bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mitochondrial DNA and respiratory chain function in spinal cords of ALS patients
Authors: Wiedemann Falk R. , Manfredi Giovanni , Mawrin Christian , Beal M. Flint , Schon Eric A. 
Published: March 2003

AbstractAmyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by selective motor neuron death. In order to address the question of a putative role of mitochondrial dysfunction in the pathogenesis of ALS, we studied the mitochondrial DNA (mtDNA) and mitochondrial respiratory chain enzyme activities in spinal cords of ALS patients and in control subjects without neuropathologic abnormalities. Using a ‘double PCR and digestion’ technique to estimate the levels of randomly distributed point mutations in two small regions of the mtDNA, we found significantly higher levels of mutant mtDNA in the spinal cord of ALS patients compared to controls. No large‐scale rearrangements were found, but the amount of mtDNA, measured by Southern blot, was significantly lower in the ALS samples. This reduction correlated well with a decrease of citrate synthase (CS) activity, a mitochondrial marker, as were the activities of respiratory chain complexes I + III, II + III, and IV, suggesting a loss of mitochondria in ALS spinal cords.
Effect of prenatal and postnatal ethanol exposure on the developmental profile of mRNAs encoding NMDA receptor subunits in rat hippocampus
Authors: Naassila Mickaël , Daoust Martine 
Published: March 2003

AbstractIt has been proposed that assembly of the final NMDA receptor complex may be modified by prenatal ethanol exposure, resulting in long‐term alterations of NMDA receptor pharmacology. We investigated the effect of prenatal and postnatal ethanol exposure on the developmental profile of mRNAs encoding NMDA receptor subunits in rat hippocampus. Female Sprague–Dawley rats were chronically intoxicated for 4 weeks with a 10% (v/v) ethanol solution administered throughout pregnancy and lactation. Hippocampus and cerebellum were isolated from pups (postnatal days 1–28) of the ethanol‐exposed and ad libitum groups. Our results, using a semiquantitative RT‐PCR technique, showed a selective effect of ethanol exposure on the various NMDA receptor subunits. Ethanol exposure significantly increased the levels of NR11XX, NR1X11 and NR2D mRNAs on postnatal days 7 and 14 and decreased the level of NR2C on postnatal day 1. Immunoblot analyses demonstrated that NR2D protein levels were increased on postnatal day 7 after ethanol exposure. However, the developmental profile of mRNAs encoding for NR2A–B, NR3L/S, GBP and Gly/TCP‐BP subunits were not affected. Moreover, no significant effects of ethanol exposure were observed on the developmental transition from expression of NR10XX to NR1XX splice variants occurring in the cerebellum on postnatal day 19. Unexpectedly, [3H]MK‐801 binding experiments showed that ethanol exposure increased the Bmax values of high‐affinity sites on postnatal days 14 and 28, with no change of Kd values. These findings indicate that prenatal and/or postnatal ethanol exposure alters the hippocampal levels of mRNAs encoding for certain subunits and the density of high‐affinity [3H]MK‐801 binding sites. As these subunits have been shown to modulate the functional properties of NMDA receptors, these results suggest that this altered expression could be involved in the neurodevelopmental disorders associated with fetal ethanol exposure.
Effect of precipitated morphine withdrawal on post‐translational processing of prothyrotropin releasing hormone (proTRH) in the ventrolateral column of the midbrain periaqueductal gray
Authors: Nillni Eduardo A. , Lee Alison , Legradi Gabor , Lechan Ronald M. 
Published: March 2003

AbstractWe have demonstrated that during opiate withdrawal, preprothyrotropin releasing hormone (preproTRH) mRNA is increased in neurons of the midbrain periaqueductal gray matter (PAG) while the concentration of TRH remained unaltered, suggesting that the processing of proTRH may be different in this region of the brain. The aim of the present study was to determine which of the proTRH‐derived peptides are affected by opiate withdrawal in the PAG. These changes were compared to other TRH‐containing areas such as the hypothalamic paraventricular nucleus (PVN), median eminence (ME) and the lateral hypothalamus (LH). Control and morphine‐treated rats 24 h following naltrexone‐precipitated withdrawal were decapitated and the brain microdissected. Pooled samples from each animal group were acid extracted, and peptides were electrophoretically separated then analyzed by specific radioimmunoassay. Opiate withdrawal caused a significant change in the level of some post‐translational processing products derived from the TRH precursor. In the PAG, opiate withdrawal resulted in an accumulation of the intervening preproTRH83−106 peptide from the N‐terminal side of the prohormone, while the levels of the C‐terminal preproTRH208‐‐285 peptide were reduced, with no change in preproTRH25−50 or TRH, itself, as compared to control animals. Immunohistochemical analysis also showed significant increases in cellular preproTRH83−106 peptide immunolabeling in the PAG. Opiate withdrawal in the lateral hypothalamus, unlike from the PAG, was accompanied by an increase in the concentration of TRH. In addition, western blot analysis showed that during opiate withdrawal, the mature form of the prohormone convertase 2 (PC2) increased only in PAG as compared with their respective controls. Thus, these results demonstrate a region‐specific regulation of TRH prohormone processing in the brain, which may engage PC2, further suggesting a role for specific proTRH‐derived peptides in the manifestations of opiate withdrawal.
An evaluation of noninvasive methods to estimate foliar chlorophyll content
Authors: Richardson Andrew D. , Duigan Shane P. , Berlyn Graeme P. 
Published: March 2003

Summary

Over the last decade, technological developments have made it possible to quickly and nondestructively assess, in situ, the chlorophyll (Chl) status of plants. We evaluated the performance of these optical methods, which are based on the absorbance or reflectance of certain wavelengths of light by intact leaves.
As our benchmark, we used standard extraction techniques to measure Chla, Chlb, and total Chl content of paper birch (Betula papyrifera) leaves. These values were compared with the nominal Chl index values obtained with two hand‐held Chl absorbance meters and several reflectance indices correlated with foliar Chl.
The noninvasive optical methods all provided reliable estimates of relative leaf Chl. However, across the range of Chl contents studied (0.0004–0.0455 mg cm−2), some reflectance indices consistently out‐performed the hand‐held meters. Most importantly, the reflectance indices that performed best   were not those most commonly used in the literature.
We report equations to convert from index values to actual Chl content, but caution that differences in leaf structure may necessitate species‐specific calibration equations.
Short‐term waterlogging has long‐term effects on the growth and physiology of wheat
Authors: Malik Al Imran , Colmer Timothy D. , Lambers Hans , Setter Timothy L. , Schortemeyer Marcus 
Published: March 2003

Summary

The effect of different durations of waterlogging and subsequent drainage is described for 3‐wk‐old wheat (Triticum aestivum) plants.
In a pot experiment, plants were subjected to waterlogging to the soil surface for 0, 3, 7, 14, 21 or 28 d, and then drained to allow recovery for up to 25 d.
During waterlogging, the seminal root system stopped growing. Adventitious roots grew to a maximum length of c. 150 mm. Leaf nitrogen concentration was severely decreased by waterlogging. When waterlogged pots were drained, seminal root mass did not recover to control values, even when waterlogging lasted only 3 or 7 d, due to death of existing apices and no initiation of new lateral roots. By contrast, adventitious roots resumed elongation after drainage. By the end of the experiment, shoot mass remained two‐ to threefold lower in plants from all waterlogged treatments compared with continuously drained controls, due to lower tiller numbers and shorter final leaf lengths in previously waterlogged plants.
The results demonstrate that even short periods (as little as 3 d) of waterlogging have considerable long‐term effects on the growth of young wheat plants.
Interleukin‐4 influences the production of microfilariae in a mouse model of Brugia infection
Authors: Devaney Eileen , Gillan Victoria , Wheatley Isla , Jenson Jessica , O’Connor Richard , Balmer Paul 
Published: March 2003

SummarySub‐cutaneous infection of interleukin (IL)‐4−/– mice on the BALB/c background with third stage larva (L3) of Brugia pahangi revealed an altered cytokine profile consistent with the absence of the Th2 promoting cytokine IL‐4. Splenocytes from IL‐4−/– mice secreted significantly more antigen (Ag)‐specific IL‐2 and interferon‐γ and significantly less Ag‐specific IL‐5, compared to those from L3‐infected wild‐type mice. However, levels of Ag‐specific IL‐13 were similar between groups. Despite the alteration in immune responses, there was no significant difference in recovery of developing worms from the peritoneal cavity of the two strains of mice at any time postinfection. However, at later time points of infection, the IL‐4−/– mice contained large numbers of microfilariae (Mf) in the peritoneal cavity while the wild‐type mice contained comparatively few Mf. The differences in Mf levels appear to relate to differences in worm fecundity in the two strains of mice, with adult female worms from the wild‐type mice containing few developing Mf. Moreover, implantation of sexually mature adult female worms into the peritoneal cavity of both strains of mice resulted in equal levels of Mf, confirming that the primary role of IL‐4 is to limit fecundity during the maturation phase of infection.
Causes of hair loss and the developments in hair rejuvenation
Authors: Rushton D. H. , Norris M. J. , Dover R. , Busuttil Nina 
Published: March 2003

SynopsisHair is considered to be a major component of an individual's general appearance. The psychological impact of hair loss results in a measurably detrimental change in self‐esteem and is associated with images of reduced worth. It is not surprising that both men and women find hair loss a stressful experience. Genetic hair loss is the major problem affecting men and by the age of 50, up to 50% will be affected. Initial attempts to regenerate the lost hair have centred on applying a topical solution of between 2% to 5% minoxidil; however, the results proved disappointing. Recently, finasteride, a type II 5α reductase inhibitor has been found to regrow a noticeable amount of hair in about 40% of balding men. Further developments in treatments have lead to the use of a dual type I and type II inhibitor where 90% of those treated regrow a noticeable amount of hair. In women the major cause of hair loss before the age of 50 is nutritional, with 30% affected. Increased and persistent hair shedding (chronic telogen effluvium) and reduced hair volume are the principle changes occurring. The main cause appears to be depleted iron stores, compromised by a suboptimal intake of the essential amino acid l‐lysine. Correction of these imbalances stops the excessive hair loss and returns the hair back to its former glory. However, it can take many months to redress the situation.
A randomized, double‐blind, placebo‐controlled trial to investigate the efficacy and safety of a Chinese herbal product (P07P) for the treatment of canine atopic dermatitis
Authors: Nagle Terry M. , Torres Sheila M. , Horne Kim L. , Grover Robert , Stevens Mike T. 
Published: March 2003

AbstractA randomized, double‐blind, placebo‐controlled trial of P07P, a product derived from a traditional Chinese herbal remedy, was undertaken in 50 dogs with atopic dermatitis. Owners recorded a daily itch score for 4–14 days before treatment and during treatment. Packets of powder containing P07P or placebo were added to the food once daily for 8 weeks. Dogs were assessed for erythema, surface damage, overall coat condition and seborrhoea by the same investigator, as well as for pruritus and general demeanour, at 0 (visit 2), 28 (visit 3) and 56 (visit 4) days of treatment or at withdrawal. Investigator and owner assessments of response were recorded after 28 and 56 days of treatment or at withdrawal. The predefined primary outcome measure was the owners’ assessment of response at the end of treatment. Nine of the 24 dogs (37.5%) in the P07P group but only 3 of the 23 dogs (13%) in the placebo group were considered to have improved, but this difference was not statistically significant (P = 0.09). There was a significantly higher withdrawal rate due to worsening of condition in the placebo group (P = 0.04). Mean daily itch score in the second 28‐day period of the study was significantly higher than baseline in the placebo group (P = 0.01) but not in the P07P group (P = 0.30). Pruritus scores showed a significant deterioration from baseline at the final visit in the placebo group (P = 0.01) but not in the P07P group (P = 1.00). There was a significant difference between the groups in change from baseline in erythema score at visit 3 (P = 0.05). There were no significant differences (P > 0.05) in surface damage, seborrhoea, overall coat condition and general demeanour scores within or between the groups throughout the study. The product was well tolerated with no severe or serious adverse events recorded. P07P may be beneficial as a novel nonsteroidal therapy for the management of dogs with atopic dermatitis.
Double mutation cpSRP43–/cpSRP54–is necessary to abolish the cpSRP pathway required for thylakoid targeting of the light‐harvesting chlorophyll proteins
Authors: Hutin Claire , Havaux Michel , Carde Jean‐Pierre , Kloppstech Klaus , Meiherhoff Karin , Hoffman Neil , Nussaume Laurent 
Published: March 2003

SummaryBiochemical and genetic studies have established that the light‐harvesting chlorophyll proteins (LHCPs) of the photosystems use the cpSRP (chloroplast signal recognition particle) pathway for their targeting to thylakoids. Previous analyses of single cpSRP mutants, chaosandffc, deficient in cpSRP43 and cpSRP54, respectively, have revealed that half of the LHCPs are still integrated into the thylakoid membranes. Surprisingly, the effects of both mutations are additive in the double mutantffc/chaosdescribed here. This mutant has pale yellow leaves at all stages of growth and drastically reduced levels of all the LHCPs except Lhcb 4. Although the chloroplasts have a normal shape, the thylakoid structure is affected by the mutation, probably as a consequence of reduction of all the LHCPs. ELIPs (early light‐inducible proteins), nuclear‐encoded proteins related to the LHCP family and inducible by light stress, were also drastically reduced in the double mutant. However, proteins targeted by other chloroplastic targeting pathways (ΔpH, Sec and spontaneous pathways) accumulated to similar levels in the wild‐type and the double mutant. Therefore, the near total loss of LHCPs and ELIPs in the double mutant suggests that cpSRP is the predominant, if not exclusive, targeting pathway for these proteins. Phenotypic analysis of the double mutant, compared to the single mutants, suggests that the cpSRP subunits cpSRP43 and cpSRP54 contribute to antenna targeting in an independent but additive way.
The GAMYB protein from barley interacts with the DOF transcription factor BPBF and activates endosperm‐specific genes during seed development
Authors: Diaz Isabel , Vicente‐Carbajosa Jesús , Abraham Zamira , Martínez Manuel , Isabel‐La Moneda Inés , Carbonero Pilar 
Published: March 2003

SummaryHvGAMYB, a MYB transcription factor previously shown to be expressed in barley aleurone cells in response to gibberellin during germination, also has an important role in gene regulation during endosperm development. The mRNA was detected early (10 DAF) in the seeds where it accumulates, not only in the aleurone layer, starchy endosperm, nucellar projection and vascular tissue, but also in the immature embryo as shown by in situ hybridization analysis. The HvGAMYB protein, expressed in bacteria, binds to oligonucleotides containing the 5′‐TAACAAC‐3′ or 5′‐CAACTAAC‐3′ sequences, derived from the promoter regions of the endosperm‐specific genes Hor2 and Itr1, encoding a B‐hordein and trypsin‐inhibitor BTI‐CMe, respectively. Binding is prevented when these motifs are mutated to 5′‐TgACAAg‐3′ and 5′‐CgACTgAC‐3′. Transient expression experiments in co‐bombarded developing endosperms demonstrate that HvGAMYB trans‐activates transcription from native Hor2 and Itr1 promoters through binding to the intact motifs described above. Trans‐activation of the Hor2 promoter also requires an intact prolamine box (PB). This suggests that HvGAMYB interacts in developing barley endosperms with the PB‐binding factor BPBF, an endosperm‐specific DOF transcriptional activator of the Hor2 gene. The in vivo interaction experiment between HvGAMYB and BPBF was done in the yeast two‐hybrid system, where HvGAMYB potentiates the BPBF trans‐activation capacity through interaction with its C‐terminal domain.
Patterns of population subdivision, gene flow and genetic variability in the African wild dog (Lycaon pictus)
Authors: Girman D. J. , Vilà C. , Geffen E. , Creel S. , Mills M. G. L. , Mcnutt J. W. , Ginsberg J. , Kat P. W. , Mamiya K. H. , Wayne R. K. 
Published: March 2003

AbstractAfrican wild dogs are large, highly mobile carnivores that are known to disperse over considerable distances and are rare throughout much of their geographical range. Consequently, genetic variation within and differentiation between geographically separated populations is predicted to be minimal. We determined the genetic diversity of mitochondrial DNA (mtDNA) control region sequences and microsatellite loci in seven populations of African wild dogs. Analysis of mtDNA nucleotide diversity suggests that, historically, wild dog populations have been small relative to other large carnivores. However, population declines due to recent habitat loss have not caused a dramatic reduction in genetic diversity. We found one historical and eight recent mtDNA genotypes in 280 individuals that defined two highly divergent clades. In contrast to a previous, more limited, mtDNA analysis, sequences from these clades are not geographically restricted to eastern or southern African populations. Rather, we found a large admixture zone spanning populations from Botswana, Zimbabwe and south‐eastern Tanzania. Mitochondrial and microsatellite differentiation between populations was significant and unique mtDNA genotypes and alleles characterized the populations. However, gene flow estimates (Nm) based on microsatellite data were generally greater than one migrant per generation. In contrast, gene flow estimates based on the mtDNA control region were lower than expected given differences in the mode of inheritance of mitochondrial and nuclear markers which suggests a male bias in long‐distance dispersal.
Characterization of major histocompatibility complex DRB diversity in the endemic South African antelope Damaliscus pygargus: a comparison in two subspecies with different demographic histories
Authors: Van Der Walt J. M. , Nel L. H. , Hoelzel A. R. 
Published: March 2003

AbstractMajor histocompatibility complex (MHC) class II locus DRB was investigated by single‐strand conformation polymorphism analysis (SSCP) and sequence analysis in the endemic South African antelope, Damaliscus pygargus, of which there are two subspecies. Greater polymorphism was found in the blesbok (D. p. phillipsi) subspecies (n = 44; 22 alleles) than in the bontebok (D. p. pygargus) subspecies (n = 45; 6 alleles). Erosion of allelic diversity in bontebok was most likely the result of two severe bottleneck events caused by hunting pressure and parasitic infection. A majority of the polymorphism observed was found within the peptide binding region (PBR) where dN/dS ratios were higher than for the non‐PBR region. This, and the apparent trans‐species relationship among alleles in a bovid phylogeny, suggest the evolution of diversity by heterosis or frequency‐dependent selection.
Phylogeography of Kandelia candel in East Asiatic mangroves based on nucleotide variation of chloroplast and mitochondrial DNAs
Authors: Chiang T. Y. , Chiang Y. C. , Chen Y. J. , Chou C. H. , Havanond S. , Hong T. N. , Huang S. 
Published: March 2003

AbstractVivipary with precocious seedlings in mangrove plants was thought to be a hindrance to long‐range dispersal. To examine the extent of seedling dispersal across oceans, we investigated the phylogeny and genetic structure among East Asiatic populations of Kandelia candel based on organelle DNAs. In total, three, 28 and seven haplotypes of the chloroplast DNA (cpDNA) atpB‐rbcL spacer, cpDNA trnL‐trnF spacer, and mitochondrial DNA (mtDNA) internal transcribed spacer (ITS) were identified, respectively, from 202 individuals. Three data sets suggested consistent phylogenies recovering two differentiated lineages corresponding to geographical regions, i.e. northern South‐China‐Sea + East‐China‐Sea region and southern South‐China‐Sea region (Sarawak). Phylogenetically, the Sarawak population was closely related to the Ranong population of western Peninsula Malaysia instead of other South‐China‐Sea populations, indicating its possible origin from the Indian Ocean Rim. No geographical subdivision was detected within the northern geographical region. An analysis of molecular variance (amova) revealed low levels of genetic differentiation between and within mainland and island populations (ΦCT = 0.015, ΦSC = 0.037), indicating conspicuous long‐distance seedling dispersal across oceans. Significant linkage disequilibrium excluded the possibility of recurrent homoplasious mutations as the major force causing phylogenetic discrepancy between mtDNA and the trnL‐trnF spacer within the northern region. Instead, relative ages of alleles contributed to nonrandom chlorotype–mitotype associations and tree inconsistency. Widespread distribution and random associations (χ2 = 0.822, P = 0.189) of eight hypothetical ancestral cytotypes indicated the panmixis of populations of the northern geographical region as a whole. In contrast, rare and recently evolved alleles were restricted to marginal populations, revealing some preferential directional migration.
Evidence for the mobility of an avirulence gene, avrPpiA1, between the chromosome and plasmids of races of Pseudomonas syringae pv. pisi
Authors: Arnold Dawn Louise , Jackson Robert Wilson , Vivian Alan 
Published: March 2003

AbstractAn 8.5‐kb DNA fragment containing the avirulence gene avrPpiA1 is present in the chromosome of race 2 but not present in race 4B of Pseudomonas syringae pv. pisi. The likely acquisition of avrPpiA1 in race 2 at some time in the past was indicated by the presence of direct repeat sequences at the boundaries of the 8.5‐kb region, which was amplified by polymerase chain reaction (PCR), cloned and sequenced. The sequence analysis of the 8.5‐kb fragment revealed the presence of rulAB genes, which are usually associated with plasmids. The rulB gene had been disrupted by a 4.3‐kb length of DNA, which included avrPpiA1 and open reading frames (ORFs) with similarity to bacteriophage and transposase genes. Inverted repeats flanked the 4.3‐kb region reinforcing the possibility that a further insertion had occurred in this region. The results presented here provide evidence for the horizontal transfer of an avirulence gene and suggest that this region may be a hotspot for recombination with the chromosome.