bluuebunny/crossref_metadata_2025 huggingface dataset:
Contribution of cryofixation and freeze‐substitution to analytical microscopy: A study of Tritrichomonas foetus hydrogenosomes
Authors: Consort Ribeiro Karla , Benchimol Marlene , Farina Marcos
Published: August 2002

The hydrogenosome, an organelle that produces molecular hydrogen and ATP from the oxidation of pyruvate or malate under anaerobic conditions, presents some characteristics common to mitochondria. It is found in several trichomonad species, protists living in oxygen‐poor environments, as well as certain free‐living ciliates, rumen ciliates, and some fungi. We performed a comparative microanalytical study (energy dispersive X‐ray analysis and electron spectroscopic imaging) of different fixation methods for electron microscopy analyzing hydrogenosomes of the bovine parasite Tritrichomonas foetus. The study included the elemental composition and the mapping of calcium, phosphorus, and oxygen. A preparation of T. foetus cells, based on cryoimmobilization by high‐pressure freezing and freeze‐substitution, was compared to a second preparation based on chemical fixation followed by dehydration and routine processing. The ultrastructural preservation achieved by the cryotechnique was far superior to the chemical fixation, since it allowed the successful cryoimmobilization of intracellular ion contents. The detection of several cations (Al, Mg, Co, Ca, Fe) by X‐ray microanalysis inside the peripheral vesicle of the hydrogenosome was only possible in cryofixed cells. The presence of aluminum and cobalt ion in the hydrogenosomal vesicle was established for the first time. Electron‐spectroscopic images of calcium showed that this element, in addition to the vesicle compartment, is present in the hydrogenosome's membrane in varying concentrations, which might reflect changes in the physiology of this organelle. Microsc. Res. Tech. 53:87–92, 2001. © 2001 Wiley‐Liss, Inc.
Remodeling of extracellular matrix in gastric ulceration
Authors: Shahin M. , Konturek J.W. , Pohle T. , Schuppan D. , Herbst H. , Domschke W.
Published: August 2002

The quality of ulcer repair remains crucial for the stability of the injured tissue and for preventing recurrence. Therefore, we studied the temporo‐spatial expression of the fibrillar and basement membrane collagens (types I, III, and IV), the collagenase MMP‐2 as well as its inhibitor TIMP‐1 before and after oral administration of basic fibroblast growth factor (b‐FGF) over 30 days in acetic acid‐induced rat gastric ulcers. The alterations and the exact location of the mRNA transcripts and their precipitated proteins were visualized by means of radioactive in situ hybridization and immunohistochemistry. Our data show that hybridization signals of procollagen I could first be identified 2 hours after ulcer induction. After 12 hours the ulcer was established and the mRNA was enhanced at the ulcer margin. After 24–48 hours the other procollagen transcripts were detected and all were further upregulated over the mesenchymal cells of all gastric layers up to 21 days, then declined at 30 days. In contrast, MMP‐2 became prominent after 48 hours and up to 21 days. TIMP‐1 was enhanced at 72 hours. After oral administration of b‐FGF the transcriptional activity of the procollagens and MMP‐2 was not significantly altered, while ulcer diameter was significantly reduced. We conclude that the early onset and long duration of collagens' expression points to their central structural and functional role in gastric ulcer healing. MMP‐2 seems to be involved in both active ulceration and ECM remodeling. The timing of TIMP/MMP expression may be critical for proper restoration of gastric wall integrity. Microsc. Res. Tech. 53:396–408, 2001. © 2001 Wiley‐Liss, Inc.
Branchial innervation
Authors: Sundin Lena , Nilsson Stefan
Published: August 2002

Inspection of the dorsal end of fish gills reveals an impressive set of nerve trunks, connecting the gills to the brain. These trunks are branches of cranial nerves VII (the facial) and especially IX (the glossopharyngeal) and X (the vagus). The nerve trunks carry a variety of nervous pathways to and from the gills. A substantial fraction of the nerves running in the branchial trunks carry afferent (sensory) information from receptors within the gills. There are also efferent (motor) pathways, which control muscles within the gills, blood flow patterns and possibly secretory functions. Undertaking a more careful survey of the gills, it becomes evident that the arrangement of the microanatomy (particularly the blood vessels) and its innervation are strikingly complex. The complexity not only reflects the many functions of the gills but also illustrates that the control of blood flow patterns in the gills is of crucial importance in modifying the efficiency of its chief functions: gas transfer and salt balance. The “respiratory–osmoregulatory compromise” is maintained by minimizing the blood/water exchange (functional surface area of the gills) to a level where excessive water loss (marine teleosts) or gain (freshwater teleosts) is kept low while ensuring sufficient gas exchange. This review describes the arrangement and mechanisms of known nervous pathways, both afferent and efferent, of fish (notably teleosts) gills. Emphasis is placed primarily on the autonomic nervous system and mechanisms of blood flow control, together with an outline of the afferent (sensory) pathways of the gill arches. © 2002 Wiley‐Liss, Inc.
Retinal photoreceptors and visual pigments in Boa constrictor imperator
Authors: Sillman Arnold J. , Johnson Jacqueline L. , Loew Ellis R.
Published: August 2002

The photoreceptors of Boa constrictor, a boid snake of the subfamily Boinae, were examined with scanning electron microscopy and microspectrophotometry. The retina of B. constrictor is duplex but highly dominated by rods, cones comprising 11% of the photoreceptor population. The rather tightly packed rods have relatively long outer segments with proximal ends that are somewhat tapered. There are two morphologically distinct, single cones. The most common cone by far has a large inner segment and a relatively stout outer segment. The second cone, seen only infrequently, has a substantially smaller inner segment and a finer outer segment. The visual pigments of B. constrictor are virtually identical to those of the pythonine boid, Python regius. Three different visual pigments are present, all based on vitamin A1. The visual pigment of the rods has a wavelength of peak absorbance (λmax) at 495 ± 2 nm. The visual pigment of the more common, large cone has a λmax at 549 ± 1 nm. The small, rare cone contains a visual pigment with λmax at 357 ± 2 nm, providing the snake with sensitivity in the ultraviolet. We suggest that B. constrictor might employ UV sensitivity to locate conspecifics and/or to improve hunting efficiency. The data indicate that wavelength discrimination above 430 nm would not be possible without some input from the rods. J. Exp. Zool. 290:359–365, 2001. © 2001 Wiley‐Liss, Inc.
Covariance of ion flux measurements allows new interpretation of Xenopus laevis oocyte physiology
Authors: Faszewski Ellen E. , Kunkel Joseph G.
Published: August 2002

An animal‐vegetal net ionic current identified previously using voltage probe techniques in maturing Xenopus laevis oocytes has now been investigated using noninvasive ion‐selective microelectrodes. Three‐dimensional fluxes of hydrogen (H+), potassium (K+), and bicarbonate (HCO3–) were characterized with respect to the developmental stage and hemisphere of the oocyte and presence of surrounding follicular tissue. Variable effluxes of H+ and HCO3– were recorded from both the animal and vegetal hemispheres. Variable influxes and effluxes of K+ were also observed. The equatorial region, silent by voltage probe, exhibited fluxes of H+ and K+. Simultaneous measurement of pairs of ions allowed correlation analysis of two ion types. Notably for H+ and K+ data, positive and negative correlation at animal and vegetal poles respectively offer an explanation of the unpredictable results obtained when individual ions were observed independently. J. Exp. Zool. 290:652–661, 2001. © 2001 Wiley‐Liss, Inc.
Aid policies and growth: in search of the holy grail
Authors: Hudson John , Mosley Paul
Published: August 2002

In this paper we consider the hypothesis that aid effectiveness can be linked to ‘good policies’ and thus that aid, if it is to have maximum impact, should be directed at countries following good policies. This is an idea which we have considerable sympathy with in principle and have built upon in the past. Indeed at one level it is almost a truism and yet in practice we find little empirical evidence in support of it when we restrict good policies to mean free market policies. ‘Good policies’ appear to matter in stimulating growth, but they do not appear to impact on aid effectiveness. Unlike much of other recent work the analysis is of a simultaneous system of equations of which growth is just one. The results suggest a complex interaction between macroeconomic variables and good policies, but it also suggests the need to widen our definition of good policies to increase both the theoretical and empirical relevance of the hypothesis. Copyright © 2001 John Wiley & Sons, Ltd.
Multi‐national corporations and agricultural development: a study of contract farming in the Indian Punjab
Authors: Singh Sukhpal
Published: August 2002

This paper examines the rationale, practice and implications of contract farming under the MNCs in vegetable crops in the Indian Punjab from the new institutional economics perspective. It is found that the MNCs deal with relatively large producers, their contracts are biased against the farmer, and the contract crops perpetuate many of the existing problems of the farming sector like high chemical input intensity, unstable future incomes, and social differentiation, though contracting has led to higher farm incomes and labour employment, especially for women. There is an inherent contradiction in the objectives of the contracting parties and that of the local economy and suitable institutions and organisations are not present in the state. Copyright © 2002 John Wiley & Sons, Ltd.
Origin of evolutionary novelty: Examples from limbs
Authors: Shubin Neil H.
Published: August 2002

Classic hypotheses of vertebrate morphology are being informed by new data and new methods. Long nascent issues, such as the origin of tetrapod limbs, are being explored by paleontologists, molecular biologists, and functional anatomists. Progress in this arena will ultimately come down to knowing how macroevolutionary differences between taxa emerge from the genetic and phenotypic variation that arises within populations. The assembly of limbs over developmental and evolutionary time offers examples of the major processes at work in the origin of novelties. Recent comparative developmental analyses demonstrate that many of the mechanisms used to pattern limbs are ancient. One of the major consequences of this phenomenon is parallelism in the evolution of anatomical structures. Studies of both the fossil record and intrapopulational variation of extant populations reveal regularities in the origin of variation. These examples reveal processes acting at the level of populations that directly affect the patterns of diversity observed at higher taxonomic levels. J. Morphol. 252:15–28, 2002. © 2002 Wiley‐Liss, Inc.
Are Echiura derived from a segmented ancestor? Immunohistochemical analysis of the nervous system in developmental stages of Bonellia viridis
Authors: Hessling René , Westheide Wilfried
Published: August 2002

Despite several unquestionably homologous characters with Annelida, the Echiura have generally been considered to form a distinct taxon due to apparent lack of segmentation: neither in the body cavity nor in any other structures of the adult animals have clear signs of a metameric organization been observed. However, it must be considered that this lack of segmentation could represent a secondary condition and that Echiura are derived from segmented ancestors. An immunohistochemical analysis visualized with confocal laser‐scanning microscopy (cLSM) shows the development of serially repeated units in the nervous system of Bonellia viridis. This organization corresponds to the metameric ganglia typical of Annelida. Antibodies against the neurotransmitters serotonin (5‐hydroxytryptamine) and FMRFamide label distinct subsets of neurons. Their perikarya are arranged in discrete repetitive units in the ventral nerve cord of different larval stages. Labeling of neurotubuli using antibodies against different tubulin isoforms provides additional support for the metameric character of the nervous system. Contrary to previous descriptions, the peripheral nerves extending from the ventral nerve cord into the body wall musculature are paired and are evenly distributed; their arrangement corresponds to that of the serotoninergic perikarya. Morphological and neurochemical differentiation of the nervous system clearly proceeds from anterior to posterior, indicating the occurrence of a posterior growth zone. The serial ganglionic organization of the nervous system of Articulata is generally regarded as having evolved in conjunction with repetitive muscular units, in particular with the formation of typical annelid segments. Therefore, these results are interpreted as an indication that Echiura are derived from segmented ancestors and thus support the systematic inclusion of the Echiura within the Annelida. J. Morphol. 252:100–113, 2002. © 2002 Wiley‐Liss, Inc.
Quantitative measurements of cerebral blood flow in patients with unilateral carotid artery occlusion: A PET and MR study
Authors: Lin Weili , Celik Azim , Derdeyn Colin , An Hongyu , Lee Yueh , Videen Tom , Ostergaard Leif , Powers William J.
Published: August 2002

Although it has been demonstrated that quantitative measures of cerebral blood flow (CBF) can be obtained with the singular value decomposition (SVD) algorithm, the extent to which quantitative CBF measurements can be utilized under pathophysiological conditions has not been systematically studied. A total of five healthy volunteers and five patients with unilateral carotid artery occlusion were studied. Only magnetic resonance (MR) images were acquired for the volunteer group while both MR and positron emission tomography (PET) images were acquired for the patient group. Assessments of CBF from normal volunteers compared favorably with values reported in the literature. However, while a linear relationship was observed for each patient when MR measured CBF was compared to that obtained from PET, this linear relationship diminished when all patients were analyzed as a group (r = 0.41). A correction factor (CF) was proposed that was equal to the ratio of the area of the venous output function (VOF) in each patient to the mean VOF obtained from the volunteer group. After globally scaling the CBF of each patient based on the experimentally derived CF, a substantial improvement was observed (a slope of 1.02 and r = 0.8 for the linear regression line) in the relationship between MR estimated CBF and those obtained from PET. J. Magn. Reson. Imaging 2001;14:659–667. © 2001 Wiley‐Liss, Inc.
MRI‐guided thermal therapy of transplanted tumors in the canine prostate using a directional transurethral ultrasound applicator
Authors: Hazle John D. , Diederich Chris J. , Kangasniemi Marko , Price Roger E. , Olsson Lars E. , Stafford R. Jason
Published: August 2002

Purpose

To evaluate MRI‐based techniques for visual guidance, thermal monitoring, and assessment during transurethral ultrasound thermal therapy of implanted tumors in an in vivo canine prostate model.

Materials and Methods

Transmissible venereal tumors (TVT) were grown in the right lobe of the prostate in four dogs. High‐temperature thermal therapy was selectively applied to the tumor‐bearing lobe using a transurethral ultrasound applicator with a 180° directional heating pattern. Temperature‐sensitive MRI (MRTI) using a fast interleaved gradient‐echo echo‐planar (iGE‐EPI) imaging sequence was used for cumulative thermal dose calculations in multiple image planes during the treatment. The results from MRTI‐based dose maps and post‐treatment MRI were compared to those from histologic analysis.

Results

MRTI monitoring in multiple planes across the prostate guided the use and control of a directive ultrasound applicator for the selective ablation of the sections of the prostate that contained implanted tumors. Findings in gadolinium enhanced MRI obtained immediately after thermal therapy slightly underestimated the size of tissue necrosis after treatment, as verified by histopathologic analysis.

Conclusion

The use of multiplanar MRTI with a transurethral ultrasound applicator shows significant potential for selective thermal ablation of prostate tumor and tissue. J. Magn. Reson. Imaging 2002;15:409–417. © 2002 Wiley‐Liss, Inc.
Evaluation of the anatomical and functional properties of deglutition with various kinetic high‐speed MRI sequences
Authors: Anagnostara A. , Stoeckli S. , Weber O.M. , Kollias S.S.
Published: August 2002

We evaluated various fast MR sequences for obtaining anatomical and dynamic functional information during deglutition. Seven healthy volunteers underwent MRI of the oropharynx during swallowing of an oral positive‐contrast agent. Single‐slice imaging was performed in the median sagittal plane while subjects were in a supine position. Twenty serial images were obtained using EPI, FLASH, and turbo‐FLASH sequences. The dynamic (movement‐related) information and the anatomical resolution of the soft tissues were evaluated during deglutition. The FLASH sequence provided high‐quality images at rest. During swallowing, however, the images were significantly degraded by movement artifacts and had inferior temporal resolution. The EPI evidenced better temporal resolution, but was degraded by strong distortions and movement artifacts. The turbo‐FLASH sequence provided the best temporal resolution and sufficient spatial resolution during motion. This sequence proved optimal for the investigation of swallowing function, and is expected to be of value for the documentation of functional disturbances in patients with oropharyngeal pathology. J. Magn. Reson. Imaging 2001;14:194–199. © 2001 Wiley‐Liss, Inc.
The metabolism of norethandrolone in the horse: characterization of 16‐, 20‐ and 21‐oxygenated metabolites by gas chromatography/mass spectrometry
Authors: McKinney Andrew R. , Ridley Damon D. , Suann Craig J.
Published: August 2002

After oral administration to a thoroughbred gelding, the anabolic steroid norethandrolone was converted into a complex mixture of oxygenated metabolites. These metabolites were extracted from the urine, deconjugated by methanolysis and converted to their O‐methyloxime trimethylsilyl derivatives. Gas chromatographic/mass spectrometric analysis indicated the major metabolites to be 19‐norpregnane‐3,16,17‐triols, 19‐norpregnane‐3,17,20‐triols and 3,17‐dihydroxy‐19‐norpregnan‐21‐oic acids. Some minor metabolites were also detected. Copyright © 2001 John Wiley & Sons, Ltd.
Identification and sequencing analysis of intact proteins via collision‐induced dissociation and quadrupole time‐of‐flight mass spectrometry
Authors: Nemeth‐Cawley Jennifer F. , Rouse Jason C.
Published: August 2002

Identifying unknown proteins has become a central focal point for proteomic and biopharmaceutical development laboratories. Our laboratory investigated using quadrupole time‐of‐flight mass spectrometry (Qq/TOFMS) for the analysis of intact proteins for the purpose of identifying unknowns while limiting the number of sample‐handling steps between protein extraction and identification. Eight standard proteins, both unmodified and disulfide‐bonded and ranging in mass from 5 to 66 kDa, were analyzed using nanoelectrospray and collision‐induced dissociation to generate peptide sequence tags. An MS analysis, followed by MS/MS analyses on two to five individual protein charge states, were obtained to make an identification. Peptide sequence tags were extracted from the MS/MS data and used, in conjunction with molecular mass and source origin, to obtain protein identifications using the web‐based search engine ProteinInfo (www.proteometrics.com). All of the proteins were unambiguously identified from the input data, after which, all of the major product ions were identified for structural information. In most cases, N‐ and/or C‐terminal ions, and also stretches of consecutive product ions from the protein interior, were observed. This method was applied to the analysis and identification of an unknown detected via reversed‐phase high‐performance liquid chromatography. Copyright © 2002 John Wiley & Sons, Ltd.
Experimental hepatitis A virus infection in guinea pigs
Authors: Hornei Britt , Kämmerer Regine , Moubayed Pierre , Frings Werner , Gauss‐Müller Verena , Dotzauer Andreas
Published: August 2002

Although many of the properties of hepatitis A virus (HAV) are known, several aspects of HAV pathogenesis are still not understood, such as the mechanism underlying the hepatotropism or HAV replication in extrahepatic sites. Detailed studies of these aspects were hampered mostly by the lack of accessible animal models, since only nonhuman primates are susceptible to experimental infections. An alternative animal model would also be of interest to assess the primary replication site and for the evaluation of the safety and efficacy of vaccines. A study was undertaken to determine whether HAV can infect guinea pigs and whether they are useful as a model for studying aspects of HAV pathogenesis and for the evaluation of vaccines. HAV variants adapted to primate or guinea pig tissue culture were used to inoculate guinea pigs intraperitoneally and by the oral route. The animals were observed for clinical disease, shedding of HAV in stools, viremia, seroconversion, evidence for liver damage by biochemical liver function tests, virus presence in the liver, development of hepatic histopathological changes, and occurrence of HAV in extrahepatic organs. The animals developed an active, clinically inapparent infection with specific histopathological changes in the liver. Although virus replication occurred, as shown by RT‐PCR and isolation of infectious virus from feces and serum, it seems unlikely that guinea pigs are suitable for studying the clinical features of hepatitis A, because the clinical and laboratory parameters remained normal. However, guinea pigs appear useful for studying some aspects of HAV pathogenesis and for testing the safety of vaccines. J. Med. Virol. 64:402–409, 2001. © 2001 Wiley‐Liss, Inc.
Chronic hepatitis C infection: Influence of the viral load, genotypes, and GBV‐C/HGV coinfection on the severity of the disease in a Brazilian population
Authors: Pereira Leila M.M.B. , Spinelli Victorino , Ximenes Ricardo A. , Cavalcanti Maria S. , Melo Raul , Jucá Norma , Mizokami Masashi , McFarlane Ian G.
Published: August 2002

The distributions of the different genotypes of the hepatitis C virus (HCV) and GBV‐C virus (GBV‐C/HGV) vary geographically and information worldwide is still incomplete. In particular, there are few data on the distribution of genotypes (and their relationship to the severity of liver disease) in South America. Findings are described in 114 consecutive patients from Northeast Brazil (median age 52 years, range 18–72 years) who had abnormal levels of serum aminotransferases and seropositivity for HCV RNA. The patients were recruited from an outpatient clinic between November 1997 and April 1998. Quantitative HCV RNA and GBV‐C/HGV RNA estimations were carried out by double‐nested polymerase chain reaction (PCR) using primers from the 5′‐untranslated regions (UTRs) of the genomes. HCV genotypes were determined by restriction fragment length polymorphism (RFLP) analysis with 5′‐UTR primers and by PCR with type‐specific 5′‐UTR primers. GBV‐C/HGV‐RNA genotypes were determined by RFLP with specific 5′‐UTR primers and phylogenetic trees were constructed using the Neighbour‐Joining and Drawtree programs. Histological features were graded and staged according to international criteria. Of the 114 patients, 35 (30.7%) patients had cirrhosis and 22 (27.8%) had mild, 51 (64.6%) had moderate, and 6 (7.6%) had severe chronic hepatitis. Median HCV viral load was 106 genome equivalents per millilitre (range 104–109/ml). Frequencies of genotypes were 5.3% type 1a, 44.7% type 1b, 3.5% type 2, 41.2% type 3, and 5.3% mixed types. GBV‐C/HGV‐RNA was detected in the sera of 12 (10.5%) patients and was distributed among three phylogenetic groups. There were no significant differences between patients with the predominant HCV genotypes (1b and 3) with respect to gender, age group, viral load, severity of liver disease, or coinfection with GBV‐C/HGV. J. Med. Virol. 67:27–32, 2002. © 2002 Wiley‐Liss, Inc.
Expression of mRNA for plasminogen activators and protease nexin‐1 in innervated and denervated mouse skeletal muscle
Authors: Magnusson Caroline , Högklint Lars , Libelius Rolf , Tågerud Sven
Published: August 2002

Plasminogen activators (urokinase‐type, u‐PA and tissue‐type, t‐PA) are serine proteases that have been suggested to play important roles in synaptic remodeling. The enzymatic activity of u‐PA in particular has previously been shown to increase dramatically after denervation of skeletal muscle. Using 32P‐labeled riboprobes and Northern blots the expression of mRNA for u‐PA, t‐PA and the inhibitor protease nexin‐1 (PN‐1) has been studied in innervated and 1–10‐days denervated hind‐limb muscle from mouse. Using RNA extracted from innervated and 6‐days‐denervated mouse hemidiaphragm muscles the expression of these mRNAs has also been investigated in synaptic and extrasynaptic muscle regions. For both u‐PA and t‐PA the observed autoradiographic signals were similar for RNA extracted from innervated and denervated leg muscles. The signals were also similar for RNA extracted from perisynaptic and extrasynaptic regions of hemidiaphragm muscle but u‐PA signals were lower in denervated than in innervated hemidiaphragm. No such difference was observed for t‐PA. PN‐1 mRNA levels were also found to decrease after denervation in the hemidiaphragm but no substantial decrease was observed in denervated hind‐limb muscles. No difference was observed between PN‐1 expression in perisynaptic and extrasynaptic regions. The effect of denervation on PA enzymatic activity in skeletal muscle is therefore likely to be mediated at some post‐transcriptional level. J. Neurosci. Res. 66:457–463, 2001. © 2001 Wiley‐Liss, Inc.
Synucleins in glaucoma: Implication of γ‐synuclein in glaucomatous alterations in the optic nerve
Authors: Surgucheva Irina , McMahan Belinda , Ahmed Farid , Tomarev Stanislav , Wax Martin B. , Surguchov Andrei
Published: August 2002

Synucleins are small proteins associated with neurodegenerative diseases and some forms of cancer. They are studied predominantly in the brain; information about their presence and functions in ocular tissues is scarce. Here we describe the localization of three members of the synuclein family in the optic nerve of donors with different types of glaucoma compared with control samples from donors without ocular diseases. We did not find significant differences in the localization of α‐ and β‐synucleins in the optic nerve or retina of glaucoma patients compared with controls, whereas considerable redistribution of γ‐synuclein occurred in the glaucomatous optic nerve compared with control eye without glaucoma. In the optic nerve from control and glaucomatous individuals, nerve bundles are immunopositive for γ‐synuclein; however, a strong γ‐synuclein‐immunopositive staining in a subset of glial cells was observed in the lamina and postlamina cribrosa regions of the optic nerve only in glaucoma patients. In the optic nerve of rats with episcleral vein cauterization used as an animal model of glaucoma, the quantity of both γ‐synuclein mRNA and protein was decreased compared with the optic nerves of control animals. Incubation of rat astrocyte culture at elevated hydrostatic pressure reduced the amount of γ‐synuclein but did not affect the quantities of actin and glial fibrillary acidic protein. These data suggest that significant changes in the pattern of expression and/or localization occur in the glaucomatous optic nerve for γ‐synuclein but not for α‐ and β‐members of the synuclein family. © 2002 Wiley‐Liss, Inc.
Hypoxanthine impairs morphogenesis and enhances proliferation of a neuroblastoma model of Lesch Nyhan syndrome
Authors: Ma Margaret H. Y. , Stacey N. Charles , Connolly Gerald P.
Published: August 2002

Extracellular purines have essential roles in neuronal development; hence, disruptions in their metabolism as reported in Lesch Nyhan syndrome (LNS) could result in developmental abnormalities. The deficiency of hypoxanthine‐guanine phosphoribosyl transferase (HGPRT) in LNS leads to increased hypoxanthine and uric acid production. We have reported that HGPRT‐deficient B103‐4C neuroblastoma, a neuronal model of LNS, proliferated less and differentiated more than their HGPRT‐positive B103 counterparts. Here, we sought to determine whether differences in proliferation and differentiation would occur when these cells were cultured in the presence of hypoxanthine or in a hypoxanthine‐/serum‐free chemically defined media (NBMN2). In media with 1% serum, hypoxanthine (50 μM) significantly increased the proliferation of both cell lines with a greater effect on B103‐4C cells. In 1% serum media, hypoxanthine increased differentiation of B103 but decreased B103‐4C differentiation. In NBMN2, B103 proliferated far more than B103‐4C, but both cell types differentiated to the same extent. These results are interpreted to suggest that elevated levels of central nervous system (CNS) hypoxanthine as reported in LNS may affect neuronal development, and to implicate hypoxanthine and abnormal neuronal development as causative factors in the etiology of LNS. J. Neurosci. Res. 63:500–508, 2001. © 2001 Wiley‐Liss, Inc.
Early detection of the start of the wet season in semiarid tropical climates of western Africa
Authors: Dodd Doris E.S. , Jolliffe Ian T.
Published: August 2002

An earlier paper (Jolliffe IT, Sarria‐Dodd DE. 1994. International Journal of Climatology 14: 71–76) investigated the problem of deciding when the wet season has started in tropical and sub‐tropical climates. In particular, methodology based on linear discriminant analysis was developed for using data from the current season to make the decision, rather than relying only on information from previous seasons. It was shown, for three stations in eastern Africa, that the methodology was potentially valuable. The present study is much larger, using data from 24 stations, covering a range of annual rainfall totals, in western Africa. It is confirmed that linear discriminant analysis can indeed be useful in detecting when the wet season has started, and hence in deciding when to plant crops. As well as being a larger analysis than that reported previously, the present study also extends the previous work by investigating an alternative definition of the start of the wet season and by including ‘date’ as a potential explanatory variable. Copyright © 2001 Royal Meteorological Society
Developments and prospects in synoptic climatology
Authors: Yarnal Brent , Comrie Andrew C. , Frakes Brent , Brown David P.
Published: August 2002

Developments in synoptic climatology in the 1990s included advances in traditional synoptic climatology, empirical downscaling, and dynamical downscaling (i.e. regional climate modelling). The research emphasis in traditional, empirical–statistical approaches to synoptic climatology shifted from methodological development to applications of widely accepted classification techniques, including manual, correlation‐based, eigenvector‐based, compositing and indexing schemes. In contrast, most efforts in empirical downscaling, which became a well‐established field of synoptic climatology during the 1990s, were directed to model development; applications were of secondary concern. Similarly, regional climate models (RCMs) burst onto the scene during the decade and focused on model development, although important progress was made in linking or coupling RCMs to regional or local surface climate systems. This paper discusses prospects for the future of traditional synoptic climatology, empirical downscaling and regional climate modelling. It concludes by looking at the present role of geographic information system (GIS) concepts in synoptic climatology and the potential future role of GIS to the field. Copyright © 2001 Royal Meteorological Society
Spatial and temporal variabilities of rainfall in tropical South America as derived from Climate Prediction Center merged analysis of precipitation
Authors: Matsuyama H. , Marengo J.A. , Obregon G.O. , Nobre C.A.
Published: August 2002

We investigated the spatial and temporal variabilities of Climate Prediction Center merged analysis of precipitation (CMAP) in tropical South America from 1979 to 1998. First, we validated CMAP using other hydrometeorological data. In comparison with the high‐density precipitation data of the Global Historical Climatology Network (GHCN) Ver. 2, CMAP reproduces the spatial pattern well, although it underestimates (overestimates) heavy (light) precipitation. CMAP also reproduces the interannual variability well, compared with the discharge data of the River Amazon.

Next, we applied the rotated empirical orthogonal function (REOF) to CMAP after subtracting the annual cycle. Simultaneous and lag correlations were calculated among the scores of REOFs 1 to 4, the southern oscillation index, and the dipole index of the Atlantic. REOF 1 (15%) represents the north–south pattern that exhibits the maximum precipitation in the summer hemisphere. REOF 2 (12%) indicates the gradual decrease of precipitation in the northern part of tropical South America, reflecting the effect of the Atlantic. REOF 3 (11%) exhibits an east–west pattern related to El Niño. In REOF 4 (7%), the centre of the factor loading is located in Colombia, and the score jumps abruptly around 1985–86.

The Lepage test detected the abrupt increase of CMAP in 1985–86 around Colombia. Since such a jump is not found in GHCN Ver. 2, the discontinuous changes of CMAP and REOF 4 around 1985–86 are artificial and peculiar to CMAP. In this region, CMAP should be applied with caution when evaluating recent trends and the interannual variability. The importance of the abrupt increase of precipitation around Colombia is also addressed. Copyright © 2002 Royal Meteorological Society.
Synthesis and properties of axially substituted zirconium(IV) and hafnium(IV) phthalocyanines with organic ligands
Authors: TOMACHYNSKI L. A. , CHERNII V. YA. , VOLKOV S. V.
Published: August 2002

Water-soluble phthalocyaninato zirconium(IV) and hafnium(IV) complexes have been synthesized for the first time. An increased solubility in comparison to PcZrCl 2 and PcHfCl 2 was caused by the introduction of gallic, 1,8-dihydroxynaphthalene-3,6-disulfonic (chromotropic), and 5-sulfosalicylic acids in the axial position. The new compounds were characterized by 1 H NMR, IR, UV-vis and elemental analysis.
A Weichselian deglaciation model applied to the Early Permian glaciation in the northeast Karoo Basin, South Africa
Authors: Haldorsen Sylvi , Von Brunn Victor , Maud Rodney , Truter Edward D.
Published: August 2002

It generally is assumed that the Early Permian Gondwana deglaciation in South Africa started with a collapse of the marine ice‐sheet. The northeast part of the Karoo Basin became ice‐free as a result of this collapse. The deglaciation here probably took place under temperate glacial conditions. Three glacial phases have been identified. Phase 1: the marine ice retreat of 400 km over the northeast Karoo Basin, which may have been completed over a few thousand years. The glaciers grounded in the shallower areas around the shore of the basin. Phase 2: the smaller, now mainly continental ice‐sheet here re‐stabilised and remained more or less stationary for several tens of thousand years. During this phase, between 50 and 200 m of massive glaciomarine mud with dropstones accumulated in the open, marine basin that became ice‐free during Phase 1. Isostatic uplift, as a response to the first rapid deglaciation phase, can be traced in the inland part of the region. Phase 3: the final deglaciation may have taken 10 to 20 kyr. After this time no new ice sheet was built up over southern Africa. The entire Early Permian deglaciation of the northeast Karoo Basin was completed within thousands rather than millions of years. Phases 1 and 3 had lengths similar to typical Quaternary deglaciations, whereas Phase 2 was a long, stable phase, more similar to a full Quaternary glaciation. Copyright © 2001 John Wiley & Sons, Ltd.
Micro‐Raman study of Ba1 − xSrxTiO3 ceramics
Authors: Dobal P. S. , Dixit A. , Katiyar R. S. , Garcia D. , Guo R. , Bhalla A. S.
Published: August 2002

A Raman spectroscopic study was performed to investigate Ba1−xSrxTiO3 ceramics prepared using a solid‐state reaction technique. A single‐phase perovskite structure of the ceramics was verified and no mechanical stresses or grain size effects were identified within the sensitivity of the Raman micro‐probe. The tetragonal to cubic transition temperature that was found to decrease linearly from 137 to 7 °C with increasing Sr content from x = 0.00 to x = 0.35 corroborated the dielectric results on single crystals. Copyright © 2001 John Wiley & Sons, Ltd.
Resonant light scattering and luminescence in multimode vibronic systems: time‐dependent representation
Authors: Hizhnyakov V. , Tehver I.
Published: August 2002

The resonant secondary emission of light by impurity centres in crystals was studied, based on the Kramers and Heisenberg dispersion equation in time representation. The problem of the classification of the secondary emission is overviewed for an archetype model of a molecular centre. It is demonstrated that the Kramers and Heisenberg equation describes the ordinary and hot luminescence and the Rayleigh and the Raman scattering. The effects of the inhomogeneous distribution of zero‐phonon transitions on different components of resonant secondary emission are described. Copyright © 2001 John Wiley & Sons, Ltd.
Complex Raman amplitude recovery and dynamics from the Raman excitation profile: application to iodobenzene and azulene
Authors: Feng Z. W. , Lee Soo‐Y.
Published: August 2002

Recovering the complex amplitude or phase from an intensity, which is given as the modulus square of the amplitude, is a problem common to diverse physical areas. The focus of this paper is on the Raman excitation profile — the Raman intensity of a mode as a function of the excitation energy — which is given by the modulus square of the Raman amplitude. Three methods, with different principles, are presented for amplitude or phase recovery: the dispersion or energy‐frame method; the z‐transform or time‐frame method; and the maximum entropy method. A comparison function technique is introduced to address the usual situation where the measured intensity is band‐limited. There are two classes of problems, minimum phase and non‐minimum phase, and the mapping from the intensity to the complex amplitude may not be unique. The non‐minimum phase situation occurs when the analytically extended complex amplitude, with the energy E replaced by ξ = γ − iE, has zeros in the right‐half complex plane. These zeros have implications for the system dynamics. An algorithm is presented to search for the critical zeros. The characteristics of the zeros are studied with a two‐mode harmonic model, and the theory is applied to the Raman excitation profiles of iodobenzene and azulene. Copyright © 2001 John Wiley & Sons, Ltd.
Phase transition in WO3 microcrystals obtained by sintering process
Authors: Filho A. G. Souza , Filho J. Mendes , Freire V. N. , Ayala A. P. , Sasaki J. M. , Freire P. T. C. , Melo F. E. A. , Julião J. F. , Gomes U. U.
Published: August 2002

The vibrational properties of WO3 ceramics in the 30–300 K temperature range were probed by Raman spectroscopy. Starting with WO3 ceramics at room temperature presenting monoclinic (V) and triclinic (VI) mixed phases, structural transitions related to decreasing temperature were observed. At low temperatures a monoclinic (VII) and a new mixed phase were observed, the former characteristic of WO3 bulk and the latter associated to microcrystals. The analysis of the spectra indicated that the new phase develops gradually and it comes mainly from the monoclinic (V) phase. Copyright © 2001 John Wiley & Sons, Ltd.
Sherry wine vinegar: physicochemical changes during the acetification process
Authors: Morales M L , Tesfaye W , García‐Parrilla M C , Casas J A , Troncoso A M
Published: August 2002

The quality of a wine vinegar is determined by the raw wine substrate and the acetification process employed in its production. Attempts to characterise vinegars have been based on these two features, along with variables such as total extract, glycerol, organic acids, volatile compounds and phenolic composition. When the final products are analysed, it is difficult to evaluate to what extent quality differences are due to the raw material or to differences in production methods, so it is necessary to determine the influence of each feature separately. The present work focuses on monitoring physicochemical changes during the acetification of sherry wine by submerged culture. ANOVA showed significant differences for ethanol, acetic and lactic acids and some volatile compounds (methanol, 1‐propanol, 2‐methyl‐1‐propanol, 2‐methyl‐1‐butanol, 3‐methyl‐1‐butanol, acetoin, acetaldehyde, ethyl acetate and ethyl lactate). However, no statistical changes were found for phenolic compounds during acetification. The phenolic composition of the final product was determined by the substrate employed. In addition, the influence of cycle duration on the chemical composition was studied; the only compound affected by this factor was 2‐methyl‐1‐butanol.

© 2001 Society of Chemical Industry
Gas chromatographic analysis of alkylresorcinols in rye (Secale cereale L) grains
Authors: Ross Alastair B , Kamal‐Eldin Afaf , Jung Charlotta , Shepherd Martin J , Åman Per
Published: August 2002

A method was established for fast and easy analysis of 5‐n‐alkylresorcinols in rye grains, considering effects of milling (intact grains versus flour), extraction solvent (ethyl acetate, methanol and acetone), extraction volume per gram of sample (20 and 40 ml) and extraction time (3, 6, 18 and 24 h). For intact kernels, extraction of 1 g samples with ethyl acetate (40 ml, 24 h) is recommended. The ease of extraction is consistent with the presence of alkylresorcinols in the outer layers of the kernel and their absence in the endosperm. The extracts were analysed (without further purification or derivatisation) by gas chromatography using methyl behenate (C22:0, fatty acid methyl ester) as internal standard. Alkylresorcinols were identified by gas chromatography/mass spectrometry, and the major homologues were found to contain alkyl chains of C17:0, C19:0, C21:0, C23:0 and C25:0. The methodology was then applied to analyse the alkylresorcinol content in 15 rye cultivars grown at two locations in Sweden. Total alkylresorcinol contents varied within the range 549–1022 µg g−1, and the average percentages of the different alkylresorcinols were: 17:0, 23%; 19:0, 32%; 21:0, 26%; 23:0, 11%; and 25:0, 8%.

© 2001 Society of Chemical Industry
Follow‐up of sentinel node negative breast cancer patients without axillary lymph node dissection
Authors: Schrenk Peter , Hatzl‐Griesenhofer Margit , Shamiyeh Andreas , Waynad Wolfgang
Published: August 2002

Background

The purpose of this study was to evaluate the feasibility of sentinel lymph node biopsy in breast cancer patients at our institution and to report the follow‐up status of node‐negative patients with removal of only the sentinel node.

Methods

A total of 247 breast cancer patients underwent sentinel node (SN) mapping between June of 1996 and September of 2000. The SN was identified by using a combination of vital blue dye and a radiolabeled colloid.

Results

A SN was identified in 227 of 247 patients (91.9%). One hundred forty‐five were SN negative, 82 were SN positive. All SN‐positive patients underwent axillary dissection of level I and II, whereas 83 patients with a negative SN had SN biopsy only. Median follow‐up of these patients at 22 months revealed no axillary recurrence; the morbidity resulting from SN biopsy was negligible.

Conclusions

Although the follow‐up is very short, SN biopsy only in node‐negative breast cancer patients had no negative impact on the axillary failure rate and resulted in negligible morbidity. J. Surg. Oncol. 2001;77:165–170. © 2001 Wiley‐Liss, Inc.
Effect of galium arsenide diode laser on human periodontal disease: A microbiological and clinical study
Authors: Yilmaz Selçuk , Kuru Bahar , Kuru Leyla , Noyan Ülkü , Argun Dilek , Kadir Tanju
Published: August 2002

Background and Objective

The present study is aimed to describe short‐term results on selected microbiological and clinical parameters obtained by treatment with soft laser in conjunction with methylene blue and/or mechanical subgingival debridement in human periodontal disease.

Study Design/Materials and Methods

Ten patients, in whom each dental quadrant was randomly designated to receive one of four types of treatment procedures, were included in the study. Groups of quadrants received: scaling/root planing (SRP); laser application (L); SRP combined with L (SRP/L); oral hygiene instructions (OHI). Four single rooted teeth (one in each quadrant), having an interproximal site with a probing depth of 4 mm mesio‐buccally, were selected in each patient. The selected teeth were first assessed for microbiological (one site/tooth) and then for clinical variables (six sites/tooth). Supragingival irrigation with methylene blue was performed prior to laser application. The microbiological (proportions of obligate anaerobes) and clinical measurements (plaque and gingival indices, bleeding on probing, probing pocket depth) were evaluated over a period of 32 days.

Results

Only the SRP/L and SRP groups provided significant reductions in the proportions of obligate anaerobes before and after treatments with no significant differences in between. Parallel to the microbiological changes, both SRP/L and SRP resulted in similar clinical improvements, whereas L alone revealed a limited effect similar to OHI.

Conclusion

Within the limits of this study, methylene blue/soft laser therapy provided no additional microbiological and clinical benefits over conventional mechanical debridement. Lasers Surg. Med. 30:60–66, 2002. © 2002 Wiley‐Liss, Inc.
Diode laser hair removal of the black patient
Authors: Greppi Ivani
Published: August 2002

Background and Objective

The 810‐nm wavelength diode laser can safely and successfully treat all skin types, including dark pigmented skin.

Study Design/Materials and Methods

Eight Fitzpatrick level V–VI skin type patients, four of which presented with the diagnosis of pseudofolliculitis barbae, were treated with the diode laser for hair removal using low‐energy settings and long pulse duration.

Results

All eight patients had excellent results with unwanted hair greatly reduced, and pseudofolliculitis barbae resolved.

Conclusions

Diode lasers can be used on dark pigmented skin with positive outcomes. Complications such as hypopigmentation, or hyperpigmentation occurred, but all were transient and resolved within a few months. Lasers Surg. Med. 28:150–155, 2001. © 2001 Wiley‐Liss, Inc.