keith Karen E. , Maddison Mark , Moule Sharon , Price Claire , Quail Michael A. , Rabbinowitsch Ester , Rutherford Kim , Sanders Mandy , Simmonds Mark , Songsivilai Sirirurg , Stevens Kim , Tumapa Sarinna , Vesaratchavest Monkgol , Whitehead Sally , Yeats Corin , Barrell Bart G. , Oyston Petra C. F. , Parkhill Julian
Published: September 2004

Burkholderia pseudomallei
is a recognized biothreat agent and the causative agent of melioidosis. This Gram-negative bacterium exists as a soil saprophyte in melioidosis-endemic areas of the world and accounts for 20% of community-acquired septicaemias in northeastern Thailand where half of those affected die. Here we report the complete genome of
B. pseudomallei
, which is composed of two chromosomes of 4.07 megabase pairs and 3.17 megabase pairs, showing significant functional partitioning of genes between them. The large chromosome encodes many of the core functions associated with central metabolism and cell growth, whereas the small chromosome carries more accessory functions associated with adaptation and survival in different niches. Genomic comparisons with closely and more distantly related bacteria revealed a greater level of gene order conservation and a greater number of orthologous genes on the large chromosome, suggesting that the two replicons have distinct evolutionary origins. A striking feature of the genome was the presence of 16 genomic islands (GIs) that together made up 6.1% of the genome. Further analysis revealed these islands to be variably present in a collection of invasive and soil isolates but entirely absent from the clonally related organism
B. mallei
. We propose that variable horizontal gene acquisition by
B. pseudomallei
is an important feature of recent genetic evolution and that this has resulted in a genetically diverse pathogenic species.
Structural flexibility in the
Burkholderia mallei
genome
Authors: Nierman William C. , DeShazer David , Kim H. Stanley , Tettelin Herve , Nelson Karen E. , Feldblyum Tamara , Ulrich Ricky L. , Ronning Catherine M. , Brinkac Lauren M. , Daugherty Sean C. , Davidsen Tanja D. , Deboy Robert T. , Dimitrov George , Dodson Robert J. , Durkin A. Scott , Gwinn Michelle L. , Haft Daniel H. , Khouri Hoda , Kolonay James F. , Madupu Ramana , Mohammoud Yasmin , Nelson William C. , Radune Diana , Romero Claudia M. , Sarria Saul , Selengut Jeremy , Shamblin Christine , Sullivan Steven A. , White Owen , Yu Yan , Zafar Nikhat , Zhou Liwei , Fraser Claire M.
Published: September 2004

The complete genome sequence of
Burkholderia mallei
ATCC 23344 provides insight into this highly infectious bacterium's pathogenicity and evolutionary history.
B. mallei
, the etiologic agent of glanders, has come under renewed scientific investigation as a result of recent concerns about its past and potential future use as a biological weapon. Genome analysis identified a number of putative virulence factors whose function was supported by comparative genome hybridization and expression profiling of the bacterium in hamster liver
in vivo
. The genome contains numerous insertion sequence elements that have mediated extensive deletions and rearrangements of the genome relative to
Burkholderia pseudomallei
. The genome also contains a vast number (>12,000) of simple sequence repeats. Variation in simple sequence repeats in key genes can provide a mechanism for generating antigenic variation that may account for the mammalian host's inability to mount a durable adaptive immune response to a
B. mallei
infection.
Tropism illuminated: Lymphocyte-based pathways blazed by lethal morbillivirus through the host immune system
Authors: von Messling Veronika , Milosevic Dragana , Cattaneo Roberto
Published: September 2004

The immunosuppressive properties of morbilliviruses including measles and canine distemper virus (CDV) are well known, but the host cells supporting infection are poorly characterized. To identify these cells, a recombinant CDV expressing green fluorescent protein was produced by reverse genetics based on a wild-type strain lethal for ferrets. This recombinant virus fully retained virulence and blazed three lymphocyte-based pathways through the immune system of its host: first, it infected rapidly and massively circulating B and T cells; second, it took over and damaged secondary lymphatic organs including spleen, lymph nodes, and gut-associated and mucosal lymphoid tissues; third, it infected most thymocytes. In contrast, replication in epithelial cells was initially not detectable, but substantial before host death. Thus, CDV initially infects lymphocytes and massively replicates therein, thereby causing immunosuppression and preparing systemic invasion and host escape.
Premature aggregation of type IV collagen and early lethality in lysyl hydroxylase 3 null mice
Authors: Rautavuoma Kati , Takaluoma Kati , Sormunen Raija , Myllyharju Johanna , Kivirikko Kari I. , Soininen Raija
Published: September 2004

Collagens carry hydroxylysine residues that act as attachment sites for carbohydrate units and are important for the stability of crosslinks but have been regarded as nonessential for vertebrate survival. We generated mice with targeted inactivation of the gene for one of the three lysyl hydroxylase isoenzymes, LH3. The null embryos developed seemingly normally until embryonic day 8.5, but development was then retarded, with death around embryonic day 9.5. Electron microscopy (EM) revealed fragmentation of basement membranes (BMs), and immuno-EM detected type IV collagen within the dilated endoplasmic reticulum and in extracellular aggregates, but the typical BM staining was absent. Amorphous intracellular and extracellular particles were also seen by collagen IV immunofluorescence. SDS/PAGE analysis demonstrated increased mobilities of the type IV collagen chains, consistent with the absence of hydroxylysine residues and carbohydrates linked to them. These results demonstrate that LH3 is indispensable for biosynthesis of type IV collagen and for BM stability during early development and that loss of LH3's functions leads to embryonic lethality. We propose that the premature aggregation of collagen IV is due to the absence of the hydroxylysine-linked carbohydrates, which thus play an essential role in its supramolecular assembly.
The channel architecture of aquaporin 0 at a 2.2-Å resolution
Authors: Harries William E. C. , Akhavan David , Miercke Larry J. W. , Khademi Shahram , Stroud Robert M.
Published: September 2004

We determined the x-ray structure of bovine aquaporin 0 (AQP0) to a resolution of 2.2 Å. The structure of this eukaryotic, integral membrane protein suggests that the selectivity of AQP0 for water transport is based on the identity and location of signature amino acid residues that are hallmarks of the water-selective arm of the AQP family of proteins. Furthermore, the channel lumen is narrowed only by two, quasi-2-fold related tyrosine side chains that might account for reduced water conductance relative to other AQPs. The channel is functionally open to the passage of water because there are eight discreet water molecules within the channel. Comparison of this structure with the recent electron-diffraction structure of the junctional form of sheep AQP0 at pH 6.0 that was interpreted as closed shows no global change in the structure of AQP0 and only small changes in side-chain positions. We observed no structural change to the channel or the molecule as a whole at pH 10, which could be interpreted as the postulated pH-gating mechanism of AQP0-mediated water transport at pH >6.5. Contrary to the electron-diffraction structure, the comparison shows no evidence of channel gating induced by association of the extracellular domains of AQP0 at pH 6.0. Our structure aids the analysis of the interaction of the extracellular domains and the possibility of a cell–cell adhesion role for AQP0. In addition, our structure illustrates the basis for formation of certain types of cataracts that are the result of mutations.
High-throughput microarray detection of olfactory receptor gene expression in the mouse
Authors: Zhang Xinmin , Rogers Matthew , Tian Huikai , Zhang Xiaohong , Zou Dong-Jing , Liu Jian , Ma Minghong , Shepherd Gordon M. , Firestein Stuart J.
Published: September 2004

The large number of olfactory receptor genes necessitates high throughput methods to analyze their expression patterns. We have therefore designed a high-density oligonucleotide array containing all known mouse olfactory receptor (OR) and V1R vomeronasal receptor genes. This custom array detected a large number of receptor genes, demonstrating specific expression in the olfactory sensory epithelium for ≈800 OR genes previously designated as ORs based solely on genomic sequences. The array also enabled us to monitor the spatial and temporal distribution of gene expression for the entire OR family. Interestingly, OR genes showing spatially segregated expression patterns were also segregated on the chromosomes. This correlation between genomic location and spatial expression provides unique insights about the regulation of this large family of genes.
Electronic spin state of iron in lower mantle perovskite
Authors: Li Jie , Struzhkin Viktor V. , Mao Ho-kwang , Shu Jinfu , Hemley Russell J. , Fei Yingwei , Mysen Bjorn , Dera Przemek , Prakapenka Vitali , Shen Guoyin
Published: September 2004

The electronic spin state of iron in lower mantle perovskite is one of the fundamental parameters that governs the physics and chemistry of the most voluminous and massive shell in the Earth. We present experimental evidence for spin-pairing transition in aluminum-bearing silicate perovskite (Mg,Fe)(Si,Al)O
3
under the lower mantle pressures. Our results demonstrate that as pressure increases, iron in perovskite transforms gradually from the initial high-spin state toward the final low-spin state. At 100 GPa, both aluminum-free and aluminum-bearing samples exhibit a mixed spin state. The residual magnetic moment in the aluminum-bearing perovskite is significantly higher than that in its aluminum-free counterpart. The observed spin evolution with pressure can be explained by the presence of multiple iron species and the occurrence of partial spin-paring transitions in the perovskite. Pressure-induced spin-pairing transitions in the perovskite would have important bearing on the magnetic, thermoelastic, and transport properties of the lower mantle, and on the distribution of iron in the Earth's interior.
A universal telomerase RNA core structure includes structured motifs required for binding the telomerase reverse transcriptase protein
Authors: Lin Jue , Ly Hinh , Hussain Arif , Abraham Mira , Pearl Sivan , Tzfati Yehuda , Parslow Tristram G. , Blackburn Elizabeth H.
Published: September 2004

Telomerase synthesizes telomeric DNA by copying a short template sequence within its telomerase RNA component. We delineated nucleotides and base-pairings within a previously mapped central domain of the
Saccharomyces cerevisiae
telomerase RNA (TLC1) that are important for telomerase function and for binding to the telomerase catalytic protein Est2p. Phylogenetic comparison of telomerase RNA sequences from several budding yeasts revealed a core structure common to
Saccharomyces
and
Kluyveromyces
yeast species. We show that in this structure three conserved sequences interact to provide a binding site for Est2p positioned near the template. These results, combined with previous studies on telomerase RNAs from other budding yeasts, vertebrates, and ciliates, define a minimal universal core for telomerase RNAs.
Insertional assembly of actin filament barbed ends in association with formins produces piconewton forces
Authors: Kovar David R. , Pollard Thomas D.
Published: September 2004

Formins are large multidomain proteins required for assembly of actin cables that contribute to the polarity and division of animal and fungal cells.
F
ormin
h
omology-1 (FH1) domains bind profilin, and highly conserved FH2 domains nucleate actin filaments. We characterized the effects of two formins, budding yeast Bni1p and fission yeast Cdc12p, on actin assembly. We used evanescent wave fluorescence microscopy to observe assembly of actin filaments (
i
) nucleated by soluble formin FH1FH2 domains and (
ii
) associated with formin FH1FH2 domains immobilized on microscope slides. Bni1p(FH1FH2)p and Cdc12p(FH1FH2)p nucleated new actin filaments or captured the barbed ends of preformed actin filaments that grew by insertion of subunits between the immobilized formin and the barbed end of the filament. Both formins remained bound to growing actin filament barbed ends for >1,000 sec. Elongation of a filament between an immobilized formin and a second anchor point buckled filament segments as short as 0.7 μm, demonstrating that polymerization of single actin filaments produces forces of >1 piconewton, close to the theoretical maximum. After buckling, further growth produced long loops that did not supercoil, suggesting that formins do not stair step along the two subunits exposed on the growing barbed end. In agreement, Arp2/3 complex branched filaments did not rotate as they grew from formins attached to the slide surface. Formins are not mechanistically identical because barbed end elongation from Cdc12(FH1FH2)p, but not Bni1(FH1FH2)p, requires profilin. However, profilin increased the rate of Bni1(FH1FH2)p-mediated barbed end elongation from 75% to 100% of full-speed.