bluuebunny/crossref_metadata_2025 huggingface dataset:
Cerebellar and other neurological soft signs in antipsychotic‐naïve schizophrenia
Authors: Varambally S. , Venkatasubramanian G. , Thirthalli J. , Janakiramaiah N. , Gangadhar B. N.
Published: May 2006

Objective: Cerebellar neurological abnormalities in schizophrenia have been associated with severe negative symptoms, cognitive deficits, and smaller cerebellar volume. This study assessed the comparative discriminant validity between Cerebellar Soft Signs (CSS) vs. other neurological soft signs (ONSS) [in discriminating between schizophrenia patients and healthy controls] as well as the relationship between the soft signs and psychopathology.

Method: Antipsychotic‐naïve schizophrenia patients (n = 32) and healthy subjects (n = 32) were examined using International Co‐Operative Ataxia Rating Scale and Neurological Evaluation Scale.

Results: Mean CSS scores, ONSS total score, and Sensory Integration Signs sub‐score were significantly higher in patients. Discriminant analysis revealed two CSS sub‐scores (but none of the ONSS scores) to be significant (P < 0.0001) accounting for 78% of classification. CSS total score, Posture sub‐score, and Oculomotor sub‐score had significant positive correlation with negative syndrome score.

Conclusion: Findings support intrinsic cerebellar dysfunction in schizophrenia. The observations are discussed in relationship with cognitive dysmetria.
Rapidly growing nodular pseudoangiomatous stromal hyperplasia of the breast in an 18‐year‐old girl
Authors: ŽÚBOR P. , KAJO K. , DUSSAN C. A. , SZUNYOGH N. , DANKO J.
Published: May 2006

Pseudoangiomatous stromal hyperplasia (PASH) of the breast is a rare benign proliferation of mesenchymal stromal cells with irregular slit‐like formations resembling angiomatous structures. In the majority of cases this lesion is a focal microscopic finding in breast biopsies performed for benign or malignant diseases. It may present in a pure diffuse or nodular form. The exact etiology and pathogenesis of this tumor‐like lesion is still unknown, but a proliferative response of myofibroblasts to hormonal stimuli has been postulated. A large 12×9×3.5 cm rapidly growing nodular form of PASH of the breast in an 18‐year‐old woman is here described with clinical and histological findings. A possible hormonal etiology was indicated by elevated progesterone (three‐fold) and decreased estrogen serum levels. Different diagnostic lesions, such as giant fibroadenoma and low‐grade angiosarcoma, are discussed. To the authors' knowledge this is only the fourth case of nodular PASH of the breast reported in the English literature.
Lethal outcome in xanthogranulomatous endometritis
Authors: NOACK FRANK , BRIESE JULIANE , STELLMACHER FLORIAN , HORNUNG DANIELA , HORNY HANS‐PETER
Published: May 2006

Xanthogranulomatous inflammation is rare, mainly involving the kidneys, while primary xanthogranulomatous endometritis (XE) is a very unusual finding, histologically characterized by partial or complete replacement of the mucosa by granulation tissue with an abundance of foamy histiocytes, siderophages and multinucleated giant cells. We present the case of a 69‐year‐old woman with a short history of abdominal pain and a palpable mass in the pouch of Douglas. Dilatation of the cervix drained a pyometra. Histological examination of the curettage rendered the diagnosis of XE. Microbiological studies revealed enterococcus spp. and Peptostreptococcus magnus. Despite antibiotic treatment the patient died of heart failure due to systemic inflammation. Autopsy confirmed the diagnosis of XE with transmural extension into the peritoneal cavity. Such a lethal course of XE is extraordinary. Proposed causes of XE include obstruction, infection and hemorrhage. Demonstration of enterococcus spp. and P. magnus supports the probable significance of bacteria in the development of XE. Because this condition may mimic malignant disease macroscopically and histologically, knowledge of XE is of major importance for both pathologists and gynecologists.
Oxidative/nitrosative stress and peroxiredoxin 2 are associated with grade and prognosis of human renal carcinoma
Authors: SOINI Y. , KALLIO J. P. , HIRVIKOSKI P. , HELIN H. , KELLOKUMPU‐LEHTINEN P. , KANG S. W. , TAMMELA T. L. J. , PELTONIEMI M. , MARTIKAINEN P. M. , KINNULA V. L.
Published: May 2006

Peroxiredoxins (Prxs) 1–6 were assessed in 138 renal cell carcinomas (RCC) using immunohistochemistry and selected samples by Western blotting analysis. Oxidative/nitrosative damage was evaluated using nitrotyrosine immunoreactivity. The expressions of Prxs were correlated with tumor grade and survival and nitrotyrosine reactivity. Non‐malignant kidney tubular cells showed positivity with variable intensity for all six Prxs. In RCCs, most cases were positive for Prxs 1 and 2, while only 15–20% of tumors showed expression for Prxs 3 and 4. Prx 2 was associated with tumors of a lower grade (p=0.009) and with a lower frequency of distant metastases (p=0.046). Patients with tumors expressing Prx2 had better prognosis (p=0.027). Instead, nitrotyrosine was significantly associated with high grade tumors (p=0.001). Compared with the non‐malignant kidney tubular cells, low Prx expression in the tumor cells can make them more susceptible to oxidative damage. Prx 2 was more abundantly expressed in low grade tumors, suggesting that this protein could play a role in preventing the development of oxidative damage, which in turn can lead to the activation of pathways leading to aggressive tumors.
Expression of androgen receptors and inhibin/activin α and βA subunits in breast apocrine lesions
Authors: SHIM HYO SUB , JUNG WOO HEE , KIM HAERYOUNG , PARK KYEONGMEE , CHO NAM HOON
Published: May 2006

The importance of androgens and their receptors inhibin and activin remains unknown for mammary epithelial cells. We investigated the role of these hormones in breast apocrine lesions (BAL) using immunohistochemistry to study androgen receptors (AR) and the inhibin/activin α and βA subunits. Forty‐two cases of BAL were evaluated, including 22 cases of fibrocystic disease (FCD) showing prominent apocrine changes, 10 intraductal papillomas with extensive apocrine metaplasia, 5 cases of apocrine carcinoma in situ (CIS), and 5 cases of apocrine carcinoma. Fifty non‐apocrine lesions were included as controls: 20 cases of FCD, 5 cases of DCIS, and 25 cases of invasive ductal carcinoma. AR was more frequently expressed in BAL than in non‐apocrine lesions (p=0.001). AR expression was not related to tumor progression. AR showed a significant positive correlation with βA subunits (r=0.832, p<0.001), and an inverse correlation with α subunits (r=−0.233). The α and βA subunits demonstrated a significant inverse correlation with each other (r=−0.271, p=0.0048). As the expression of the α and βA subunits reflects inhibin and activin A, respectively, AR and activin A may be implicated in apocrine morphogenesis, but not in tumor progression.
Co‐infection ratios versus inflammation, growth factors and progression of early atheromas
Authors: HIGUCHI MARIA L. , GÓIS JOSÉ M. , REIS MARCIA M. , HIGUCHI‐DOS‐SANTOS MARILIA H. , DIAMENT JAYME , SOUSA JANUÁRIO M. , RAMIRES JOSÉ A. F. , OLIVEIRA SÉRGIO A.
Published: May 2006

Mycoplasma pneumoniae (MP) and Chlamydophila pneumoniae (CP) antigens are encountered in complicated atheromas and may be implicated in the diversity of atherosclerotic lesions. Mycoplasma can downregulate the immune system, altering levels of inflammation, which may favor the proliferation of other co‐infectious agents. In the present study we analyze whether initially stable human atheromas exhibit different ratios of MP/CP antigens compared to ongoing atheromatous lesions. Two groups were examined for the presence of inflammatory cells, macrophages, growth factors and infectious agents: Group I (GI), n=16, early stable atheromas, <4 CD68+ macrophages/400×field, showing a normal distribution and a fibrous cap; Group II (GII), n=14, growing atheromas, ≥4 CD68+ cells/400×field, lacking a fibrous cap, showing a non‐normal macrophage distribution. The amounts of CP (but not MP) antigens and lymphocytes in GI were significantly lower than in GII. MP/CP ratios were higher in GI. MP correlated with CP and PDGFB in GI (r=0.79 and r=0.83, p<0.001), but not in GII (r=−0.4 and r=−0.08, p=0.81). MP and CP antigens are already present in early atheromas, and a higher MP/CP ratio correlates with increased growth factors, lower inflammation and plaque stability.
Transcription levels of invasion‐related genes in prostate cancer cells are modified by inhibitors of tyrosine kinase
Authors: SKOGSETH HAAKON , FOLLESTAD TURID , LARSSON ERIK , HALGUNSET JOSTEIN
Published: May 2006

Previous reports have shown that genistein and tyrphostin AG‐1478, two tyrosine kinase inhibitors (TKIs), exert multiple cellular effects in prostate carcinoma cells, e.g. a reduction in the production of urokinase plasminogen activator (uPA) and its receptor uPAR, and a decrease in the cells' ability to invade an artificial basement membrane. Microarray technology was used to measure alterations in mRNA levels caused by TKI treatment in two prostatic carcinoma cell lines, PC‐3 and DU‐145. Genistein treatment led to a reduction of at least 50% in 78 genes in PC‐3, while 82 were twofold upregulated. In DU‐145, the same treatment resulted in a 50% decreased transcript level in 120 genes, and increased expression in 25 genes. Tyrphostin AG‐1478 produced a 50% reduction in mRNA levels in 58 genes in DU‐145, whereas no alterations were demonstrated using the tyrphostin in PC‐3 cells. Among the effects of TKIs, a lowered uPA and uPAR transcription was demonstrated in genistein‐treated cells, while a few metalloproteinases (MMPs) were affected. Transcription of various integrin subunits was also downregulated overall. Several alterations in gene transcription were demonstrated in PC‐3 and DU‐145 after TKI treatment. This knowledge could be of importance in the search for new therapeutic strategies in prostate cancer treatment, and the interplay between the various effects needs to be investigated further.
Florid cystic endosalpingiosis of the spleen
Authors: TANAHASHI JIN , KASHIMA KENJI , DAA TSUTOMU , KONDO YOSHIYUKI , KITANO SEIGO , YOKOYAMA SHIGEO
Published: May 2006

A case of endosalpingiosis appearing as a huge multilocular cyst in the spleen of a 31‐year‐old woman is reported. The cystic lumens were smooth, and lined by fallopian tubal epithelium containing ciliated and secretory cells. The epithelial lining showed neither atypia nor foci of papillary proliferation, with only 3–5% MIB‐1 labeling index. The epithelial lining was histochemically negative for mucin, but positive for MUC1 and progesterone receptor. Despite the appearance of a tumor‐like mass, it was diagnosed as florid cystic endosalpingiosis as there was a normal tube‐like epithelium. Regarding etiology, it was considered to derive from the secondary müllerian system of the splenic capsule.
Mycobacterium abscessus: an emerging rapid‐growing potential pathogen
Authors: PETRINI BJÖRN
Published: May 2006

Mycobacterium abscessus is the most pathogenic and chemotherapy‐resistant rapid‐growing mycobacterium. It is commonly associated with contaminated traumatic skin wounds and with post‐surgical soft tissue infections. It is also one of the mycobacteria that are most often isolated from cystic fibrosis patients. It is essential to differentiate this species from the formerly indistinct “M. chelonae‐complex”, as chemotherapy is especially difficult in M. abscessussenso strictu. Clarithromycin or azithromycin are the only regular oral antimycobacterial agents with an effect on M. abscessus, and should preferably be supplemented with other drugs since long‐term monotherapy may cause resistance. Amikacin is a major parenteral drug against M. abscessus that should also be given in combination with another drug. The recently introduced drug tigecycline may prove to be an important addition to chemotherapy, but has yet to be fully clinically evaluated as an antimycobacterial agent. Surgery can be curative, or at least helpful, in the healing of M. abscessus infection, and if conducted, it should include the removal of all foreign or necrotic material. There is increasing awareness of M. abscessus as an emerging pathogen.
Preoperative CA125 as a prognostic factor in stage I epithelial ovarian cancer
Authors: PETRI ANETTE LYKKE , HØGDALL ESTRID , CHRISTENSEN IB JARLE , KJAER SUSANNE KRÜGER , BLAAKÆR JAN , HØGDALL CLAUS KIM
Published: May 2006

The purpose of the present study was to evaluate preoperative CA125 as a prognostic factor in stage I epithelial ovarian cancer (EOC). Preoperative serum CA125 levels from 118 women with FIGO (International Federation of Gynaecology and Obstetrics) stage I EOC were analysed and the prognostic value was evaluated and compared with other prognostic factors (age, grade, substages, histologic type). By the Kaplan‐Meier estimate we demonstrated that patients with stage I EOC and preoperative serum CA125 levels <65 U/mL had a significantly longer survival compared to stage I EOC patients with preoperative serum CA125≥65 U/mL (p=0.01). The results from the present study may be useful for decision making respecting postoperative chemotherapy in stage I EOC patients. Serum CA125 levels might therefore be included as a prognostic factor in future clinical trials of stage I EOC.
Melanin content and MC1R function independently affect UVR‐induced DNA damage in cultured human melanocytes
Authors: Hauser Jennifer E. , Kadekaro Ana Luisa , Kavanagh Renny J. , Wakamatsu Kazumasa , Terzieva Silva , Schwemberger Sandy , Babcock George , Rao M. B. , Ito Shosuke , Abdel‐Malek Zalfa A.
Published: May 2006

Malignant transformation of melanocytes leads to melanoma, the most fatal form of skin cancer. Ultraviolet radiation (UVR)‐induced DNA photoproducts play an important role in melanomagenesis. Cutaneous melanin content represents a major photoprotective mechanism against UVR‐induced DNA damage, and generally correlates inversely with the risk of skin cancer, including melanoma. Melanoma risk is also determined by susceptibility genes, one of which is the melanocortin 1 receptor (MC1R) gene. Certain MC1R alleles are strongly associated with melanoma. We hereby present experimental evidence for the role of two melanoma risk factors, constitutive pigmentation, as assessed by total melanin, eumelanin and pheomelanin contents, and MC1R genotype and function, in determining the induction and repair of DNA photoproducts in cultured human melanocytes after irradiation with increasing doses of UVR. We found that total melanin and eumelanin contents (MC and EC) correlated inversely with the extent of UVR‐induced growth arrest, apoptosis and induction of cyclobutane pyrimidine dimers (CPD), but not with hydrogen peroxide release in melanocytes expressing functional MC1R. In comparison, melanocytes with loss‐of‐function MC1R, regardless of their MC or EC, sustained more UVR‐induced apoptosis and CPD, and exhibited reduced CPD repair. Therefore, MC, mainly EC, and MC1R function are independent determinants of UVR‐induced DNA damage in melanocytes.
Pigment pattern formation in the quail mutant of the silkworm, Bombyx mori: parallel increase of pteridine biosynthesis and pigmentation of melanin and ommochromes
Authors: Kato Tomomi , Sawada Hiroshi , Yamamoto Takayuki , Mase Keisuke , Nakagoshi Motoko
Published: May 2006

The larval pigment pattern in the silkworm, Bombyx mori, is formed by melanin, ommochromes and pteridines. During development all these pigments are synthesized autonomously, and possibly also with mutual interaction between them, to yield unique pigment patterns. In order to find the key trigger for such pigment pattern formation, developmental changes in pteridine biosynthesis were studied using the quail mutant (q/q), which has darker larval marks formed by melanin and an abundance of ommochromes in the integument. In the current study, emphasis has been placed on the analysis of GTP‐cyclohydrolase I (GTP‐CH I), which is a key enzyme for the biosynthesis of pteridines, during the development of the silkworm. Results of Northern blotting showed that in the quail mutant strong signals of GTP‐CH I mRNA appeared around each period of ecdysis, while no such signals appeared in the background strain (+q/q) used. Also, both GTP‐CH I activities and pteridine content were higher in the quail mutant compared with the background strain. These results strongly suggest that pteridine biosynthesis is closely linked to the formation of melanin and ommochromes. It is also suggested here that in the silkworm a recessive gene (q) may be involved in the regulation of its pigment pattern formation.
Induction of melanocytes from embryonic stem cells and their therapeutic potential
Authors: Motohashi Tsutomu , Aoki Hitomi , Yoshimura Naoko , Kunisada Takahiro
Published: May 2006

Embryonic stem (ES) cells from many organisms have the capacity to generate in vitro a wide variety of cell types depending on their environment. Understanding precisely how such toti‐ or pluripotent cells may be driven towards a specific lineage represents a major challenge if our ambition of using ES cells to generate a ready supply of healthy cells for cell‐based therapies for a range of diseases is to be realized. Recent advances have demonstrated that melanocytes and retinal pigmented epithelial (RPE) cells exhibiting the characteristics of their natural counterparts can be induced from undifferentiated ES cells grown on monolayers of specific stromal cell lines or by using a combination of Wnt3a, Endothelin‐3 and SCF. The ability to induce pigment cells from ES cells promises to facilitate our understanding of the precise molecular mechanisms underlying this process and moreover enable us to distinguish the program of gene expression that underpins the choice made between generating a nerual crest‐type melanocyte versus an RPE cell. Moreover, once the combination of signals required to induce a particular type of pigment cell are characterized, the way may be open for future cell‐based therapy for various diseases caused by defective pigment cells.
The other pigment cell: specification and development of the pigmented epithelium of the vertebrate eye
Authors: Bharti Kapil , Nguyen Minh‐Thanh T. , Skuntz Susan , Bertuzzi Stefano , Arnheiter Heinz
Published: May 2006

Vertebrate retinal pigment epithelium (RPE) cells are derived from the multipotent optic neuroepithelium, develop in close proximity to the retina, and are indispensible for eye organogenesis and vision. Recent advances in our understanding of RPE development provide evidence for how critical signaling factors operating in dorso‐ventral and distal‐proximal gradients interact with key transcription factors to specify three distinct domains in the budding optic neuroepithelium: the distal future retina, the proximal future optic stalk/optic nerve, and the dorsal future RPE. Concomitantly with domain specification, the eye primordium progresses from a vesicle to a cup, RPE pigmentation extends towards the ventral side, and the future ciliary body and iris form from the margin zone between RPE and retina. While much has been learned about the molecular networks controlling RPE cell specification, key questions concerning the cell proliferative parameters in RPE and the subsequent morphogenetic events still need to be addressed in greater detail.
Evaluation of palatal saliva flow rate and oral manifestations in patients with Sjögren's syndrome
Authors: Márton K , Boros I , Varga G , Zelles T , Fejérdy P , Zeher M , Nagy G
Published: May 2006

Objective:  The purpose of this study was to describe the oral properties of Sjögren's syndrome (SS), including the determination of palatal saliva (PS) flow rate.

Subjects and methods:  Forty‐nine SS patients and 43 healthy controls participated. Subjective symptoms were recorded and clinical assessments of the oral mucosal, dental and periodontal status were made. Unstimulated whole saliva (WS) and PS flow rates, the number of decayed, missing and filled teeth (DMF‐T number), the gingival bleeding index (GBI) and the periodontal probing depth (PPD) were determined.

Results:  Despite the decrease in the flow rate of WS in SS patients, PS was not different from those of the controls (1.57 ± 1.02 and 1.35 ± 2.5 μl cm−2 min−1, respectively). GBI (20.0% vs. 10.5%, respectively), DMF‐T (27.1 ± 6.12 vs. 23.0 ± 6.99, respectively) and PPD (2.28 ± 1.09 mm vs. 1.82 ± 0.73 mm, respectively) were higher in SS compared with the controls (P < 0.05). DMF‐T and PPD showed a positive correlation with anti‐SSA and/or anti‐SSB antibody positivity in the serum (P < 0.05).

Conclusions:  Data of the present study suggest that the subjective feeling of xerostomia in SS patients is the result of a decrease in the volume of the whole saliva, and not of the viscous PS. Correlation of DMF‐T and PPD with autoantibody positivity reveals that the oral health status of SS patients may be associated with the general autoimmune process.
The molecular basis of heme oxygenase deficiency in the pcd1 mutant of pea
Authors: Linley Philip J. , Landsberger Martin , Kohchi Takayuki , Cooper Jon B. , Terry Matthew J.
Published: May 2006

The pcd1 mutant of pea lacks heme oxygenase (HO) activity required for the synthesis of the phytochrome chromophore and is consequently severely deficient in all responses mediated by the phytochrome family of plant photoreceptors. Here we describe the isolation of the gene encoding pea heme oxygenase 1 (PsHO1) and confirm the presence of a mutation in this gene in the pcd1 mutant. PsHO1 shows a high degree of sequence homology to other higher plant HOs, in particular with those from other legume species. Expression of PsHO1 increased in response to white light, but did not respond strongly to narrow band light treatments. Analysis of the biochemical activity of PsHO1 expressed in Escherichia coli demonstrated requirements for reduced ferredoxin, a secondary reductant such as ascorbate and an iron chelator for maximum enzyme activity. Using the crystal structure data from homologous animal and bacterial HOs we have modelled the structure of PsHO1 and demonstrated a high degree of structural conservation despite limited primary sequence homology. However, the catalytic site of PsHO1 is larger than that of animal HOs indicating that it may accommodate an ascorbate molecule in close proximity to the heme. This could provide an explanation for why plant HOs show a strong and saturable dependence on this reductant.
Conformation and mode of membrane interaction in cyclotides
Authors: Shenkarev Zakhar O. , Nadezhdin Kirill D. , Sobol Vladimir A. , Sobol Alexander G. , Skjeldal Lars , Arseniev Alexander S.
Published: May 2006

Cyclotides are a family of bioactive plant peptides that are characterized by a circular protein backbone and three conserved tightly packed disulfide bonds. The antimicrobial and hemolytic properties of cyclotides, along with the relative hydrophobicity of the peptides, point to the biological membrane as a target for cyclotides. To assess the membrane‐induced conformation and orientation of cyclotides, the interaction of the Möbius cyclotide, kalata B1, from the African perennial plant Oldenlandia affinis, with dodecylphosphocholine micelles was studied using NMR spectroscopy. Under conditions where the cyclotide formed a well‐defined complex with micelles, the spatial structure of kalata B1 was calculated from NOE and J couplings data, and the model for the peptide–micelle complex was built using 5‐ and 16‐doxylstearate relaxation probes. The binding of divalent cations to the peptide–micelle complex was quantified by Mn2+ titration. The results show that the peptide binds to the micelle surface, with relatively high affinity, via two hydrophobic loops (loop 5, Trp19–Val21; and loop6, Leu27–Val29). The charged residues (Glu3 and Arg24), along with the cation‐binding site (near Glu3) are segregated on the other side of the molecule and in contact with polar head groups of detergent. The spatial structure of kalata B1 is only slightly changed during incorporation into micelles and represents a distorted triple‐stranded β‐sheet cross‐linked by a cystine knot. Detailed structural analysis and comparison with other knottins revealed structural conservation of the two‐disulfide motif in cyclic and acyclic peptides. The results thus obtained provide the first model for interaction of cyclotides with membranes and permit consideration of the cyclotides as membrane‐active cationic antimicrobial peptides.
Characterization of the flavin association in hexose oxidase from Chondrus crispus
Authors: Rand Thomas , Qvist Karsten B. , Walter Clive P. , Poulsen Charlotte H.
Published: May 2006

Hexose oxidase (EC 1.1.3.5) from Hansenula polymorpha was found to exhibit a dual covalent association of FAD with His79 via an 8α‐histidyl linkage as well as a covalent association between Cys138 and C‐6 of the isoalloxazine moiety of FAD. Spectral properties of the wild‐type enzyme exhibited maxima at 364 nm and 437 nm as well as a distinct shoulder at 445 nm. An H79K mutant enzyme exhibited only one maximum at 437 nm. The difference absorption spectrum between an oxidized and a substrate‐reduced enzyme preparation showed maxima at 360 nm and 445 nm corresponding to an apparent novel type of association. Hexose oxidase showed a low, pH‐independent fluorescence at 525 nm when excited at 450 nm. Flavin was released from the holoenzyme by treatment with trypsin. Sequencing of the flavopeptide revealed two peptides comprising positions 74–91 and 132–157 associated with FAD in equimolar amounts. A homology model of hexose oxidase was constructed using the crystal structure of glucooligosaccharide oxidase from Acremonium strictum as template. The model placed both of the sequences found above in the close vicinity of the FAD cofactor, and suggests covalent bonds between both His79 and Cys138 and FAD, in accordance with the chemical evidence. Based on the results, hexose oxidase is identified as incorporating FAD with a double covalent association with His79 and Cys138 in the holoenzyme. A reaction mechanism involving the concerted action of Tyr488 and Asp409 in hexose oxidase is suggested as the initiator of the proton abstraction from the substrate molecule in the active site.
An inserted loop region of stromal ascorbate peroxidase is involved in its hydrogen peroxide‐mediated inactivation
Authors: Kitajima Sakihito , Tomizawa Ken‐ichi , Shigeoka Shigeru , Yokota Akiho
Published: May 2006

Ascorbate peroxidase isoforms localized in the stroma and thylakoid of higher plant chloroplasts are rapidly inactivated by hydrogen peroxide if the second substrate, ascorbate, is depleted. However, cytosolic and microbody‐localized isoforms from higher plants as well as ascorbate peroxidase B, an ascorbate peroxidase of a red alga Galdieria partita, are relatively tolerant. We constructed various chimeric ascorbate peroxidases in which regions of ascorbate peroxidase B, from sites internal to the C‐terminal end, were exchanged with corresponding regions of the stromal ascorbate peroxidase of spinach. Analysis of these showed that a region between residues 245 and 287 was involved in the inactivation by hydrogen peroxide. A 16‐residue amino acid sequence (249–264) found in this region of the stromal ascorbate peroxidase was not found in other ascorbate peroxidase isoforms. A chimeric ascorbate peroxidase B with this sequence inserted was inactivated by hydrogen peroxide within a few minutes. The sequence forms a loop that binds noncovalently to heme in cytosolic ascorbate peroxidase of pea but does not bind to it in stromal ascorbate peroxidase of tobacco, and binds to cations in both ascorbate peroxidases. The higher susceptibility of the stromal ascorbate peroxidase may be due to a distorted interaction of the loop with the cation and/or the heme.
Production and characterization of a thermostable L‐threonine dehydrogenase from the hyperthermophilic archaeon Pyrococcus furiosus
Authors: Machielsen Ronnie , van der Oost John
Published: May 2006

The gene encoding a threonine dehydrogenase (TDH) has been identified in the hyperthermophilic archaeon Pyrococcus furiosus. The Pf‐TDH protein has been functionally produced in Escherichia coli and purified to homogeneity. The enzyme has a tetrameric conformation with a molecular mass of ≈ 155 kDa. The catalytic activity of the enzyme increases up to 100 °C, and a half‐life of 11 min at this temperature indicates its thermostability. The enzyme is specific for NAD(H), and maximal specific activities were detected with l‐threonine (10.3 U·mg−1) and acetoin (3.9 U·mg−1) in the oxidative and reductive reactions, respectively. Pf‐TDH also utilizes l‐serine and d‐threonine as substrate, but could not oxidize other l‐amino acids. The enzyme requires bivalent cations such as Zn2+ and Co2+ for activity and contains at least one zinc atom per subunit. Km values for l‐threonine and NAD+ at 70 °C were 1.5 mm and 0.055 mm, respectively.
Silencing the constitutive active transcription factor CREB by the LKB1‐SIK signaling cascade
Authors: Katoh Yoshiko , Takemori Hiroshi , Lin Xing‐zi , Tamura Mitsuhiro , Muraoka Masaaki , Satoh Tomohiro , Tsuchiya Yuko , Min Li , Doi Junko , Miyauchi Akira , Witters Lee A. , Nakamura Haruki , Okamoto Mitsuhiro
Published: May 2006

Cyclic AMP responsive element (CRE)‐binding protein (CREB) is known to activate transcription when its Ser133 is phosphorylated. Two independent investigations have suggested the presence of Ser133‐independent activation. One study identified a kinase, salt‐inducible kinase (SIK), which repressed CREB; the other isolated a novel CREB‐specific coactivator, transducer of regulated CREB activity (TORC), which upregulated CREB activity. These two opposing signals are connected by the fact that SIK phosphorylates TORC and induces its nuclear export. Because LKB1 has been reported to be an upstream kinase of SIK, we used LKB1‐defective HeLa cells to further elucidate TORC‐dependent CREB activation. In the absence of LKB1, SIK was unable to phosphorylate TORC, which led to constitutive activation of CRE activity. Overexpression of LKB1 in HeLa cells improved the CRE‐dependent transcription in a regulated manner. The inactivation of kinase cascades by 10 nm staurosporine in LKB1‐positive HEK293 cells also induced unregulated, constitutively activated, CRE activity. Treatment with staurosporine completely inhibited SIK kinase activity without any significant effect on the phosphorylation level at the LKB1‐phosphorylatable site in SIK or the activity of AMPK, another target of LKB1. Constitutive activation of CREB in LKB1‐defective cells or in staurosporine‐treated cells was not accompanied by CREB phosphorylation at Ser133. The results suggest that LKB1 and its downstream SIK play an important role in silencing CREB activity via the phosphorylation of TORC, and such silencing may be indispensable for the regulated activation of CREB.
Closely related colon cancer cell lines display different sensitivity to polyunsaturated fatty acids, accumulate different lipid classes and downregulate sterol regulatory element‐binding protein 1
Authors: Schønberg Svanhild A. , Lundemo Anne G. , Fladvad Torill , Holmgren Kristin , Bremseth Hilde , Nilsen Asbjørn , Gederaas Odrun , Tvedt Kåre E. , Egeberg Kjartan W. , Krokan Hans E.
Published: May 2006

N‐6 polyunsaturated fatty acids (PUFAs) may be associated with increased risk of colon cancer, whereas n‐3 PUFAs may have a protective effect. We examined the effects of docosahexaenoic acid (DHA), eicosapentaenoic acid and arachidonic acid on the colon carcinoma cell lines SW480 derived from a primary tumour, and SW620 derived from a metastasis of the same tumour. DHA had the strongest growth‐inhibitory effect on both cell lines. SW620 was relatively more growth‐inhibited than SW480, but SW620 also had the highest growth rate in the absence of PUFAs. Flow cytometry revealed an increase in the fraction of cells in the G2/M phase of the cell cycle, particularly for SW620 cells. Growth inhibition was apparently not caused by increased lipid peroxidation, reduced glutathione or low activity of glutathione peroxidase. Transmission electron microscopy revealed formation of cytoplasmic lipid droplets after DHA treatment. In SW620 cells an eightfold increase in total cholesteryl esters and a 190‐fold increase in DHA‐containing cholesteryl esters were observed after DHA treatment. In contrast, SW480 cells accumulated DHA‐enriched triglycerides. Arachidonic acid accumulated in a similar manner, whereas the nontoxic oleic acid was mainly incorporated in triglycerides in both cell lines. Interestingly, nuclear sterol regulatory element‐binding protein 1 (nSREBP1), recently associated with cell growth regulation, was downregulated after DHA treatment in both cell lines. Our results demonstrate cell‐specific mechanisms for the processing and storage of cytotoxic PUFAs in closely related cell lines, and suggest downregulation of nSREBP1 as a possible contributor to the growth inhibitory effect of DHA.
Involvement of caspase 1 and its activator Ipaf upstream of mitochondrial events in apoptosis
Authors: Thalappilly Subhash , Sadasivam Subhashini , Radha Vegesna , Swarup Ghanshyam
Published: May 2006

PTP‐S2/TC45 is a nuclear protein tyrosine phosphatase that activates p53 and induces caspase 1‐dependent apoptosis. We analyzed the role of ICE protease‐activating factor (Ipaf), an activator of caspase 1 in p53‐dependent apoptosis. We also determined the sequence of events that lead to apoptosis upon caspase 1 activation by Ipaf. PTP‐S2 expression induced Ipaf mRNA in MCF‐7 cells which was dependent on p53. PTP‐S2‐induced apoptosis was inhibited by a dominant‐negative mutant of Ipaf and also by an Ipaf‐directed short‐hairpin RNA. Doxorubicin‐induced apoptosis was potentiated by the expression of caspase 1 (but not by a catalytic mutant of caspase 1) and required endogenous Ipaf. Doxorubicin treatment of MCF‐7 cells resulted in activation of exogenous caspase 1, which was partly dependent on endogenous Ipaf. An activated form of Ipaf induced caspase 1‐dependent apoptosis that was inhibited by Bcl2 and also by a dominant inhibitor of caspase 9 (caspase 9s). Caspase 1‐dependent apoptosis induced by doxorubicin was also inhibited by Bcl2 and caspase 9s, but caspase 1 activation by activated Ipaf was not inhibited by Bcl2. Mitochondrial membrane permeabilization was induced by caspase 1 and activated Ipaf, which was inhibited by Bcl2, but not by caspase 9s. Expression of caspase 1 with activated Ipaf resulted in the activation of Bax at mitochondria. Our results suggest that Ipaf is involved in PTP‐S2‐induced apoptosis and that caspase 1, when activated by Ipaf, causes release of mitochondrial proteins (cytochrome c and Omi) through Bax activation, thereby functioning as an initiator caspase.
RNA reprogramming of α‐mannosidase mRNA sequences in vitro by myxomycete group IC1 and IE ribozymes
Authors: Fiskaa Tonje , Lundblad Eirik W. , Henriksen Jørn R. , Johansen Steinar D. , Einvik Christer
Published: May 2006

Trans‐splicing group I ribozymes have been introduced in order to mediate RNA reprogramming (including RNA repair) of therapeutically relevant RNA transcripts. Efficient RNA reprogramming depends on the appropriate efficiency of the reaction, and several attempts, including optimization of target recognition and ribozyme catalysis, have been performed. In most studies, the Tetrahymena group IC1 ribozyme has been applied. Here we investigate the potential of group IC1 and group IE intron ribozymes, derived from the myxomycetes Didymium and Fuligo, in addition to the Tetrahymena ribozyme, for RNA reprogramming of a mutated α‐mannosidase mRNA sequence. Randomized internal guide sequences were introduced for all four ribozymes and used to select accessible sites within isolated mutant α‐mannosidase mRNA from mammalian COS‐7 cells. Two accessible sites common to all the group I ribozymes were identified and further investigated in RNA reprogramming by trans‐splicing analyses. All the myxomycete ribozymes performed the trans‐splicing reaction with high fidelity, resulting in the conversion of mutated α‐mannosidase RNA into wild‐type sequence. RNA protection analysis revealed that the myxomycete ribozymes perform trans‐splicing at approximately similar efficiencies as the Tetrahymena ribozyme. Interestingly, the relative efficiency among the ribozymes tested correlates with structural features of the P4–P6‐folding domain, consistent with the fact that efficient folding is essential for group I intron trans‐splicing.
Testosterone: Estradiol Ratio Changes Associated with Long-Term Tadalafil Administration: A Pilot Study
Authors: Greco Emanuela A. , Pili Marcello , Bruzziches Roberto , Corona Giovanni , Spera Giovanni , Aversa Antonio
Published: May 2006

Introduction

It has been reported that lack of sexual activity due to erectile dysfunction (ED) may be associated with testosterone (T) decline.

Aim

To investigate whether the known changes in sex hormones associated with resumption of sexual activity are sustained in the long term.

Main Outcome Measures

Primary endpoints were variations from baseline of steroid hormones: total T, free T (f T), and estradiol (E). Secondary endpoints were variations of erectile function domain scores at International Index of Erectile Function-5 (IIEF-5).

Methods

In an open-label fashion, 20 patients (mean age 54.8 ± 8.4 years) received tadalafil 10–20 mg on demand for 12 months. Exclusion criteria were those reported for phosphodiesterase inhibitors, including hypogonadism and hyperprolactinemia.

Results

Tadalafil assumption was safe and well tolerated (overall adverse effects in 15% of patients) and none discontinued medication. A significant decrease in E levels occurred at the end of the study (from 19.9 ± 9.6 to 16.6 ± 8.1 ng/dL, P = 0.042 vs. baseline), with parallel increase in the T:E ratio (26.3 ± 15.3 to 32.6 ± 17.7, P = 0.05), whereas no changes in T and f T serum levels were observed, respectively (411.4 ± 131.4 to 434.2 ± 177.1 ng/dL and 47.7 ± 15.3 to 49.9 ± 19.1 pmol/L, not significant). Interestingly, nonparametric subgroup analysis for related samples revealed that E decrease was detectable only in lean (N = 14) but not in obese (N = 6, body mass index > 27.5 kg/m2) subjects (17.8 ± 10.1 vs. 13.5 ± 6.8, P < 0.05). A net increase in IIEF-5 scores was observed at the endpoint (13.7 ± 5.9 vs. 25.7 ± 2.9, P < 0.0001).

Conclusions

Sustained improvement in sexual function after 12 months of tadalafil administration is associated with increased T:E ratio mainly related to reduction of E levels. We hypothesize that androgen–estrogen cross-talk and possible inhibition of aromatase activity during chronic exposure to tadalafil might have a role in the regulation of erectile function.
An Effect on the Subjective Sexual Response in Premenopausal Women with Sexual Arousal Disorder by Bremelanotide (PT-141), a Melanocortin Receptor Agonist
Authors: Diamond Lisa E. , Earle Dennis C. , Heiman Julia R. , Rosen Raymond C. , Perelman Michael. A. , Harning Ronald
Published: May 2006

Introduction

Melanocortins affect multiple physiological responses, including sexual behaviors. Bremelanotide is a synthetic peptide melanocortin analog of α-melanocyte-stimulating hormone that is an agonist at melanocortin receptors MC3R and MC4R.

Aim

To evaluate a single intranasal dose of bremelanotide for potential effects on physiological and subjective measurements of sexual arousal and desire in premenopausal women with sexual arousal disorder.

Main Outcome Measures

Change in vaginal pulse amplitude during neutral and erotic videos after treatment with bremelanotide or placebo and subjects’ perceptions of physiological and sexual response within 24 hours of treatment with bremelanotide or placebo.

Methods

Eighteen premenopausal women with a primary diagnosis of female sexual arousal disorder were randomly assigned to receive a single intranasal dose of 20 mg bremelanotide or matching placebo in a double-blind manner during the first in-clinic treatment session, and the alternate medication during the second in-clinic treatment session. During each session, subjects viewed a 20-minute neutral video followed by a 20-minute sexually explicit video. Vaginal photoplethysmography was used to monitor vaginal vasocongestion and questionnaires were used to evaluate perceptions of sexual response within the following 24-hour period.

Results

More women reported moderate or high sexual desire following bremelanotide treatment vs. placebo (P = 0.0114), and a trend toward more positive responses regarding feelings of genital arousal occurred after bremelanotide compared with placebo (P = 0.0833). Among women who attempted sexual intercourse within 24 hours after treatment, significantly more were satisfied with their level of sexual arousal following bremelanotide, compared with placebo (P = 0.0256). Vaginal vasocongestion did not change significantly while viewing erotic videos following bremelanotide administration compared with placebo.

Conclusion

This preliminary evaluation suggests the potential for bremelanotide to positively affect desire and arousal in women with female sexual arousal disorder and indicates that bremelanotide is a promising candidate for further evaluation in an at-home study.
Solid‐State SO2 Sensor Using a Sodium‐Ionic Conductor and a Metal–Sulfide Electrode
Authors: Shimizu Youichi , Okimoto Miho , Souda Noriko
Published: May 2006

All solid‐state sulfur oxides (SOx) sensor devices combined with a sodium ionic conductor (Na5DySi4O12) disk and metal sulfide‐sensing electrodes synthesized via solution routes have been systematically investigated for the detection of SO2 in the range of 20–200 ppm at 150–400°C. Among the various sulfide‐sensing electrodes tested, the metal monosulfide‐based electrodes gave good SO2 sensitivity at 400°C. The Pb1−xCdxS (x=0.1, 0.2)‐based solid electrolyte sensor element showed the best sensing characteristics, i.e., the EMF response was almost linear to the logarithm of SO2 concentration in the range between 40 and 400 ppm, with a 90% response time to 100 ppm SO2 of about 3–15 min, and also showed high selectivity to SO2 at 400°C.
An Investigation of Current Reversal Mode for Gas Sensing With a Solid Electroyte
Authors: Hills Matthew Paul , Schwandt Carsten , Vasant Kumar Ramachandran
Published: May 2006

Current reversal mode (CRM) is a dynamic measuring technique, which has the potential to determine accurately the equilibrium emf of a solid electrolyte sensor, while providing additional information regarding sensor resistance. This can be exploited as a diagnostic tool. A fundamental study, using an oxygen sensor with yttria‐stabilized zirconia as the solid electrolyte, has been performed to identify the CRM parameters of frequency and bias voltage for making accurate measurements. A mathematical model has been developed for the application of CRM in terms of an equivalent electrical circuit. The predictions of the model agree well with the experimental data.
Temperature Dependence of Thermal Reflection Behavior of Al2O3–TiO2 Multilayer Thermal Energy Window Coating
Authors: Ikegami M. , Matsumura K. , Kagawa Y. , Kamei M.
Published: May 2006

An Al2O3–TiO2 multilayer‐coated sapphire thermal energy window coating has been fabricated using an ultra‐high‐speed vacuum sputtering method. Thermal reflection spectra of the coated material in the wavelength range from 1.43 to 3.33 μm are measured in ambient air at temperatures of 298, 773, and 1173 K. The result shows that the light reflectance of ∼70% is achieved using a layered structure and this performance continues up to 1173 K. Thermal reflection energy of the coated material at T=1173 K is estimated to be about three times higher than that of uncoated sapphire, suggesting the potential of this coating to control thermal radiation energy.
Processes Driving Ontogenetic Succession of Galls in a Canopy Tree1
Authors: Fonseca Carlos Roberto , Fleck Tomás , Fernandes Geraldo Wilson
Published: May 2006

Herbivores can be associated with distinct ontogenetic stages of their host in a nonseasonal, directional, and continuous pattern of colonization and extinction of species populations called ontogenetic succession, but the processes behind this pattern are still largely unknown. We used plants of Cryptocarya aschersoniana Mez (Lauraceae) belonging to different ontogenetic stages, to examine how the density of different gall‐inducing insects varies along the ontogeny of the host, and how gall density is influenced by mechanisms associated with host quality (plant height, plant shape, leaf area, specific leaf area, and hypersensitivity), and by mechanisms associated with their natural enemies (parasitoids, pathogens, and predators). In a remnant of Araucaria Forest, located in the São Francisco de Paula National Forest (Brazil), gall density (ind./100 g of leaf ) was obtained for 42 plants of C. aschersoniana divided into three height classes. Two galling species were recorded, showing quite distinct density patterns among height classes of C. aschersoniana. While Hymenoptera gall density decreased almost 50 times from small plants to canopy trees, Hemiptera gall density increased almost 10 times. Path analyses showed that Hymenoptera density was higher in smaller plants, independent of other host traits, while Hemiptera density was higher in plants exhibiting smaller leaves. Natural enemies were not detected in the Hemiptera population, and mortality rates due to predators, parasitoids, and pathogens did not affect Hymenoptera density. Processes associated with plant quality play the main role in generating the observed ontogenetic succession pattern.
A stability study of Pluto's moon system
Authors: Nagy I. , Süli Á. , Érdi B.
Published: May 2006

The dynamical structure of the orbital element space of the Pluto-Charon system is studied in the model of the spatial circular restricted three-body problem by using numerical methods. With the two newly discovered small satellites S/2005 P1 and S/2005 P2, the Pluto-Charon system can be considered as the first known binary system in which celestial bodies move in P-type orbits. It is shown that the two satellites are in the stable region of the orbital element space and their origin by capture is unlikely. Also the large mass parameter allows the satellites to be regarded as a model of a new class of exoplanets orbiting around stellar binary systems.
GRB 990413: insight into the thermal phase evolution
Authors: Bosnjak Z. , Celotti A. , Ghirlanda G.
Published: May 2006

GRB 990413 shows a very hard spectrum [with a low-energy spectral component F(ν) ∝2.49] which is well represented by a blackbody model with characteristic temperature ∼70 keV. It thus belongs to the subset of gamma-ray bursts (GRBs) which might be revealing a thermal phase. We find that the temperature/luminosity evolution is consistent with that found in the other ‘thermal’ GRBs. The time-resolved spectral analysis indicates the presence of a second non-thermal component contributing (for about 1 s) up to 30 per cent of the total flux. Differently from the other thermal GRBs, GRB 990413 shows significantly high level of variability and the evolution of the thermal/non-thermal spectral components is strongly correlated with the flux variations. This GRB thus offers the unique opportunity to test the standard fireball photospheric and internal shock phases and their reciprocal influence. GRB 990413 was not selected on the basis of its spectrum and thus hints to the possibility that this early behaviour might be more common than currently known.