bluuebunny/crossref_metadata_2025 huggingface dataset:
Endoplasmic reticulum degradation impedes olfactory G-protein coupled receptor functional expression
Authors: Lu Min , Staszewski Lena , Echeverri Fernando , Xu Hong , Moyer Bryan D
Published: September 2004

Background

Research on olfactory G-protein coupled receptors (GPCRs) has been severely impeded by poor functional expression in heterologous systems. Previously, we demonstrated that inefficient olfactory receptor (OR) expression at the plasma membrane is attributable, in part, to degradation of endoplasmic reticulum (ER)-retained ORs by the ubiquitin-proteasome system and sequestration of ORs in ER aggregates that are degraded by autophagy. Thus, experiments were performed to test the hypothesis that attenuation of ER degradation improves OR functional expression in heterologous cells.

Results

To develop means to increase the functional expression of ORs, we devised an approach to measure activation of the mOREG OR (Unigene # Mm.196680; Olfr73) through coupling to an olfactory cyclic nucleotide-gated cation channel (CNG). This system, which utilizes signal transduction machinery coupled to OR activation in native olfactory sensory neurons, was used to demonstrate that degradation, both by the ubiquitin-proteasome system and autophagy, limits mOREG functional expression. The stimulatory effects of proteasome and autophagy inhibitors on mOREG function required export from the ER and trafficking through the biosynthetic pathway.

Conclusions

These findings demonstrate that poor functional expression of mOREG in heterologous cells is improved by blocking proteolysis. Inhibition of ER degradation may improve the function of other ORs and assist future efforts to elucidate the molecular basis of odor discrimination.
Gene family evolution: an in-depth theoretical and simulation analysis of non-linear birth-death-innovation models
Authors: Karev Georgy P , Wolf Yuri I , Berezovskaya Faina S , Koonin Eugene V
Published: September 2004

Background

The size distribution of gene families in a broad range of genomes is well approximated by a generalized Pareto function. Evolution of ensembles of gene families can be described with Birth, Death, and Innovation Models (BDIMs). Analysis of the properties of different versions of BDIMs has the potential of revealing important features of genome evolution.

Results

In this work, we extend our previous analysis of stochastic BDIMs.

In addition to the previously examined rational BDIMs, we introduce potentially more realistic logistic BDIMs, in which birth/death rates are limited for the largest families, and show that their properties are similar to those of models that include no such limitation. We show that the mean time required for the formation of the largest gene families detected in eukaryotic genomes is limited by the mean number of duplications per gene and does not increase indefinitely with the model degree. Instead, this time reaches a minimum value, which corresponds to a non-linear rational BDIM with the degree of approximately 2.7. Even for this BDIM, the mean time of the largest family formation is orders of magnitude greater than any realistic estimates based on the timescale of life's evolution. We employed the embedding chains technique to estimate the expected number of elementary evolutionary events (gene duplications and deletions) preceding the formation of gene families of the observed size and found that the mean number of events exceeds the family size by orders of magnitude, suggesting a highly dynamic process of genome evolution. The variance of the time required for the formation of the largest families was found to be extremely large, with the coefficient of variation >> 1. This indicates that some gene families might grow much faster than the mean rate such that the minimal time required for family formation is more relevant for a realistic representation of genome evolution than the mean time. We determined this minimal time using Monte Carlo simulations of family growth from an ensemble of simultaneously evolving singletons. In these simulations, the time elapsed before the formation of the largest family was much shorter than the estimated mean time and was compatible with the timescale of evolution of eukaryotes.

Conclusions

The analysis of stochastic BDIMs presented here shows that non-linear versions of such models can well approximate not only the size distribution of gene families but also the dynamics of their formation during genome evolution. The fact that only higher degree BDIMs are compatible with the observed characteristics of genome evolution suggests that the growth of gene families is self-accelerating, which might reflect differential selective pressure acting on different genes.
A high-resolution radiation hybrid map of chicken chromosome 5 and comparison with human chromosomes
Authors: Pitel Frédérique , Abasht Behnam , Morisson Mireille , Crooijmans Richard PMA , Vignoles Florence , Leroux Sophie , Feve Katia , Bardes Suzanne , Milan Denis , Lagarrigue Sandrine , Groenen Martien AM , Douaire Madeleine , Vignal Alain
Published: September 2004

Background

The resolution of radiation hybrid (RH) maps is intermediate between that of the genetic and BAC (Bacterial Artificial Chromosome) contig maps. Moreover, once framework RH maps of a genome have been constructed, a quick location of markers by simple PCR on the RH panel is possible. The chicken ChickRH6 panel recently produced was used here to construct a high resolution RH map of chicken GGA5. To confirm the validity of the map and to provide valuable comparative mapping information, both markers from the genetic map and a high number of ESTs (Expressed Sequence Tags) were used. Finally, this RH map was used for testing the accuracy of the chicken genome assembly for chromosome 5.

Results

A total of 169 markers (21 microsatellites and 148 ESTs) were typed on the ChickRH6 RH panel, of which 134 were assigned to GGA5. The final map is composed of 73 framework markers extending over a 1315.6 cR distance. The remaining 61 markers were placed alongside the framework markers within confidence intervals.

Conclusion

The high resolution framework map obtained in this study has markers covering the entire chicken chromosome 5 and reveals the existence of a high number of rearrangements when compared to the human genome. Only two discrepancies were observed in relation to the sequence assembly recently reported for this chromosome.
Distinct gene expression profiles in different B-cell compartments in human peripheral lymphoid organs
Authors: Shen Yulei , Iqbal Javeed , Xiao Li , Lynch Ryan C , Rosenwald Andreas , Staudt Louis M , Sherman Simon , Dybkaer Karen , Zhou Guimei , Eudy James D , Delabie Jan , McKeithan Timothy W , Chan Wing C
Published: September 2004

Background

There are three major B-cell compartments in peripheral lymphoid organs: the germinal center (GC), the mantle zone (MNZ) and the marginal zone (MGZ). Unique sets of B-cells reside in these compartments, and they have specific functional roles in humoral immune response. MNZ B cells are naïve cells in a quiescent state and may participate in GC reactions upon proper stimulation. The adult splenic MGZ contains mostly memory B cells and is also known to provide a rapid response to particulate antigens. The GC B-cells proliferate rapidly and undergo selection and affinity maturation. The B-cell maturational process is accompanied by changes in the expression of cell-surface and intracellular proteins and requires signals from the specialized microenvironments.

Results

We performed laser microdissection of the three compartments for gene expression profiling by cDNA microarray. The transcriptional program of the GC was dominated by upregulation of genes associated with proliferation and DNA repair or recombination. The MNZ and MGZ showed increased expression of genes promoting cellular quiescence. The three compartments also revealed distinct repertoires of apoptosis-associated genes, chemokines and chemokine receptors. The MNZ and GC showed upregulation of CCL20 and CCL18 respectively. The MGZ was characterized by high expression of many chemokines genes e.g. CXCL12, CCL3, CCL14 and IFN-associated genes, consistent with its role in rapid response to infections. A stromal signature was identified including genes associated with macrophages or with synthesis of extracellular matrix and genes that influenced lymphocyte migration and survival. Differentially expressed genes that did not belong to the above categories include the well characterized BCL6 and CD10 and many others whose function is not known.

Conclusions

Transcriptional profiling of B-cell compartments has identified groups of genes involved in critical molecular and cellular events that affect proliferation, survival migration, and differentiation of the cells. The gene expression study of normal B-cell compartments may additionally contribute to our understanding of the molecular abnormalities of the corresponding lymphoid tumors.
Comparative effect of intraoperative propacetamol versus placebo on morphine consumption after elective reduction mammoplasty under remifentanil-based anesthesia: a randomized control trial [ISRCTN71723173]
Authors: Binhas Michèle , Decailliot François , Rezaiguia-Delclaux Saïda , Suen Powen , Dumerat Marc , François Véronique , Combes Xavier , Duvaldestin Philippe
Published: September 2004

Background

Postoperative administration of paracetamol or its prodrug propacetamol has been shown to decrease pain with a morphine sparing effect. However, the effect of propacetamol administered intra-operatively on post-operative pain and early postoperative morphine consumption has not been clearly evaluated. In order to evaluate the effectiveness of analgesic protocols in the management of post-operative pain, a standardized anesthesia protocol without long-acting opioids is crucial. Thus, for ethical reasons, the surgical procedure under general anesthesia with remifentanil as the only intraoperative analgesic must be associated with a moderate predictable postoperative pain.

Methods

We were interested in determining the postoperative effect of propacetamol administered intraoperatively after intraoperative remifentanil. Thirty-six adult women undergoing mammoplasty with remifentanil-based anesthesia were randomly assigned to receive propacetamol 2 g or placebo one hour before the end of surgery. After remifentanil interruption and tracheal extubation in recovery room, pain was assessed and intravenous titrated morphine was given. The primary end-point was the cumulative dose of morphine administered in the recovery room. The secondary end-points were the pain score after tracheal extubation and one hour after, the delay for obtaining a Simplified Numerical Pain Scale (SNPS) less than 4, and the incidence of morphine side effects in the recovery room.

For intergroup comparisons, categorical variables were compared using the chi-squared test and continuous variables were compared using the Student t test or Mann-Whitney U test, as appropriate. A p value less than 0.05 was considered as significant.

Results

In recovery room, morphine consumption was lower in the propacetamol group than in the placebo group (p = 0.01). Pain scores were similar in both groups after tracheal extubation and lower in the propacetamol group (p = 0.003) one hour after tracheal extubation. The time to reach a SNPS < 4 was significantly shorter in the propacetamol group (p = 0.02). The incidence of morphine related side effects did not differ between the two groups.

Conclusions

Intraoperative propacetamol administration with remifentanil based-anesthesia improved significantly early postoperative pain by sparing morphine and shortening the delay to achieve pain relief.
Nosocomial outbreak of neonatal Salmonella enterica serotype Enteritidis meningitis in a rural hospital in northern Tanzania
Authors: Vaagland Hogne , Blomberg Bjørn , Krüger Carsten , Naman Naftali , Jureen Roland , Langeland Nina
Published: September 2004

Background

Clinicians at Haydom Lutheran Hospital, a rural hospital in northern Tanzania noted an unusually high case-fatality rate of pediatric meningitis and suspected an outbreak of an unknown agent or an organism resistant to the empirical therapy.

Methods

We established a provisional microbiology laboratory to investigate the suspected outbreak. Blood and spinal fluid specimens were taken from children below the age of seven years with suspected meningitis. The blood and spinal fluid specimens were inoculated in commercial blood culture bottles and locally prepared Thayer-Martin medium in slanted tubes, respectively. The bacterial isolates were sent to Norway for further investigation, including susceptibility testing and pulsed-field gel-electrophoresis (PFGE).

Results

Among 24 children with suspected meningitis and/or septicemia, five neonates had meningitis caused by Salmonella enterica serotype Enteritidis, all of whom died. Two children had S. Enteritidis septicemia without meningitis and both survived. Genotyping with PFGE suggested a clonal outbreak. The salmonella strain was resistant to ampicillin and sensitive to gentamicin, the two drugs commonly used to treat neonatal meningitis at the hospital.

Conclusion

The investigation reminds us that nontyphoidal salmonellae can cause meningitis associated with very high case-fatality rates. Resistance to multiple antimicrobial agents increases the risk of treatment failure and may have contributed to the fatal outcome in all of the five patients with salmonella meningitis. The investigation indicated that the outbreak was nosocomial and the outbreak subsided after hygienic measures were instituted. Establishing a provisional microbiological laboratory is a valuable and affordable tool to investigate and control outbreaks even in remote rural areas.
Methylation profiles of thirty four promoter-CpG islands and concordant methylation behaviours of sixteen genes that may contribute to carcinogenesis of astrocytoma
Authors: Yu Jian , Zhang Hongyu , Gu Jun , Lin Song , Li Junhua , Lu Wei , Wang Yifei , Zhu Jingde
Published: September 2004

Background

Astrocytoma is a common aggressive intracranial tumor and presents a formidable challenge in the clinic. Association of altered DNA methylation patterns of the promoter CpG islands with the expression profile of cancer-related genes, has been found in many human tumors. Therefore, DNA methylation status as such may serve as an epigenetic biomarker for both diagnosis and prognosis of human tumors, including astrocytoma.

Methods

We used the methylation specific PCR in conjunction with sequencing verification to establish the methylation profile of the promoter CpG island of thirty four genes in astrocytoma tissues from fifty three patients (The WHO grading:. I: 14, II: 15, III: 12 and IV: 12 cases, respectively). In addition, compatible tissues (normal tissues distant from lesion) from three non-astrocytoma patients were included as the control.

Results

Seventeen genes (ABL, APC, APAF1, BRCA1, CSPG2, DAPK1, hMLH1, LKB1, PTEN, p14
ARF
, p15
INK4b
, p27
KIP1
, p57
KIP2
, RASSF1C, RB1, SURVIVIN, and VHL) displayed a uniformly unmethylated pattern in all the astrocytoma and non-astrocytoma tissues examined. However, the MAGEA1 gene that was inactivated and hypermethylated in non-astrocytoma tissues, was partially demethylated in 24.5% of the astrocytoma tissues (co-existence of the hypermethylated and demethylated alleles). Of the astrocytoma associated hypermethylated genes, the methylation pattern of the CDH13, cyclin a1, DBCCR1, EPO, MYOD1, and p16
INK4a
genes changed in no more than 5.66% (3/53) of astrocytoma tissues compared to non-astrocytoma controls, while the RASSF1A, p73, AR, MGMT, CDH1, OCT6,, MT1A, WT1, and IRF7 genes were more frequently hypermethylated in 69.8%, 47.2%, 41.5%, 35.8%, 32%, 30.2%, 30.2%, 30.2% and 26.4% of astrocytoma tissues, respectively. Demethylation mediated inducible expression of the CDH13, MAGEA1, MGMT, p73 and RASSF1A genes was established in an astrocytoma cell line (U251), demonstrating that expression of these genes is likely regulated by DNA methylation. AR gene hypermethylation was found exclusively in female patients (22/27, 81%, 0/26, 0%, P < 0.001), while the IRF7 gene hypermethylation preferentially occurred in the male counterparts (11/26, 42.3% to 3/27, 11%, P < 0.05). Applying the mathematic method "the Discovery of Association Rules", we have identified groups consisting of up to three genes that more likely display the altered methylation patterns in concert in astrocytoma.

Conclusions

Of the thirty four genes examined, sixteen genes exhibited astrocytoma associated changes in the methylation profile. In addition to the possible pathological significance, the established concordant methylation profiles of the subsets consisting of two to three target genes may provide useful clues to the development of the useful prognostic as well as diagnostic assays for astrocytoma.
The role of circulating anti-p53 antibodies in patients with advanced non-small cell lung cancer and their correlation to clinical parameters and survival
Authors: Bergqvist Michael , Brattström Daniel , Larsson Anders , Hesselius Patrik , Brodin Ola , Wagenius Gunnar
Published: September 2004

Background

Lung cancer causes approximately one million deaths each year worldwide and protein p53 has been shown to be involved in the intricate processes regulating response to radiation and/or chemotherapeutic treatment. Consequently, since antibodies against p53 (anti-p53 antibodies) are associated with mutations within the p53 gene it seems likely that these antibodies could, hypothetically, be correlated with prognosis.

Methods

Serum samples from patients with non-small cell lung cancer (NSCLC) admitted to the Department of Oncology, University Hospital, Uppsala, Sweden, during 1983–1996 were studied. Anti-p53 abs were measured using a sandwich ELISA (Dianova, Hamburg, Germany).

Results

The present study included 84 patients with stage IIIA-IV (advanced NSCLC). At least three serum samples from each patient were collected and altogether 529 serum samples were analysed for the presence of anti-p53 antibodies. The median value of anti-p53 antibodies was 0.06 (range 0 – 139.8). Seventeen percent of investigated NSCLC first serum samples (n = 84) expressed elevated levels of anti-p53 antibodies. Anti-p53 antibodies were not correlated to tumour volume or platelets.

Survival analysis showed that anti-p53 antibodies were not associated with survival as revealed by univariate analysis (p = 0.29). However, patients with adenocarcinoma had a significantly poorer survival if they expressed anti-p53 antibodies (p = 0.01), whereas this was not found for patients with squamous cell carcinoma (p = 0.13). In patients where the blood samples were collected during radiation therapy, a statistically significant correlation towards poorer survival was found (p = 0.05) when elevated anti-p53 antibodies levels were present. No correlations to survival were found for serum samples collected prior to radiation therapy, during chemotherapy, or during follow-up. When anti-p53 antibodies were measured continuously, no increase in median anti-p53 values was observed the closer the individual patient come to death.

Conclusion

The result of the present retrospective study indicates that anti-p53 antibodies are not suitable for predictions concerning selection of patients with a more favourable outcome. Further prospective studies are, though, needed to fully elucidate this issue.
Evaluation of the prophylactic use of mitomycin-C to inhibit haze formation after photorefractive keratectomy in high myopia: a prospective clinical study
Authors: Hashemi Hassan , Taheri Seied Mohammad Reza , Fotouhi Akbar , Kheiltash Azita
Published: September 2004

Background

To study the effect of prophylactic application of mitomycin-C on haze formation in photorefractive keratectomy (PRK) for high myopia.

Methods

Fifty-four eyes of 28 myopic patients were enrolled in this prospective study. All eyes were operated by PRK followed by 0.02% mitomycin-C application for two minutes and washed with 20 ml normal saline afterwards. All eyes were examined thoroughly on the first 7 days and one month after surgery; 48 eyes (88.9%) at 3 and 6 months postoperatively. Hanna grading (in the scale of 0 to 4+) was used for assessment of corneal haze.

Results

The mean spherical equivalent refraction (SE) was -7.08 diopters (D) ± 1.11 (SD) preoperatively. Six months after surgery, 37 eyes (77.1%) achieved an uncorrected visual acuity (UCVA) of 20/20 or better, all eyes had a UCVA of 20/40 or better and 45 (93.7%) eyes had an SE within ± 1.00D. One month postoperatively, 2 eyes (3.7%) had grade 0.5+ of haze, while at 3 and 6 months after surgery no visited eye had haze at all. All eyes had a best corrected visual acuity (BCVA) of 20/40 or better and there were no lost lines in BCVA by 6 months after surgery. In spatial frequencies of 6 and 12 cycles per degree contrast sensitivity had decreased immediately after PRK and it had increased 1.5 lines by the 6th postoperative month compared to the preoperative data.

Conclusions

The results show the efficacy of mitomycin-C in preventing corneal haze after treatment of high myopia with PRK. This method- PRK + mitomycin-C – can be considered an alternative treatment for myopic patients whose corneal thicknesses are inadequate for laser in situ keratomileusis (LASIK). However, the results should be confirmed in longer follow-ups.
Elevated midbrain serotonin transporter availability in mixed mania: a case report
Authors: Tolmunen Tommi , Joensuu Mikko , Saarinen Pirjo Irmeli , Mussalo Hanna , Ahola Pasi , Vanninen Ritva , Kuikka Jyrki , Tiihonen Jari , Lehtonen Johannes
Published: September 2004

Background

Results obtained from brain imaging studies indicate that serotonin transporter (SERT) and dopamine transporter (DAT) densities are altered in major depression. However, no such studies have been published on current mania or hypomania.

Case presentation

In this single photon emission computed tomography (SPECT) study with [123I]nor-β-CIT we present a case with simultaneous symptoms of major depression and hypomania. She had an elevated serotonin transporter availability (SERT) in the midbrain and elevated dopamine transporter availability (DAT) in the striatum, which normalised in a one-year follow-up period during which she received eight months of psychodynamic psychotherapy.

Conclusions

To our knowledge, this is the first report on SERT and DAT associated with mania. In our case the availability of both SERT in the midbrain and DAT in the striatum were elevated at baseline and declined during psychotherapy, while the SERT and DAT of the depressed controls increased during psychotherapy. Symptoms of hypomania in the case were alleviated during psychotherapy. Clinical recovery was also reflected in the Hamilton Depression Rating Scale (HDRS) scores.
Seal of transparency heritage in the CISMeF quality-controlled health gateway
Authors: Darmoni SJ , Dahamna B , Roth-Berghofer Thomas R
Published: September 2004

Background

It is an absolute necessity to continually assess the quality of health information on the Internet. Quality-controlled subject gateways are Internet services which apply a selected set of targeted measures to support systematic resource discovery.

Methods

The CISMeF health gateway became a contributor to the MedCIRCLE project to evaluate 270 health information providers. The transparency heritage consists of using the evaluation performed on providers that are referenced in the CISMeF catalogue for evaluating the documents they publish, thus passing on the transparency label from the publishers to their documents.

Results

Each site rated in CISMeF has a record in the CISMeF database that generates an RDF into HTML file. The search tool Doc'CISMeF displays information originating from every publisher evaluated with a specific MedCIRCLE button, which is linked to the MedCIRCLE central repository. Starting with 270 websites, this trust heritage has led to 6,480 evaluated resources in CISMeF (49.8% of the 13,012 resources included in CISMeF).

Conclusion

With the MedCIRCLE project and transparency heritage, CISMeF became an explicit third party.
Doublet method for very fast autocoding
Authors: Berman Jules J
Published: September 2004

Background

Autocoding (or automatic concept indexing) occurs when a software program extracts terms contained within text and maps them to a standard list of concepts contained in a nomenclature. The purpose of autocoding is to provide a way of organizing large documents by the concepts represented in the text. Because textual data accumulates rapidly in biomedical institutions, the computational methods used to autocode text must be very fast. The purpose of this paper is to describe the doublet method, a new algorithm for very fast autocoding.

Methods

An autocoder was written that transforms plain-text into intercalated word doublets (e.g. "The ciliary body produces aqueous humor" becomes "The ciliary, ciliary body, body produces, produces aqueous, aqueous humor"). Each doublet is checked against an index of doublets extracted from a standard nomenclature. Matching doublets are assigned a numeric code specific for each doublet found in the nomenclature. Text doublets that do not match the index of doublets extracted from the nomenclature are not part of valid nomenclature terms. Runs of matching doublets from text are concatenated and matched against nomenclature terms (also represented as runs of doublets).

Results

The doublet autocoder was compared for speed and performance against a previously published phrase autocoder. Both autocoders are Perl scripts, and both autocoders used an identical text (a 170+ Megabyte collection of abstracts collected through a PubMed search) and the same nomenclature (neocl.xml, containing over 102,271 unique names of neoplasms). In side-by-side comparison on the same computer, the doublet method autocoder was 8.4 times faster than the phrase autocoder (211 seconds versus 1,776 seconds). The doublet method codes 0.8 Megabytes of text per second on a desktop computer with a 1.6 GHz processor. In addition, the doublet autocoder successfully matched terms that were missed by the phrase autocoder, while the phrase autocoder found no terms that were missed by the doublet autocoder.

Conclusions

The doublet method of autocoding is a novel algorithm for rapid text autocoding. The method will work with any nomenclature and will parse any ascii plain-text. An implementation of the algorithm in Perl is provided with this article. The algorithm, the Perl implementation, the neoplasm nomenclature, and Perl itself, are all open source materials.
Delta-9 tetrahydrocannabinol (THC) inhibits lytic replication of gamma oncogenic herpesviruses in vitro
Authors: Medveczky Maria M , Sherwood Tracy A , Klein Thomas W , Friedman Herman , Medveczky Peter G
Published: September 2004

Background

The major psychoactive cannabinoid compound of marijuana, delta-9 tetrahydrocannabinol (THC), has been shown to modulate immune responses and lymphocyte function. After primary infection the viral DNA genome of gamma herpesviruses persists in lymphoid cell nuclei in a latent episomal circular form. In response to extracellular signals, the latent virus can be activated, which leads to production of infectious virus progeny. Therefore, we evaluated the potential effects of THC on gamma herpesvirus replication.

Methods

Tissue cultures infected with various gamma herpesviruses were cultured in the presence of increasing concentrations of THC and the amount of viral DNA or infectious virus yield was compared to those of control cultures. The effect of THC on Kaposi's Sarcoma Associated Herpesvirus (KSHV) and Epstein-Barr virus (EBV) replication was measured by the Gardella method and replication of herpesvirus saimiri (HVS) of monkeys, murine gamma herpesvirus 68 (MHV 68), and herpes simplex type 1 (HSV-1) was measured by yield reduction assays. Inhibition of the immediate early ORF 50 gene promoter activity was measured by the dual luciferase method.

Results

Micromolar concentrations of THC inhibit KSHV and EBV reactivation in virus infected/immortalized B cells. THC also strongly inhibits lytic replication of MHV 68 and HVS in vitro. Importantly, concentrations of THC that inhibit virus replication of gamma herpesviruses have no effect on cell growth or HSV-1 replication, indicating selectivity. THC was shown to selectively inhibit the immediate early ORF 50 gene promoter of KSHV and MHV 68.

Conclusions

THC specifically targets viral and/or cellular mechanisms required for replication and possibly shared by these gamma herpesviruses, and the endocannabinoid system is possibly involved in regulating gamma herpesvirus latency and lytic replication. The immediate early gene ORF 50 promoter activity was specifically inhibited by THC. These studies may also provide the foundation for the development of antiviral strategies utilizing non-psychoactive derivatives of THC.
Priming nonlinear searches for pathway identification
Authors: Veflingstad Siren R , Almeida Jonas , Voit Eberhard O
Published: September 2004

Background

Dense time series of metabolite concentrations or of the expression patterns of proteins may be available in the near future as a result of the rapid development of novel, high-throughput experimental techniques. Such time series implicitly contain valuable information about the connectivity and regulatory structure of the underlying metabolic or proteomic networks. The extraction of this information is a challenging task because it usually requires nonlinear estimation methods that involve iterative search algorithms. Priming these algorithms with high-quality initial guesses can greatly accelerate the search process. In this article, we propose to obtain such guesses by preprocessing the temporal profile data and fitting them preliminarily by multivariate linear regression.

Results

The results of a small-scale analysis indicate that the regression coefficients reflect the connectivity of the network quite well. Using the mathematical modeling framework of Biochemical Systems Theory (BST), we also show that the regression coefficients may be translated into constraints on the parameter values of the nonlinear BST model, thereby reducing the parameter search space considerably.

Conclusion

The proposed method provides a good approach for obtaining a preliminary network structure from dense time series. This will be more valuable as the systems become larger, because preprocessing and effective priming can significantly limit the search space of parameters defining the network connectivity, thereby facilitating the nonlinear estimation task.
Identification of the 15FRFG domain in HIV-1 Gag p6 essential for Vpr packaging into the virion
Authors: Zhu Henghu , Jian Heng , Zhao Ling-Jun
Published: September 2004

The auxiliary regulatory protein Vpr of HIV-1 is packaged in the virion through interaction with the Gag C-terminal p6 domain. Virion packaging of Vpr is critical for Vpr to exert functions in the HIV-1 life cycle. Previous studies suggest that Vpr interacts with a (Lxx)4 domain in p6 for virion packaging. In the present study, mutational analysis of HIV-1 Gag p6 domain was performed in the context of the HIV-1 genome to examine the effect on virion packaging of Vpr. Surprisingly, Ala substitutions for Leu44 and Phe45 in the (Lxx)4 domain or deletion of the whole (Lxx)4 domain (amino acid #35–52 of the Gag p6 domain) did not affect Vpr virion packaging. Vpr virion packaging was normal when amino acid #1–23 of the Gag p6 domain was preserved. Most importantly, Ala substitutions for Phe15, Arg16 and Phe17 in the context of amino acid #1–23 of the Gag p6 domain abolished Vpr virion packaging. Single Ala substitutions for Phe15 and Phe17 also abolished Vpr virion packaging, whereas Ala substitution for Arg16 had no effect. Our studies have revealed a novel signal sequence for Vpr packaging into the HIV-1 virion. The 15FRFG domain in p6 resembles the FxFG repeat sequences commonly found in proteins of the nuclear pore complex. These results have provided novel insights into the process of virion packaging of Vpr and suggest for the first time that Vpr may recognize the FxFG domain for both virion packaging and association with nuclear pores.
Differential expression and function of IgA receptors (CD89 and CD71) during maturation of dendritic cells
Authors: Pasquier Benoit , Lepelletier Yves , Baude Cédric , Hermine Olivier , Monteiro Renato C
Published: September 2004

Dendritic cells (DC) are the most efficient antigen-presenting cells residing in mainly peripheral tissues. Antigen uptake by DC is particularly efficient, being mediated by various receptors such as lectin, scavenger receptors, and Fc receptors (FcRs). Immunoglobulin A (IgA) is part of the first-line immune barrier in mucosae, where DC are numerous. A member of the FcR family, FcαRI, is expressed on interstitial DC. We report here that monocyte-derived DC (Mo-DC) express another IgA receptor (IgA-R), the transferrin receptor (TfR), even in the absence of DC proliferation in vitro. Upon incubation with inflammatory cytokines such as tumor necrosis factor α and interleukin (IL)-1β or maturating agents (lipopolysaccharide, CD40 ligand), FcαRI and TfR expression on Mo-DC was specifically up-regulated, whereas FcγRs and FcɛRI expression was down-regulated. Both IgA-Rs were functional, being able to mediate endocytosis by immature and activated Mo-DC. Although FcαRI internalized IgA complexes on both types of DC, TfR was only able to mediate IgA complex internalization by immature cells. Cross-linking of FcαRI but not of TfR resulted in up-regulation of major histocompatibility complex (MHC) class II/CD86 expression and secretion of IL-10 and IL-12 by immature Mo-DC. Moreover, in activated Mo-DC, cross-linking of FcαRI could up-regulated MHC class II/CD86 and triggered IL-10 secretion. Our findings led us to propose that FcαRI expressed by interstitial-type DC could play a critical role to sample IgA-recognized antigens and also during DC activation.
Proliferation of Rat Granulosa Cells during the Periovulatory Interval
Authors: Cannon Jennifer D. , Cherian-Shaw Mary , Chaffin Charles L.
Published: September 2004

Granulosa cell proliferation during luteinization and terminal differentiation has historically been assumed to decline rapidly after an ovulatory stimulus. In contrast, terminal differentiation in other cell types has recently been associated with a transient increase in proliferation, suggesting that this may occur in the ovarian follicle. The goal of the current study was to test the hypothesis that an ovulatory stimulus to rats results in additional granulosa cell proliferation before cell cycle arrest. Immature rats were given a single injection of pregnant mare serum gonadotropin (PMSG) followed by human chorionic gonadotropin (hCG) to initiate periovulatory events. The proportion of granulosa cells in S phase did not change until 12 h after hCG, although the majority of the post-hCG proliferation was localized to cumulus granulosa cells for up to 10 h after hCG. The expression of cyclin D2 mRNA did not decline until 12 h after hCG, although both cyclin-dependent kinase (Cdk)4 and Cdk6 mRNA increased at 6 h. Protein levels of cyclin D2 and Cdk4 did not change as a result of hCG, whereas cyclin E increased 6 h after hCG. Kinase activity of Cdk2 dropped markedly by 4 h after hCG, but a slight increase in activity was evident 6–8 h after hCG. These data suggest that cumulus granulosa cells continue to proliferate for up to 10 h after an ovulatory stimulus, possibly via cyclin E/Cdk2. It is concluded that proliferation is maintained in granulosa cells in the proximity of the oocyte during luteinization of the rat follicle.
Rosiglitazone Enhances Glucose Tolerance by Mechanisms Other than Reduction of Fatty Acid Accumulation within Skeletal Muscle
Authors: Lessard Sarah J. , Giudice Sonia L. Lo , Lau Winnie , Reid Julianne J. , Turner Nigel , Febbraio Mark A. , Hawley John A. , Watt Matthew J.
Published: September 2004

We hypothesized that improved glucose tolerance with rosiglitazone treatment would coincide with decreased levels of im triacylglycerol (IMTG), diacylglycerol, and ceramide. Obese Zucker rats were randomly divided into two experimental groups: control (n = 9) and rosiglitazone (n = 9), with lean Zucker rats (n = 9) acting as a control group for obese controls. Rats received either vehicle or 3 mg/kg rosiglitazone for 6 wk. Glucose tolerance was impaired (P < 0.01) in obese compared with lean rats, but was normalized after rosiglitazone treatment. IMTG content was higher in obese compared with lean rats (70.5 ± 5.1 vs. 27.5 ± 2.0 μmol/g dry mass; P < 0.05) and increased an additional 30% (P < 0.05) with rosiglitazone treatment. Intramuscular fatty acid composition shifted toward a higher proportion of monounsaturates (P < 0.05) in obese rosiglitazone-treated rats due to an increase in palmitoleate (16:1; P < 0.05). Rosiglitazone treatment increased (P < 0.05) skeletal muscle diacylglycerol and ceramide levels by 65% and 100%, respectively, compared with obese rats, but elevated muscle diacylglycerol was not associated with changes in the total or membrane contents of the diacylglycerol-sensitive protein kinase C isoforms θ, δ, α, and β. In summary, we observed a disassociation among skeletal muscle IMTG, diacylglycerol and ceramide content, and glucose tolerance with rosiglitazone treatment in obese Zucker rats. Our data suggest, therefore, that rosiglitazone enhances glucose tolerance by mechanisms other than reduction of fatty acid accumulation within skeletal muscle.
Gender and Puberty Interact on the Stress-Induced Activation of Parvocellular Neurosecretory Neurons and Corticotropin-Releasing Hormone Messenger Ribonucleic Acid Expression in the Rat
Authors: Viau Victor , Bingham Brenda , Davis Jennifer , Lee Patricia , Wong Margaret
Published: September 2004

Individual variations in hypothalamic-pituitary-adrenal (HPA) function are most evident at or beyond the time of puberty, when marked changes in sex steroid release occur. To explore the nature by which gender differences in HPA function emerge we examined in prepubertal (∼30-d-old) and postpubertal (∼60-d-old) male and female rats HPA activity under basal conditions and in response to 30 min of restraint. Within the ACTH-regulating, medial parvocellular portion of the paraventricular nucleus, restraint-induced Fos protein and arginine vasopressin heteronuclear RNA were lower in 60- than in 30-d-old males. No such age-related shift in the response of these synaptic and transcriptional markers of cellular activation occurred in female rats. Basal CRH mRNA expression levels in the paraventricular nucleus increased with age in female but not male rats. Conversely, only male rats showed an age-related increase in basal CRH mRNA in the central amygdala, suggesting that neuronal and neurosecretory CRH-expressing cell types are subject to different pubertal and gender influences. We conclude that gonadal regulation of the HPA axis develops via distinct mechanisms in males and females. Puberty-related shifts in parvocellular neurosecretory function in males are emphasized by stress-induced shifts in neuronal activation, whereas biosynthetic alterations dominate in female rats.
Role of Neuronal Energy Status in the Regulation of Adenosine 5′-Monophosphate-Activated Protein Kinase, Orexigenic Neuropeptides Expression, and Feeding Behavior
Authors: Lee Kichoon , Li Bing , Xi Xiaochun , Suh Yeunsu , Martin Roy J.
Published: September 2004

Nutrient sensing in the hypothalamus is tightly related to food intake regulation. However, the mechanisms by which the nutrient-sensing cells of the brain translate this signal of energy need into feeding behavior via regulation of neuropeptide expression are not known. To address this issue, we investigated two neuronal cell lines expressing agouti-related protein (AgRP), ex vivo hypothalamic tissues, and in vivo whole animals. Maintaining cells in a low cellular ATP concentration generated by low glucose, 2-deoxyglucose (2-DG), ATP synthesis inhibitor, and 5-aminoimidazole-4-carboxamide 1-β-d-ribofuranoside increased phosphorylation of AMP-activated protein kinase (AMPK) and increased AgRP expression, whereas maintaining cells in high ATP status by high glucose and pyruvate supplementation in 2-DG-treated cells decreased phosphorylation of AMPK and decreased AgRP expression. Overexpression of a dominant-inhibitory mutant of AMPK significantly decreased low-glucose- or 2-DG-induced AgRP expression. Furthermore, ex vivo hypothalamus culture in high glucose concentrations decreased both expression and phosphorylation of AMPK and expression of both AgRP and neuropeptide Y, whereas pyruvate supplementation suppressed a 2-DG-induced AgRP expression. Finally, our in vivo studies clearly show that central administration of pyruvate dramatically delayed 2-DG-induced food intake. These data indicate that modulation of ATP levels in neuronal cells triggers a cascade of events via AMPK that modulate feeding behavior to restore energy status of cells.
An Evaluation of California's Adolescent Sibling Pregnancy Prevention Program
Authors: East Patricia , Kiernan Elizabeth , Chávez Gilberto
Published: September 2004

CONTEXT: The siblings of adolescents who have been pregnant or are parents have disproportionately high rates of teenage pregnancies and births. California's Adolescent Sibling Pregnancy Prevention Program is targeted at these high‐risk youths.

METHODS: An evaluation of the program was conducted in 1997–1999 with 1,176 predominantly Hispanic 11–17‐year‐olds who had at least one sibling who was an adolescent parent or had been pregnant–731 youths who were program clients and 445 youths who received no systematic services. All evaluation participants completed an interview and questionnaire at enrollment and again nine months later.

RESULTS: Female program clients had a significantly lower pregnancy rate than comparison females over the evaluation period (4% vs. 7%), as well as a lower rate of sexual initiation (7% vs. 16%). They also significantly decreased their frequency of school truancy, whereas this outcome increased among comparison females; program females had significantly more definite intentions of remaining abstinent at posttest than comparison females. Consistency of contraceptive use increased over time among males in the program and decreased among comparison males. Delivery of group services was correlated with delayed onset of intercourse among males, and the receipt of services related to psychosocial skills was correlated with greater contraceptive use at last sex among all sexually experienced youth.

CONCLUSIONS: This new program, which serves a population known to be at very high risk for early pregnancy, appears to be effective at reducing rates of pregnancy and improving several pregnancy‐related risk behaviors.
Family Planning Providers' Perspectives On Dual Protection
Authors: Mantell Joanne E. , Hoffman Susie , Exner Theresa M. , Stein Zena A. , Atkins Kim
Published: September 2004

CONTEXT: Family planning providers can play an important role in helping women to identify their risk of HIV and other sexually transmitted diseases (STDs) and to adopt preventive measures. In‐depth investigation of providers' attitudes about approaches to STD risk assessment, contraceptive counseling and dual protection–concurrent protection from STDs and unintended pregnancy–has been limited.

METHODS: In semistructured interviews conducted in 1998, 22 health care providers from a large New York City agency offering contraceptive and STD services described how they balanced STD and pregnancy concerns, viewed risk assessment and assessed various contraceptive methods.

RESULTS: STD prevention was seen as an integral part of family planning counseling, and most providers believed that risk assessment should be conducted universally. Providers viewed dual protection as use of condoms along with an effective contraceptive; few advocated use of the male or female condom alone. The female condom was believed to be a disease prevention method of last resort and was considered appropriate only for specific groups of women. Although providers lacked understanding about the effectiveness of the female condom and how to counsel clients concerning its use, they expressed interest in learning more.

CONCLUSIONS: Training is needed to reduce providers' negative perceptions of the female condom and to reinforce the importance of individualized counseling tailored to women's specific circumstances. Studies are needed on how to encourage family planning providers to promote male and female condoms as effective contraceptive methods.
Shrinkage stress of wood during drying under superheated steam above 100°C
Authors: Cheng W. , Morooka T. , Liu Y. , Norimoto M.
Published: September 2004

In order to reduce the internal stress of wood during drying,
an attempt was made to dry wood with superheated
steam above 100°C. Sugi (Cryptomeria japonica D. Don)
wood specimens were dried with radial restraint using
superheated steam at up to 180°C, and the resulting
restrained shrinkage stress was examined. A load cell
capable of measuring shrinkage stress inside an autoclave
was developed and the shrinkage stress was
measured at temperatures from 80 to 180°C and a relative
humidity of 0% to 80%. It was found that the shrinkage
stress decreased dramatically with drying above
140°C and above 60% relative humidity. It was also
found that the shrinkage stress above 140°C occurred
even at 100% RH and was ascribed to the structural
change in cell-wall components.
Microstructure Response in Copper and Copper Alloys Irradiated with Fission Neutrons with Controlled Temperature Variations
Authors: Muroga T , Watanabe H
Published: September 2004

The effects of temperature variation on microstructural evolution were investigated for Cu, Cu-5Ni, Cu-3.5Zn, and Cu-5Ni-2Zn irradiated in JMTR and HFIR. The low temperature pre-irradiation at 477 K to 533 K was shown not to influence microstructural evolution significantly during the following irradiation at 613 K to 693 K. On the other hand, downward temperature shift during irradiation was shown to produce void formation in Cu and Cu-3.5Zn. The mechanism of the temperature variation effects was discussed based on the defect properties and the details of the temperature transient history during irradiation.
Creep Deformation in V-4Cr-4Ti in a Low-Oxygen Lithium Environment
Authors: Grossbeck ML
Published: September 2004

Vanadium alloys, especially V-Cr-Ti alloys, are candidates for first wall and blanket structures of fusion reactors. However, a major vulnerability of this class of alloys is the affinity for oxygen and other interstitial solutes. Oxygen, nitrogen, carbon, and hydrogen can severely harden and embrittle vanadium alloys. Oxygen is particularly troublesome because of its prevalence and its relatively high diffusivity. In determining creep behavior, the effects of oxygen must be understood. In the present study, specimens, in the form of pressurized tubes, were exposed to liquid lithium, the coolant of choice for vanadium systems, at temperatures of 665, 765, and 800°C. Under these conditions, oxygen is removed from the vanadium alloy by the lithium. The data produced were compared with data from similar specimens tested in a high vacuum environment, where the oxygen level in the alloy is expected to slowly increase, at Pacific Northwest National Laboratory in order to evaluate the effect of oxygen. The Li-exposure resulted in higher creep rates and shorter rupture times. The effect was most clear at 800°C, where deformations 4–6 times higher were observed for the Li-exposed specimens.