bluuebunny/crossref_metadata_2025 huggingface dataset:
Activities of Two Novel Macrolides, GW 773546 and GW 708408, Compared with Those of Telithromycin, Erythromycin, Azithromycin, and Clarithromycin against
Haemophilus influenzae
Authors: Kosowska Klaudia , Credito Kim , Pankuch Glenn A. , Hoellman Dianne , Lin Gengrong , Clark Catherine , Dewasse Bonifacio , McGhee Pamela , Jacobs Michael R. , Appelbaum Peter C.
Published: October 2004

The MIC at which 50% of strains are inhibited (MIC
50
) and the MIC
90
of GW 773546, a novel macrolide, were 1.0 and 2.0 μg/ml, respectively, for 223 β-lactamase-positive, β-lactamase-negative, and β-lactamase-negative ampicillin-resistant
Haemophilus influenzae
strains. The MIC
50
s and MIC
90
s of GW 708408, a second novel macrolide, and telithromycin, an established ketolide, were 2.0 and 4.0 μg/ml, respectively, while the MIC
50
and MIC
90
of azithromycin were 1.0 and 2.0 μg/ml, respectively. The MIC
50
and MIC
90
of erythromycin were 4.0 and 8.0 μg/ml, respectively; and those of clarithromycin were 4.0 and 16.0 μg/ml, respectively. All compounds except telithromycin were bactericidal (99.9% killing) against nine strains at two times the MIC after 24 h. Telithromycin was bactericidal against eight of the nine strains. In addition, both novel macrolides and telithromycin at two times the MIC showed 99% killing of all nine strains after 12 h and 90% killing of all strains after 6 h. After 24 h, all drugs were bactericidal against four to seven strains when they were tested at the MIC. Ten of 11 strains tested by multistep selection analysis yielded resistant clones after 14 to 43 passages with erythromycin. Azithromycin gave resistant clones of all strains after 20 to 50 passages, and clarithromycin gave resistant clones of 9 of 11 strains after 14 to 41 passages. By comparison, GW 708408 gave resistant clones of 9 of 11 strains after 14 to 44 passages, and GW 773546 gave resistant clones of 10 of 11 strains after 14 to 45 passages. Telithromycin gave resistant clones of 7 of 11 strains after 18 to 45 passages. Mutations mostly in the L22 and L4 ribosomal proteins and 23S rRNA were detected in resistant strains selected with all compounds, with alterations in the L22 protein predominating. Single-step resistance selection studies at the MIC yielded spontaneous resistant mutants at frequencies of 1.5 × 10
−9
to 2.2 × 10
−6
with GW 773546, 1.5 × 10
−9
to 6.0 × 10
−4
with GW 708408, and 7.1 × 10
−9
to 3.8 × 10
−4
with telithromycin, whereas the frequencies were 1.3 × 10
−9
to 6.0 × 10
−4
with erythromycin and azithromycin and 2.0 × 10
−9
to 2.0 × 10
−3
with clarithromycin. Alterations in the L22 protein (which were predominant) and the L4 protein were present in mutants selected by the single-step selection process. The postantibiotic effects of GW 773546, GW 708408, and telithromycin for seven
H. influenzae
strains were 6.6 h (range, 5.2 to 8.8 h), 4.7 h (range, 2.6 to 6.9 h), and 6.4 h (range, 3.8 to 9.7 h), respectively. The results of in vitro studies obtained with both novel macrolides were similar to those obtained with telithromycin and better than those obtained with older macrolides.
Chemical Diversity of Polyene Macrolides Produced by
Streptomyces noursei
ATCC 11455 and Recombinant Strain ERD44 with Genetically Altered Polyketide Synthase NysC
Authors: Bruheim Per , Borgos Sven E.F. , Tsan Pascale , Sletta Håvard , Ellingsen Trond E. , Lancelin Jean-Marc , Zotchev Sergey B.
Published: October 2004

The gram-positive bacterium
Streptomyces noursei
ATCC 11455 produces a complex mixture of polyene macrolides generally termed nystatins. Although the structures for nystatins A
1
and A
3
have been reported, the identities of other components of the nystatin complex remain obscure. Analyses of the culture extract from the
S. noursei
wild type revealed the presence of several nystatin-related compounds for which chemical structures could be suggested on the basis of their molecular weights, their UV spectra, and knowledge of the nystatin biosynthetic pathway. Nuclear magnetic resonance (NMR) studies with one of these polyene macrolides identified it as a nystatin analogue containing a mycarose moiety at C-35. A similar investigation was performed with the culture extract of the ERD44 mutant, which has a genetically altered polyketide synthase (PKS) NysC and which was previously shown to produce a heptaene nystatin analogue. The latter compound, tentatively named S44HP, and its derivative, which contains two deoxysugar moieties, were purified; and their structures were confirmed by NMR analysis. Nystatin analogues with an expanded macrolactone ring were also observed in the extract of the ERD44 mutant, suggesting that the altered PKS can “stutter” during the polyketide chain assembly. These data provide new insights into the biosynthesis of polyene macrolide antibiotics and the functionalities of PKSs and post-PKS modification enzymes.
OXA-60, a Chromosomal, Inducible, and Imipenem-Hydrolyzing Class D β-Lactamase fromRalstonia pickettii
Authors: Girlich Delphine , Naas Thierry , Nordmann Patrice
Published: October 2004

A chromosomally encoded oxacillinase, OXA-22, had been characterized fromRalstonia pickettiiPIC-1 that did not explain by itself the resistance profile of this strain to β-lactams. Thus, further analysis of the genetic background of this species led to the identification of another oxacillinase, OXA-60, that was expressed only after β-lactam induction. This chromosomally encoded oxacillinase shared 19% amino acid identity with OXA-22. It has a narrow-spectrum hydrolysis profile that includes imipenem. OXA-60-like enzymes were identified in severalR. pickettiistrains. Gene inactivation and induction studies of theblaOXA-60andblaOXA-22genes inR. pickettiiidentified the relative contribution of each oxacillinase to the resistance profile ofR. pickettiito β-lactams.
Hypermutation and the Preexistence of Antibiotic-Resistant
Pseudomonas aeruginosa
Mutants: Implications for Susceptibility Testing and Treatment of Chronic Infections
Authors: Oliver Antonio , Levin Bruce R. , Juan Carlos , Baquero Fernando , Blázquez Jesús
Published: October 2004

Whether or not resistant mutants will be present before the start of antibiotic treatment of an initially susceptible population of bacteria depends on the size of the infecting population, the rate of mutation to resistance, and the amount of time that the population has been maintained. In the present investigation, we argue that for the treatment of chronic infections caused by hypermutable
Pseudomonas aeruginosa
of the sort frequently found in cystic fibrosis patients, mutants resistant to all single antipseudomonal drugs will almost invariably be present in a high proportion at the onset of treatment, and consequently, these strains should be considered resistant to all agents when they are used as monotherapy. Using a construct of
P. aeruginosa
strain PAO1 with a
mutS
deletion (strain PAOΔ
mutS
), we show that when in vitro populations of less than 5 × 10
4
seemingly susceptible hypermutable bacteria are confronted with any of 11 antipseudomonal agents, mutants for which the MICs and the minimum bactericidal concentrations are in the range of clinical resistance will almost invariably ascend to dominance within 24 to 36 h. This does not occur for PAO1 without the
mutS
deletion. The results of our detailed analysis of this evolution of acquired resistance to two of these antibiotics, imipenem and ciprofloxacin, indicate that although the rates of mutation to resistance in PAOΔ
mutS
are on the order of 1 × 10
−6
per generation, resistant mutants are very likely to either be present in cultures of between 2 × 10
4
and 4 × 10
4
bacteria or arise after the bacterial populations are confronted with antibiotics. We also demonstrate with in vitro experiments that the problem of acquired resistance to treatment with single antibiotics can be thwarted by combination therapy with pairs of antibiotics of different classes with synergistic activities. We discuss the clinical implications of our analysis of these observations.
Evolution of the Antimicrobial Resistance ofStaphylococcusspp. in Spain: Five Nationwide Prevalence Studies, 1986 to 2002
Authors: Cuevas Oscar , Cercenado Emilia , Vindel Ana , Guinea Jesús , Sánchez-Conde Matilde , Sánchez-Somolinos Mar , Bouza Emilio
Published: October 2004

Data regarding the evolution ofStaphylococcusresistance in a whole country have a definite influence on the design of empirical treatment regimens. Nevertheless, incidence studies over long periods of time are expensive and very difficult to carry out. In order to ascertain the present situation of the antimicrobial resistance ofStaphylococcusin Spain and the change of this resistance over time, we performed five point prevalence studies (1986 to 2002) in a large group of Spanish hospitals (from 68 institutions in 1986 to 143 in 2002) collecting allStaphylococcusstrains isolated on a single selected day. All microorganisms were identified in the five studies at the same laboratory, and antimicrobial susceptibility testing was performed against 17 antimicrobial agents by the agar dilution method and a microdilution method. During this period, there was an overall increase in resistance to most antimicrobials amongStaphylococcus aureus/coagulase-negative staphylococci, mainly to oxacillin (1.5%/32.5% in 1986 versus 31.2%/61.3% in 2002) (P< 0.001), erythromycin (7%/41.1% in 1986 versus 31.7%/63% in 2002) (P< 0.001), gentamicin (5.2%/25.4% in 1986 versus 16.9%/27.8% in 2002) (P< 0.001;P= 0.5), and ciprofloxacin (0.6%/1.1% in 1986 versus 33.9%/44.9% in 2002) (P< 0.001). All of the isolates were uniformly susceptible to glycopeptides, linezolid, and quinupristin/dalfopristin. Resistance ofS. aureusto trimethoprim/sulfamethoxazole was very low (from 0.5% to 2.1%) (P= 0.152). Periodic performance of prevalence studies is a useful, inexpensive, and easy tool to know the nationwide situation of a microorganism and its resistance to antimicrobials; it also helps us assess the emergence and spread of antimicrobial resistance.
Infections with NontyphoidalSalmonellaSpecies Producing TEM-63 or a Novel TEM Enzyme, TEM-131, in South Africa
Authors: Kruger Tersia , Szabo Dora , Keddy Karen H. , Deeley Kathleen , Marsh Jane W. , Hujer Andrea M. , Bonomo Robert A. , Paterson David L.
Published: October 2004

Salmonellaspp. producing extended-spectrum beta-lactamases (ESBLs) have been reported in many countries, but there is no information on their prevalence in Africa. ESBL-producingSalmonella entericaserotype Isangi andS. entericaserotype Typhimurium strains have been noted in South Africa since 2001. A total of 160 consecutive isolates ofSalmonellaspp. were collected from 13 hospitals located in different cities in South Africa over a 5-month period from December 2002 to April 2003. All strains were screened for production of ESBLs by the double disk diffusion test and for AmpC production by assessing resistance to cefoxitin.blaSHV,blaTEM,blaCTX-M, andblaCMY-2were sought from all ESBL-positive and cefoxitin-resistant isolates. A total of 15.6% (25 of 160) isolates produced SHV or TEM ESBLs, and 1.9% (3 of 160) produced CMY-2. NineS. entericaserotype Typhimurium, eightS. entericaserotype Isangi, and threeS. entericaserotype Muenchen strains produced either TEM-63 or a derivative of TEM-63 designated TEM-131. Both TEM-63 and TEM-131 have an isoelectric point of 5.6, and their sequences have the following amino acid substitutions compared to the TEM-1 sequence: Leu21Phe, Glu104Lys, Arg164Ser, and Met182Thr. Additionally, TEM-131 has an Ala237Thr substitution. ESBL-producingSalmonellaspp. have become a significant public health problem in South Africa with particular implications for the treatment of serious nontyphoidalSalmonellainfections in children, for whom extended-spectrum cephalosporins were the preferred treatment.
Molecular Mechanisms of Primary Resistance to Flucytosine in
Candida albicans
Authors: Hope William W. , Tabernero Lydia , Denning David W. , Anderson Michael J.
Published: October 2004

Primary resistance in
Candida albicans
to flucytosine (5-FC) was investigated in 25 strains by identifying and sequencing the genes
FCA1
,
FUR1
,
FCY21
, and
FCY22
, which code for cytosine deaminase, uracil phosphoribosyltransferase (UPRT), and two purine-cytosine permeases, respectively. These proteins are involved in pyrimidine salvage and 5-FC metabolism. An association between a polymorphic nucleotide and resistance to 5-FC was found within
FUR1
where the substitution of cytidylate for thymidylate at nucleotide position 301 results in the replacement of arginine with cysteine at amino acid position 101 in UPRT. Isolates that are homozygous for this mutation display increased levels of resistance to 5-FC, whereas heterozygous isolates have reduced susceptibility. Three-dimensional protein modeling of UPRT suggests that the Arg101Cys mutation disturbs the quaternary structure of the enzyme, which is postulated to compromise optimal enzyme activity. A single resistant isolate, lacking the above polymorphism in
FUR1
, has a homozygous polymorphism in
FCA1
that results in a glycine-to-aspartate substitution at position 28 in cytosine deaminase.
In Vitro Evolution of Itraconazole Resistance in
Aspergillus fumigatus
Involves Multiple Mechanisms of Resistance
Authors: da Silva Ferreira Márcia Eliana , Capellaro José Luiz , dos Reis Marques Everaldo , Malavazi Iran , Perlin David , Park Steven , Anderson James B. , Colombo Arnaldo L. , Arthington-Skaggs Beth A. , Goldman Maria Helena S. , Goldman Gustavo H.
Published: October 2004

We investigated the evolution of resistance to the antifungal drug itraconazole in replicate populations of
Aspergillus fumigatus
that were founded from a strain with a genotype of sensitivity to a single drug and then propagated under uniform conditions. For each population, conidia were serially transferred 10 times to agar medium either with or without itraconazole. After 10 transfers in medium supplemented with itraconazole, 10 itraconazole-resistant mutant strains were isolated from two populations. These mutant strains had different growth rates and different levels of itraconazole resistance. Analysis of the ergosterol contents of these mutants showed that they accumulate ergosterol when they are grown in the presence of itraconazole. The replacement of the
CYP51A
gene of the wild-type strain changed the susceptibility pattern of this strain to one of itraconazole resistance only when
CYP51A
genes with N22D and M220I mutations were used as selectable marker genes. Real-time quantitative reverse transcription-PCR was used to assess the levels of expression of the
Afumdr1
,
Afumdr2
,
Afumdr3
,
Afumdr4
,
AtrF
transporter,
CYP51A
, and
CYP51B
genes in these mutant strains. Most mutants showed either constitutive high-level expression or induction upon exposure of
Afumdr3
,
Afumdr4
, and
AtrF
to itraconazole. Our results suggest that overexpression of drug efflux pumps and/or selection of drug target site mutations are at least partially responsible for itraconazole resistance and could be considered mechanisms for the emergence of clinical resistance to this drug.
Evidence for Biliary Excretion of Vancomycin into Stool during Intravenous Therapy: Potential Implications for Rectal Colonization with Vancomycin-Resistant Enterococci
Authors: Currie Brian P. , Lemos-Filho Luciano
Published: October 2004

Sixty-three stool samples and five bile samples were prospectively collected from 33 patients receiving intravenous vancomycin therapy and were quantitatively analyzed for vancomycin by a competitive immunoassay. Vancomycin was excreted via bile into the stools of almost all patients at concentrations of 3.3 to 94.8 μg/ml after ≥5 days of a therapy of 1 g every 12 h.
Novel Mutations within the
embB
Gene in Ethambutol-Susceptible Clinical Isolates of
Mycobacterium tuberculosis
Authors: Lee Ann S. G. , Othman Siti Noor Khadijah , Ho Yu Min , Wong Sin Yew
Published: October 2004

Genetic analysis of the
embB
gene revealed mutations in 17 (68%) of 25 ethambutol (EMB) resistant isolates (M306I, M306V, M306L, Q497R) but also in 4 (20%) of 20 EMB-susceptible isolates of
Mycobacterium tuberculosis
, namely, an ATG→ATM substitution resulting in M306I, G406N, and the novel alterations M423I and A659T.
Antimicrobial Susceptibility Patterns among Viridans Group Streptococcal Isolates from Infective Endocarditis Patients from 1971 to 1986 and 1994 to 2002
Authors: Prabhu Rajesh M. , Piper Kerryl E. , Baddour Larry M. , Steckelberg James M. , Wilson Walter R. , Patel Robin
Published: October 2004

To determine whether changes in antimicrobial resistance have occurred among viridans group streptococci, we retrospectively examined 50 viridans group streptococcal isolates recovered from patients with infective endocarditis over 3 decades. Resistance rates (percent resistant isolates 1971 to 1986 and 1994 to 2002) were as follows: levofloxacin, 0 and 9; penicillin and clindamycin, 0 and 4; and erythromycin and azithromycin, 11 and 26, respectively.
Pharmacokinetics of Indinavir at 800, 600, and 400 Milligrams Administered with Ritonavir at 100 Milligrams and Efavirenz in Ethnic Chinese Patients Infected with Human Immunodeficiency Virus
Authors: Lee Lawrence S. , Panchalingam Anushia , Yap Marline C. , Paton Nicholas I.
Published: October 2004

We assessed the pharmacokinetics of three different doses of indinavir in five patients. All doses achieved trough concentrations above efficacy thresholds. Toxic trough concentrations were observed in all patients receiving 800 mg, in two patients receiving 600 mg, and in none receiving 400 mg. Indinavir at 400 mg may be efficacious and less toxic in patients taking ritonavir and efavirenz.
Comparison of Simultaneous Splenic Sample PCR with Blood Sample PCR for Diagnosis and Treatment of Experimental
Ehrlichia canis
Infection
Authors: Harrus Shimon , Kenny Martin , Miara Limor , Aizenberg Itzhak , Waner Trevor , Shaw Susan
Published: October 2004

This report presents evidence that dogs recover from acute canine monocytic ehrlichiosis (CME) after 16 days of doxycycline treatment (10 mg/kg of body weight every 24 h). Blood PCR was as valuable as splenic aspirate PCR for early diagnosis of acute CME. Splenic aspirate PCR was, however, superior to blood PCR for the evaluation of ehrlichial elimination.
COMPRESSION OF IMAGES REPRESENTED USING MULTI-TRANSFORMS
Authors: RAMASWAMY ARUN , MIKHAEL WASFY B.
Published: October 2004

Constrained image representation employing multi-transforms has been recently developed. First, the image is divided into smaller non-overlapping subimages. Each subimage is resolved appropriately into 2-D subsignals, each of which is compactly represented in a specific transform domain. The subimage is efficiently represented by superimposing the dominant components corresponding to the subsignals. The residual error, which is the difference between the original subimage and the reconstructed subimage is minimized by adaptive algorithms. An optimization strategy selects the dominant coefficients from the various domains for adaptation. An efficient coding technique is presented to code the multi-transform coefficients. An image representation example is presented employing the DCT-Haar combination. Objective evaluations are made where it is shown that images represented using the multi-transform technique are more accurate than using the DCT for the same number of retained transform coefficients. Test subimages with a high amount of detail represented using the proposed technique show an SNR improvement of about 3 to 4 dB over using DCT alone. Finally, images, coded at bit rates of 0.44 bits/pixel and 1.23 bits/pixel employing the proposed technique verify the good quality of reconstruction.
SYNCHRONIZING NONAUTONOMOUS CHAOTIC SYSTEMS WITHOUT PHASE-LOCKING
Authors: WAH WU CHAI , ZHONG GUO-QUN , CHUA LEON O.
Published: October 2004

Pecora and Carroll1 have shown how two nonautonomous chaotic circuits driven by periodic forcing can be synchronized using the master-slave driving principle. However, in their scheme, the periodic forcing in both circuits needs to be phase-locked through some additional circuitry for the system to synchronize. In this paper, we show two ways in which this can be avoided.

In the first scheme, the two circuits are connected in a master-slave driving configuration and the periodic forcing is included in the driving signal such that it eliminates the need for the slave circuit to have an external periodic forcing signal. In addition, we can recover the periodic forcing signal at the slave circuit.

In the second scheme, the two circuits are connected in a mutual coupling configuration. The two circuits will synchronize regardless of what the periodic forcing signals of the two circuits are. In particular, the two periodic forcing signals could have different phases, different frequencies, or different shapes.

We discuss two interpretations of these synchronization schemes. First, we consider them as communication systems when the periodic forcing signal is replaced by a properly encoded information signal. We illustrate this in a physical circuit implementation. Second, we consider them as synchronization schemes for nonidentical systems by considering the external forcing signal as an error signal due to the difference between the two systems.
COMPLEMENTARY POLE-PAIR FILTERS AND POLE-PARAMETER TRANSFORMATIONS
Authors: PAI K.R. , MURTHY K.V.V. , RAMACHANDRAN V.
Published: October 2004

It is well known that the poles of a Butterworth filter (BF) are uniformly placed on the unit circle in the s-plane. If the order of the filter is a binary power (i.e., n=2k, k being an integer), then the pole-locations of such Butterworth filters exhibit very interesting symmetry properties in the s-plane. In this paper, first we point out that the pole-vectors of the Butterworth filters (of order n=2k) can be subjected to “prescribed symmetrical swinging”, such that certain symmetry properties present in the original pole-pattern can be maintained invariant. Then, we introduce a new family of filters called “Complementary Pole-Pair Filters (CPPFs)”, generated by judiciously exploiting the symmetry-invariant property referred to above. The Q-constraint can be easily incorporated into the design considerations of the new family of filters; accordingly, the CPPFs are classified as Low-Q filters (LQFs) and High-Q Filters (HQFs). Performances of LQFs and HQFs are analyzed and compared with that of the generic Butterworth filter. Also, the possibility of generating additional transitional filters is indicated. Design constraints are derived. Numerical examples are worked out for illustrations.

A new transformation referred to as the “Pole-Parameter Transformation (PPT)”, which modifies the pole-parameters of a given reference filter to obtain a low-Qp filter, but with increased order of complexity, is formulated. This enables us to generate new families of Transitional Filters. The transitional nature involved between Butterworth and Chebyshev filters is brought out. The performance of new filters obtained are compared with those available in the literature. The CPP Filters coupled with the PPT provide a basis for generating a large family of transitional filters, and serves to commendably place the known classical filters as particular members of a large general family.
PERFORMANCE OF THE RELAXATION ALGORITHM FOR MAXIMUM-CUT PROBLEMS
Authors: URAHAMA KIICHI , NISHIYUKI HIROSHI
Published: October 2004

A relaxation algorithm is presented for solving a class of combinatorial optimization problems called set-partitioning tasks. The convergence property of the presented algorithm is investigated theoretically. A performance guarantee is derived theoretically for the present algorithm applied to an NP-hard example problem called the maximum-cut graph partitioning. The experimental examination of its performance manifests its superiority in computational speed to the conventional gradient method.
MICROPHONE ARRAY SYSTEM IN ACOUSTICAL SOURCE LOCALIZATION USING LEAST SQUARE ESTIMATION
Authors: JIAN MING , KOT ALEX C. , ER MENG H.
Published: October 2004

In this paper, we address the problem of acoustical source localization using a five-elements microphone array system. The time delay estimation of signal arrival for any given pair of microphones using least square technique is proposed. These estimated time delays are used in the geometric location method to determine the location of the acoustical source which, in our case, is the position of talker of interest. Computer simulations are carried out in a teleconferencing room scenario. It is shown that the location of the acoustical source can be estimated effectively as signal-to-noise ratio is larger than 20 dB in a high reverberation environment.
THE RESIDUAL BOUNDS OF FINITE ALGEBRAS
Authors: MCKENZIE RALPH
Published: October 2004

We exhibit, for every finite cardinal λ≥3 and also for each of λ=ω, ω1, (2ω)+, a fourelement algebra that generates a precisely residually < λ variety. We exhibit an eight-element simple algebra with eight operations that is inherently non-finitely-based and generates a precisely residually countable variety.
A SYNTACTICAL PROOF OF LOCALITY OF DA
Authors: ALMEIDA JORGE
Published: October 2004

Using purely syntactical arguments, it is shown that every nontrivial pseudovariety of monoids contained in DO whose corresponding variety of languages is closed under unambiguous product, for instance DA, is local in the sense of Tilson.
ON LANGUAGES FACTORIZING THE FREE MONOID
Authors: ANSELMO MARCELLA , RESTIVO ANTONIO
Published: October 2004

A language X⊂A* is called factorizing if there exists a language Y⊂A* such that XY = A* This work was partially supported by ESPRIT-EBRA project ASMICS contact 6317 and project 40% MURST “Algoritmi, Modelli di Calcolo e Strutture Informative”. and the product is unambiguous. First we give a combinatorial characterization of factorizing languages. Further we prove that it is decidable whether a regular language X is factorizing and we construct an automaton recognizing the corresponding language Y. For finite languages we show that it suffices to consider words of bounded length. A complete characterization of factorizing languages with three words and explicit regular expression for the corresponding language Y are also given. Finally we prove a more general result stating that, given two regular languages X and T, it is decidable whether there exists a language Y such that XY=T and the product is unambiguous.
ON SUBSEMIGROUPS AND IDEALS IN FREE PRODUCTS OF SEMIGROUPS
Authors: CAMPBELL C.M. , ROBERTSON E.F. , RUŠKUC N. , THOMAS R.M.
Published: October 2004

Subsemigroups and ideals of free products of semigroups are studied with respect to the properties of being finitely generated or finitely presented. It is proved that the free product of any two semigroups, at least one of which is nontrivial, contains a two-sided ideal which is not finitely generated as a semigroup, and also contains a subsemigroup which is finitely generated but not finitely presented. By way of contrast, in the free product of two trivial semigroups, every subsemigroup is finitely generated and finitely presented. Further, it is proved that an ideal of a free product of finitely presented semigroups, which is finitely generated as a semigroup, is also finitely presented. It is not known whether one-sided ideals of free products have the same property, but it is shown that they do when the free factors are free commutative.
AN ALGEBRAIC MONOID APPROACH TO LINEAR ASSOCIATIVE ALGEBRAS, II
Authors: HUANG WENXUE
Published: October 2004

Let A be a linear associative K-algebra with unity (LAA), K an algebraically closed field. A K–subalgebra of A containing the unity of A is referred to as a sub-LAA of A. A with respect to the multiplication (respectively, Lie bracket) is an algebraic monoid (respectively, Lie algebra) over K, denoted by AM (respectively, AL). Let G(A) and J(A) denote the unit group of AM and Jacobson radical of A, respectively. The following are proved in this paper. (i) If BM is a Borel submonoid of AM, the Zariski closure of a Borel subgroup of G(A), then B is a sub-LAA of A and [Formula: see text], where [Formula: see text] is the set of Borel submonoids of AM. (ii) If dim A≠3, then G(A) is nilpotent iff for every proper sub-LAA N of A, G(N) is nilpotent. In addition, a relationship of Borel submonoids of AM and Borel subalgebras of AL is revealed.
Immunomodulation of human natural killer cell cytotoxic function by organochlorine pesticides
Authors: Reed Adrian , Dzon Leticia , Loganathan Bommanna G , Whalen Margaret M
Published: October 2004

Organochlorine pesticides are used worldwide. To our knowledge there have been no studies dealing with the effects of these agents under in vitro conditions on human natural killer (NK) cell cytotoxic function. NK cells play a central role in immune defense against tumor development and viral infections. Thus, any agent that interferes with the ability of NK cells to lyse their targets could increase the risk of tumor incidence and/or viral infections. In this study, we examined the effects of organochlorine pesticides and some of their breakdown products on the ability of human NK cells to lyse tumor cells. A total of 11 compounds were tested. The compounds were tested in both purified NK cells as well as a cell preparation that contained other mononuclear cells (predominantly T cells) and NK lymphocytes (referred to as T/NK cells). Lymphocytes were exposed to the compounds for periods of time ranging from 1 hour to 6 days. Exposure of highly purified NK cells to 5 μ M α-chlordane, γ-chlordane, 4,4'-DDT, heptachlor, oxychlordane, or pentachlorophenol (PCP) inhibited their ability to destroy K562 tumor-cells by 88±5, 92±8, 61±13%, 64±10%, 69±11%, 76±12%, respectively, after a 24h exposure. The loss of cytotoxic function seen with α-and γ-chlordane remained essentially constant out to 6 days, while that seen with 4,4'-DDT, oxychordane and PCP increased with longer exposures (6 d). PCP was the most effective of the compounds tested at decreasing NK function. Of the compounds that caused decreased lytic function when tested in purified NK cells, only PCP and oxychordane decreased the lytic function of the T/NK cell preparation after any exposure. The results provide evidence of relative toxic potential for the 11 compounds and their immunomodulatory effects on other mononuclear cells (such as T-cells, B-cells, and monocytes) as well as NK lymphocyte function.
Ochratoxin A levels in human plasma and foods in Lebanon
Authors: Assaf Hind , Betbeder Anne-Marie , Creppy Edmond E , Pallardy Marc , Azouri Hayat
Published: October 2004

Ochratoxin A (OTA) is a widespread mycotoxin which contaminates food such as cereals, beer, coffee, wine and products of animal origin. OTA is known for its nephrotoxic, immunotoxic and carcinogenic properties. The prevalence of OTA in human blood and foodstuffs has been investigated in many countries. In this study, exposure of the Lebanese population to OTA was evaluated and the contamination of the most commonly consumed foods in Lebanon by OTA was assessed. Plasma samples from healthy individuals and also cereals and beer samples obtained from markets were collected from the different regions of Lebanon. OTA was detectable in 33% of tested plasma samples ( n=250) with a concentration ranging from 0.1 to 0.87 ng/mL and a mean of 0.17±0.01 ng/mL. No sex and age differences were found. The frequency of OTA-positive plasma samples obtained in the South of Lebanon and in the Bekaa valley (50 and 47%, respectively) was significantly higher compared to plasma samples obtained in the Beirut/Mount Lebanon region (19%). Food analyses showed that wheat, burghul and beer were contaminated with a mean value of 0.15±0.03 μg/kg, 0.21±0.04 μg/kg and 0.19±0.12ng/mL, respectively. These data suggest that the Lebanese population is exposed to OTA through food ingestion at concentrations lower than the tolerable daily intake.
Selective Formation of Alkoxo-bridged Titanium(IV) Polynuclear Complexes with Polyaminopolycarboxylate: First Titanium(IV) Octanuclear Complex Containing Cubic-type {Ti4(μ-oxo)4}2(μ-alkoxo)4 Core
Authors: Miyashita Yoshitaro , Islam Md Monirul , Amir Nagina , Fujisawa Kiyoshi , Okamoto Ken-ichi
Published: October 2004

Two kinds of alkoxo-bridged Ti(IV) polynuclear complexes were selectively obtained depending on reaction conditions. Crystal structures of the dinuclear complex [Ti2(μ-dptaO)2]2− and the novel octanuclear complex [{Ti4(μ-O)4}2(μ-dptaO)4]4− (H4dptaOH = 2-hydroxypropane-1,3-diamine-N,N,N′,N′-tetraacetic acid) were determined. The obtained complexes were spectrochemically characterized.
Using performance indicators to improve performance
Authors: Mullen Penelope M.
Published: October 2004

The recent introduction of performance assessment within the UK NHS, incorporating numerous performance indicators (PIs) and league tables, has led to health care organisations facing large numbers of targets and a star rating system with associated rewards and penalties. However, there is considerable evidence that using PIs for judgement rather than learning provides perverse incentives and can prove counterproductive. Drawing on earlier PI systems which, supplemented by expert systems, were designed to promote learning and exploration particularly by encouraging analysis of interactions between different indicators, a series of 'mini case studies' is presented. These reveal interesting relationships and suggest explanations for variations in performance, areas worth exploring further and possible approaches to improving performance - approaches not apparent from individual indicators and league tables. It is concluded that presentation of PIs in a format that encourages exploration and analysis could greatly enhance the potential of the current PIs to improve NHS performance.
An audit of the process of developing the Health Improvement Programme into the Strategic and Financial Framework in two Health Authorities
Authors: Carlisle J. , Shickle D. , Suckling R. , Singleton C. , Bentley C.
Published: October 2004

Health Improvement Programmes (HImPs) are a means of documenting the health needs of a population and are intended to be translated into commissioning decisions by the Strategic and Financial Framework (SaFF). This paper examines some major influences on the process of translating the HImP into the SaFF. The Directors of Public Health in two Health Authorities were concerned that the development of the SaFF did not always represent a clear progression from the HImP. An audit to pinpoint where commissioning decisions did not match the identified health improvement needs in two Health Authorities was carried out between November 2000 and February 2001. The overall findings confirmed that needs identified in the HImPs were not fully reflected in the service provision described in the final SaFFs. The audit provided evidence that was useful in identifying major issues and influences that facilitated or hindered the development of the SaFF from the HImP. Some of the ways in which HImP priorities disappeared from the SaFF and non-HImP priorities appeared in it were also distinguished. The conclusion is that a clear, criterion-based process should enable health and social care communities and Primary Care Trusts to develop a more responsive commissioning process in future, and specific recommendations to that effect are made.
Characterization of a Monoclonal Antibody, HTA28, Recognizing a Histone H3 Phosphorylation Site as a Useful Marker of M-phase Cells
Authors: Hirata Akihiro , Inada Ken-ichi , Tsukamoto Tetsuya , Sakai Hiroki , Mizoshita Tsutomu , Yanai Tokuma , Masegi Toshiaki , Goto Hidemasa , Inagaki Masaki , Tatematsu Masae
Published: October 2004

Mitosis is a valuable indicator of active tissue proliferation but, other than morphological characteristics, there have hitherto been no markers available to detect only M-phase cells. However, a newly established monoclonal antibody (MAb), HTA28, recognizing histone H3 (H3) harboring phosphoserine 28, allows visualization with mitotic chromosomal condensation. In this study we investigated the use of HTA28 for immunohistochemical (IHC) detection of M-phase cells in the regenerating rat liver after partial hepatectomy (PH). Groups of three to five rats were sacrificed at intervals up to 72 hr after PH and proliferation was then assessed by IHC staining using HTA28 and other markers. The temporal pattern of the HTA28 staining index (SI) was very similar to that for the mitotic index (MI), also showing similarities to the bromodeoxyuridine (BrdU) labeling index (LI) with a time lag. The HTA28 SI proved to be higher than MI at every time point in line with HTA28 immunoreactivity maintained for all stages of M-phase. The spatial distribution of HTA28-positive cells corresponded with those of other proliferative cell markers. These therefore provide strong evidence for the applicability of HTA28 as an M-phase marker. We also showed that antigenicity for HTA28 is lost if tissue is not immediately fixed after sampling.
Immunolocalization of Caveolin-1 in Rat and Human Mesothelium
Authors: von Ruhland Christopher J. , Campbell Lee , Gumbleton Mark , Jasani Bharat , Newman Geoffrey R.
Published: October 2004

Flask-shaped vesicles have been described as caveolae in mesothelial cells in a number of animal species based on morphological criteria only. Using an antibody against caveolin-1, said to be a biochemical marker of caveolae, immunoelectron microscopy suggests that many but not all such vesicles in mesothelial cells are caveolae. Mesothelial cells from different anatomical sites showed obvious variations in both the population density and distribution of these flask-shaped vesicles and in their density of immunostaining. Lung and pericardial sac had the highest staining density. In some sites (e.g., lung, bladder, colon) caveolae were equally distributed between apical and basolateral surfaces, whereas in others (e.g., spleen, liver), they were predominantly apical. Additional immunopositive sites in the peritoneal membrane were identified, including the epineurium of peripheral nerves and the endothelium of lymphatic vessels. We further suggest that variations in the number of mesothelial cell caveolae and the density of their immunolabeling may have implications for our understanding of certain diseases such as malignant mesothelioma, especially in view of the recent hypothesis that it may be caused by SV40, a virus that appears to enter cells via caveolae.
Non-Structural Carbohydrates and Catalytic Activities of Sucrose Metabolizing Enzymes in Trunks of Two Juglans Species and their Role in Heartwood Formation
Authors: Magel Elisabeth , Abdel-Latif Amani , Hampp Rüdiger
Published: October 2004

In trunks of Juglans nigra and the hybrid J. major × J. regia, the presence of non-structural carbohydrates, sucrose synthesizing and degrading enzymes, and their correlation with heartwood formation was investigated. Contents of starch and sucrose were highest in the youngest sapwood, decreased with increasing age of the tissue, and were absent in the heartwood. Pools of the monosaccharides glucose and fructose were low in the sapwood, and fructose was absent from the heartwood. Glucose transiently increased at the sapwood heartwood boundary in trunks of the hybrid. In black walnut stems, however, glucose started to accumulate within the transition zone and reached considerable amounts in the heartwood. Cold-adaptation in walnut wood was characterized by accumulation of soluble sugars. Sucrose formation was enabled by enhanced rates of sucrose-phosphate synthase (SPS, EC 2.4.1.14). Mid-winter starch-sugar interconversion was accompanied by increases in the activity of sucrose synthase (SuSy, EC 2.4.1.13; black walnut), or acid invertases (EC 3.2.1.26; hybrid). In the tissues undergoing heartwood formation, sucrose breakdown was enhanced from late summer until early winter. Sucrolysis was dominated by acid invertases with minor contribution of sucrose synthase. The catalytic activity of UDP-glucose pyrophosphorylase (EC 2.7.7.9), involved in the metabolization of the sucrose cleavage products, followed this seasonal trend and showed elevated activities from late summer until early winter. These data are further proof for the earlier made hypothesis (Hauch and Magel 1998) that the in situ synthesis of heartwood flavonoids relies on an interaction between primary (sucrose) and secondary metabolism. Flavonoids, however, constitute only a minor fraction in the heartwood of walnut and the bulk of heartwood phenolics seem to derive from transformation of phenolic precursors. Therefore, these recent findings together with earlier data are taken as evidence that more than one type of heartwood formation exists.
Annual Rhythm of Xylem Growth in Rubberwood (Hevea brasiliensis) Trees Grown in Malaysia
Authors: Ohashi Yoji , Sahri Mohd Hamami , Yoshizawa Nobuo , Itoh Takao
Published: October 2004

The periodicity of the growth increment in six rubber wood (Hevea brasiliensis Muell. Arg.) trees grown in Peninsula Malaysia was investigated continuously throughout three years using the pinning and the band-dendrometer method. The pinning and dendrometer data were analyzed for obtaining the correlation with the seasonal rhythm of radial growth and circumferential increments.

The data of growth increments measured with the dendrometer continuously for three years indicated growth dormancy during the first three to five months (from January to March or May) each year in all the sample trees, in which annual ring-like features were observed. This means that rubber wood trees have an annual rhythm in the xylem growth. The boundary zone consisted of flattened wood fibers with thin walls, axial parenchyma cells, and small vessels. On the other hand, those obtained from the pinning method showed a vague growth dormancy around March every year. It seemed that growth measurement in tropical trees using the dendrometer is useful for detecting the growth rhythm of cambium.
The Condition, after 31 Years Exposure, of Pine Stakes Treated with Ammoniacal Copper-Based Preservatives
Authors: Häger Bror , Johnson Gary C. , Thornton John D. , Gardner W. David
Published: October 2004

Pinus sylvestris sapwood stakes were treated with various copper–containing waterborne and oilborne preservatives and exposed in ground for 31 years at Walpeup, Australia. Most of the waterborne preservative treatments contained basic copper carbonate and one or more of the following additives: arsenic pentoxide, pyridine, sodium pentachlorophenate, tannin and benzoic, boric, chromic, salicylic and sorbic acids. Basic copper carbonate and sulphate, at 0.95 kg m−3 of copper, protected the stakes from significant subterranean termite attack at a site in Australia providing a moderate termite hazard. Three additives (arsenic pentoxide at 0.95 kg m−3, sodium pentachlorophenate at 0.93 kg m−3 and fluoride at 0.9 kg m−3) significantly improved the efficacy of basic copper carbonate when used at retentions of 1.7 to 2.0 kg m−3 of copper. The six waterborne preservative combinations that performed best (i.e. rating greater than 6.5 out of 8) against both the termite and decay hazards over the 31 year period contained basic copper carbonate (at least 1.79 kg m−3 of copper) plus arsenic pentoxide (at least 0.92 kg m−3). Three of the six combinations also contained chromic acid. The oilborne preservative combination performing best contained basic copper carbonate (1.33 kg m−3) and pentachlorophenol (6.64 kg m−3) in tall oil. A treatment containing a similar amount of pentachlorophenol in tall oil, but no basic copper carbonate was significantly less effective. Other treatments containing basic copper carbonate and pentachlorophenol in tall oil or the copper compound with sodium pentachlorophenate in oil emulsion performed well. The implications of these results for the current generation of copper-based preservatives are discussed.
Thermomechanical (TMP) and Chemo-Thermomechanical Pulps (CTMP) for Medium Density Fibreboards (MDF)
Authors: Roffael Edmone , Dix Brigitte , Schneider Thomas
Published: October 2004

Thermomechanical (TMP) and chemo-thermomechanical pulps (CTMP) were prepared from spruce under different pulping conditions. The fibres were dried at 70 °C and medium density fibreboards (MDF) were made therefrom in pilot plant scale using urea-formaldehyde resins as a binder. The results of testing the physical-mechanical properties reveal that the pulping temperature has a significant influence on the thickness swelling and water absorption of the boards. MDF prepared from fibres produced at high pulping temperature (180 °C) generally show lower thickness swelling and water absorption than MDF made from fibres produced at low pulping temperature (140°C and 160 °C). However, high pulping temperature may have a negative effect on the internal bond strength of the boards. In general, CTMP leads to MDF with higher internal bonding strength compared to those derived from TMP. In addition, the influence of different drying conditions (150 °C and 170 °C) of TMP and CTMP on the physical-mechanical properties of MDF was assessed. MDF made from CTMP showed lower thickness swelling when dried under high temperature.
Characterisation of Fungal Degraded Birch Wood by FTIR and Py-GC
Authors: Backa Stefan , Brolin Anders , Nilsson Thomas
Published: October 2004

Rot fungi Fomitopsis pinicola and Sterum hirsutum were employed in preparing decayed birch wood
samples. The degree of decay was determined as weight loss. The samples were analysed by analytical
pyrolysis (PY) and infrared spectroscopy (FTIR) and correlated to weight loss by means of multivariate
calibration.

The above techniques provided both quantitative assessments and qualitative interpretations. The PY
technique can distinguish between the fungi at all degrees of decay while FTIR failed at low weight losses.
This may be due to fungal biomass, the amount of which is difficult to determine in the decayed sample.
Both analytical techniques can be calibrated to predict weight losses from 0 to 45%. Different fungal
degradation patterns could also be identified, especially when pyrolysis was used. F. pinicola degraded
lignin to a lesser extent at the same weight loss than did S. hirsutum. General degradation mechanisms
could be confirmed for the fungi studied.
The Effects of Specific Volatile Organic Compounds Produced by Trichoderma Spp. on the Growth of Wood Decay Basidiomycetes
Authors: Humphris Sonia N. , Wheatley Ron E. , Bruce Alan
Published: October 2004

Previous work by Srinivasan et al. (1992) and Bruce et al. (1996) has shown that inhibition of wood
decay fungi by volatile organic compounds produced by Trichoderma spp. is dependent on the type of
growth media and age of the Trichoderma colony. Wheatley et al. (1997) identified five volatile organic
compounds produced by Trichoderma spp. that may be inhibitory to wood decay fungi. The effects of
four of these compounds (Acetone, 2-methyl-1-butanol, heptanal and octanal) were tested over a range
of concentrations against four selected wood decay fungi. Fungi were incubated in malt extract broth
under appropriate conditions and growth was estimated by biomass production and respiration rates.
Growth of all four fungi was affected by at least one of the compounds, usually by inhibition but occasionally
stimulation. All but two of the fungus/chemical combinations showed significant effects on biomass
development (P < 0.05) and fifteen of the sixteen combinations produced a significant concentration
effect on respiration rates (P < 0.05). The aldehydes, heptanal and octanal, were very effective
against all four wood decay fungi. All four fungi were inhibited by more than 80% at 25 μg ml−1 by
heptanal and three of the four fungi were totally inhibited at 250 μg ml−1. Acetone did not inhibit the
four wood decay fungi and even stimulated fungal growth at some concentrations. 2-methyl-1-butanol
was only effective at the highest concentration of 2500 μg ml−1. The implications of these results for the
biological control of wood decay fungi and future studies are discussed.