bluuebunny/crossref_metadata_2025 huggingface dataset:
Anterior Capsulotomy for Treatment of Refractory Obsessive-Compulsive Disorder: Results in a Young and an Old Patient
Authors: Christensen Daniel D. , Laitinen Lauri V. , Schmidt Leonard J. , Hariz Marwan I.
Published: August 2003

The objective of this case report was to assess the effect of anterior capsulotomy for obsessive-compulsive disorder (OCD) in 2 patients beyond extremes of age ranges of published radiofrequency capsulotomy. The youngest patient developed OCD at age 10 with increasing symptoms of tension and worry. The symptoms were refractory to medications and behavioral therapy. He underwent anterior capsulotomy at age 18. The older patient was 64 at the time of surgery. His OCD began about age 17 with checking and counting rituals. His obsessions extended into other areas such as fear of injuring people while driving. His work performance was greatly compromised. Despite medication trials his rituals and obsessions intensified. After 47 years of severe symptoms he underwent surgery. The youngest patient returned to high school full-time and graduated. He was able to read and comprehend without obsessing about the meaning of words. His thinking and behavior became symptom free and he married 4.5 years after surgery. His score on the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) after surgery on no medication is zero. The older patient improved gradually without medication. He could play with and touch his grandchildren for the first time. He could drive a car again and his Y-BOCS dropped from 30 preoperatively to 8. Twenty-four months after surgery he is essentially free of obsessions, compulsions and anxiety. We conclude that treatment-refractory OCD may be alleviated by anterior radiofrequency capsulotomy in the young and the old patient. This study expands the documented age range of response from 18 to 64.
Neurovascular Compression Associated with Trigeminal Neuralgia and Systemic Arterial Hypertension: Surgical Treatment
Authors: Sendeski Mauricio , Aguiar Paulo Henrique , Zanetti Marcus Vinicius , Teixeira Manoel Jacobsen , Cescato Valter Ângelo
Published: August 2003

Objective and Importance: To highlight arterial hypertension as an additional factor favoring surgical indication in neurovascular compression syndromes such as trigeminal neuralgia, hemifacial spasm, and glossopharyngeal neuralgia. Clinical Presentation: A 52-year-old woman with trigeminal neuralgia concomitant with systemic arterial hypertension, submitted initially to unsatisfactory conservative treatment, presents tortuousness and enlargement of the vertebral artery (VA) topography on magnetic resonance imaging (MRI). A microsurgical neurovascular decompression of the trigeminal nerve and the medulla was performed, revealing that the compression was due to the superior cerebellar artery instead of the VA. Both the neuralgia and the hypertension were controlled with no need of medication during a 1-year follow-up. Conclusion: Surgical indication in neurovascular compression disorders should be reinforced in the presence of concomitant arterial hypertension and a compatible MRI examination.
Gene Duplication with Displacement and Rearrangement: Origin of the Bacterial Replication Protein PriB from the Single-Stranded DNA-Binding Protein Ssb
Authors: Ponomarev Vladimir A. , Makarova Kira S. , Aravind L. , Koonin Eugene V.
Published: August 2003

PriB is a proteobacterial protein that is involved in the pre-primosomal step of DNA replication and, unexpectedly, is encoded with a ribosomal protein operon. Detailed sequence comparisons and analysis of operon organization show that PriB evolved from the single-stranded DNA-binding (Ssb) via gene duplication with subsequent rapid sequence diversification. Duplication of the ssb gene was accompanied by a genome rearrangement which resulted in one of the paralogs retaining the original position, whereas the other was relocated. The functional specialization of the resulting paralogs apparently proceeded in an unexpected fashion: the original Ssb function remained with the relocated paralog, whereas the one within the ribosomal protein operon acquired a new, specialized function in replication.
Registration of Stroke through the Belgian Sentinel Network and Factors Influencing Stroke Mortality
Authors: Devroey Dirk , van Casteren Viviane , Buntinx Frank
Published: August 2003

Introduction: Stroke is one of the leading causes of death. Belgian stroke mortality rates are only available from the death certificates notification. Objectives: To estimate stroke incidence, mortality and case fatality, to compare our figures with those available from the death certificates notification and from neighboring countries, and identifying factors influencing survival. Methods: A nationwide prospective registration by 178 Belgian general practitioners recording all cerebrovascular events in 1998–1999. All events, including those for which medical care was immediately found in hospital, were included. Results: The yearly age-and-gender-adjusted stroke attack rates were estimated at 185 cases per 100,000 inhabitants (95% CI = 169–202). After 12 months, 47% of the patients died, resulting in an estimated yearly stroke mortality rate of 88 per 100,000 inhabitants (95% CI = 73–105). The case fatality rate among men (39%; 95% CI = 29–51) was lower than among women (50%; 95% CI = 39–63) (p < 0.05). In a forward stepwise logistic regression diabetes, stroke history, hemorrhagic stroke, coma, swallow deficit and urinary incontinence had a negative influence on stroke survival. Treated hypertension had a beneficial effect on survival. Conclusions: Stroke mortality rates estimated by the sentinel practices are fairly comparable with those based on the death certificates notification. The stroke attack rates correspond with those of neighboring countries. The role of treated hypertension on the outcome of strokes remains controversial in this registration.
X chromosome inactivation, differentiation, and DNA methylation revisited, with a tribute to Susumu Ohno
Authors: Riggs A.D.
Published: August 2003

X chromosome inactivation and DNA methylation are reviewed, with emphasis on the contributions of Susumu Ohno and the predictions made in my 1975 paper (Riggs, 1975), in which I proposed the “maintenance methylase” model for somatic inheritance of methylation patterns and suggested that DNA methylation would be involved in mammalian X chromosome inactivation and development. The maintenance methylase model is discussed and updated to consider methylation patterns in cell populations that have occasional, stochastic methylation changes by de novo methylation or demethylation, either active or passive. The “way station” model for the spread of X inactivation by LINE-1 elements is also considered, and some recent results from my laboratory are briefly reviewed.
Evolution of the human X – a smart and sexy chromosome that controls speciation and development
Authors: Graves J.A.M. , Gécz J. , Hameister H.
Published: August 2003

In humans, as in other mammals, sex is determined by an XX female/XY male chromosome system. Most attention has focused on the small, degenerate Y chromosome, which bears the male-dominant gene SRY. The X, in contrast, has been considered a well-behaved and immaculately conserved element that has hardly changed since the pre-mammal days when it was just another autosome pair. However, the X, uniquely in the genome, is present in two copies in females and only one in males. This has had dire consequences genetically on the evolution of its activity – and now it appears, on its gene content and/or the function of its genes. Here we will discuss the origin of the human X, and the evolution of dosage compensation and gene content, in the light of recent demonstrations that particular functions in sex and reproduction and cognition have accumulated on it.
DMRT1 in a ratite bird: evidence for a role in sex determination and discovery of a putative regulatory element
Authors: Shetty S. , Kirby P. , Zarkower D. , Graves J.A.M.
Published: August 2003

Unlike mammals, birds have a ZZ male/ZW female sex-determining system. In most birds, the Z is large and gene rich, whereas the W is small and heterochromatic, but the ancient group of ratite birds are characterized by sex chromosomes that are virtually homomorphic. Any gene differentially present on the ratite Z and W is therefore a strong candidate for a sex-determining role. We have cloned part of the candidate bird sex-determining gene DMRT1 from the emu, a ratite bird, and have shown that it is expressed during the stages of development corresponding to gonadal differentiation in the chicken. The gene maps to the distal region of the Z short arm and is absent from the large W chromosome. Because most sequences on the emu W chromosome are shared with the Z, the Z-specific location constitutes strong evidence that differential dosage of DMRT1 is involved in sex determination in all birds. The sequence of emu DMRT1 has 88% homology with chicken DMRT1 and 65% with human DMRT1. Unexpectedly, an unexpressed 270-bp region in intron 3 of emu DMRT1 showed 90% homology with a sequence in the corresponding intron of human DMRT1. This extraordinarily high conservation across 300 million years of evolution suggests an important function, perhaps involved in control of DMRT1 expression and vertebrate sex determination.
The X chromosome and fragile X mental retardation
Authors: Oostra B.A. , Willemsen R.
Published: August 2003

Fragile X syndrome represents the most common inherited cause of mental retardation. It is caused by a stretch of CGG repeats within the fragile X gene, which increases in length as it is transmitted from generation to generation. Once the repeat exceeds a threshold length, no protein is produced, resulting in the fragile X phenotype. Both X chromosome inactivation and inactivation of the FMR1 gene are the result of methylation. X inactivation occurs earlier than inactivation of the FMR1 gene. The instability to a full mutation is dependent on the sex of the transmitting parent and occurs only from mother to child. For most X-chromosomal diseases, female carriers do not express the phenotype. A clear exception is fragile X syndrome. It is clear that more than 50% of the neurons have to express the protein to ensure a normal phenotype in females. This means that a normal phenotype in female carriers of a full mutation is accompanied by a distortion of the normal distribution of X inactivation.
Clinical and molecular contributions to the understanding of X-linked mental retardation
Authors: Stevenson R.E. , Schwartz C.E.
Published: August 2003

X-linked mental retardation (XLMR) was first recognized in the 1940s, long before any human genes had been mapped. It is now estimated that XLMR has a prevalence of 2.6 cases per 1,000 population, accounting for over 10% of all cases of mental retardation. It is likely that over 150 genes are associated with XLMR. Fragile X syndrome, the most common form of XLMR, has a prevalence of about 1 in 4,000 males. Clinically, XLMR exists in syndromic (mental retardation with other somatic, neurological, behavioral, or metabolic findings) and nonsyndromic (mental retardation without other distinguishing features) forms. However, recent findings have caused this distinction to become blurred as mutations in some genes have been found in both syndromic and nonsyndromic XLMR. Progress in XLMR gene identification has allowed some insight into various pathways and cellular activities involved in developing cognitive functions. The genes involve signaling pathways, transcription factors, cytoskeletal organization, cell adhesion and migration, and maintenance of the cell membrane potential.
Microphthalmia with linear skin defects syndrome (MLS): a male with a mosaic paracentric inversion of Xp
Authors: Kutsche K. , Werner W. , Bartsch O. , von der Wense A. , Meinecke P. , Gal A.
Published: August 2003

The microphthalmia with linear skin defects syndrome (MLS) is an X-linked dominant disorder with male lethality. In the majority of the patients reported, the MLS syndrome is caused by segmental monosomy of the Xp22.3 region. To date, five male patients with MLS and 46,XX karyotype (“XX males”) have been described. Here we report on the first male case with MLS and an XY complement. The patient showed agenesis of the corpus callosum, histiocytoid cardiomyopathy, and lactic acidosis but no microphthalmia, and carried a mosaic subtle inversion of the short arm of the X chromosome in 15% of his peripheral blood lymphocytes, 46,Y,inv(X)(p22.13∼22.2p22.32∼22.33)[49]/46,XY[271]. By fluorescence in situ hybridization (FISH), we showed that YAC 225H10 spans the breakpoint in Xp22.3. End-sequencing and database analysis revealed a YAC insert of at least 416 kb containing the genes HCCS and AMELX, and exons 2–16 of ARHGAP6. Molecular cytogenetic data suggest that the Xp22.3 inversion breakpoint is located in intron 1 of ARHGAP6, the gene encoding the Rho GTPase activating protein 6. Future molecular studies in karyotypically normal female MLS patients to detect submicroscopic rearrangements including the ARHGAP6 gene as well as mutation screening of ARHGAP6 in patients with no obvious chromosomal rearrangements will clarify the role of this gene in MLS syndrome.
FLJ14813 Missense Mutation: A Candidate for Autosomal Dominant Thrombocytopenia on Human Chromosome 10
Authors: Gandhi Manish J. , Cummings Carrie L. , Drachman Jonathan G.
Published: August 2003

The gene for a novel nonsyndromic autosomal dominant thrombocytopenia has been previously mapped to a region on human chromosome 10p11-12 (THC2, OMIM number *188000). This disorder is characterized by moderate thrombocytopenia and incomplete differentiation of megakaryocytes. We report here a novel missense mutation in the human gene FLJ14813 that segregates perfectly with thrombocytopenia in our kindred of 51 family members. The mutation is not detected in 94 random unrelated and unaffected individuals, nor is it reported in the Entrez single nucleotide polymorphism (SNP) database. A substitution of cytosine for guanidine (G to C) at nucleotide position 565 was present in all thrombocytopenic family members, causing a predicted substitution of aspartic acid for glutamic acid (E167D) in exon four.
Osteopenia in Patients with Glomerular Diseases Requiring Long-Term Corticosteroid Therapy
Authors: Barbosa de Deus Rogério , Conde Ferreira Alessandra , Mastroianni Kirsztajn Gianna , Pfeferman Heilberg Ita
Published: August 2003

Background: Chronic corticosteroid (CS) use is associated with bone mass loss. Methods: Bone mineral density (BMD) was assessed in 72 patients (25 males/47 premenopausal females) with glomerular diseases, primary (n = 35) or secondary to systemic lupus erythematosus (n = 37) with normal renal function, who were taking CS, as prednisone and/or methylprednisolone, in doses ≧7.5 mg/day, for a period of at least 6 months. Cumulative dose and duration of prior CS therapy, as well as biochemical parameters and other factors contributing to bone loss were evaluated. Results: We found 37 (52%) patients with low BMD (29 with osteopenia and 8 with osteoporosis). The low BMD group presented a lower mean weight and body mass index (BMI) versus the normal BMD group (62 ± 15 vs. 70 ± 10 kg and 25 ± 4 vs. 27 ± 5, mean ± SD, p < 0.05). The estimated calcium intake was lower than 400 mg/day in all patients with low BMD, and they had taken furosemide as a concomitant drug for a longer mean period of time when compared to normal BMDpatients (30 ± 29 vs. 16 ± 27 months, p < 0.05). A higher mean number of pulses per patient and mean cumulative dose of methylprednisolone were observed in the low versus normal BMD group (7.7 ± 4.0 vs. 5.6 ± 4.0 pulses and 6.5 ± 3.9 vs. 3.9 ± 2.7 g, p < 0.05). Conclusions: These findings suggest a high frequency of osteopenia among young and premenopausal patients with glomerular diseases given long-term corticosteroid therapy. The lower BMI and calcium intake, as well as the concomitant furosemide use, might have contributed to such a bone loss. The higher number of pulse therapies leading to higher cumulative intravenous doses of corticosteroid mainly in lupus nephritis patients shows that pulse therapy may be deleterious to bone.
Comparative Analysis of the Angiotensin-II Receptor in Placental Vascular Endothelial Cells in Preeclamptic and Normotensive Patients
Authors: Laskowska Marzena , Vinson Gavin P. , Szumiło Justyna , Laskowska Katarzyna , Leszczyńska-Gorzelak Bożena , Oleszczuk Jan
Published: August 2003

The aim of this study was to compare the immunoreactivity of angiotensin-II receptor type 1 (AT1R) in the vascular endothelial cells of human placental vessels in normal and preeclamptic pregnancies. Immunohistochemistry was used to examine the localization of AT1R in the vascular endothelium of human placental vessels. In preeclamptic patients without intrauterine growth retardation (IUGR) the mean histological index H score was significantly higher, but significantly decreased in patients with preeclampsia complicated by IUGR in comparison with the control group. Immunolocalization of AT1R in vascular endothelial cells in our study supports the view that angiotensin II may play a role in the regulation of vascular tone and vascular resistance and the actions of other vasoactive factors, vasodilators or vasoconstrictors. However, our results confirmed that AT1R immunoreactivity is elevated in vascular endothelial cells of human placenta from pregnancies complicated by preeclampsia, suggesting a higher activity of the renin-angiotensin-aldosterone system (RAAS) in women with preeclampsia. On the other hand reduced immunoreactivity of AT1R in placental vascular endothelial cells in pregnancy complicated by preeclampsia with IUGR may result from chronic higher RAAS activity and may suggest the decreased ability to compensate and the inability to restore the normal balance between vasodilators and vasoconstrictors. These results may also reflect destructive changes and dysfunction of the vascular endothelium in preeclamptic pregnancy with IUGR.
Feedback loops comprising Dll1, Dll3 and Mesp2, and differential involvement of Psen1 are essential for rostrocaudal patterning of somites
Authors: Takahashi Yu , Inoue Tohru , Gossler Achim , Saga Yumiko
Published: August 2003

Elaborate metamerism in vertebrate somitogenesis is based on segmental gene expression in the anterior presomitic mesoderm (PSM). Notch signal pathways with Notch ligands Dll1 and Dll3, and the transcription factor Mesp2 are implicated in the rostrocaudal patterning of the somite. We have previously shown that changes in the Mesp2 expression domain from a presumptive one somite into a rostral half somite results in differential activation of two types of Notch pathways, dependent or independent of presenilin 1 (Psen1),which is a Notch signal mediator. To further refine our hypothesis, we have analyzed genetic interactions between Dll1, Dll3, Mesp2 and Psen1, and elucidated the roles of Dll1- and Dll3-Notch pathways,with or without Psen1, in rostrocaudal patterning. Dll1 and Dll3 are co-expressed in the PSM and so far are considered to have partially redundant functions. We find in this study that positive and negative feedback loops comprising Dll1 and Mesp2 appear to be crucial for this patterning, and Dll3 may be required for the coordination of the Dll1-Mesp2 loop. Additionally, our epistatic analysis revealed that Mesp2 affects rostrocaudal properties more directly than Dll1 or Dll3. Finally, we find that Psen1 is involved differently in the regulation of rostral and caudal genes. Psen1 is required for Dll1-Notch signaling for activation of Dll1, while the Psen1-independent Dll3-Notch pathway may counteract the Psen1-dependent Dll1-Notch pathway. These observations suggest that Dll1 and Dll3 may have non-redundant, even counteracting functions. We conclude from our analyses that Mesp2 functions as a central mediator of such Notch pathways and regulates the gene expression required for rostrocaudal patterning of somites.
The Pax-homeobox geneeyegoneis involved in the subdivision of the thorax ofDrosophila
Authors: Aldaz Silvia , Morata Ginés , Azpiazu Natalia
Published: August 2003

The eyegone (eyg) gene is known to be involved in the development of the eye structures of Drosophila. We show that eyg and its related gene, twin of eyegone (toe), are also expressed in part of the anterior compartment of the adult mesothorax (notum). We report experiments concerning the role of these genes in the notum. In the absence of eyg function the anterior-central region does not develop, whereas ectopic activity of either eyg or toe induces the formation of the anterior-central pattern in the posterior or lateral region of the notum. These results demonstrate that eyg and toe play a role in the genetic subdivision of the notum, although the experiments indicate that eyg exerts the principal function. However, by itself the Eyg product cannot induce the formation of notum patterns; its thoracic function requires co-expression with the Iroquois (Iro) genes. We show that the restriction of eyg activity to the anterior-central region of the wing disc is achieved by the antagonistic regulatory activities of the Iro and pnr genes, which promote eyg expression, and those of the Hh and Dpp pathways, which act as repressors. We argue that eyg is a subordinate gene of the Iro genes, and that pnr mediates their thoracic patterning function. The activity of eyg gives rise to a new notum subdivision that acts upon the pre-extant one generated by the Iro genes and pnr. As a result the notum becomes subdivided into four distinct genetic domains.
The expression and function of theachaete-scutegenes inTribolium castaneumreveals conservation and variation in neural pattern formation and cell fate specification
Authors: Wheeler Scott R. , Carrico Michelle L. , Wilson Beth A. , Brown Susan J. , Skeath James B.
Published: August 2003

The study of achaete-scute (ac/sc) genes has recently become a paradigm to understand the evolution and development of the arthropod nervous system. We describe the identification and characterization of the ac/sc genes in the coleopteran insect species Tribolium castaneum. We have identified two Tribolium ac/sc genes -achaete-scute homolog (Tc-ASH) a proneural gene and asense (Tc-ase) a neural precursor gene that reside in a gene complex. Focusing on the embryonic central nervous system we find that Tc-ASH is expressed in all neural precursors and the proneural clusters from which they segregate. Through RNAi and misexpression studies we show that Tc-ASH is necessary for neural precursor formation in Tribolium and sufficient for neural precursor formation in Drosophila. Comparison of the function of the Drosophila and Tribolium proneural ac/sc genes suggests that in the Drosophila lineage these genes have maintained their ancestral function in neural precursor formation and have acquired a new role in the fate specification of individual neural precursors. Furthermore, we find that Tc-ase is expressed in all neural precursors suggesting an important and conserved role for asense genes in insect nervous system development. Our analysis of the Tribolium ac/sc genes indicates significant plasticity in gene number, expression and function, and implicates these modifications in the evolution of arthropod neural development.
Reduced leaf complexity in tomato wiry mutants suggests a role forPHANandKNOXgenes in generating compound leaves
Authors: Kim Minsung , Pham Thinh , Hamidi Ashley , McCormick Sheila , Kuzoff Robert K. , Sinha Neelima
Published: August 2003

Recent work on species with simple leaves suggests that the juxtaposition of abaxial (lower) and adaxial (upper) cell fates (dorsiventrality) in leaf primordia is necessary for lamina outgrowth. However, how leaf dorsiventral symmetry affects leaflet formation in species with compound leaves is largely unknown. In four non-allelic dorsiventrality-defective mutants in tomato, wiry, wiry3, wiry4 and wiry6, partial or complete loss of ab-adaxiality was observed in leaves as well as in lateral organs in the flower, and the number of leaflets in leaves was reduced significantly. Morphological analyses and expression patterns of molecular markers for ab-adaxiality [LePHANTASTICA (LePHAN) and LeYABBY B(LeYAB B)] indicated that ab-adaxial cell fates were altered in mutant leaves. Reduction in expression of both LeT6 (a tomato KNOX gene) and LePHAN during post-primordial leaf development was correlated with a reduction in leaflet formation in the wiry mutants. LePHAN expression in LeT6 overexpression mutants suggests that LeT6 is a negative regulator of LePHAN. KNOXexpression is known to be correlated with leaflet formation and we show that LeT6 requires LePHAN activity to form leaflets. These phenotypes and gene expression patterns suggest that the abaxial and adaxial domains of leaf primordia are important for leaflet primordia formation, and thus also important for compound leaf development. Furthermore, the regulatory relationship between LePHAN and KNOX genes is different from that proposed for simple-leafed species. We propose that this change in the regulatory relationship between KNOX genes and LePHAN plays a role in compound leaf development and is an important feature that distinguishes simple leaves from compound leaves.
Wise, a context-dependent activator and inhibitor of Wnt signalling
Authors: Itasaki Nobue , Jones C. Michael , Mercurio Sara , Rowe Alison , Domingos Pedro M. , Smith James C. , Krumlauf Robb
Published: August 2003

We have isolated a novel secreted molecule, Wise, by a functional screen for activities that alter the anteroposterior character of neuralised Xenopus animal caps. Wise encodes a secreted protein capable of inducing posterior neural markers at a distance. Phenotypes arising from ectopic expression or depletion of Wise resemble those obtained when Wnt signalling is altered. In animal cap assays, posterior neural markers can be induced by Wnt family members, and induction of these markers by Wise requires components of the canonical Wnt pathway. This indicates that in this context Wise activates the Wnt signalling cascade by mimicking some of the effects of Wnt ligands. Activation of the pathway was further confirmed by nuclear accumulation of β-catenin driven by Wise. By contrast, in an assay for secondary axis induction, extracellularly Wise antagonises the axis-inducing ability of Wnt8. Thus, Wise can activate or inhibit Wnt signalling in a context-dependent manner. The Wise protein physically interacts with the Wnt co-receptor,lipoprotein receptor-related protein 6 (LRP6), and is able to compete with Wnt8 for binding to LRP6. These activities of Wise provide a new mechanism for integrating inputs through the Wnt coreceptor complex to modulate the balance of Wnt signalling.
An investigation of cutting forces in horizontal-mode peripheral milling of curved surfaces
Authors: Zhang L , Zheng L , Zhang Z-H
Published: August 2003

This paper investigates the cutting forces in peripheral milling of curved surfaces on the horizontal milling machine. An analytical model of cutting forces is presented. The effect of the workpiace curvature is taken into account in the model construction. Based on the relationship of differential cutting forces and chip load, the total cutting forces are formulated by integration of the differential cutting forces along the cutting flutes in the feed, cross-feed and axial directions. This formulation leads to an explicit expression for the force waveforms as algebraic functions of cutter variables, process parameters, machining configuration and workpiece geometry. Experiments are performed over a wide range of conditions on the horizontal milling machine to verify the model and meanwhile the effects of the process parameters on the cutting forces are revealed. The presented model facilitates force estimation and provides a basis for the analysis, prediction and improvement of surface accuracy in the horizontal-mode peripheral milling of curved surfaces.
Improvement of the yield of physiologically active oligosaccharides in continuous hydrolysis of chitosan using immobilized chitosanases
Authors: Kuroiwa Takashi , Ichikawa Sosaku , Sato Seigo , Mukataka Sukekuni
Published: August 2003

The continuous production of chitosan oligosaccharides using a packed‐bed enzyme reactor was investigated as to the effects of the operation conditions on the yield of pentamers and hexamers of chitosan oligosaccharides. A column reactor packed with immobilized chitosanases prepared by the multipoint attachment method was used for continuous hydrolysis of chitosan. In this reactor, the decrease of the yield of the target intermediate oligosaccharides due to axial mixing was negligible. The surface enzyme density of the support and flow rate of the substrate solution significantly affected the maximum yield of pentamers and hexamers. These effects were summarized as a correlation with the Damköhler number (Da), defined as the ratio of the maximum reaction rate to the maximum mass transfer rate. The optimum condition was determined based on Da. Under the optimized condition (Da = 0.12), pentamers and hexamers could be produced continuously for a month with a yield of over 35% (7 kg/m3 in concentration). © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 84: 121–127, 2003.
Using financing to motivate a for‐profit health care provider to deliver family planning services: Is it a cost‐effective intervention? A study of AAR health services in Kenya
Authors: Chee Grace
Published: August 2003

Despite much discussion of the role of private health care providers, there are no tried and tested models for supporting for‐profit providers in ways that produce cost‐effective public health outcomes. This paper examines the cost effectiveness of using a loan mechanism to motivate a for‐profit provider to deliver family planning services. The intervention examined directly resulted in a private provider delivering family planning services, however, it did not create a long‐term financial incentive for the private provider to promote the use of family planning. The cost effectiveness of this intervention is analysed using a methodology that captures long term sustainability of the intervention within a traditional family planning outcome measure, such as couple years protection (CYP), by discounting future expected CYPs. Depending on the method for analysing costs and assumptions regarding future CYPs, this intervention produced family planning outcomes at no or very low cost ($0–$4.11 per CYP). The analysis demonstrates that innovative family planning interventions with private providers should be considered as they can be more cost effective than traditional programmes. Copyright © 2003 John Wiley & Sons, Ltd.
Characteristics of organic matter as indicators of pollution from small‐scale livestock and nitrate contamination of shallow groundwater in an agricultural area
Authors: Kim Rak‐Hyeon , Lee Jeongho , Chang Ho‐Wan
Published: August 2003

The main purpose of this study was to examine the hydrogeochemical factors leading to nitrate contamination of shallow groundwater in an agricultural area. Another purpose was to identify relationships between variations in organic matter levels (as estimated by the BOD and COD parameters) of groundwater that transports effluent from small‐scale livestock holdings. Major cations, anions, BOD and COD of organic matter and total coliforms were analysed. It was found that groundwaters beneath cultivated areas and areas carrying livestock had higher concentrations of calcium, nitrate and chloride than did freshwater. Above all, the nitrification process increased concentrations of nitrate. Nitrate levels were depressed in some places where the groundwater was low in dissolved oxygen. Groundwaters affected by livestock activities showed high concentrations of organic matter (BOD, COD) and high microbial concentrations (as indicated by total coliforms). The COD/BOD ratio increased in the downward direction. It was inferred that this was due to the faster loss of easily biodegradable organic matter compared with non‐biodegradable organic matter proceeding away from a discharge. Accordingly, it is possible to trace effluent in a small area back to a point source by monitoring the COD/BOD ratio of groundwater. Copyright © 2003 John Wiley & Sons, Ltd.
Predicting space–time variability of hourly streamflow and the role of climate seasonality: Mahurangi Catchment, New Zealand
Authors: Atkinson S. E. , Sivapalan M. , Viney N. R. , Woods R. A.
Published: August 2003

We present a systematic approach to achieving accurate hourly streamflow predictions at locations internal to a catchment, potentially with minimal calibration. Each step in this approach is meant to provide insight into the relative importance of catchment and climatic properties (rainfall, soil, vegetation, topography), their spatial variability, and their influence on the spatial and temporal variability of streamflows. This has been made possible through the use of a simple conceptual model design requiring minimal calibration and with physically meaningful catchment parameters estimated mostly a priori from landscape data, and climatic variables. Eight model types originating from this simple conceptual model design, with complexity ranging from lumped to fully distributed, were tested over summer and winter periods at the Mahurangi Catchment, New Zealand, and the preferred model identified using statistical assessment criteria. Results of the simulations suggest that, although the required model complexity was found to be a function of the season (summer versus winter), a fully distributed representation is most appropriate for accurate predictions under all seasonal climate conditions. Using this model, the success of hourly flow predictions in space–time was assessed and sensitivity analysis used to identify the dominant controls on the timing and magnitude of hourly flow predictions and to investigate the adequacy of the assumption of homogeneity for a number of catchment properties. Copyright © 2003 John Wiley & Sons, Ltd.
Simple two‐state protein folding kinetics requires near‐levinthal thermodynamic cooperativity
Authors: Kaya Hüseyin , Chan Hue Sun
Published: August 2003

Simple two‐state folding kinetics of many small single‐domain proteins are characterized by chevron plots with linear folding and unfolding arms consistent with an apparent two‐state description of equilibrium thermodynamics. This phenomenon is hereby recognized as a nontrivial heteropolymer property capable of providing fundamental insight into protein energetics. Many current protein chain models, including common lattice and continuum Gō models with explicit native biases, fail to reproduce this generic protein property. Here we show that simple two‐state kinetics is obtainable from models with a cooperative interplay between core burial and local conformational propensities or an extra strongly favorable energy for the native structure. These predictions suggest that intramolecular recognition in real two‐state proteins is more specific than that envisioned by common Gō‐like constructs with pairwise additive energies. The many‐body interactions in the present kinetically two‐state models lead to high thermodynamic cooperativity as measured by their van't Hoff to calorimetric enthalpy ratios, implying that the native and denatured conformational populations are well separated in enthalpy by a high free‐energy barrier. It has been observed experimentally that deviations from Arrhenius behavior are often more severe for folding than for unfolding. This asymmetry may be rationalized by one of the present modeling scenarios if the effective many‐body cooperative interactions stabilizing the native structure against unfolding is less dependent on temperature than the interactions that drive the folding kinetics. Proteins 2003;52:510–523. © 2003 Wiley‐Liss, Inc.
Nitrogen fixation genetics and regulation in a Pseudomonas stutzeri strain associated with rice
Authors: Desnoues Nicole , Lin Min , Guo Xianwu , Ma Luyan , Carreño-Lopez Ricardo , Elmerich Claudine
Published: August 2003

The Pseudomonas stutzeri strain A1501 (formerly known as Alcaligenes faecalis) fixes nitrogen under microaerobic conditions in the free-living state and colonizes rice endophytically. The authors characterized a region in strain A1501, corresponding to most of the nif genes and the rnf genes, involved in electron transport to nitrogenase in Rhodobacter capsulatus. The region contained three groups of genes arranged in the same order as in Azotobacter vinelandii: (1) nifB fdx ORF3 nifQ ORF5 ORF6; (2) nifLA-rnfABCDGEF-nifY2/nafY; (3) ORF13 ORF12-nifHDK-nifTY ORF1 ORF2-nifEN. Unlike in A. vinelandii, where these genes are not contiguous on the chromosome, but broken into two regions of the genome, the genes characterized here in P. stutzeri are contiguous and present on a 30 kb region in the genome of this organism. Insertion mutagenesis confirmed that most of the nif and the rnf genes in A1501 were essential for nitrogen fixation. Using lacZ fusions it was found that nif and rnf gene expression was under the control of ntrBC, nifLA and rpoN and that the rnf gene products were involved in the regulation of the nitrogen fixation process.
A multi‐attribute motivational model of consumer choice based on a new outranking relation
Authors: Tavares L. Valadares
Published: August 2003

Multiple models have been proposed to describe different patterns of consumer behavior, that is becoming more complex and diversified (so called “postmodern consumer”), but little attention has been given to explore the potential of the approach based on pairwise comparisons. In this paper, a new model of consumer choice is developed considering that: the space of the perceptual attributes includes two sub‐spaces; the motivational attributes which are responsible for the generation of a motivational drive or force; other relevant decisional attributes. The process of choice is modeled by an outranking relation that is appropriate to describe pairwise comparisons. An example is presented illustrating the applicability of this model to the choice of a sport car, based on the two groups of attributes. There is general agreement about the impossibility of developing an universal model for consumer choice but it is expected that this model can enrich the list of available candidates. Major advantages are: the explicit distinction between motivational and non‐motivational attributes. These two groups play a different role in the process of consumer decision making; the description of the consumer choice in terms of successive pairwise comparisons; and the use of a new outranking relation appropriate to model the choice made by the consumer in terms of his motivation and avoiding the integration of multiple attributes through the usual weighting functions which are hardly confirmed by empirical evidences.
The use of problem structuring methods in strategic health planning
Authors: Thunhurst Colin
Published: August 2003

Problem structuring methods have emerged as a powerful weapon in the armoury of operational research over the past twenty years. This paper will present and discuss the value of adopting formal problem structuring methods as part of the strategic health planning process. It will outline how problem structuring methods were embedded into the strategic health planning system developed for provincial health planning in Pakistan. It will draw upon the author's recent experience of using this system to assist the Government of the North West Frontier Province of Pakistan to develop a ‘Master’ Health Plan for the Federally Administered Tribal Areas of Pakistan. It will discuss the systematic use of problem structuring methods in the District Implementation Planning Process in Malawi. It will consider the value of adopting similar methods in developed health systems, particularly their role in bridging the gap in a ‘partnership model’ between community groups and statutory decision‐makers.
The Changing Social Contexts of Deforestation in the Brazilian Amazon
Authors: Perz Stephen G.
Published: August 2003

Objective. This article reviews changes in the social contexts of deforestation in the Brazilian Amazon from the 1970s to the 1990s, moving from the household to the global level. Methods. I draw on satellite imagery, state publications, farm surveys, ethnographic field work, and policy analyses for a comparative analysis that shows how land cover, agriculture, demographics, politics, and markets have changed over time. Results. Alterations in the social contexts of deforestation appear on all levels considered, from household demographic evolution and new land use strategies to a regional demographic transition and the emergence of cattle and timber economies, to a “greening” of Brazilian development policy and changes in national land markets, to multilateral bank loans for new infrastructure and local‐international alliances between grassroots and environmental organizations. Conclusions. The social contexts of deforestation are very complex and changing and call for greater attention by social scientists to land cover and land use change.
Scientific Expertise and Natural Resource Decisions: Social Science Participation on Interdisciplinary Scientific Committees
Authors: Freudenburg William R. , Gramling Robert
Published: August 2003

Social scientists should seek greater involvement in interdisciplinary scientific committees, which often play important roles in natural resource management. In addition to our acknowledged areas of expertise, we have the ability to educate other disciplines about social sciences and, importantly, also about the realities of biophysical science input into policy processes. Two examples are worth noting. First, the asymmetry of scientific challenge can mean that biophysical science views/interpretations with favorable implications for organized groups’ interests may have been “accepted” with little scrutiny, relative to work having unfavorable implications. Second and paradoxically, the structure of decision making can mean that preferences for “scientific caution” will result in resource management decisions that are anything but cautious. These and other observations need to be tested through participant observation by a greater number of social scientists on scientific committees in the future.
Determinants of Women's Entry into Self–Employment
Authors: Taniguchi Hiromi
Published: August 2003

Objective. Building on recent studies that have shown how employment– and family–related characteristics are uniquely intertwined in facilitating women's decisions to work for themselves, I examine the process of transitions into self–employment among white, African–American, and Hispanic women. Methods. This study analyzes data from the National Longitudinal Survey of Youth, a national probability sample of those born between 1957 and 1964, which allows me to apply a dynamic model for studying women's employment transitions. Results. Regardless of race or ethnicity, factors such as work experience and the presence of a spouse encourage women to become self–employed. At the same time, the distributions of these characteristics for African–American women, and to a lesser extent Latinas as well, significantly account for their slower entry into self–employment. The effect of children on women's entry into self–employment, which earlier studies often found to be positive, especially among whites, is mixed. Conclusions. These findings reveal significant racial/ethnic differences in the process of female self–employment and also call into question the view that self–employment allows working mothers to better combine their careers with family responsibilities than does wage/salary sector employment.
Bacterial Diversity in Cases of Lung Infection in Cystic Fibrosis Patients: 16S Ribosomal DNA (rDNA) Length Heterogeneity PCR and 16S rDNA Terminal Restriction Fragment Length Polymorphism Profiling
Authors: Rogers G. B. , Hart C. A. , Mason J. R. , Hughes M. , Walshaw M. J. , Bruce K. D.
Published: August 2003

The leading cause of morbidity and mortality in cystic fibrosis (CF) patients stems from repeated bacterial respiratory infections. Many bacterial species have been cultured from CF specimens and so are associated with lung disease. Despite this, much remains to be determined. In the present study, we characterized without prior cultivation the total bacterial community present in specimens taken from adult CF patients, extracting DNA directly from 14 bronchoscopy or sputum samples. Bacterial 16S ribosomal DNA (rRNA) gene PCR products were amplified from extracted nucleic acids, with analyses by terminal restriction fragment length polymorphism (T-RFLP), length heterogeneity PCR (LH-PCR), and sequencing of individual cloned PCR products to characterize these communities. Using the same loading of PCR products, 12 distinct T-RFLP profiles were identified that had between 3 and 32 T-RFLP bands. Nine distinct LH-PCR profiles were identified containing between one and four bands. T-RFLP bands were detected in certain samples at positions that corresponded to pathogens cultured from CF samples, e.g.,
Burkholderia cepacia
and
Haemophilus influenzae
. In every sample studied, one T-RFLP band was identified that corresponded to that produced by
Pseudomonas aeruginosa.
A total of 103 16S rRNA gene clones were examined from five patients.
P. aeruginosa
was the most commonly identified species (59% of clones).
Stenotrophomonas
species were also common, with eight other (typically anaerobic) bacterial species identified within the remaining 17 clones. In conclusion, T-RFLP analysis coupled with 16S rRNA gene sequencing is a powerful means of analyzing the composition and diversity of the bacterial community in specimens sampled from CF patients.
Enzootic Transmission of
Anaplasma bovis
in Nantucket Cottontail Rabbits
Authors: Goethert Heidi K. , Telford Sam R.
Published: August 2003

Serological studies of cottontail rabbits sampled from Nantucket Island, Mass., have suggested exposure to at least two ehrlichiae. The agent of human granulocytic ehrlichiosis (
Anaplasma phagocytophilum
) is intensely enzootic in rabbits there, but the identity of the other ehrlichial infection remains undescribed. We sampled rabbits over five transmission seasons and tested their blood and tissues for evidence of infection using PCR targeting an
Ehrlichia
genus-wide 16S rDNA target. Sequence analysis of positive amplicons revealed the presence of
Anaplasma bovis
, an agent not known to be present in North America. The average annual prevalence of
A. bovis
within rabbits, as determined by PCR of blood samples, was 18%.
Haemaphysalis leporispalustris
appears to serve as vector. The public health (human or veterinary) significance of this finding remains speculative.
Rhizobium
(
Agrobacterium
)
radiobacter
Identified as a Cause of Chronic Endophthalmitis Subsequent to Cataract Extraction
Authors: Namdari Hassan , Hamzavi Sirus , Peairs Randall R.
Published: August 2003

Herein, we report a case of chronic endophthalmitis caused by a ceftazidime-resistant
Rhizobium radiobacter
strain in a 62-year-old male. The patient underwent an uneventful cataract extraction of the right eye a week prior to the appearance of symptoms (pain, redness, and blurring vision) which developed following a golf outing. Upon admission the patient received an emergency vitrectomy. The patient remained symptomatic, and
R. radiobacter
was isolated repeatedly from vitreous fluid cultures over a 5-month period. Ultimately, the infection responded to intravitreal gentamicin, oral ciprofloxacin, and removal of the lens implant.