bluuebunny/crossref_metadata_2025 huggingface dataset:
Improved microvessel repair: Laser welding with an anti‐thrombotic solder
Authors: Stewart Robert B. , Bass Lawrence S. , Thompson Jeffrey K. , Nikoi Naa Dei , Becker Glenn , Kung Robert T.V.
Published: October 2002

Background and Objectives

Concentrated protein solutions can be used as thermally polymerized solders in laser welding. Solders supplemented with biologically active chemicals may provide in situ drug delivery for localized therapeutics. These studies characterize a serum albumin (SA) solder containing heparin, designed to reduce microvascular thrombosis rates.

Study Design/Materials and Methods

Samples of heparin added to 30% SA to obtain heparin‐to‐albumin molar ratios (HAMR) of 4:1 and 2:1 were thermally polymerized, and heparin release into saline was measured. Using a rat thrombosis model, patency was determined for suture, and 0 U/ml (control), 2.5 U/ml, 50 U/ml heparin solder repairs.

Results

Heparin release was five times higher for 4:1 than 2:1 HAMR solder acutely, but was equivalent after 2 days. Animal patency rates were: 50% suture, 0% control, 50% low heparin, 66% high heparin (P < 0.05 vs. control).

Conclusions

Solders incorporating heparin should provide in situ anti‐thrombotic therapy reducing the risk of microvascular thromboses. Lasers Surg. Med. 31:36–40, 2002. © 2002 Wiley‐Liss, Inc.
Photomechanical delivery of 100‐nm microspheres through the stratum corneum: Implications for transdermal drug delivery
Authors: Lee Shun , McAuliffe Daniel J. , Kollias Nikiforos , Flotte Thomas J. , Doukas Apostolos G.
Published: October 2002

Background and Objectives

Photomechanical waves (PWs) render the stratum corneum permeable and allow molecules to diffuse into the epidermis. The aim of this study was to investigate the probe size that could be delivered through the stratum corneum and into the epidermis.

Study Design/Materials and Methods

A single PW was applied onto the rat skin in vivo. Aqueous suspensions of fluorescent microspheres, 100 nm in diameter, were used as probes for transdermal delivery. The presence of the microspheres in the epidermis was measured by a fiber‐based spectrofluorimeter after the stratum corneum was removed by tape‐stripping (TS).

Results

Exposure of the rat skin to a PW permeabilized the stratum corneum and allowed the fluorescent microspheres to diffuse into the epidermis.

Conclusions

The experiments show that PWs can facilitate the delivery of very large molecules and probes into the epidermis. Lasers Surg. Med. 31:207–210, 2002. © 2002 Wiley‐Liss, Inc.
GPX5 is present in the mouse caput and cauda epididymidis lumen at three different locations
Authors: Rejraji Hanae , Vernet Patrick , Drevet JoËl R.
Published: October 2002

In mice, GPX5 is a secreted protein abundantly synthesized by the caput epididymidis. The protein is secreted as early as the initial segment of the caput and is found subsequently associated with the sperm plasma membrane in a sub‐acrosomic localization. We show here that GPX5 is present in the caput and cauda epididymides lumens in three different locations: either free as a soluble protein in the caput epididymal fluid, weakly bound to caput sperm membranes, or, finally, associated to lipid‐containing structures conferring to the protein a protective effect against proteolytic digestions. Within the cauda epididymidis, the amount of free GPX5 is low compared to the caput and the association with sperm membranes proved to be more solid. In both caput and cauda sperm samples, the association of GPX5 with the sperm membrane protects GPX5 from proteolytic cleavages. Protection against proteolytic digestions can be overcome by physical treatments of epididymal fluid and sperm samples such as ultrasounds or very acidic pH. These data suggest that complex phenomena and structures participate in the transfer and binding of the caput‐secreted GPX5 protein to the sperm plasma membrane. Mol. Reprod. Dev. 63: 96–103, 2002. © 2002 Wiley‐Liss, Inc.
Effects of the aromatase inhibitor fadrozole on plasma sex steroid secretion, spermatogenesis and epididymis morphology in the lizard, Podarcis sicula
Authors: Cardone Anna , Comitato Raffaella , Bellini Luigi , Angelini Francesco
Published: October 2002

Recently, increasing importance has been attached to the role of estrogens and their receptors in male reproduction, since they have been found to be abundant in the male reproductive tract. In the lizard, Podarcis sicula, a seasonal breeder, estrogens seem to be involved in the regulation of testicular activity. Particularly, it has been hypothesized that the block of spermatogenesis and the complete regression of the epididymis and other secondary sexual characters (SSCs) in autumn might be due to high estrogen levels. To investigate the role of estrogens in the reproductive process of male lizards, we utilized Fadrozole ((AI) [4‐(5,6,7,8‐tetrahydroimidazole [1,5‐a] pyridin‐5‐yl)‐benzonitrile monohydrochloride] (CGS 16949A)), a nonsteroidal inhibitor of aromatase, the enzyme involved in the aromatization of androgens to estrogens, evaluating its effects on plasma sex‐hormone release, spermatogenesis and epididymis morphology. For this purpose, adult male lizards, captured during the autumnal recrudescence, were intraperitoneally injected with 0.5 μg and 5 μg/g/body weight of AI for 15 and 30 days. In the animals treated with the higher AI dose, estrogen levels decreased if compared to the control groups, whereas androgen levels increased. Furthermore, histologic sections of testes and epididymes showed that the 30‐day treatment with AI‐induced spermatogenesis resumption with release of sperms into the large lumen of the seminiferous tubules, and the epididymes appeared more developed with moderately secreting columnar canal cells. Therefore, it is proposed that failure of spermatogenesis in autumn might be due to high estrogen levels. Mol. Reprod. Dev. 63: 63–70, 2002. © 2002 Wiley‐Liss, Inc.
Questionnaires for women with urinary symptoms
Authors: Graham Christopher W. , Dmochowski Roger R.
Published: October 2002

Aims

To identify the characteristics of optimal symptom questionnaires in women with lower urinary tract symptoms (LUTS).

Methods

Literature review.

Results

Although numerous questionnaires have been developed for the evaluation of female LUTS, no one instrument has emerged as that preferred for collecting and reporting subjective information about LUTS in women. Questionnaires currently available range widely in intended purpose, extent and style, and in the quality of testing used to validate them.

Conclusions

Questionnaires should be constructed based on scientifically sound validation techniques that reflect disease and/or symptoms in the target population. They should be concise, easily administered and scored, discriminant between sphincter and bladder causes of incontinence, and able to measure severity and the effect of the symptom on the patient. Neurourol. Urodynam. 21:473–481, 2002. © Wiley‐Liss, Inc.
Flapwise bending vibration of rotating plates
Authors: Yoo H. H. , Kim S. K.
Published: October 2002

Linear equations of motion for the flapwise bending vibration analysis of rotating plates are derived in the present work. The equations of motion are transformed into dimensionless forms in which three dimensionless parameters are identified. The effects of the dimensionless parameters on the characteristics of the flapwise bending vibration of rotating plates are investigated. The accuracy of the present modelling method is verified through comparing its numerical results to those obtained by an existing method in the related literature. Eigenvalue loci crossing and eigenvalue loci veering phenomena are observed and discussed. The variations of mode shapes associated with the phenomena are also exhibited. Copyright © 2002 John Wiley & Sons, Ltd.
Infant and caregiving factors affecting weight‐for‐age and motor development of full‐term and premature infants at 1 year post‐term
Authors: Pridham Karen F. , Brown Roger , Clark Roseanne , Sondel Sherie , Green Christopher
Published: October 2002

Guided by a theoretical process model, we examined direct and indirect effects of infants' biologic condition and experience, the caregiving environment, and caloric intake variables on two outcomes, weight‐for‐age and motor development, for 52 full‐term and 47 premature infants at 12 months post‐term age. For full‐term infants, birth weight and infant expression of positive affect and behavior during feeding had predicted positive direct effects on weight‐for‐age. Infant regulation of negative affect and behavior had an unexpected negative effect on this outcome. For premature infants, severity of acute illness, mother's regulation of negative affect and feeding behavior, and caloric intake affected weight‐for‐age in unpredicted directions. Caregiving variables had indirect effects, through caloric intake, on both outcomes only for premature infants. The findings suggest the theoretical process model differs for premature infants and full‐term infants, both in the contributing variables and in the processes of effects. © 2002 Wiley Periodicals, Inc. Res Nurs Health 25:394–410, 2002
Nuchal translucency measurements in consecutive normal pregnancies. Is there a predisposition to increased levels?
Authors: Maymon R. , Padoa A. , Dreazen E. , Herman A.
Published: October 2002

Objective

The current study aims to assess the relative risk of isolated increased nuchal translucency (NT) in consecutive normal pregnancies.

Methods

A retrospective search of the fetal medicine unit database in which NT assessment was conducted. Only singleton fetuses with an unremarkable pregnancy outcome were included in this study. The repeated NT either at a threshold of >2.5 mm or ⩾95th centile of the normal range for various CRLs (2 mm at a CRL ⩽44 mm to 2.85 mm at CRLs 83–84 mm) was assessed. Pearson's correlation was applied to investigate any correlation between a log10 NT obtained in two consecutive pregnancies. The chance of an increased NT in the first pregnancy followed by similar results in the subsequent one was assessed using Fisher's exact test.

Results

Ninety‐two pregnant women with two consecutive normal pregnancies were identified. There was a highly significant correlation between the log10 NT values measured in the consecutive pregnancies (r = 0.38; p < 0.001). The relative risk of an isolated NT ⩾2.5 mm in the first pregnancy to be followed by a similar finding in the subsequent one was 18.21 (95% confidence interval [CI]: 3.62–91.55). The relative risk of an isolated NT ⩾95th centile in the first pregnancy to be followed by a similar result in the subsequent one was 21 (95% CI: 4.53–97.44).

Conclusion

The current results indicate a significant correlation of NT values in consecutive unaffected pregnancies. There also was a predisposition for a repeated isolated increased NT in subsequent pregnancies. Additional series and more information are needed before firm conclusions can be made. Copyright © 2002 John Wiley & Sons, Ltd.
Decreased first trimester PAPP‐A is a predictor of adverse pregnancy outcome
Authors: Yaron Yuval , Heifetz Sigal , Ochshorn Yifat , Lehavi Ofer , Orr‐Urtreger Avi
Published: October 2002

Objective

Low levels of maternal serum pregnancy associated plasma protein‐A (PAPP‐A) have been linked to chromosome anomalies such as trisomy 21, 13 and 18, triploidy and sex chromosome aneuploidy. Low levels of PAPP‐A have also been implicated in spontaneous miscarriage. The purpose of this study was to evaluate whether low levels of first trimester PAPP‐A are predictive of other adverse pregnancy outcomes.

Study design

The study included patients with singleton pregnancies who underwent combined first trimester screening using nuchal translucency (NT) and maternal serum free β‐human chorionic gonadotrophin (free β‐hCG) and PAPP‐A at 10–13 weeks' gestation. Patients with chromosome aberrations or fetal anomalies were excluded. Serum marker levels were expressed as gestational age‐specific multiples of the median (MoMs). The incidences of various adverse pregnancy outcomes (spontaneous preterm labor, fetal growth restriction (FGR), proteinuric and non‐proteinuric pregnancy induced hypertension (PIH), intrauterine fetal demise, oligohydramnios, spontaneous miscarriage and placental abruption) were evaluated, according to maternal PAPP‐A MoM levels.

Results

Of the 1622 patients in the study, pregnancy complications were observed in 184 (11.3%). Patients with PAPP‐A ⩽0.25 MoM had significantly higher rates of FGR (RR = 3.12), proteinuric PIH (RR = 6.09), spontaneous miscarriage (RR = 8.76). No statistically significant differences were noted for other adverse outcomes evaluated Women with PAPP‐A ⩽0.50 MoM also had significantly higher rates of FGR (RR = 3.30) and spontaneous miscarriage (RR = 3.78).

Conclusions

We conclude that decreased levels of first trimester maternal serum PAPP‐A are predictive not only of chromosome anomalies but also of adverse pregnancy outcome. Copyright © 2002 John Wiley & Sons, Ltd.
Molecular prenatal diagnosis of Smith–Lemli–Opitz syndrome is reliable and efficient
Authors: Loeffler Judith , Utermann Gerd , Witsch‐Baumgartner Martina
Published: October 2002

Smith–Lemli–Opitz (RSH) syndrome (SLOS, OMIM 270400) is a relatively common, autosomal recessive disorder of cholesterol biosynthesis with a broad spectrum of phenotypic abnormalities caused by mutations of the 7‐dehydrocholesterol reductase gene (DHCR7) on chromosome 11. Prenatal diagnosis can be established by detection of elevated 7‐dehydrocholesterol or of SLOS‐causing mutations in the DHCR7 gene. We report here our experience with molecular prenatal diagnosis of SLOS. Mutation analysis of the DHCR7 gene was performed in chorionic villus samples of 13 pregnancies of couples with a family history of SLOS and known SLOS genotypes. This approach is accurate and reliable. If facilities for biochemical analysis are not available, or in cases with ambiguous biochemical patterns, molecular prenatal diagnosis is an attractive, alternative option. Copyright © 2002 John Wiley & Sons, Ltd.
Fetal fibrochondrogenesis at 26 weeks' gestation
Authors: Randrianaivo Hanitra , Haddad Georges , Roman Horatiu , Lise Anne , Toutain Annick , Le Merrer Martine , Moraine Claude
Published: October 2002

An Erratum has been published for this article in Prenatal Diagnosis 22(13) 2002, 1241.

Fibrochondrogenesis is a rare and lethal osteochondrodysplasia with an autosomal recessive mode of inheritance. We report a male fetus in which the diagnosis of lethal osteochondrodysplasia was suspected on prenatal ultrasound and radiological examinations during the second trimester of pregnancy. After termination of pregnancy, fibrochondrogenesis was diagnosed by radiological examination and histological study of fetal bones. Interwoven fibrous septa and fibroblastic degeneration of chondrocytes are pathognomonic. The recurrence rate is 25% and accurate diagnosis is necessary to enable genetic counselling. Copyright © 2002 John Wiley & Sons, Ltd.
Enantiomer‐selective polymerization of (RS)‐(phenoxymethyl)thiirane with diethylzinc/L‐amino acid
Authors: Imai Tomoko , Hayakawa Kohei , Satoh Toshifumi , Kaga Harumi , Kakuchi Toyoji
Published: October 2002

Enantiomer‐selective polymerization of (RS)‐(phenoxymethyl)thiirane (RS‐1) was carried out with ZnEt2/L‐α‐amino acid as an initiator system, and the effect of the initiator system on the enantiomer selectivity was examined with various amino acids. All polymerizations heterogeneously proceeded, and every initiating system was effective in producing optically active polymers. For the polymerization of RS‐1 with diethylzinc (ZnEt2)/L‐leucine (1/1), the conversion was 43.7% in 12 days, and the number‐average molecular weight of the polymer was 18,000. The enantiomer selectivity was maximum when the molar ratio of the two components in the ZnEt2/L‐α‐amino acid system was 1:1. When the ZnEt2/L‐leucine (1/1) system was used in the polymerization, the best result was obtained with an enantiomer‐selectivity value of 5.36. During the polymerization, the S enantiomer was preferentially consumed, and the isotactic‐rich polymer was enriched in the S configurational units produced. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3443–3448, 2002
Viscoelasticity and tack of poly(vinyl pyrrolidone)–poly(ethylene glycol) blends
Authors: Roos Alexandra , Creton Costantino , Novikov Mikhail B. , Feldstein Mikhail M.
Published: October 2002

The adhesive properties of blends of high molecular weight poly(vinyl pyrrolidone) (PVP) and low molecular weight poly(ethylene glycol) (PEG) were systematically investigated with a probe test and correlated with their viscoelastic properties. The material parameters that were varied were the PEG content (31–41 wt %) and the hydration rate. The 36% PEG showed the best balance of properties for a pressure‐sensitive adhesive. At low debonding rates, the debonding took place through the formation of a fibrillar structure, whereas at high debonding rates, the debonding was brittle. This transition was attributed to the breakage and reformation of hydrogen bonds between PVP units and OH groups on PEG during the large strain of the polymer chains in elongation. This transition was observed, albeit shifted in frequency, for all three compositions, and the characteristic relaxation times of the hydrogen‐bonded network were estimated. A comparison between the tack properties of the adhesives and their linear viscoelastic properties showed a very strong decoupling between the small‐strain and large‐strain properties of the adhesive, which was indicative of a pronounced deviation from rubber elasticity in the behavior of the blends. This deviation, also seen during tensile tests, was attributed to the peculiar phase behavior of the blends. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2395–2409, 2002
Salt‐promoted protein folding, preferential binding, or electrostatic screening?
Authors: Stellwagen Earle , Olivieri Erna , Righetti Pier Giorgio
Published: October 2002

The extended coil/molten globule conformational equilibrium exhibited by ferricytochrome c in 10 to 20 mM HCl was examined using free boundary capillary electrophoresis. Addition of the osmolyte glucitol, also called sorbitol, to shift the conformational equilibrium toward the molten globule markedly diminished the mobility of the protein. This diminution can be entirely assigned to the relative viscosity of the added glucitol. The insensitivity of the viscosity corrected protein mobility to added glucitol suggests that both the extended coil and molten globule conformations of cytochrome c are free draining in an electrophoresis measurement. Addition of a neutral salt to shift the conformational equilibrium toward the molten globule conformation also markedly diminished the mobility of the protein. This diminution can be entirely assigned to the electrostatic screening afforded by the added salt. The onset of the conformational transition observed by optical measurements and the onset of electrostatic screening observed by mobility measurements appear to be in common for some but not all neutral salts. The exception suggests that preferential binding of the anion of a neutral salt to the molten globule conformation and not electrostatic screening is principally responsible for the shift in the conformational equilibrium of cytochrome c in acidic solutions. Proteins 2002;49:147–153. © 2002 Wiley‐Liss, Inc.
DNA‐based immunotherapy: potential for treatment of chronic viral hepatitis?
Authors: Beckebaum Susanne , Cicinnati Vito R. , Gerken Guido
Published: October 2002

Persistent HBV and HCV infection represent major causes of chronic liver disease with a high risk of progression to liver cirrhosis and hepatocellular carcinoma (HCC). Conventional protein‐based vaccines are highly efficacious in preventing HBV infection; whereas in therapeutic settings with chronically infected patients, results have been disappointing. Prophylactic vaccination against HCV infection has not yet been achieved due to many impediments including frequent spontaneous mutations of the virus with escape from immune system control. Using animal models it has been demonstrated that DNA‐based immunisation strategies may overcome this problem because of their potential to induce immunity against multiple viral epitopes. DNA‐based vaccines mimic the effect of live attenuated viral vaccines, eliciting cell mediated immunity in addition to inducing humoral responses. Efficacy may further be improved by addition of DNA encoding immunomodulatory cytokines and more recently, direct genetic modulation of antigen‐presenting cells, such as dendritic cells (DC), has been shown to increase antigen‐specific immune responses. This review focuses on immunological aspects of chronic HBV and HCV infection and on the potential of DNA‐ and DC‐based vaccines for the treatment of chronic viral hepatitis. Copyright © 2002 John Wiley & Sons, Ltd.
Reachability of nonlinear fed‐batch fermentation processes
Authors: Szederkényi G. , Kovács M. , Hangos K. M.
Published: October 2002

The reachability of a simple nonlinear fed‐batch fermentation process model is investigated in this paper. It is shown that the known difficulties of controlling such processes are primarily caused by the fact that the rank of the reachability distribution is always less than the number of state variables.

Furthermore, a co‐ordinates transformation is calculated analytically that shows the nonlinear combination of the state variables which is independent of the input. The results of the reachability analysis and that of the co‐ordinates transformation are independent of the source function in the system model.

The results are extended to the four state variable non‐isotherm case, and to nonlinear fed‐batch chemical reactors with general reaction kinetics. Copyright © 2002 John Wiley & Sons, Ltd.
Dynamic neural network calibration of quartz transducers
Authors: Schultz R.L.
Published: October 2002

The performance of quartz pressure transducers is often compromised when subjected to thermal transients. In this paper, a new method of calibrating quartz transducers in which a neural network is used to accomplish a dynamic calibration of a transducer pair for a range of temperatures and pressures will be described. When a quartz pressure transducer is exposed to an environmental temperature change, thermal stress is induced in the sensing element. This thermal stress causes erroneous pressure readings until thermal equilibrium is achieved within the transducer. In order to compensate the undesirable transient thermal effects on the pressure transducer performance, multiple past and future temperature‐and‐pressure sensor outputs are used as inputs to a calibrating neural network. This new method allows the time‐dependent qualities of the quartz‐oscillator transducer to be included in the calibration scheme. This method can be applied generally to other types of transducers that are subjected to transient environmental effects and is not limited to quartz‐oscillator transducers. A theoretical discussion of this technology is presented, followed by experimental results obtained by applying the method to quartz pressure transducer calibration. Copyright © 2002 John Wiley & Sons, Ltd.
Spatial control of cell attachment using plasma micropatterned polymers
Authors: Mitchell S. A. , Emmison N. , Shard A. G.
Published: October 2002

Surface chemical patterns of plasma‐polymerized hexane were produced using a simple masking technique. The rate of proliferation of Chinese hamster ovary (CHO) cells on the treated surfaces compared with untreated tissue culture polystyrene (TCPS) were found to correlate strongly with surface oxygen concentration. A topographical pattern resolution of better than 5 µm was achieved on a freshly cleaved mica surface. A similar chemical pattern resolution on TCPS was evidenced by the spatially selective attachment of CHO cells cultured in 10% serum. Copyright © 2002 John Wiley & Sons, Ltd.
A New Aquatic Species of Verrucaria from Alpine Australia
Authors: McCarthy P. M.
Published: October 2002

Verrucaria cootapatambensis sp. nov. is described from sandstone boulders in an alpine, snow-melt creek in Kosciuszko National Park, New South Wales, Australia.
Hydroclimatic Change in Southern Manitoba Since A.D. 1409 Inferred from Tree Rings
Authors: St. George Scott , Nielsen Erik
Published: October 2002

A record of estimated annual (prior August to current July) precipitation derived from a regional bur oak (Quercus macrocarpa Michx.) tree-ring chronology indicates that southern Manitoba's hydroclimate has been relatively stable over the last 200 yr. Although this stability was interrupted briefly by pronounced wet intervals in the late A.D. 1820s and 1850s, hydroclimatic conditions since permanent Euro-Canadian settlement were much less variable and persistent than those prior to A.D. 1790. The reconstruction indicates that the Red River basin experienced extremely dry conditions between A.D. 1670 and 1775, with below-normal precipitation occurring approximately 2 years out of 3. Annual precipitation was estimated at more than two standard deviations below the mean during A.D. 1477, 1485, 1556, 1595, 1612, 1644, 1661, 1743, 1900, and 1980. Comparisons with limnological records from North Dakota and Minnesota suggest that multidecadal fluctuations in regional hydroclimate have been remarkably coherent across the northeastern Great Plains during the last 600 yr. However, individual dry years in the Red River basin were usually associated with larger scale drought across much of the North American interior.
Programmed death in yeast as adaptation?
Authors: Skulachev Vladimir P.
Published: October 2002

During recent years, several pieces of indirect evidence of a programmed death in yeast have been published. Among them there are observations that some mammalian pro‐ or anti‐apoptotic proteins induce or prevent the death of yeast; some toxic compounds kill yeast at lower concentrations if protein synthesis is operative; this death, as well as the death due to certain mutations, shows some apoptotic markers. In April 2002, the yeast programmed death concept received direct support. Madeo et al. [Madeo et al., Mol. Cell 9 (2002) 911–917] disclosed a caspase which is activated by H2O2 or aging and is required for the protein‐synthesis‐dependent death of yeast. Thus, a specific apoptosis‐mediating protein was identified for the first time in Saccharomyces cerevisiae. Independently, Severin and Hyman [Severin, F.F., Hyman, A.A., Curr. Biol. 12 (2002) R233–R235] discovered that death of yeast, induced by a high level of a pheromone, is programmed. In particular, the death was found to be prevented by cycloheximide and cyclosporin A. It required mitochondrial DNA, cytochrome c and the pheromone‐initiated protein kinase cascade. When haploids of opposite mating types were mixed, some cells died, the inhibitory pattern being the same as in the case of the killing by pheromone. Inhibition of mating proved to be favorable for death. Thus, pheromone not only activates mating but also eliminates yeast cells failing to mate. Such an effect should (i) stimulate switch of the yeast population from vegetative to sexual reproduction, and (ii) shorten the life span and, hence, accelerate changing of generations. As a result, the probability of appearance of new traits could be enhanced when ambient conditions turned for the worse.
Purification and characterization of a short insect toxin from the venom of the scorpion Buthus tamulus
Authors: Dhawan Ritu , Joseph Suresh , Sethi Anurag , Lala Anil K
Published: October 2002

A short chain peptide has been isolated from the venom of a red scorpion of Indian origin, Buthus tamulus. This peptide was purified using ion exchange and reverse phase chromatography and was characterized by molecular weight determination and amino acid sequence. The primary structure analysis shows that BtITx3 is a short peptide of 35 amino acid residues having a molecular weight of 3796 Da. The toxin shows toxicity towards the Lepidopteran species of insect Helicoverpa armigera causing flaccid paralysis and even death within 24 h. It shows more than 50% homology with the short insectotoxins having four disulfide bridges, which suggests that the toxin belongs to the class of short chain toxins blocking the chloride ion channels. This sequence homology study has also helped to bring out the structure–function relationship between the various short toxins. Homology modeling done by using template structure of a known toxin indicated that this toxin consists of a similar α/β scaffold, as present in other scorpion toxins.
Dopamine re‐uptake inhibitor GBR‐12909 induction of aberrant behaviors in animal models of dopamine dysfunction
Authors: Loupe Pippa S. , Bredemeier Jonna D. , Schroeder Stephen R. , Tessel Richard E.
Published: October 2002

Many individuals with mental retardation exhibit chronic aberrant behaviors (CABs) that includes hyperactive, stereotyped, aggressive, and self‐injurious behaviors. Brain imaging studies have found that several of these individuals have abnormalities in their dopaminergic neurotransmitter systems that are thought to be responsible in part, for the development of these behaviors. The present study evaluated the effects of a selective dopamine re‐uptake blocker, GBR‐12909 in three animal models of varying striatal dopamine concentrations. The three animal models included the neonatal 6‐hydroxydopamine (6‐OHDA)‐lesioned rat, a model of dopamine neuronal depletion, the prenatal methylazoxymethanol (MAM)‐exposed rat, a model of hyper‐dopaminergic innervation and control rats, a model of normal dopaminergic function. The animals were given five daily injections of GBR‐12909 and videotaped observations were conducted immediately following the injections and 6 h later. The results of the study indicate that the MAM‐treated rats exhibited more hyperactive behaviors than either the 6‐OHDA or the control animals in response to the GBR‐12909 injections. However, the 6‐OHDA and control rats exhibited more self‐injurious behaviors than the MAM rats. Interestingly, the topography of the self‐injurious behavior exhibited differed from that we have previously observed in 6‐OHDA lesioned rats following dopamine agonists and resembles the mouthing behaviors seen in some individuals with mental retardation, in particular those with Rett syndrome. These findings indicate the models of varying dopaminergic function interact differently with a dopamine re‐uptake blocker than dopamine agonists and that the partially dopamine depleted model may model the behaviors seen in individuals with Rett syndrome.
From the Editor Vol 10 No 1-4
Authors: Lahey Karen Eilers
Published: October 2002

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Author Index 2001
Authors: Lahey Karen Eilers
Published: October 2002

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Titles Index
Authors: Lahey Karen Eilers
Published: October 2002

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Virulent but not Avirulent Mycobacterium tuberculosis Can Evade the Growth Inhibitory Action of a T Helper 1–dependent, Nitric Oxide Synthase 2–independent Defense in Mice
Authors: Jung Yu-Jin , LaCourse Ronald , Ryan Lynn , North Robert J.
Published: October 2002

Control of infection with virulent Mycobacterium tuberculosis (Mtb) in mice is dependent on the generation of T helper (Th)1-mediated immunity that serves, via secretion of interferon (IFN)-γ and other cytokines, to upregulate the antimycobacterial function of macrophages of which the synthesis of inducible nitric oxide synthase (NOS)2 is an essential event. As a means to understanding the basis of Mtb virulence, the ability of gene-deleted mice incapable of making NOS2 (NOS2−/−), gp91Phox subunit of the respiratory burst NADPH-oxidase complex (Phox−/−), or either enzyme (NOS2/Phox−/−), to control airborne infection with the avirulent R1Rv and H37Ra strains of Mtb was compared with their ability control infection with the virulent H37Rv strain. NOS2−/−, Phox−/−, and NOS2/Phox−/− mice showed no deficiency in ability to control infection with either strain of avirulent Mtb. By contrast, NOS2−/− mice, but not Phox−/− mice, were incapable of controlling H37Rv infection and died early from neutrophil-dominated lung pathology. Control of infection with avirulent, as well as virulent Mtb, depended on the synthesis of IFN-γ, and was associated with a substantial increase in the synthesis in the lungs of mRNA for IFN-γ and NOS2, and with production of NOS2 by macrophages at sites of infection. The results indicate that virulent, but not avirulent, Mtb can overcome the growth inhibitory action of a Th1–dependent, NOS2-independent mechanism of defense.
Is “lean” a universal production system?
Authors: Cooney Richard
Published: October 2002

This paper sets out to test the claim made in the lean production literature that the lean production system is universally applicable. The proponents of the lean production model insist that it will supersede both mass production and specialised batch production; but this paper argues that, whilst lean production practices have been adopted and adapted by many producers, batch production has an enduring value from both a work design and a manufacturing process design perspective. The paper reviews the evidence for the persistence of batch production and of craft work methods in both luxury vehicle manufacture and specialty component manufacture and highlights the conditions under which batch production remains viable.
Tacit knowledge in professional firms: the teachings of firms in very puzzling situations
Authors: Baumard Philippe
Published: October 2002

Professional firms (i.e. consulting, lawyers, etc.) accumulate and apply knowledge that they build collaboratively with their clients, partners and other knowledge intensive firms. Tacit knowledge, i.e. knowledge that can be acted, but cannot be expressed, circulates back‐and‐forth from clients to consultants. This paper explores patterns of capitalization of tacit knowledge in professional firms.
Scientific knowledge and implications for its diffusion
Authors: Zellner Christian , Fornahl Dirk
Published: October 2002

Considers some external aspects influencing the dynamics of firms’ knowledge base. Argues that the successful management of the knowledge base in a fast changing innovative environment is closely related to three kinds of knowledge acquisition channels, these are: the recruitment of people; the external informal networks of employees; and formal cooperation of the firm with other institutional agents. Focusing on firms’ interaction with research institutions, suggests a typology of scientific knowledge which allows us to analyse how different types of knowledge are associated with different knowledge acquisition channels. Because of the close interlinkages among the channels, knowledge (unlike information) is not freely floating in the system. Rather, its effective transfer and commercial exploitation is contingent on the mobility of people, as well as the extent to which they draw on their informal networks. Spells out some of the implications for recruitment policy and firm location.
PERTURBATIVE EXPANSIONS IN THE INCLUSIVE DECAY OF THE TAU-LEPTON
Authors: MILTON KIMBALL A. , SOLOVTSOVA OLGA P.
Published: October 2002

A comparative analysis is performed for various forms of perturbative expansions in spacelike and timelike regions. As applied to the inclusive decay of the τ-lepton, comparison is given for the results derived within the framework of the standard perturbation theory and the analytic approach that modernizes perturbative expansions so that the new approximations reflect basic principles of the theory: renormalization invariance, spectrality, and causality. Advantages and self-consistency of the analytic approach in describing τ-lepton decay are demonstrated.
GRAVITATIONAL PERTURBATIONS OF THE KERR BLACK HOLE DUE TO ARBITRARY SOURCES
Authors: MORENO CLAUDIA , NÚÑEZ DARÍO
Published: October 2002

We describe the Kerr black hole in the ingoing and outgoing Kerr–Schild horizon penetrating coordinates. Starting from the null vector naturally defined in these coordinates, we construct the null tetrad for each case, as well as the corresponding geometrical quantities allowing us to explicitly derive the field equations for the perturbed scalar projections Ψ0(1) and Ψ4(1) of the Weyl tensor, including arbitrary source terms. This perturbative description, including arbitrary sources, described in horizon penetrating coordinates is desirable in several lines of research on black holes, and contributes to the implementation of a formalism aimed to study the evolution of the spacetime in the region where two black holes are close together.
PSEUDO-SCHWARZSCHILD DESCRIPTION OF ACCRETION-POWERED SPHERICAL OUTFLOW
Authors: DAS TAPAS K.
Published: October 2002

Using two different pseudo-Schwarzschild potentials proposed by Artemova et al.,1 we formulate and solve the equations governing spherically symmetric transonic inflow and outflow in presence of a relativistic hadronic-pressure-mediated steady, standing, spherical shock around the central compact object. Then we self-consistently connect the accretion-wind solutions to calculate the mass outflow rate [Formula: see text] in terms of a minimum number of flow parameters. We also study the dependence of this rate on various boundary conditions governing the flow.
OPTIMAL PERTURBATION OF UNCERTAIN SYSTEMS
Authors: FARRELL BRIAN F. , IOANNOU PETROS J.
Published: October 2002

In studies of perturbation dynamics in physical systems, certain specification of the governing perturbation dynamical system is generally lacking, either because the perturbation system is imperfectly known or because its specification is intrinsically uncertain, while a statistical characterization of the perturbation dynamical system is often available. In this report exact and asymptotically valid equations are derived for the ensemble mean and moment dynamics of uncertain systems. These results are used to extend the concept of optimal deterministic perturbation of certain systems to uncertain systems. Remarkably, the optimal perturbation problem has a simple solution: In uncertain systems there is a sure initial condition producing the greatest expected second moment perturbation growth.
Rapid confirmation of Southeast Asian and Filipino α‐thalassemia genotypes from newborn screening specimens
Authors: Bhardwaj Urvashi , Zhang Yao‐Hua , Blackburn William , McCabe Linda L. , McCabe Edward R.B.
Published: October 2002

α+‐Thalassemia (−α) is prevalent throughout tropical and subtropical regions of world, whereas α0‐thalassemia (−−) occurs at higher frequency in Southeast Asia. Homozygosity for the α0‐thalassemia deletion (−−/−−) is a serious health problem in Southeast Asia and the Philippines and is responsible for the majority of hydrops fetalis in this region. Asian immigration in United States has impacted the demography of genetic disease in U.S. As Asians comprise of 10% of all California births and represent a population at highest risk for α0‐thalassemia, we developed a rapid and efficient PCR approach to detect the common α0‐thalassemia deletions in Southeast Asians and Filipinos using newborn screening specimen. Am. J. Hematol. 71:56–58, 2002. © 2002 Wiley‐Liss, Inc.
Periventricular cerebral white matter lesions predict rate of cognitive decline
Authors: De Groot Jan Cees , De Leeuw Frank‐Erik , Oudkerk Matthijs , Van Gijn Jan , Hofman Albert , Jolles Jellemer , Breteler Monique M. B.
Published: October 2002

The prospect of declining cognitive functions is a major fear for many elderly persons. Cerebral white matter lesions, as commonly found with magnetic resonance imaging, have been associated with cognitive dysfunction in cross‐sectional studies. Only a few longitudinal studies using small cohorts confirmed these findings. We examined the relation between severity of white matter lesions and cognitive decline over a nearly 10‐year period in 563 elderly subjects sampled from the general nondemented Dutch population. Severity of white matter lesions was scored for periventricular and subcortical regions separately using an extensive semiquantitative scale. Cognitive function was measured by the Mini‐Mental State Examination at regular time intervals during 1990 to 2000, and magnetic resonance imaging scans were made in 1995 to 1996. More severe white matter lesions were associated with more rapid cognitive decline over a mean follow‐up period of 7.3 years (standard deviation, 1.5). After adjusting for age, gender, educational level, measures of depression, and brain atrophy and infarcts, subjects with severe periventricular white matter lesions experienced cognitive decline nearly three times as fast (0.28 Mini‐Mental State Examination points/year [95% confidence interval, 0.20–0.36]) as the average (0.10 points/year [95% confidence interval, 0.09–0.11]). There was no independent relationship between severity of subcortical white matter lesions and rate of cognitive decline.
Cell transplantation for stroke
Authors: Savitz Sean I. , Rosenbaum Daniel M. , Dinsmore Jonathan H. , Wechsler Lawrence R. , Caplan Louis R.
Published: October 2002

Cell transplantation has emerged as an experimental approach to restore brain function after stroke. Various cell types including porcine fetal cells, stem cells, immortalized cell lines, and marrow stromal cells are under investigation in experimental and clinical stroke trials. This review discusses the unique advantages and limitations of the different graft sources and emphasizes the current, limited knowledge about their biology. The survival, integration, and efficacy of neural transplants in stroke patients will depend on the type, severity, chronicity, adequacy of circulation, and location of the stroke lesion. Ann Neurol 2002;52:266–275
Knowledge management in three organizations: An exploratory study
Authors: Gray Southon F. C. , Todd Ross J. , Seneque Megan
Published: October 2002

A major professional concern for people undertaking knowledge management initiatives is interpreting the field for managers and others in their organization. This exploratory research sought to investigate the dynamics of knowledge in organizations: how (if at all) it was perceived, interpreted, utilized, and integrated into the functions, processes, and outputs of the organization. Three organizations with differing functions and outputs were studied: a law firm, an educational institution, and a suburban local council, each being between 100 and 200 employees in size. Semistructured interviews (both individual and small group) were carried out with people at all levels to gather perceptions of the dynamics of knowledge in that organization. It was found that knowledge structures and cultures differed substantially between organizations, and were heavily influenced by the commercial environment and the governing structures. People at all levels had substantial awareness of the nature of knowledge within the organization, and there were a significant number of initiatives targeted at improving the way that knowledge was used. The concept of knowledge itself was quite unproblematic, although it was considerably more complex and nuanced than most definitions allow for. Information services had an important, although not a central role in knowledge dynamics. These findings raise a number of questions about the suitability of much knowledge management theory.
Knowledge management: Hype, hope, or help?
Authors: Blair David C.
Published: October 2002

This article examines the nature of Knowledge Management—how it differs from Data Management and Information Management, and its relationship to the development of Expert Systems and Decision Support Systems. It also examines the importance of Communities of Practice and Tacit Knowledge for Knowledge Management. The discussion is organized around five explicit questions. One: What is “knowledge”? Two: Why are people, especially managers, thinking about Knowledge Management? Three: What are the enabling technologies for Knowledge Management? Four: What are the prerequisites for Knowledge Management? Five: What are the major challenges for Knowledge Management?
Conceptualizing documentation on the Web: An evaluation of different heuristic‐based models for counting links between university Web sites
Authors: Thelwall Mike
Published: October 2002

All known previous Web link studies have used the Web page as the primary indivisible source document for counting purposes. Arguments are presented to explain why this is not necessarily optimal and why other alternatives have the potential to produce better results. This is despite the fact that individual Web files are often the only choice if search engines are used for raw data and are the easiest basic Web unit to identify. The central issue is of defining the Web “document”: that which should comprise the single indissoluble unit of coherent material. Three alternative heuristics are defined for the educational arena based upon the directory, the domain and the whole university site. These are then compared by implementing them on a set of 108 UK university institutional Web sites under the assumption that a more effective heuristic will tend to produce results that correlate more highly with institutional research productivity. It was discovered that the domain and directory models were able to successfully reduce the impact of anomalous linking behavior between pairs of Web sites, with the latter being the method of choice. Reasons are then given as to why a document model on its own cannot eliminate all anomalies in Web linking behavior. Finally, the results from all models give a clear confirmation of the very strong association between the research productivity of a UK university and the number of incoming links from its peers' Web sites.
Comparative pharmacokinetics of single doses of doxylamine succinate following intranasal, oral and intravenous administration in rats
Authors: Pelser Andries , Müller Douw G. , du Plessis Jeanetta , du Preez Jan L. , Goosen Colleen
Published: October 2002

The intranasal route of administration provides a potential useful way of administering a range of systemic drugs. In order to assess the feasibility of this approach for the treatment of nausea and vomiting, doxylamine succinate was studied in rats for the pharmacokinetics (AUC, Cmax, tmax) following intranasal, oral and intravenous administrations.

Subjects (six male Sprague–Dawley rats per time interval for each route of administration) received 2‐mg doses of doxylamine succinate orally and I‐mg doses intranasally and intravenously, respectively. The various formulations were formulated in isotonic saline (0.9% w/v) at 25±1°C. Doxylamine succinate concentrations in plasma were determined with a high‐performance liquid chromatographic assay and a liquid–liquid extraction procedure. Intranasal and oral bioavailabilities were determined from AUC values relative to those after intravenous dosing.

Intranasal bioavailability was greater than that of oral doxylamine succinate (70.8 vs 24.7%). The intranasal and oral routes of administration differed significantly from the intravenous route of administration. Peak plasma concentration (Cmax) was 887.6 ng/ml (S.D. 74.4), 281.4 ng/ml (S.D. 24.6) and 1296.4 ng/ml (S.D. 388.9) for the intranasal, oral and intravenous routes, respectively. The time to achieve Cmax for the intranasal route (tmax=0.5 h) was faster than for the oral route (tmax=1.5 h), but no statistically significant differences between the Cmax values were found using 95% confidence intervals. The results of this study show that doxylamine succinate is rapidly and effectively absorbed from the nasal mucosa. Copyright © 2002 John Wiley & Sons, Ltd.