bluuebunny/crossref_metadata_2025 huggingface dataset:
Methods for peptide identification by spectral comparison
Authors: Liu Jian , Bell Alexander W , Bergeron John JM , Yanofsky Corey M , Carrillo Brian , Beaudrie Christian EH , Kearney Robert E
Published: January 2007

Background

Tandem mass spectrometry followed by database search is currently the predominant technology for peptide sequencing in shotgun proteomics experiments. Most methods compare experimentally observed spectra to the theoretical spectra predicted from the sequences in protein databases. There is a growing interest, however, in comparing unknown experimental spectra to a library of previously identified spectra. This approach has the advantage of taking into account instrument-dependent factors and peptide-specific differences in fragmentation probabilities. It is also computationally more efficient for high-throughput proteomics studies.

Results

This paper investigates computational issues related to this spectral comparison approach. Different methods have been empirically evaluated over several large sets of spectra. First, we illustrate that the peak intensities follow a Poisson distribution. This implies that applying a square root transform will optimally stabilize the peak intensity variance. Our results show that the square root did indeed outperform other transforms, resulting in improved accuracy of spectral matching. Second, different measures of spectral similarity were compared, and the results illustrated that the correlation coefficient was most robust. Finally, we examine how to assemble multiple spectra associated with the same peptide to generate a synthetic reference spectrum. Ensemble averaging is shown to provide the best combination of accuracy and efficiency.

Conclusion

Our results demonstrate that when combined, these methods can boost the sensitivity and specificity of spectral comparison. Therefore they are capable of enhancing and complementing existing tools for consistent and accurate peptide identification.
Skeletal muscle oxygen saturation does not estimate mixed venous oxygen saturation in patients with severe left heart failure and additional severe sepsis or septic shock
Authors: Podbregar Matej , Možina Hugon
Published: January 2007

Introduction

Low cardiac output states such as left heart failure are characterized by preserved oxygen extraction ratio, which is in contrast to severe sepsis. Near infrared spectroscopy (NIRS) allows noninvasive estimation of skeletal muscle tissue oxygenation (StO2). The aim of the study was to determine the relationship between StO2 and mixed venous oxygen saturation (SvO2) in patients with severe left heart failure with or without additional severe sepsis or septic shock.

Methods

Sixty-five patients with severe left heart failure due to primary heart disease were divided into two groups: groups A (n = 24) and B (n = 41) included patients without and with additional severe sepsis/septic shock, respectively. Thenar muscle StO2 was measured using NIRS in the patients and in 15 healthy volunteers.

Results

StO2 was lower in group A than in group B and in healthy volunteers (58 ± 13%, 90 ± 7% and 84 ± 4%, respectively; P < 0.001). StO2 was higher in group B than in healthy volunteers (P = 0.02). In group A StO2 correlated with SvO2 (r = 0.689, P = 0.002), although StO2 overestimated SvO2 (bias -2.3%, precision 4.6%). In group A changes in StO2 correlated with changes in SvO2 (r = 0.836, P < 0.001; ΔSvO2 = 0.84 × ΔStO2 - 0.67). In group B important differences between these variables were observed. Plasma lactate concentrations correlated negatively with StO2 values only in group A (r = -0.522, P = 0.009; lactate = -0.104 × StO2 + 10.25).

Conclusion

Skeletal muscle StO2 does not estimate SvO2 in patients with severe left heart failure and additional severe sepsis or septic shock. However, in patients with severe left heart failure without additional severe sepsis or septic shock, StO2 values could be used to provide rapid, noninvasive estimation of SvO2; furthermore, the trend in StO2 may be considered a surrogate for the trend in SvO2.

Trial Registration: NCT00384644
CpG-B ODNs potently induce low levels of IFN-αβ and induce IFN-αβ-dependent MHC-I cross-presentation in DCs as effectively as CpG-A and CpG-C ODNs
Authors: Gray Reginald C , Kuchtey John , Harding Clifford V
Published: January 2007

Deoxycytidyl-deoxyguanosine [(CpG)3] oligodeoxynucleotides (ODNs) signal through TLR9 to induce type-I IFN (IFN-αβ) and IFN-αβ-dependent MHC-I cross-presentation of exogenous antigens by dendritic cells (DCs). A puzzle was presented by our observation that three ODN classes, CpG-A, CpG-B, and CpG-C, had similar efficacy for induction of IFN-αβ-dependent MHC-I antigen cross-presentation by myeloid DCs despite greatly differing for induction of IFN-αβ (CpG-A>CpG-C>>CpG-B). All ODN classes similarly enhanced plasmacytoid DC (pDC) presentation of exogenous MHC-I-restricted peptide, although pDCs did not cross-process protein antigen. MHC-I and the transporter for antigen presentation were induced by all ODN classes or IFN-α. CpG-B ODNs were slightly more potent than CpG-A or CpG-C ODNs for induction of low levels of IFN-αβ but less efficacious at high concentrations than CpG-A or CpG-C ODNs. Low levels of IFN-αβ induced by CpG-B ODNs sufficed for full induction of MHC-I cross-presentation. Thus, CpG-B ODNs are slightly more potent but less efficacious than CpG-A and CpG-C ODNs for induction of IFN-αβ. High sensitivity to IFN-αβ allows CpG-B ODNs to be equally efficacious for induction of MHC-I cross-presentation. CpG-B ODNs may be effective for inducing therapeutic responses that require low levels of IFN-αβ and may avoid unnecessarily high induction of IFN-αβ.
CHOP Alone Compared With CHOP Plus Radiotherapy for Localized Aggressive Lymphoma in Elderly Patients: A Study by the Groupe d’Etude des Lymphomes de l’Adulte
Authors: Bonnet Christophe , Fillet Georges , Mounier Nicolas , Ganem Gérard , Molina Thierry Jo , Thiéblemont Catherine , Fermé Christophe , Quesnel Bruno , Martin Claude , Gisselbrecht Christian , Tilly Hervé , Reyes Félix
Published: January 2007

Purpose

Chemoradiotherapy has been considered standard treatment for patients with limited-stage aggressive lymphoma on the basis of trials conducted before the introduction of the International Prognostic Index. To evaluate this approach in elderly patients with low-risk localized lymphoma, we conducted a trial comparing chemoradiotherapy with chemotherapy alone.

Patients and Methods

Previously untreated patients older than 60 years with localized stage I or II histologically aggressive lymphoma and no adverse prognostic factors of the International Prognostic Index were randomly assigned to receive either four cycles of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) plus involved-field radiotherapy (299 patients) or chemotherapy alone with four cycles of CHOP (277 patients).

Results

With a median follow-up time of 7 years, event-free and overall survival did not differ between the two treatment groups (P = .6 and P = .5, respectively). The 5-year estimates of event-free survival were 61% for patients receiving chemotherapy alone and 64% for patients receiving CHOP plus radiotherapy; the 5-year estimates of overall survival were 72% and 68%, respectively. In a multivariate analysis, overall survival was affected by stage II disease (P < .001) and male sex (P = .03).

Conclusion

In this large prospective study, CHOP plus radiotherapy did not provide any advantage over CHOP alone for the treatment of low-risk localized aggressive lymphoma in elderly patients.
Cisplatin-Induced Long-Term Hearing Impairment Is Associated With Specific Glutathione S-Transferase Genotypes in Testicular Cancer Survivors
Authors: Oldenburg Jan , Kraggerud Sigrid M. , Cvancarova Milada , Lothe Ragnhild A. , Fossa Sophie D.
Published: January 2007

Purpose

Cisplatin, a cornerstone of combination chemotherapy in the treatment of testicular cancer, induces hearing impairment with considerable interindividual variations. These differences might be a result of functional polymorphisms in cisplatin-detoxifying enzymes like glutathione S-transferases (GSTs).

Patients and Methods

We identified 173 cisplatin-treated testicular cancer survivors (TCSs) who had participated in a long-term survey that included audiometric testing and lymphocyte sampling. The hearing decibel thresholds at 4,000 Hz were categorized into leveled scales by normative decibel percentiles. Known functional polymorphisms (positive or negative) in GSTT1 and GSTM1 and codon 105 A/G (Ile/Val) in GSTP1 were analyzed by multiplex polymerase chain reaction, followed by restriction enzyme cutting, and separated by gel electrophoresis.

Results

The risk of having an inferior audiometric result was more than four times higher in TCSs with 105Ile/105Ile-GSTP1 or 105Val/105Ile-GSTP1 compared with 105Val/105Val-GSTP1 (odds ratio [OR] = 4.21; 95% CI, 1.99 to 8.88; P < .001 when modeled by ordinal logistic regression [OLR]). GSTM1 positivity was detrimental for hearing ability. Two combined genotypes were associated with hearing ability. The presence of pattern 1 (GSTT1 positive, GSTM1 positive, and 105Ile/105Ile-GSTP1) was associated with hearing impairment (OR = 2.76; 95% CI, 1.35 to 5.64; P = .005, OLR). TCSs with pattern 2 (GSTT1 positive, GSTM1 positive, and 105Val/105Val-GSTP1) had better hearing ability than TCSs without this pattern (OR = 5.35; 95% CI, 2.25 to 12.76; P < .001, OLR).

Conclusion

The presence of both alleles of 105Val-GSTP1 offered protection against cisplatin-induced hearing impairment. Two genotype patterns with good and poor protection against cisplatin-induced ototoxicity were identified.
Functional genomics inTrypanosoma bruceiidentifies evolutionarily conserved components of motile flagella
Authors: Baron Desiree M. , Ralston Katherine S. , Kabututu Zakayi P. , Hill Kent L.
Published: January 2007

Cilia and flagella are highly conserved, complex organelles involved in a variety of important functions. Flagella are required for motility of several human pathogens and ciliary defects lead to a variety of fatal and debilitating human diseases. Many of the major structural components of cilia and flagella are known, but little is known about regulation of flagellar beat. Trypanosoma brucei, the causative agent of African sleeping sickness, provides an excellent model for studying flagellar motility. We have used comparative genomics to identify a core group of 50 genes unique to organisms with motile flagella. These genes, referred to as T. brucei components of motile flagella (TbCMF) include 30 novel genes, and human homologues of many of the TbCMF genes map to loci associated with human ciliary diseases. To characterize TbCMF protein function we used RNA interference to target 41 TbCMF genes. Sedimentation assays and direct observation demonstrated clear motility defects in a majority of these knockdown mutants. Epitope tagging, fluorescence localization and biochemical fractionation demonstrated flagellar localization for several TbCMF proteins. Finally, ultrastructural analysis identified a family of novel TbCMF proteins that function to maintain connections between outer doublet microtubules, suggesting that they are the first identified components of nexin links. Overall, our results provide insights into the workings of the eukaryotic flagellum, identify several novel human disease gene candidates, reveal unique aspects of the trypanosome flagellum and underscore the value of T. brucei as an experimental system for studying flagellar biology.
Is the Prevalence of Paget's Disease of Bone Decreasing?
Authors: Cundy Tim
Published: January 2007

Secular trends in the severity and prevalence of Paget's disease over a 30-year period are described. Paget's disease has become less prevalent and patients are presenting later, with less severe disease than previously. These data suggest that environmental factors are important in the etiology of Paget's disease.

Introduction: Data from several countries support the view that there are important secular trends in the prevalence and severity of Paget's disease. In this paper, recent trends in the epidemiology of Paget's disease are described.

Materials and Methods: A database of all newly referred patients (n = 1487) with Paget's disease (1973–2002 inclusive, 30 years) was examined. Of these subjects, 56% had scintiscans. Plasma total alkaline phosphatase (total ALP) activity and disease extent on scintiscan were used as indices of severity. A radiographic prevalence survey of 1019 subjects of European origin >55 years of age in Dunedin was undertaken—∼20 years after an earlier survey had shown New Zealand to be a high prevalence area.

Results: The number of new referrals with Paget's disease declined sharply from 1994 onward, to one half the rate seen 20 years earlier, whereas the mean age at presentation increased by 4 years per decade (p < 0.0001). Total ALP at diagnosis, disease extent on scintiscan, and the number of bones involved were all negatively correlated with both date of birth (p < 0.0001) and year of presentation (p < 0.0001), indicating that more recently born and presenting subjects had substantially less severe bone disease. The radiographic survey showed that the current prevalence was only ∼50% of that in the 1983 survey (p = 0.012).

Conclusions: Although there are a number of potential biases, these data are consistent with a continued secular trend to presentation in older subjects with less extensive skeletal involvement and a declining prevalence of Paget's disease.
Paget's Disease of Bone in Italy
Authors: Gennari Luigi , Merlotti Daniela , Martini Giuseppe , Nuti Ranuccio
Published: January 2007

Epidemiological studies of Paget's disease of bone (PDB) suggest a pronounced geographical variation in the prevalence of the disease and a decrease in prevalence and clinical severity over time. To analyze epidemiological and clinical features of PDB in Italy, we recently established a registry of Italian PDB cases and performed radiological, biochemical, and bone scan surveys in the towns of Siena and Turin. The overall prevalence of PDB in Italy varied between 0.7% and 2.4%. Prevalence rates increased with age and were higher in men than in women. We observed clinically confirmed familial aggregation in 15–26% of cases. Pedigree analysis indicated an autosomal dominant pattern of inheritance with variable penetrance. SQSTM1 gene analysis in two Italian studies revealed the presence of at least three different mutations accounting for both familial and sporadic cases. Interestingly, no decrease in the prevalence of PDB over time was observed, the opposite of what is described in populations of British descent. However, clinical severity of PDB cases included in the Registry in 2002–2004 seemed reduced with respect to that of PDB patients from the previous epidemiological studies, including a 1950–1956 Italian study. Of interest, a consistent association between PDB and animal-related factors and a significantly higher prevalence of the disease in rural than in urban districts were observed. These findings are in keeping with an important role of the environment in the pathogenesis of PDB, perhaps facilitating the expression of the disease in genetically susceptible subjects. Finally, there was also preliminary evidence indicating regional clustering of PDB in Italy, with a concentration of cases in rural districts of Campania and Tuscany. These districts may represent high prevalence areas of PDB in Italy, similar to what has been observed in other countries. Extrapolation estimates suggest that ∼150,000–300,000 subjects may be affected with PDB in our country. These results confirm PDB to be the most common bone remodeling disorder in elderly people in Italy, excluding osteoporosis.
Clinical and Cellular Phenotypes Associated With Sequestosome 1 (SQSTM1) Mutations
Authors: Leach Robin J , Singer Frederick R , Ench Yasmin , Wisdom Julie H , Pina Diana S , Johnson-Pais Teresa L
Published: January 2007

Familial Paget's disease of bone has been shown to be associated with mutations in the ubiquitin-associated (UBA) domain of the sequestosome 1 (SQSTM1) gene. We have clinical findings on five families with diverse racial and ethnic backgrounds who all harbor SQSTM1 UBA domain mutations (P387L, P392L, D391fsX394, P392fsX394). Intrafamilial expressivity was highly variable. The probands in two of the families had early-onset disease involving a large number of bones and highly elevated prediagnostic levels of serum alkaline phosphatase. Affected siblings in these same families had limited bone involvement and were only diagnosed by technetium-99m methylene diphosphonate (MDP) bone scans. Furthermore, there was at least one subject in each family with no evidence of Paget's disease, although they carried one mutated copy of the SQSTM1 gene. A total of 18 such individuals were identified across the five kindreds. Thus, the gene seems to have highly variable expressivity, as well as incomplete penetrance, supporting the role of this gene as a predisposition gene for familial Paget's disease of the bone. Molecular studies of the SQSTM1 protein showed different cellular aggregation phenotypes depending on the nature of the mutation. In general, the point mutations formed larger cytoplasmic aggregates than the wildtype or truncation mutations. This aggregation phenotype was not altered on removal of the N-terminal PB1 dimerization domain, implying that aggregate formation is not wholly mediated by interaction through the PB1 domain. Although there was a genotype/phenotype correlation on the cellular level, this was not apparent on the clinical level. This supports the argument that other nongenetic factors play an important role in the pathogenesis of the disease.
Experimental Models of Paget's Disease
Authors: Kurihara Noriyoshi , Zhou Hua , Reddy Sakamuri V , Garcia Palacios Veronica , Subler Mark A , Dempster David W , Windle Jolene J , Roodman G David
Published: January 2007

We targeted the MVNP gene to the OCL lineage in transgenic mice. These mice developed abnormal OCLs and bone lesions similar to those found in Paget's patients. These results show that persistent expression of MVNP in OCLs can induce pagetic-like bone lesions in vivo.

Introduction: Paget's disease (PD) is one of the most exaggerated examples of abnormal bone remodeling, with increased bone resorption and excessive new bone formation. However, its etiology is unclear. A viral etiology for PD has been suggested based on the presence of paramyxoviral-like nuclear inclusions, detection of measles virus nucleocapsid (MVNP) mRNA or protein in osteoclasts (OCLs) from PD lesions, and in vitro studies showing that transfection of normal OCL precursors with the MVNP gene results in formation of OCLs that express a pagetic phenotype (increased numbers of OCLs; increased responsivity to 1,25(OH)2D3, RANKL, and TNF-α; increased expression of the TAFII-17 gene, and increased bone resorption capacity).

Materials and Methods: We targeted MVNP to cells in the OCL lineage in transgenic mice using the TRACP promoter.

Results: Histomorphometric analysis showed that there was a 64% increase in OCL perimeter (p = 6.0002) and 37% increase in osteoblast (OBL) perimeter in MVNP mice. In a mouse that was 14 months of age, there was a 225% increase in OBL perimeter and 149% in OBL perimeter. This was accompanied by increased cancellous bone volume (83%) and trabecular width (47%) and number (25%), with a marked increase in the amount of woven bone. In contrast, cancellous bone volume decreased between 3 and 12 months in wildtype (WT) mice, whereas cancellous bone volume in MVNP mice increased over the same time period. Ex vivo studies showed that the numbers of OCLs formed in marrow cultures from MVNP mice were increased, and the OCLs were hyper-responsive to 1,25(OH)2D3 and had an increased bone resorbing capacity compared with WT cultures.

Conclusion: These results show that expression of MVNP in OCL in vivo results in a bone phenotype that is characteristic of PD.
Surgical Management of Paget's Disease of Bone
Authors: Parvizi Javad , Klein Gregg R , Sim Franklin H
Published: January 2007

Paget's disease is a chronic nonmetabolic bone disorder that is characterized by increased bone resorption, bone formation, and remodeling. This unbalanced process may lead to osseous deformities, structural weakness, and altered joint biomechanics, all of which can make surgical reconstruction difficult. Although few patients with Paget's disease ever need surgical treatment, successful surgical management of orthopedic manifestations of the disease has improved the quality of life for these patients. Surgical options include corrective osteotomy for long bone deformity, fracture fixation, joint arthroplasty, spinal decompression, and tumor resection. Patients are at increased risk for surgical complications such as blood loss and heterotopic bone formation. Issues relating to the surgical management of patients with Paget's disease such as appropriate preoperative diagnosis, technical challenges of surgery, and strategies to improve the long-term outcome of surgical intervention are discussed.
Effects Of a One-Month Treatment With PTH(1–34) on Bone Formation on Cancellous, Endocortical, and Periosteal Surfaces of the Human Ilium
Authors: Lindsay Robert , Zhou Hua , Cosman Felicia , Nieves Jeri , Dempster David W , Hodsman Anthony B
Published: January 2007

Using bone histomorphometry, we found that a 1-month treatment with PTH(1–34) [hPTH(1–34)] stimulated new bone formation on cancellous, endocortical, and periosteal bone surfaces. Enhanced bone formation was associated with an increase in osteoblast apoptosis.

Introduction: The precise mechanisms by which hPTH(1–34) increases bone mass and improves bone structure are unclear. Using bone histomorphometry, we studied the early effects of treating postmenopausal women with osteoporosis with hPTH(1–34).

Materials and Methods: Tetracycline-labeled iliac crest bone biopsies were obtained from 27 postmenopausal women with osteoporosis who were treated for 1 month with hPTH(1–34), 50 μg daily subcutaneously. The results were compared with tetracycline-labeled biopsies from a representative control group of 13 postmenopausal women with osteoporosis.

Results: The bone formation rate on the cancellous and endocortical surfaces was higher in hPTH(1–34)–treated women than in control women by factors of 4.5 and 5.0, respectively. We also showed a 4-fold increase in bone formation rate on the periosteal surface, suggesting that hPTH(1–34) has the potential to increase bone diameter in humans. On the cancellous and endocortical surfaces, the increased bone formation rate was primarily caused by stimulation of formation in ongoing remodeling units, with a modest amount of increased formation on previously quiescent surfaces. hPTH(1–34)–stimulated bone formation was associated with an increase in osteoblast apoptosis, which may reflect enhanced turnover of the osteoblast population and may contribute to the anabolic action of hPTH(1–34).

Conclusions: These findings provide new insight into the cellular basis by which hPTH(1–34) improves cancellous and cortical bone architecture and geometry in patients with osteoporosis.
Genetic and Environmental Determinants of Volumetric and Areal BMD in Multi-Generational Families of African Ancestry: The Tobago Family Health Study
Authors: Wang Xiaojing , Wheeler Victor W , Patrick Alan L , Bunker Clareann H , Zmuda Joseph M
Published: January 2007

BMD is higher and fracture risk is lower among individuals of African versus European descent, but little is known about the genetic architecture of BMD in the former group. Heritabilities of areal and volumetric BMD were moderate in our large families of African descent but differed for trabecular and cortical BMD.

Introduction: Populations of African ancestry have lower osteoporotic fracture risk and higher BMD than other ethnic groups. However, there is a paucity of information regarding the genetic and environmental influences on bone health among populations of African heritage.

Materials and Methods: We dissected the genetic architecture of areal BMD measured by DXA at the proximal femur, lumbar spine, and whole body and volumetric BMD measured by pQCT at the distal and proximal radius and tibia in 283 women and 188 men ≤18 years of age (mean, 43 years) from eight multigenerational Afro-Caribbean families (mean family size > 50). Using quantitative genetic methods, we estimated the residual heritability and the effects of anthropometric, demographic, lifestyle, and medical variables on areal and volumetric BMD.

Results: Compared with U.S. non-Hispanic blacks and whites, areal BMD at the femoral neck was highest in the Afro-Caribbean men and women at all ages. Trabecular volumetric BMD decreased linearly with increasing age, whereas cortical volumetric BMD did not decrease until age 40–49, especially in women. Anthropometric, lifestyle, and medical factors accounted for 12–32% of the variation in areal and volumetric BMD, and residual heritabilities (range, 0.23–0.52) were similar to those reported in other ethnic groups. Heritability of cortical BMD was substantially lower than that of areal or trabecular volumetric BMD, although the measured covariates accounted for a similar proportion of the total phenotypic variation.

Conclusions: Our study is the first comprehensive genetic epidemiologic analysis of volumetric BMD measured by QCT and the first analysis of these traits in extended families of African descent. Genes account for as much or more of the total variation in areal and volumetric BMD than do environmental factors, but these effects seem to differ for trabecular and cortical bone.
Spatial Reference Frames of Visual, Vestibular, and Multimodal Heading Signals in the Dorsal Subdivision of the Medial Superior Temporal Area
Authors: Fetsch Christopher R. , Wang Sentao , Gu Yong , DeAngelis Gregory C. , Angelaki Dora E.
Published: January 2007

Heading perception is a complex task that generally requires the integration of visual and vestibular cues. This sensory integration is complicated by the fact that these two modalities encode motion in distinct spatial reference frames (visual, eye-centered; vestibular, head-centered). Visual and vestibular heading signals converge in the primate dorsal subdivision of the medial superior temporal area (MSTd), a region thought to contribute to heading perception, but the reference frames of these signals remain unknown. We measured the heading tuning of MSTd neurons by presenting optic flow (visual condition), inertial motion (vestibular condition), or a congruent combination of both cues (combined condition). Static eye position was varied from trial to trial to determine the reference frame of tuning (eye-centered, head-centered, or intermediate). We found that tuning for optic flow was predominantly eye-centered, whereas tuning for inertial motion was intermediate but closer to head-centered. Reference frames in the two unimodal conditions were rarely matched in single neurons and uncorrelated across the population. Notably, reference frames in the combined condition varied as a function of the relative strength and spatial congruency of visual and vestibular tuning. This represents the first investigation of spatial reference frames in a naturalistic, multimodal condition in which cues may be integrated to improve perceptual performance. Our results compare favorably with the predictions of a recent neural network model that uses a recurrent architecture to perform optimal cue integration, suggesting that the brain could use a similar computational strategy to integrate sensory signals expressed in distinct frames of reference.
In VivoIdentification and Manipulation of the Ca2+Selectivity Filter in theDrosophilaTransient Receptor Potential Channel
Authors: Liu Che H. , Wang Tao , Postma Marten , Obukhov Alexander G. , Montell Craig , Hardie Roger C.
Published: January 2007

Null mutations in thetransient receptor potential(trp) gene eliminate the major, Ca2+-selective component of the light-sensitive conductance inDrosophilaphotoreceptors. Although it is the prototypical member of the TRP ion channel superfamily, conclusive evidence that TRP is a pore-forming channel subunitin vivois lacking. We show here that mutating a specific acidic residue (Asp621) in the putative pore virtually eliminated Ca2+permeationin vivoand altered other biophysical properties of the native TRP conductance. The results identify Asp621as a critical residue of the TRP Ca2+selectivity filter, provide the first rigorous demonstration that a TRP protein is a pore-forming subunit in any native system, and point to the likely location of the pore in mammalian canonical TRP channels. The specific elimination of Ca2+permeation in TRP also provided a unique opportunity to address the roles of Ca2+influxin vivo. We found that Asp621mutations profoundly affected several key aspects of the light response and caused light-dependent retinal degeneration.
Ankyrin-Dependent and -Independent Mechanisms Orchestrate Axonal Compartmentalization of L1 Family Members Neurofascin and L1/Neuron–Glia Cell Adhesion Molecule
Authors: Boiko Tatiana , Vakulenko Max , Ewers Helge , Yap Chan Choo , Norden Caren , Winckler Bettina
Published: January 2007

Axonal initial segments (IS) and nodes of Ranvier are functionally important membrane subdomains in which the clustering of electrogenic channels enables action potential initiation and propagation. In addition, the initial segment contributes to neuronal polarity by serving as a diffusion barrier. To study the mechanisms of axonal compartmentalization, we focused on two L1 family of cell adhesion molecules (L1-CAMs) [L1/neuron–glia cell adhesion molecule (L1/NgCAM) and neurofascin (NF)] and two neuronal ankyrins (ankB and ankG). NF and ankG accumulate specifically at the initial segment, whereas L1/NgCAM and ankB are expressed along the entire lengths of axons. We find that L1/NgCAM and NF show distinct modes of steady-state accumulation during axon outgrowth in cultured hippocampal neurons. Despite their different steady-state localizations, both L1/NgCAM and NF show slow diffusion and low detergent extractability specifically in the initial segment but fast diffusion and high detergent extractability in the distal axon. We propose that L1-CAMs do not strongly bind ankB in the distal axon because of spatial regulation of ankyrin affinity by phosphorylation. NF, conversely, is initially enriched in an ankyrin-independent manner in the axon generally and accumulates progressively in the initial segment attributable to preferential binding to ankG. Our results suggest that NF and L1/NgCAM accumulate in the axon by an ankyrin-independent pathway, but retention at the IS requires ankyrin binding.
Deficiency in Na,K-ATPase α Isoform Genes Alters Spatial Learning, Motor Activity, and Anxiety in Mice
Authors: Moseley Amy E. , Williams Michael T. , Schaefer Tori L. , Bohanan Cynthia S. , Neumann Jon C. , Behbehani Michael M. , Vorhees Charles V. , Lingrel Jerry B
Published: January 2007

Several disorders have been associated with mutations in Na,K-ATPase α isoforms (rapid-onset dystonia parkinsonism, familial hemiplegic migraine type-2), as well as reduction in Na,K-ATPase content (depression and Alzheimer's disease), thereby raising the issue of whether haploinsufficiency or altered enzymatic function contribute to disease etiology. Three isoforms are expressed in the brain: the α1 isoform is found in many cell types, the α2 isoform is predominantly expressed in astrocytes, and the α3 isoform is exclusively expressed in neurons. Here we show that mice heterozygous for the α2 isoform display increased anxiety-related behavior, reduced locomotor activity, and impaired spatial learning in the Morris water maze. Mice heterozygous for the α3 isoform displayed spatial learning and memory deficits unrelated to differences in cued learning in the Morris maze, increased locomotor activity, an increased locomotor response to methamphetamine, and a 40% reduction in hippocampal NMDA receptor expression. In contrast, heterozygous α1 isoform mice showed increased locomotor response to methamphetamine and increased basal and stimulated corticosterone in plasma. The learning and memory deficits observed in the α2 and α3 heterozygous mice reveal the Na,K-ATPase to be an important factor in the functioning of pathways associated with spatial learning. The neurobehavioral changes seen in heterozygous mice suggest that these mouse models may be useful in future investigations of the associated human CNS disorders.
Metastability of Active CA3 Networks
Authors: Sasaki Takuya , Matsuki Norio , Ikegaya Yuji
Published: January 2007

The brain is spontaneously active even in the absence of external input. This ongoing background activity impacts neural information processing. We used functional multineuron calcium imaging (fMCI) to analyze the net structure of spontaneous CA3 network activity in hippocampal slice cultures loaded with Oregon Green 488 BAPTA-1 using a spinning disk confocal microscope (10–30 frames/s). Principal component analysis revealed that network states, defined by active cell ensembles, were stable but heterogenous and discrete. These states were stabilized through synaptic activity and maintained against external perturbations. A few discrete states emerged during our observation period of up to 30 min. Networks tended to stay in a single state for tens of seconds and then suddenly jump to a new state. After a state transition, the old state was rarely, if ever, revisited by the network during our observation period. This temporal profile of state transitions could not be simulated by a hidden Markov model, indicating that the state dynamics is nonrandomly organized. Within each state, the pattern of network activity tended to stabilize in a specific configuration. Neither maintenance nor transition of the network states required NMDA receptor activity. These findings suggest that the network states are metastable, rather than multistable, and might be governed by local attractor-like dynamics. The fMCI data analyzed here are available athttp://hippocampus.jp/data/
Tonic Enhancement of Endocannabinoid-Mediated Retrograde Suppression of Inhibition by Cholinergic Interneuron Activity in the Striatum
Authors: Narushima Madoka , Uchigashima Motokazu , Fukaya Masahiro , Matsui Minoru , Manabe Toshiya , Hashimoto Kouichi , Watanabe Masahiko , Kano Masanobu
Published: January 2007

Tonically active cholinergic interneurons in the striatum modulate activities of striatal outputs from medium spiny (MS) neurons and significantly influence overall functions of the basal ganglia. Cellular mechanisms of this modulation are not fully understood. Here we show that ambient acetylcholine (ACh) derived from tonically active cholinergic interneurons constitutively upregulates depolarization-induced release of endocannabinoids from MS neurons. The released endocannabinoids cause transient suppression of inhibitory synaptic inputs to MS neurons through acting retrogradely onto presynaptic CB1cannabinoid receptors. The effects were mediated by postsynaptic M1subtype of muscarinic ACh receptors, because the action of a muscarinic agonist to release endocannabinoids and the enhancement of depolarization-induced endocannabinoid release by ambient ACh were both deficient in M1knock-out mice and were blocked by postsynaptic infusion of guanosine-5′-O-(2-thiodiphosphate). Suppression of spontaneous firings of cholinergic interneurons by inhibitingIhcurrent reduced the depolarization-induced release of endocannabinoids. Conversely, elevation of ambient ACh concentration by inhibiting choline esterase significantly enhanced the endocannabinoid release. Paired recording from a cholinergic interneuron and an MS neuron revealed that the activity of single cholinergic neuron could influence endocannabinoid-mediated signaling in neighboring MS neurons. These results clearly indicate that striatal endocannabinoid-mediated modulation is under the control of cholinergic interneuron activity. By immunofluorescent and immunoelectron microscopic examinations, we demonstrated that M1receptor was densely distributed in perikarya and dendrites of dopamine D1or D2receptor-positive MS neurons. Thus, we have disclosed a novel mechanism by which the muscarinic system regulates striatal output and may contribute to motor control.
Imaging Cerebral Gene Transcripts in Live Animals
Authors: Liu Christina H. , Kim Young R. , Ren Jia Q. , Eichler Florian , Rosen Bruce R. , Liu Philip K.
Published: January 2007

To circumvent the limitations of using postmortem brain in molecular assays, we used avidin–biotin binding to couple superparamagnetic iron oxide nanoparticles (SPIONs) (15–20 nm) to phosphorothioate-modified oligodeoxynucleotides (sODNs) with sequence complementary to c-fosand β-actinmRNA (SPION-cfos and SPION-βactin, respectively) (14–22 nm). The Stern–Volmer constant for the complex of SPION and fluorescein isothiocyanate (FITC)-sODN is 3.1 × 106/m. We studied the feasibility of using the conjugates forin vivomagnetic resonance imaging (MRI) to monitor gene transcription, and demonstrated that these complexes at 40 μg of Fe per kilogram of body weight were retained at least 1 d after intracerebroventricular infusion into the left ventricle of C57Black6 mice. SPION retention measured by MRI as T2* or R2* maps (R2* = 1/T2*) was compared with histology of iron oxide (Prussian blue) and FITC-labeled sODN. We observed significant reduction in magnetic resonance (MR) T2* signal in the right cortex and striatum; retention of SPION-cfos and SPION-βactin positively correlated with c-fosand β-actinmRNA maps obtained fromin situhybridization. Histological examination showed that intracellular iron oxide and FITC-sODN correlated positively within vivoMR signal reduction. Furthermore, in animals that were administered SPION-cfos and amphetamine (4 mg/kg, i.p.), retention was significantly elevated in the nucleus accumbens, striatum, and medial prefrontal cortex of the forebrain. Control groups that received SPION-cfos and saline or that received a SPION conjugate with a random-sequence probe and amphetamine showed no retention. These results demonstrated that SPION-sODN conjugates can detect active transcriptions of specific mRNA species in living animals with MRI.
Aβ40 Inhibits Amyloid DepositionIn Vivo
Authors: Kim Jungsu , Onstead Luisa , Randle Suzanne , Price Robert , Smithson Lisa , Zwizinski Craig , Dickson Dennis W. , Golde Todd , McGowan Eileen
Published: January 2007

Numerous studies have established a pivotal role for Aβ42 in Alzheimer's disease (AD) pathogenesis. In contrast, although Aβ40 is the predominant form of amyloid β (Aβ) produced and accumulates to a variable degree in the human AD brain, its role in AD pathogenesis has not been established. It has generally been assumed that an increase in Aβ40 would accelerate amyloid plaque formationin vivo. We have crossed BRI-Aβ40 mice that selectively express high levels of Aβ40 with both Tg2576 (APPswe, K670N+M671L) mice and BRI-Aβ42A mice expressing Aβ42 selectively and analyzed parenchymal and cerebrovascular Aβ deposition in the bitransgenic mice compared with their singly transgenic littermates. In the bitransgenic mice, the increased steady-state levels of Aβ40 decreased Aβ deposition by 60–90%. These results demonstrate that Aβ42 and Aβ40 have opposing effects on amyloid deposition: Aβ42 promotes amyloid deposition but Aβ40 inhibits it. In addition, increasing Aβ40 levels protected BRI-Aβ40/Tg2576 mice from the premature-death phenotype observed in Tg2576 mice. The protective properties of Aβ40 with respect to amyloid deposition suggest that strategies that preferentially target Aβ40 may actually worsen the disease course and that selective increases in Aβ40 levels may actually reduce the risk for development of AD.
Intrasellar pressure and tumor volume in pituitary tumor: relation study
Authors: Gondim Jackson A. , Tella Jr. Osvaldo I. , Schops Michele
Published: January 2007

OBJECTIVE: To determine if there was a relationship between intrassellar pressure (ISP) and pituitary tumor volume. METHOD: Between August 2002 and May 2004, 60 patients aged between 13 and 75 years old (39 males), having a pituitary adenoma were submitted to an endoscope transseptal approach. During the surgery and before tumor resection, 2 mm of the sella’s floor were removed and a 1.5 mm dural opening made to place a transducer into the pituitary adenoma. The transducer was connected to a pressure monitor. RESULTS: The intrasellar pressure, ranged from 2-51 mmHg and was measured based on the classification of Hardy-Vezina. The most elevated was in the type II macro adenomas with 32.6 mmHg, sharply superior to the value of a normal intracranial pressure. CONCLUSION: These values showed that the macroadenomas confined to the sella, without destruction of the floor and integrity of the diaphragm, type II of Hardy-Vezina, presented a value of ISP much higher than intra-extrasellar macroadenoma’s.
Dor e parestesias nos membros superiores e diagnóstico da síndrome do túnel do carpo
Authors: Barbosa Valéria Ribeiro Nogueira , Dantas Fábio Galvão , Cardoso Maria Aparecida Alves , Medeiros Jovany Luis Alves de
Published: January 2007

Nós avaliamos a freqüência e localização de dor e parestesias em pacientes com síndrome do túnel do carpo (STC) e em indivíduos da população geral, pareados por gênero e idade. Determinamos a sensibilidade e a especificidade desses sintomas para o diagnóstico de STC. Dor foi um sintoma comum nos dois grupos de pacientes. Parestesia ocorreu com mais freqüência em pacientes com STC (p<0,05). No grupo com STC, a dor era localizada no pescoço (42,8%), membros superiores (36,8%) e mãos (82,8%). Nos pacientes sem STC, a dor se localizava na cabeça (11,4%), região axial (37,1%) e membros inferiores (22,8%). Nós concluímos que, em relação ao diagnóstico de STC, dor e parestesias apresentam sensibilidade baixa e especificidade alta quando as queixas estão presentes nos membros superiores; e sensibilidade e especificidade altas (>75%) quando são localizadas nas mãos.
Fatal intracerebral hemorrhage secondary to Lonomia obliqua caterpillar envenoming: case report
Authors: Kowacs Pedro André , Cardoso Juliana , Entres Marlene , Novak Edison Mattos , Werneck Lineu César
Published: January 2007

The case of a 70 year-old, previously healthy woman who developed a severe bleeding diathesis shortly after touching a Lonomia obliqua caterpillar and finally died from multiple intracerebral hemorrhages is described. Brain hemorrhages are the leading cause of death in patients envenomed by the Lonomia species. The pertinent literature is reviewed and the most relevant clinical features highlighted, with emphasis on diagnosis. The use of new therapeutic options such as anti-Lonomia serum is discussed.
Cerebral X-linked adrenoleukodystrophy: follow-up with magnetic resonance imaging
Authors: Gasparetto Emerson L. , Rosa Juliana Mecunhe , Davaus Taísa , Carvalho Neto Arnolfo de
Published: January 2007

OBJECTIVE: To report a case of childhood cerebral X-linked adrenoleukodystrophy (X-ADL), emphasizing the magnetic resonance imaging (MRI) findings at initial evaluation and at the follow-up. CASE REPORT: Five year-old boy, who was asymptomatic, presented with diagnosis of X-ADL for MRI evaluation. The initial brain MRI showed a focal area of enhancement at the splenium of the corpus calosum. One year later, the follow-up MRI showed a progression of the corpus calosus lesion, as well as other lesions in the parietal and occipital lobes. CONCLUSION: The brain MRI follow-up of patients with X-ADL is important to show the progression of the lesions.
Intoxication with oral hypoglycemics as a cause of diffuse brain injury: case report
Authors: Gasparetto Emerson L. , Bianchet Leila Caroline , Davaus Taisa , Carvalho Neto Arnolfo de
Published: January 2007

OBJECTIVE: To present the imaging findings of a patient with diffuse brain injury secondary to intoxication with oral hypoglycemics. CASE REPORT: A nine years-old boy presented with generalized tonic-clonic convulsions and decreased consciousness. Laboratory investigation demonstrated blood glucose level of 21 mg/dL. The magnetic resonance imaging showed cortical and subcortical temporo-parieto-occipital areas of high signal on T2 and low signal on T1, with high signal on the diffusion-weighted images and low signal on apparent diffusion coefficient maps. CONCLUSION: Cortical and subcortical temporal, parietal and occipital ischemic lesions may be seen in patients with intoxication by oral hypoglycemics.
Produção da cenoura e efeito na fertilidade do solo e nutrição decorrente da solarização do solo para controle da tiririca
Authors: Ricci Marta dos Santos Freire , Oliveira Fabio Freire de , Miranda Simone Cordeiro de , Costa Janaina Ribeiro
Published: January 2007

Dentre os desafios do cultivo orgânico de hortaliças destaca-se o controle de plantas daninhas, devido à proibição do uso de herbicidas. Entre as invasoras, a tiririca (Cyperus rotundus L.) é de difícil controle pela sua alta competitividade. A solarização é uma alternativa para desinfestação do solo, a qual consiste em cobri-lo com plástico transparente, com bons resultados no controle da tiririca. A fim de avaliar a influência do preparo e do revolvimento do solo sobre a eficiência da solarização no controle da tiririca, bem como seu posterior efeito sobre o cultivo da cenoura, foi realizado um experimento na Fazendinha Agroecológica, em Seropédica (RJ). O experimento foi disposto em blocos ao acaso com três repetições, em arranjo fatorial 2 x 3 mais uma testemunha adicional, sendo: 1) solo solarizado, preparado (com grade aradora) e revolvido 30 dias após a solarização (manualmente com auxílio de uma enxada); 2) solo solarizado, preparado e revolvido aos 60 dias; 3) solo solarizado, preparado e não revolvido; 4) solo solarizado, não preparado e revolvido aos 30 dias; 5) solo solarizado, não preparado e revolvido aos 60 dias; 6) solo solarizado, não preparado e não revolvido; solo não solarizado, não preparado e não revolvido (testemunha). A solarização iniciou-se em 29/1/2002, e durou cem dias. A solarização reduziu em 86% a infestação de tiririca no cultivo da cenoura. Até 10 cm de profundidade, a temperatura do solo foi superior nas parcelas solarizadas, porém a 5 cm, a solarização foi mais eficiente quando associada ao preparo do solo, não havendo efeito do revolvimento. A solarização aumentou os valores da biomassa microbiana e dos teores de Ca, Mg e P do solo. O desenvolvimento da cenoura foi influenciado pela solarização que resultou em maior produtividade.
Distribuição espacial do sistema radicular do cafeeiro fertirrigado por gotejamento em Campinas
Authors: Barreto Carlos Vinícius Garcia , Sakai Emílio , Arruda Flávio Bussmeyer , Silva Emerson Alves da , Pires Regina Célia de Matos
Published: January 2007

Este estudo teve como objetivo avaliar o efeito da fertirrigação por gotejamento, utilizando-se emissores com diferentes espaçamentos (0,50 ou 0,80 m) e profundidades de instalação (superficial, 0,10 e 0,20 m), na distribuição espacial do sistema radicular do cafeeiro. Observaram-se no cafeeiro irrigado e adubado de forma convencional diferentes condições de desenvolvimento radicular, variando conforme os tratamentos impostos. Para as plantas irrigadas por tubogotejadores com emissores espaçados a cada 0,50 m, a profundidade radicular efetiva foi menor (média de 0,63 m) do que a observada para as plantas irrigadas por emissores posicionados a cada 0,80 m (média de 0,70 m). No manejo nutricional por fertirrigação observou-se menor desigualdade na profundidade radicular efetiva entre os tratamentos, bem como, em um aumento médio de 51,1% de densidade de raízes. Houve tendência de manutenção do volume radicular na região próxima aos emissores, enquanto nos pontos mais distantes do desenvolvimento do bulbo úmido, o crescimento radicular foi de 77%. A irrigação das plantas por tubogotejadores enterrados a 0,10 m de profundidade proporcionou maior desenvolvimento radicular em resposta à fertirrigação.