bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of active metabolite(s) from 1α‐hydroxyvitamin D3 by human monocytic leukemia cells
Authors: Okabe-Kado Junko , Honma Yoshio , Kasukabe Takashi , Hozumi Motoo
Published: July 2002

Synthesis of the biologically active metabolite(s) from 1α‐hydroxyvitamin D3 (1α(OH)D3) was examined in various types of human leukemia cell lines. Untreated monocytoid leukemia cells (U937 and HE/S) metabolized 1α(OH)D3 to the active metabolite(s), possibly 1α,24‐ and/or 1α, 25‐dihydroxyvitamin D3, and these cells were efficiently induced to differentiate by treatment with 1α(OH)D3. However, the other types of leukemia cells did not efficiently metabolize it and were not induced to differentiate by 1α(OH)D3. The possible therapeutic advantage of 1α(OH)D3 in the treatment of monocytic leukemia is discussed.
Plasma membrane redox activity correlates with N‐myc expression in neuroblastoma cells
Authors: Medina Miguel Angel , del Castillo-Olivares Antonio , Schweigerer Lothar
Published: July 2002

In different neuroblastoma cell lines and transfected clones, an increasing plasma membrane redox activity correlates with amplification and enhanced expression of the N‐myc oncogene. Furthermore, plasma membrane redox activity is partially inhibited by retinoic acid in neuroblastoma cells with multiple copies of the N‐myc oncogene but not in neuroblastoma cells with only one copy of this gene.
Site‐directed mutagenesis of yeast phosphoglycerate kinase
Authors: Barber Michael D. , Gambling Steven J. , Watson Herman C. , Littlechild Jennifer A.
Published: July 2002

In the absence of a structure of the closed form of phosphoglycerate kinase we have modified by site directed mutagenesis several of the residues which, on the basis of the open form structure, are likely to be involved in substrate binding and catalysis. Here we report on the kinetic and anion activation properties of the yeast enzyme modified at positions 65, 121 and 168. In each case an arginine, thought to be involved in the binding of the sugar substrate's non‐transferable phosphate group, has been replaced by lysine (same charge) and by methionine (no charge). K
m values for 3‐phosphoglycerate of all six mutant enzymes are only marginally higher than that of the wild‐type enzyme. Removing the charge associated with two of the three arginine residues appears to influence (as judged by the measured K
m's) the binding of ATP. Although binding affinity is not necessarily coupled to turnover the substitutions which have the greatest effect on the K
m's do correlate with the reduction in enzymes maximum velocity. The one exception to this generalisation is the R65K mutant which, surprisingly, has a significantly higher k
cat than the wild‐type enzyme. In the open form structure of the pig muscle enzyme each of the three substituted arginines residues are seen to make two hydrogen bonds to the sugar substrate's non‐transferable phosphate. From this it might be expected that anion activation would be similarly affected by the substitution of any one of these three residues. Although the interpretation of such effects are complicated by the fact that one of the mutants (R65M) unfolds at low salt concentrations, this appears not to be the case. Replacing Arg121 and Arg121 with methionine reduces the anion activation whereas a lysine in either of these two positions practically destroys the effect. With the substitutions at residue 65 the opposite is observed in that the lysine mutant shows anion activation whereas the methionine mutant does not.
Calcium transport mediated by NhaA, a Na+/H+ antiporter from Escherichia coli
Authors: Dibrov P.A.
Published: July 2002

In everted membrane vesicles of E. coli strain EP432/pGM42, which has only one Na+/H+ antiporter (NhaA), external CaC4 inhibits dissipation of the respiration‐dependent ΔpH in response to the addition of NaCl at pH 7.5, and decreases equilibrium concentration of the intravesicular Na+. In the NhaA proteoliposomes, imposition of an artificial ΔpH (acid inside) leads to the several‐fold accumulation of calcium. The apparent K
m for this ΔpH‐driven Ca2+ uptake at pH 8.5 is 2 mM, and the V
max is 1.79 of protein. Dissipation of ΔpH causes release of calcium from the vesicles. CaCl2 was found to inhibit the ΔpH‐driven Na+ uptake mediated by reconstituted NhaA, and vice versa. Further, heterological Ca2+/Na+ exchange has been demonstrated in proteoliposomes containing NhaA. Transmembrane electric potential difference proved to drive this process. All these data are consistent with the assumption that NhaA can also catalyze Ca2+/H+ exchange.
Kinetic studies of the active sites functioning in the quinohemoprotein fructose dehydrogenase
Authors: Marcinkeviciene Jovita , Johansson Gillis
Published: July 2002

Steady‐state kinetic analysis was performed on the reaction between d‐fructose and ferricyanide with the quinohemoprotein fructose dehydrogenase from Gluconobacter species. The d‐fructose oxidation dependence on the ferricyanide concentration resulted in a series of parallel reciprocal plots, and the reaction was assumed to proceed by a ping‐pong type of mechanism. A reciprocal plot of the reduction of ferricyanide at saturating concentration of d‐fructose gave a break which was considered to appear as a result of the two active centers, namely PQQ and heme e functioning. A scheme of action is proposed and the bimolecular rate constant of the d‐fructose oxidation, the k
cat for PQQ and the electron transfer rate between the PQQH2 and heme c are calculated and account for 2.2 ± 0.4.104 M−1s−1, (93 ± 14) and (162 ± 7) s−1, respectively.
1H and 15N assignments and secondary structure of the PI3K SH3 domain
Authors: Koyama Satoshi , Yu Hongtao , Dalgarno David C. , Shin Tae Bum , Zydowsky Lynne D. , Schreiber Stuart L.
Published: July 2002

The sequential 1H and 15N assignments of the SH3 domain of human phosphatidyl inositol 3'‐kinase (PI3K) were determined by a combination of homonuclear and heteronuclear NMR experiments. With the exception of several protons belonging to lysine and proline residues, all proton and proton‐bearing amide nitrogen resonances were assigned. Based on the sequential nuclear Overhauser effects (NOEs), 3
J
NH‐CαH coupling constants and locations of slowly exchanging amide protons, we determined that the secondary structures of the protein consists of six β‐strands, two β‐turns and four short helices. Additional long range NOEs indicate that these β‐strands form two antiparallel β‐sheets. The topology of secondary structural elements of the PI3K SH3 domain is similar to those of the SH3 domains from c‐Src and α‐spectrin, suggesting that the SH3 family has a common tertiary structural motif.
Comparison of properties of mistletoe lectin I A‐chain and ricin B‐Chain conjugate with native toxins
Authors: Tonevitsky A.G. , Toptygin A.Yu. , Shamshiev A.T. , Agapov I.I. , Ershova E.V. , Pfuller U. , Pfuller K.
Published: July 2002

Chimeric toxic protein was prepared from the mistletoe lectin I A‐chain and ricin B‐chain by using the disulfide exchange reaction. Ricin and chimeric protein were indistinguishable in binding to immobilized asialofetuin in ELISA. Chimeric protein was more toxic to Jurkat cells than native mistletoe lectin I, but not so effective as native ricin. In the presence of NH4Cl, which enhances the toxicity of some toxins and immunotoxins, but does not influence ricin toxicity, both ricin and chimeric toxin had equal cytotoxic activity. The possibility is discussed that the ricin B‐chain protects the ricin A‐chain (RTA) from degradation during delivering RTA from the cell surface to the place where RTA is translocated into the cytosol.
Mutations to kirromycin resistance occur in the interface of domains I and III of EF‐Tu·GTP
Authors: Abdulkarim Farhad , Liljas Lars , Hughes Diarmaid
Published: July 2002

The antibiotic kirromycin inhibits protein synthesis by binding to EF‐Tu and preventing its release from the ribosome after GTP hydrolysis. We have isolated and sequenced a collection of kirromycin resistant tuf mutations and identified thirteen single amino acid substitutions at seven different sites in EF‐Tu. These have been mapped onto the 3D structures of EF‐Tu·GTP and EF‐Tu·GDP. In the active GTP form of EF‐Tu the mutations cluster on each side of the interface between domains I and III. We propose that this domain interface is the binding site for kirromycin.
Monoclonal antibodies against the acetylcholine receptor γ‐subunit as site specific probes for receptor tyrosine phosphorylation
Authors: Tzartos Socrates J. , Tzartos Elisabeth , Tzartos John S.
Published: July 2002

Tyrosine phosphorylation of the nicotinic acetylcholine receptor (AChR) may be involved in AChR desensitization and clustering. Torpedo AChR γ‐subunit is phosphorylated at Tyr365. Using overlapping synthetic peptides, we have precisely mapped the epitopes of five anti‐γ‐subunit monoclonal antibodies (mAbs) and found that the epitope(s) for the mAbs 154, 165 and 168 (γ365–370) all contain Tyr365. mAb 168 is a known blocker of AChR channel function. Using peptide analogues, Tyr365. was found to be indispensable for mAb165 binding; furthermore its binding was selectively inhibited by in vitro AChR tyrosine phosphorylation. The possible connection between γ‐subunit phosphorylation and regulation of AChR function and the proven usefulness of these mAbs as tools should facilitate functional studies of AChR γ‐subunit phosphorylation.
Effect of ganglioside GM3 on the activity and conformation of reconstituted Ca2+‐ATPase
Authors: Wang L.H. , Tu Y.P. , Yang X.Y. , Tsui Z.C. , Yang F.Y.
Published: July 2002

Trace amounts of gangliosides were found in rabbit skeletal muscle sarcoplasmic reticulum and their main part was shown, by high performance thin layer chromatography, to be GM3. Addition of GM3 to the soybean phospholipids used for reconstitution of proteoliposomes markedly increased ATP hydrolysis as well as Ca2+ uptake activity of sarcoplasmic reticulum Ca2+‐ATPase incorporated into the proteoliposomes. Conformation changes of Ca2+‐ATPase induced by GM3 were also observed by intrinsic fluorescence and circular dichroism measurements.
The level of pancreatic PLA2 receptor is closely associated with the proliferative state of rat uterine stromal cells
Authors: Tessier Christian , Rossini Gian-Paolo , Pageaux Jean-François , Cohen Hélène , Lagarde Michel , Laugier Christian , Fayard Jean-Michel
Published: July 2002

Rat uterine stromal cells (UIII) express pancreatic type PLA2 (PLA2‐I) receptor and internalize the enzyme bound to receptors. Here, we investigate the proliferating effect and alterations in binding of PLA2‐I. There is a dramatic decline in PLA2‐I binding in UIII cells as they progress from a nonconfluent proliferating state (40,000 sites/cell) to a confluent state (1300 sites/cell). Intracellular concentration of PLA2‐I changed with the alteration in binding, suggesting that regulation in the PLA2 binding capacity may have important implications in growth control mechanisms.
Two myogenic regulatory factor transcripts exhibit muscle‐specific responses to disuse and passive stretch in adult rats
Authors: Loughna Paul T. , Brownson Carol
Published: July 2002

Levels of myogenic regulatory factor (MRF) transcripts are altered in a muscle‐specific manner in response to hind limb immobilisation of adult male rats, for a 2 day period, in either a lengthened or shortened position which result in passive stretch or disuse atrophy respectively. Myogenin transcript levels were dramatically elevated in the stretched plantaris but not soleus, whereas the MRF4 transcript was significantly elevated in soleus but not plantaris. Levels of myogenin mRNA were unaffected by disuse in either muscle and MRF4 was markedly lower in plantaris in response to disuse.
Expression of the α4 neuronal nicotinic acetylcholine receptor subunit in the developing mouse hippocampus
Authors: Didier M. , Bix G. , Berman S.A. , Bursztajn S.
Published: July 2002

Neurotransmitters such as acetylcholine can control neuritogenesis of hippocampal cells. The timing of its receptors expression consequently may influence synaptogenesis and neuronal activity in the developing hippocampus. We investigated the mRNA expression of the nicotinic acetylcholine‐gated ion channel receptor (nAChR) α4 subunit in the embryonic and postnatal hippocampal formation. Although its expression level is low in the adult hippocampus, this protein consitutes the major nAChR subunit in the central nervous system. We carried out in‐situ hybridization experiments to determine whether or not the α4 AChR subunit mRNA distributions show evidence of regional and developmental regulation during hippocampal maturation. Our studies reveal that α4 AChR mRNA expression was low at the embryonic stage, but increased transiently during postnatal development reaching a maximum during the second week of life and decreasing thereafter, to a minimum at adulthood. In hippocampal regions, the peak values of α4 AChR expression were between 400 and 800% of adult α4 messenger levels. In the postnatal hippocampus, most of the cells from the pyramidal layer of the CA3 and CA2 areas displayed a strong hybridization signal for the α4 AChR subunit. In the hilus and the CA1 regions, the localization of the α4 transcripts seemed to be restricted to some interneurons and pyramidal cells, respectively. Moderate and uniform in‐situ hybridization signals were observed in granular cells from the dentate gyrus. The transient profile of α4 expression suggests that nAChRs may participate in the early postnatal maturation of hippocampal circuity.
A survey of psychosexual arousability in male patients on depot neuroleptic medication
Authors: Wesby R , Bullmore E , Earle J , Heavey A
Published: July 2002

Sexual and endocrine function in a geographically defined population of male patients receiving depot neuroleptic medication were studied (n = 119). It was predicted that psychosexual arousability would be reduced in this patient group, perhaps because of the endocrine effects of medication. Arousability was measured in 63 patients (53% of the population) using a validated questionnaire of sexual function for which normative data were available (Sexuality Experience Scales, SES 2). Blood levels of prolactin, testosterone and gonadotrophins were assayed. Physical sexual dysfunction was common, as was endocrine dysfunction. However, the sample's mean score on the global arousability scale was not significantly different from the normative mean. Arousability was negatively correlated with age and positively correlated with frequency of spontaneous penile erections, but not significantly correlated with endocrine variables or exposure to neuroleptic medication. These results suggest that sexual arousability in response to imagined or audio-visual erotic stimuli is surprisingly unimpaired in medicated male patients suffering from chronic mental illness.
Normal and cancer‐prone human cells respond differently to extremely low frequency magnetic fields
Authors: Mangiacasale Rosamaria , Tritarelli Alessandra , Sciamanna Ilaria , Cannone Maria , Lavia Patrizia , Barberis Massimo C. , Lorenzini Rodolfo , Cundari Enrico
Published: July 2002

Human lymphoblastoid cells of normal origin and from genetic instability syndromes, i.e. Fanconi anemia (FA) group C and ataxia telangectasia, were continuously exposed to extremely low frequency magnetic field (ELF‐MF). We report that ELF‐MF, though not perturbing cell cycle progression, increases the rate of cell death in normal cell lines. In contrast, cell death is not affected in cells from genetic instability syndromes; this reflects a specific failure of the apoptotic response. Reintroduction of complementation group C in FA cells re‐established the apoptotic response to ELF‐MF. Thus, genes implicated in genetic instability syndromes are relevant in modulating the response of cells to ELF‐MF.
A novel plant α4‐fucosyltransferase (Vaccinium myrtillus L.) synthesises the Lewisa adhesion determinant
Authors: Palma Angelina S. , Vila-Verde Cidália , Pires Ana Sofia , Fevereiro Pedro S. , Costa Júlia
Published: July 2002

We have partially characterised an α4‐fucosyltransferase (α4‐FucT) from Vaccinium myrtillus, which catalysed the biosynthesis of the Lewisa adhesion determinant. The enzyme was stable up to 50°C. The optimum pH was 7.0, both in the presence and in the absence of Mn2+. The enzyme was inhibited by Mn2+ and Co2+, and showed resistance towards inhibition with N‐ethylmaleimide. It transferred fucose to N‐acetylglucosamine in the type I Galβ3GlcNAc motif from oligosaccharides linked to a hydrophobic tail and glycoproteins (containing the type I motif). Sialylated oligosaccharides containing the type II Galβ4GlcNAc motif were not acceptors. The catalytic mechanism of the plant α4‐FucT possibly involves a His residue, and it must have arisen by convergent evolution relative to its mammalian counterparts.
Engineering of cholera toxin A‐subunit for carriage of epitopes at its amino end
Authors: Sanchez J , Argotte R , Buelna A
Published: July 2002

The cholera toxin A‐subunit (CTA) was genetically engineered at its amino end and tested for carriage of epitopes by fusion of the STa heat‐stable enterotoxin analogue CAELCCNPAC. Efficient holotoxin formation by complementation in trans with cholera toxin B‐subunit (CTB) indicated no decrease in affinity for CTB but evidence of reduced toxicity suggests steric interference by the decapeptide with the active site. The holotoxin was stable, able to bind to GM1 and was recognized by anti‐STa and anti‐CTA antibodies. The use of a full‐length CTA might have been a key step for successful genetic fusions. Based on these findings, it seems worthwhile pursue the development of CTA for construction of recombinant mucosal immunoadjuvants.
Expression, purification and characterization of recombinant human proinsulin
Authors: Cowley Darrin J , Mackin Robert B
Published: July 2002

We have recently developed a method to produce native human proinsulin using a bacterial expression system. A proinsulin fusion protein was recovered from inclusion bodies and cleaved using cyanogen bromide. The released proinsulin polypeptide was S‐sulfonated and purified by anion exchange chromatography. Following refolding, proinsulin was purified by reversed‐phase high‐performance liquid chromatography. Combined peptide mapping and mass spectrometric analysis indicated that the proinsulin contained the correct disulfide bridging pattern. This proinsulin will be used to study the specificity of the furin/PC family of converting enzymes by using it as a substrate in a recently developed assay.
Mycothiol, 1‐O‐(2′‐[N‐acetyl‐L‐cysteinyl]amido‐2′‐deoxy‐α‐D‐glucopyranosyl)‐D‐myo‐inositol, is the factor of NAD/factor‐dependent formaldehyde dehydrogenase
Authors: Misset-Smits Marijke , van Ophem Peter W , Sakuda Shohei , Duine Johannis A
Published: July 2002

Two different NAD/coenzyme‐dependent formaldehyde dehydrogenases exist, the well‐known NAD/GSH‐dependent (EC 1.2.1.1) and the more recently discovered NAD/Factor‐dependent enzyme. The GSH‐dependent one has been found in eukaryotes and Gram‐negative bacteria, the Factor‐dependent one in two different Gram‐positive bacteria. Previous work also showed that Factor and GSH are not interchangeable in the enzymatic reactions. Here it is revealed that the Factor is identical to mycothiol (MySH), 1‐O‐(2′‐[N‐acetyl‐L‐cysteinyl]amido‐2′‐deoxy‐α‐D‐glucopyranosyl)‐D‐myo‐inositol, a thiol compound which has recently been detected in Actinomycetes. Thus, MySH is GSH's companion as it is the coenzyme for the enzyme which henceforth can be indicated as NAD/MySH‐dependent formaldehyde dehydrogenase.
Analysis of deleted variant of hepatocyte growth factor by alanine scanning mutagenesis: identification of residues essential for its biological function and generation of mutants with enhanced mitogenic activity on rat hepatocytes
Authors: Kinosaki Masahiko , Yamaguchi Kyoji , Murakami Akihiko , Morinaga Tomonori , Ueda Masatsugu , Higashio Kanji
Published: July 2002

To understand the structure‐function relationship of hepatocyte growth factor (HGF) in more detail, we analyzed one of the other forms of HGF, deleted variant of HGF (dHGF), by alanine scanning mutagenesis. We show here that there are at least four sites important for dHGF to stimulate DNA synthesis in cultured adult rat hepatocytes, and that the residues of HGF essential for exerting its biological activity are not identical to those of dHGF. In addition, two mutants showed a decrease (approximately three‐fold) in EC50 compared with wild‐type dHGF in an assay of mitogenic activity on rat hepatocytes.
DNA triple helix stabilisation by a naphthylquinoline dimer
Authors: Keppler Melanie , Zegrocka Oliwia , Strekowski Lucjan , Fox Keith R
Published: July 2002

We have used DNase I footprinting to examine the effect of a novel naphthylquinoline dimer, designed as a triplex‐specific bis‐intercalator, on the stability of intermolecular DNA triplexes. We find that this compound efficiently promotes triplex formation between the 9‐mer oligonucleotide 5′‐TTTTTTCTT and its oligopurine duplex target at concentrations as low as 0.1 μM, enhancing the triplex stability by at least 1000‐fold. This compound, which is the first reported example of a triplex bis‐intercalator, is about 30 times more potent than the simple monofunctional ligand.
The modified Mueller‐Hillis maneuver in predicting abnormalities in second stage labor
Authors: March Michael R. , Adair C. David , Veille Jean‐Claude , Burrus David R.
Published: July 2002

Objective: To assess prospectively the utility of a modification of the Mueller‐Hillis maneuver in predicting abnormalities of the second stage of labor. Methods: The Mueller‐Hillis maneuver was modified by limiting its use to the second stage of labor during a contraction. The maneuver was performed by one examiner; descent of 1 cm or more was deemed a positive maneuver. Descent less than 1 cm was deemed a negative maneuver. Labor outcomes were analyzed according to the results of this maneuver. Resuls: Seventy patients were enrolled in this study. Fifty‐one (72.9%) had ≥1 cm descent maneuver and 19 (27.1%) had ≤1 cm descent. A descent ≥1 cm was significantly predictive of vaginal delivery (100%) and a descent s 1 cm was significantly associated with an increased cesarean section rate (P = 0.001), prolonged second stage of labor (P = 0.001), abnormal position (P = 0.01) and higher station (P = 0.001). Conclusions: A positive modified Mueller‐Hillis maneuver in second stage labor had a high predictive value for vaginal delivery, whereas a negative maneuver was significantly associated with high operative delivery rate, prolonged second stage labor and abnormal position. These results indicate that this modification of the Mueller‐Hillis maneuver needs to be considered for its utility in second stage labor.
Impact of cancer screening on women's health
Authors: Elovainio L. , Nieminen P. , Miller A.B.
Published: July 2002

Worldwide, 31% of cancers in women are in the breast or uterine cervix. Prevention of cervical cancer is effective with the use of the cervical Pap smear test if applied in an organized and continuous fashion, including treatment of precancerous lesions. At best such programs have led to a 60% decrease in cervical cancer incidence and mortality in the Nordic countries. Early detection of breast cancer in a population based screening may lead to a 30% reduction of mortality from this disease in the screened population. Measures to guarantee high coverage and attendance, adequate field facilities, organized program for quality control and adequate facilities for diagnosis and treatment are prerequisites of successful programs. In absolute terms the contribution of screening to the total mortality reduction among middle‐aged populations is small, much smaller than the potential gains from cancer prevention.
Colocalization of the cyclin B homologue P56 and β‐tubulin during the cell cycle in a unicellular eucaryote dinoflagellate
Authors: Barbier Michèle , Géraud Marie‐Line , Nicolas Gisèle , Soyer‐Gobillard Marie‐Odile
Published: July 2002

We provide evidence for an unusual behavior of the cyclin B homologue, p56, in the dinoflagellate Crypthecodinium cohnii. p56, of which we previously demonstrated the presence in this original eukaryotic protist, is present all along the cell cycle progression, and is exclusively cytoplasmic as revealed after immunofluorescence labeling with anti‐p56 Ab and counterstaining with Dapi. It was never found in the nucleus as is the case in higher eukaryotic cells. During motosis, p56 was essentially associated with the mitotic apparatus: centrosomes and mitotic spindle, as shown after double immunofluorescence labeling with anti p56 and anti β‐tubulin Ab. Using high pressure freeze fixation, we clearly detected in transmission electron microscopy (TEM) the localization of p56 cyclin B homologue and β‐tubulin: single immunogold labeling demonstrated that p56 is localized along the whole cell cortex, along the cleavage furrow of anaphase to cytokinesis cells and into cytoplasmic channels passing throughout the mitotic nucleus where is located the mitotic spindle. Double immunogold labeling realized with anti‐p56 and anti‐β‐tubulin antibodies confirm that p56 antigens colocalize with β‐tubulin in many sites. The significance of the exclusively cytoplasmic localization of the cyclin B homologue is discussed.
Toxic effect of rifampicin on human osteoblast‐like cells
Authors: Isefuku S. , Joyner C. J. , Simpson A. H. R. W.
Published: July 2002

We examined the effects of rifampicin on osteoblast‐like cells derived from adult human bone in vitro. Cancellous bone was collected from five different individuals during elective orthopaedic operations and cultured in antibiotic‐free media. Total DNA, 3H‐thymidine incorporation and alkaline phosphatase (ALP) activity were measured after the cells were cultured for 4 days in media containing concentrations of rifampicin ranging from 0 to 1000 μ/ml. Mean total DNA was decreased at concentrations of 10 μ/ml and above in the cultures obtained from four out of five individuals but these decreases were significant in the cultures from only two individuals. 3H‐thymidine incorporation, a more sensitive indicator of change in cell proliferation, and ALP activity were significantly decreased (P < 0.05) in all of the cultures containing 3 and 7 μg/ml, respectively. In the clinical setting, serum concentrations of rifampicin often exceed 10 μg/ml after systemic administration. The present study has shown that rifampicin, at these concentrations, can inhibit the proliferation of osteoblast‐like cells in vitro. Further studies should be carried out to assess whether rifampicin is detrimental to the bone repair process in vivo. © 2001 Orthopaedic Research Society. Punlished by Elsevier Science Ltd. All rights reserved.
What becomes of children hospitalized for enuresis? Results of a catch-up study
Authors: Brieger P. , Sommer S. , Blöink R. , Marneros A.
Published: July 2002

Background

The purpose of this study was to reassess former child and adolescent psychiatric patients with nocturnal enuresis as young adults and to compare them with former patients without enuretic symptoms and with a comparison group from the general population.

Method

We used a ‘catch-up’ design. From a former child and adolescent psychiatric patient cohort we identified all subjects with documented enuretic symptoms in childhood and compared them with two groups matched for gender and age – non-enuretic patients and a comparison group from the general population. Subjects were assessed as adults with standardized instruments according to the criteria of ICD-10 (SCAN, IPDE) and dimensional values for depression, satisfaction with life, global functioning and personality (NEO-FFI).

Results

We assessed 55 former patients with nocturnal enuresis (recruitment rate 68%) after a mean interval of 13.1 years. At catch-up the former enuretic patients had a lower frequency of personality disorders (ICD-10), lower mean depression values, higher global functioning and a lower rate of psychiatric treatment after the age of 18 years than did former non-enuretic patients. Former enuretic patients did not differ significantly from the comparison group from the general population concerning any of the outcome variables, although there was a non-significant trend for former enuretic patients to more often fulfill criteria for a psychiatric ICD-10 diagnosis at catch-up. There were no differences concerning personality among the three groups at catch-up.

Conclusion

Although it may constitute a mild vulnerability factor for further development, nocturnal enuresis had a good long-term outcome in a cohort of treated subjects.
Neuropsychiatric aspects of HIV infection: a liaison psychiatry study
Authors: Grassi B , Garghentini G , Gambini O , Scarone S
Published: July 2002

All the HIV-infected patients having referred to our Liaison Psychiatry Service between October 1992 and June 1994 were considered in this study. Seventy patients underwent psychiatric assessment and medical/neurological evaluation. Forty-seven of these patients were also subjected to cognitive/neuropsychological examination by means of the Milan Overall Dementia Assessment (MODA). Depressive episodes, adjustment disorders and substance abuse were the most frequently encountered diagnoses. Taking into account neuropsychological data, we found that symptomatic patients performed worse on tests than did asymptomatic ones.
Russia's external debt: infinite rescheduling?☆
Authors: Hishow Ognian N.
Published: July 2002

Since Russia defaulted on her sovereign domestic debt in the aftermath of the August 1998 crisis, questions were raised as to whether she would do the same for her huge external liabilities. Creditors worry about the possibility that Moscow will try to confront them either with a unilateral moratorium or will try to achieve an “infinite” debt restructuring. The latter would eventually mean the same since the original claims would not be serviced, but kept on the books whereas written off claims get erased. Given the economic resources of that country such a solution cannot be recommended despite some voices that Russia needs even more aid. To relieve the debt service burden the West should, however, agree to reschedule the payments.
Activation of the cardiac interleukin‐6 system in advanced heart failure
Authors: Gabriele Plenz , Zhi Fang Song , Tonny D.T. Tjan , Carsten Koenig , Hideo A. Baba , Michael Erren , Markus Flesch , Thomas Wichter , Hans H. Scheld , Mario C. Deng
Published: July 2002

Objectives:

The study objective was to assess the cardiac expression of interleukin‐6 (IL6) and its receptor (IL6R) in advanced heart failure.

Background:

While IL6 plasma levels are elevated and associated with an impaired prognosis in advanced heart failure, little is known about the intracardiac expression of the IL6 system.

Methods:

Heart tissue was obtained from 20 patients (n ‐ 10, idiopathic dilated cardiomyopathy, age 44±15 years; n ‐ 10, ischemic cardiomyopathy, age 55±8 years) at the time of transplantation. Left and right ventricular tissue was subjected to in situ hybridization, Northern blot analysis, and RT‐PCR. Signals were quantified by densitometric scanning and corrected for G3PDH‐mRNA levels. Right ventricular biopsy specimens (n ‐ 11) of patients with arrhythmias and normal cardiac function served as controls. In addition, data were correlated with cardiac catheterization and echocardiography data obtained at transplant evaluation.

Results:

Ventricular IL6 and IL6R transcripts were detected in all explant specimens examined. Expression of both mRNA species was higher than in controls (P ‐ 0.001). Left ventricular IL6 mRNA levels correlated positively with heart rate (r ‐ 0.77; P ‐ 0.009), pulmonary capillary wedge pressure (r ‐ 0.53; P ‐ 0.03), right atrial pressure (r ‐ 0.77; P ‐ 0.003), and inversely with left ventricular ejection fraction (r ‐ −0.61; P ‐ 0.03). Right ventricular IL6 mRNA levels correlated inversely with cardiac index (r ‐ −0.48; P ‐ 0.05). IL6R expression did not correlate with hemodynamic data.

Conclusions:

In advanced heart failure, cardiac IL6/IL6R mRNA expression is increased and may play a role in the pathophysiology of advanced heart failure.
Monolithic Photoelectrochemical CO2 Reduction Producing Syngas at 10% Efficiency
Authors: Kistler Tobias A. , Um Min Young , Cooper Jason K. , Sharp Ian D. , Agbo Peter
Published: April 2021

Increasing anthropogenic carbon dioxide emissions have prompted the search for photoelectrochemical (PEC) methods of converting CO2 to useful commodity products, including fuels. Ideally, such PEC approaches will be sustained using only sunlight, water, and CO2 as energetic and reactant inputs. However, low peak conversion efficiencies (<5%) have made commercialization of fully‐integrated PEC devices prohibitive. Here, a 4 cm2 monolithic PEC device exceeding 10% solar‐to‐fuel efficiency with principal fuel products of carbon monoxide and hydrogen is reported. The corresponding solar‐to‐CO and solar‐to‐H2 efficiencies are 7% and 3.5%, respectively. Screening of a range of operating conditions reveals a tunable product mixture of H2 and CO using a gold electrocatalyst. Accordingly, it is shown that device optimization yields a H2‐to‐CO ratio of 1:2 commonly present in synthesis gas (syngas). Notably, the modularity and facile fabrication of this device permit the incorporation of a broad array of materials for various applications. For example, the electrocatalyst may easily be swapped to target a different set of products.
Ruthenium(II)‐Catalyzed Direct Ortho Functionalization of 1‐Arylpyrazoles with Maleimides: A Condition Controlled Installation of Succinimides and Maleimides on Arenes
Authors: Nale Sagar D. , Thombal Raju S. , Lee Yong Rok
Published: April 2021

Ruthenium(II)‐catalyzed switchable ortho functionalization of 1‐arylpyrazoles with maleimides is developed in this study. This divergent reaction proceeds via five‐membered ruthenacycle formation and selectively installs diverse succinimides and maleimides substituents on the aromatic ring of 1‐arylpyrazoles through alkylation and alkenylation under acidic and basic conditions. This methodology features broad substrate scope, high functional group tolerance, selective functionalization, and superior reactivity.
Sinonasal and gastrointestinal bacterial composition and abundance are stable after 1 week of once‐daily oral antibiotic treatment for chronic rhinosinusitis
Authors: Siu Joey , Mackenzie Brett Wagner , Klingler Lilian , Biswas Kristi , Wang Yi , Hung Cheung‐Tak , Jeong Soo Hee , Barnett Daniel , Tingle Malcolm Drummond , Douglas Richard George
Published: April 2021

Background

Despite the widespread prescription of antibiotics for the treatment of chronic rhinosinusitis (CRS), their efficacy remains uncertain. Limited penetration of systemic antibiotics into the sinonasal mucosa has been reported previously by this group. This study aimed to investigate the short‐term effects of antibiotics on the sinus and gut microbiota as well as any relationships these had with drug distribution.

Methods

Thirty subjects undergoing functional endoscopic sinus surgery for CRS were randomized to one of three groups: (1) doxycycline (100 mg daily for 7 days); (2) roxithromycin (300 mg daily for 7 days); and (3) control (no antibiotics given). Sinonasal and stool samples collected before and after treatment were analyzed using 16S ribosomal RNA (rRNA) gene‐targeted amplicon sequencing and Droplet Digital polymerase chain reaction (PCR) for bacterial community composition and the quantification of bacterial DNA, respectively.

Results

There were no significant major bacterial community shifts or changes to bacterial diversity and load following the treatment period in all patient groups. Non‐significant trend reductions were observed in gut microbial diversity with antibiotics. For the roxithromycin group, sinonasal bacterial diversity was negatively correlated with serum drug levels and reduced overall compared to controls (p < 0.05). The relative abundance of Staphylococcus ASV129 in sinonasal samples reduced with increasing mucus doxycycline levels (p = 0.01).

Conclusion

Antibiotic prescription for CRS should be further investigated because of preliminary evidence of poor sinonasal drug penetration, unproven efficacy, and the potential impact of dysbiosis in the sinuses and off‐target sites. Further studies should consider distinguishing the presence of DNA from viable and nonviable bacteria.
Surface‐Mediated Construction of an Ultrathin Free‐Standing Covalent Organic Framework Membrane for Efficient Proton Conduction
Authors: Liu Lin , Yin Liying , Cheng Dongming , Zhao Shuai , Zang Hong‐Ying , Zhang Ning , Zhu Guangshan
Published: April 2021

As a new class of crystalline porous organic materials, covalent organic frameworks (COFs) have attracted considerable attention for proton conduction owing to their regular channels and tailored functionality. However, most COFs are insoluble and unprocessable, which makes membrane preparation for practical use a challenge. In this study, we used surface‐initiated condensation polymerization of a trialdehyde and a phenylenediamine for the synthesis of sulfonic COF (SCOF) coatings. The COF layer thickness could be finely tuned from 10 to 100 nm by controlling the polymerization time. Moreover, free‐standing COF membranes were obtained by sacrificing the bridging layer without any decomposition of the COF structure. Benefiting from the abundant sulfonic acid groups in the COF channels, the proton conductivity of the SCOF membrane reached 0.54 S cm−1 at 80 °C in pure water. To our knowledge, this is one of the highest values for a pristine COF membrane in the absence of additional additives.
Research on the rheological and flow characteristics of a supramolecular gel in fractures
Authors: Wang Bo , Sun Jinsheng , Shen Feng , Lv Kaihe , Wang Jintang
Published: April 2021

Loss circulation is one of the major concerns in drilling and well construction. An effective way to control drilling fluid loss and strengthen the wellbore is to plug fractures and holes with loss circulation materials. In this work, a hydrophobic association supramolecular hydrogel GP‐A developed by n‐dodecylacrylamide, methacrylamide and 2‐acrylamide‐2‐methylpropylsulfonic acid was proposed as a potential lost circulation material for malignant drilling fluid loss. The results show that the initial decomposition temperature of GP‐A was 172°C, and the flow characteristics conform to the Herschel‐Bulkley model with yield stress. Microstructural analysis shows that GP‐A gel with a 3D spatial network, and hydrogen bonds between branched chains form a dynamically recoverable structure. Based on POLYFLOW, the Phan Thien–Tanner model with viscoelastic parameters was used to simulate the viscoelastic flow characteristics of the fluid in fractures. The higher the concentration is, the greaterK, and the higher the inlet driving pressure, while the nonlinear relationship between the driving pressure and the gel slug length is evident. The introduction of supramolecular gel polymer as a loss circulation material is an innovative research topic, which provides a new method to simulate the flow of polymer fluid in fractures.
Synthesis and characterization of electrolyte substrate materials based on hyperbranched polyurethane elastomers for anodic bonding
Authors: Zhang Weixuan , Wang Mixue , Zhao Haocheng , Liu Xin , Liu Ruoyun , Xie Xiaoling , Wu Yuling
Published: April 2021

A series of hyperbranched polyurethane elastomers (PEO‐HBPUEs) as polymer electrolyte substrate materials was developed for anodic bonding with aluminum (Al) foil in micro‐electro‐mechanical system (MEMS) devices. The PEO‐HBPUEs were prepared by pre‐polymerization method with toluene‐2,4‐diisocyanate(TDI), polypropylene glycol (PPG), 1,4‐butanediol(BDO), trimethylolpropane(TMP), lithium bis(trifluoromethanesulphonyl)imide (LiTFSI), and polyethylene oxide (PEO)‐based electrolyte in varying proportions via solution casting technique at room temperature. All prepared PEO‐HBPUEs exhibited low glass transition temperatures, good thermal stabilities, and suitable mechanical properties. The XRD results showed that PEO‐HBPUEs are amorphous, and LiTFSI was well dissolved in the polymer matrix. The component of PEO‐based electrolyte in PEO‐HBPUEs contributed to increase the ionic conductivity, of which the highest value reached 1.23 × 10−3 S/cm at 75°C for PEO‐HBPUE4. The anodic bonding of PEO‐HBPUE substrate with Al foil was conducted by the coupling action of electric field, temperature field, and pressure field. A clear intermediate bonding layer between the substrate and Al foil was observed and the elements diffusion around bonding layer can be detected by SEM, indicating PEO‐HBPUEs and Al foil have been jointed together successfully. The highest tensile strength of the bonding interface of PEO‐HBPUE4/Al reached 1.88 MPa. All results demonstrated that the prepared PEO‐HBPUEs materials would be promising substrates for flexible MEMS device that can be applied to flexible packaging by anodic bonding technology.
A rapid LC–MS/MS method for simultaneous determination of berberine and irbesartan in rat plasma: Application to the drug–drug pharmacokinetic interaction study after oral administration in rats
Authors: Zhou Hao , Li Wenyue , Sun Ling , Li Wenfang , Liu Qian
Published: April 2021

A sensitive, reproducible, and specific liquid chromatography tandem mass spectrometry method was developed and validated to simultaneously determine the concentration of berberine (BBR) and irbesartan in Sprague–Dawley rat plasma, and applied to study the pharmacokinetic drug–drug interaction (DDI) between BBR and irbesartan in rats. In this method, diphenhydramine was used as the internal standard, and the liquid–liquid extraction method using ethyl acetate as the extraction agent was used for sample preparation. After extraction, the prepared samples were run on an Agilent Welchrom C18 column with the mobile phase consisting of methanol–acetonitrile–water solution with 0.5% formic acid (45:50:5, v/v/v) at a flow rate of 0.8 mL·min−1. The analytes BBR, irbesartan, and diphenhydramine (IS) were detected using multiple reactions monitoring mode, with the ion transitions being m/z 336.1 → m/z 320.0, m/z 429.1 → m/z 206.9, and m/z 256.2 → m/z 167.0, respectively. In the rats’ plasma, BBR had good linearity in the range of 0.5–100 ng·mL−1 with the lower limit of quantitation of 0.5 ng·mL−1, and the accuracy, intra‐day, and inter‐day precision were less than 12.33%. Irbesartan had good linearity in the range of 20–1200 ng·mL−1 with the lower limit of quantification of 20 ng·mL−1, and the accuracy, intra‐day, and inter‐day precision were less than 13.55%. The validated method was verified to meet the determination requirements of biological samples. It was the first time to study the pharmacokinetics of DDI between BBR and irbesartan successfully, which would be necessary and beneficial to explore the clinical safety and efficacy of the combination of BBR and irbesartan in the treatment of diabetic nephropathy.
Evolution of Anticariogenic Resin‐Modified Glass Ionomer Cements
Authors: Malik Zuleikha , Qasim Butt Danial , Qasim Butt Zainab , Muhammad Nawshad , Kaleem Muhammad , Liaqat Saad , Adnan Khan Muhammad , Samad Khan Abdul
Published: April 2021

With advancing technology and exponential growth in scientific research, new perspectives in dental materials are being discovered. Conservative dentistry advocates maximum tooth preservation by revised restorative materials. Resin‐modified glass ionomer cement (RMGIC) is a flexible group of dental materials that can be used for restoring, lining, luting, and sealing teeth. Much advancements have been achieved to make them inherently anticariogenic as an adjunct to their fluoride release. In an attempt to resolve issues of secondary caries, white spot lesions, and cavitation, nanoparticles of metals such as zinc, silver, and titanium have been added. Biomaterials with regenerative potential like bioactive glass and hydroxyapatite are being explored as well. Similarly, antibiotics and natural resins like propolis and chlorhexidine have shown tremendous response against caries causing the oral pathogen Streptococcus mutans. This comprehensive review sheds light on the recent research in RMGIC, contemplating the repercussions of incorporating antibacterial agents into these types of cement.
Trace Metal Loading of B‐N‐Co‐doped Graphitic Carbon for Active and Stable Bifunctional Oxygen Reduction and Oxygen Evolution Electrocatalysts
Authors: Sikdar Nivedita , Schwiderowski Philipp , Medina Danea , Dieckhöfer Stefan , Quast Thomas , Brix Ann Cathrin , Cychy Steffen , Muhler Martin , Masa Justus , Schuhmann Wolfgang
Published: April 2021

Understanding the structure‐property relations of non‐precious metal heteroatom co‐doped carbon electrocatalysts exhibiting high activity as well as long‐term durability for both ORR and OER remains challenging but is indispensable for the development of bifunctional ORR/OER electrocatalysts. We propose B‐N‐co‐doped graphitic 2D carbon nanostructures impregnated with controlled amount of transition metals (M‐BCN; M=Co, Ni, Fe, Cu) as bifunctional ORR/OER electrocatalysts. Co‐BCN outperformed the Ni‐, Fe‐, Cu‐based BCN catalysts exhibiting potential values of 0.87 V and 1.62 V at −1 mA/cm2 and 10 mA/cm2 during ORR and OER, respectively. Importantly, Co‐BCN shows bifunctional cyclic stability (Δη; EOER−EORR=0.75 V) of up to 300 cycles in 1 M KOH for a duration of 20 h with total activity loss of only 10.2 % (ORR) and 6.2 % (OER), respectively. A low loading of the metal precursors was used to preserve porosity and to facilitate the formation of metal nanoparticles or M−NxB/C type species embedded in the graphitic carbon layers. The B‐N‐co‐doped graphitic layers also protect the embedded metal nanoparticles explaining the observed long‐term stability.
An In‐Situ Self‐regeneration Catalyst for the Production of Renewable Penta‐1,3‐diene
Authors: Feng Ruilin , Qi Yanlong , Liu Shijun , Cui Long , Dai Quanquan , Bai Chenxi
Published: April 2021

Catalyst deactivation is a problem of great concern for many heterogeneous reactions. Here, an urchin‐like LaPO4 catalyst was easily developed for pentane‐2,3‐diol dehydration; it has an impressive ability to restore the activity in situ by itself during the reaction, accounting for its high stability. This facilitates the efficient production of renewable penta‐1,3‐diene from pentane‐2,3‐dione via a novel approach, where penta‐2,3‐diol was obtained as an intermediate in 95 % yield under mild conditions.
Oxidative Coordination versus C3−C(O)Me Bond Cleavage in Acetylacetonate Iridium Complexes
Authors: Rivas Christopher E. , Alvarado‐Monzon Jose C. , Gonzalez‐Garcia Gerardo , Jimenez‐Halla J. Oscar C. , Rangel‐Garcia Jesus , Cristobal Crispin , Lopez Jorge A.
Published: April 2021

Iridabicycles [Ir{κ3‐N,C,O‐(pyC(H)=C(C(O)Me)2}(Cl)(L−L)](L−L=cod (cod=1,5‐cyclooctadiene), 1 a; bipy (bipy=2,2’‐bipyridine), 1 b) have been obtained by oxidative coordination of 3‐(pyridine‐2‐yl‐methylene)pentane‐2,4‐dione L1, to the complexes [{Ir(μ‐Cl)(cod)}2] and [{Ir(μ‐Cl)(coe)2}2] (coe=cis‐cyclooctene), the latter in the presence of bipy. Remarkably, cleavage of the C3−C(O)Me bond of L1 has instead been achieved in the reaction with [Ir(Cl)(dmb)2] (dmb=2,3‐dimethylbutadiene), yielding a compound formulated as [Ir{κ2‐N,C‐(pyC(H)C(C(O)Me))}(CO)(μ‐Cl)(Me)]2, 2. Treatment of dimer 2 with DMSO or PMe3 produced the complexes[Ir{κ2‐N,C‐(pyC(H)C(C(O)Me)}(CO)Cl(Me)L] (L=DMSO, 3 a; PMe3, 3 b). Plausible mechanisms for the reactions leading to complexes 1 and 2 are proposed by means of DFT calculations.