Predicting Falls in Parkinson Disease: What Is the Value of Instrumented Testing in OFF Medication State?

BackgroundFalls are a common complication of advancing Parkinson''s disease (PD). Although numerous risk factors are known, reliable predictors of future falls are still lacking. The objective of this prospective study was to investigate clinical and instrumented tests of balance and gait in both OFF and ON medication states and to verify their utility in the prediction of future falls in PD patients.MethodsForty-five patients with idiopathic PD were examined in defined OFF and ON medication states within one examination day including PD-specific clinical tests, instrumented Timed Up and Go test (iTUG) and computerized dynamic posturography. The same gait and balance tests were performed in 22 control subjects of comparable age and sex. Participants were then followed-up for 6 months using monthly fall diaries and phone calls.ResultsDuring the follow-up period, 27/45 PD patients and 4/22 control subjects fell one or more times. Previous falls, fear of falling, more severe motor impairment in the OFF state, higher PD stage, more pronounced depressive symptoms, higher daily levodopa dose and stride time variability in the OFF state were significant risk factors for future falls in PD patients. Increased stride time variability in the OFF state in combination with faster walking cadence appears to be the most significant predictor of future falls, superior to clinical predictors.ConclusionIncorporating instrumented gait measures into the baseline assessment battery as well as accounting for both OFF and ON medication states might improve future fall prediction in PD patients. However, instrumented testing in the OFF state is not routinely performed in clinical practice and has not been used in the development of fall prevention programs in PD. New assessment methods for daylong monitoring of gait, balance and falls are thus required to more effectively address the risk of falling in PD patients.     

Vacuole dynamics in the salivary glands of Drosophila melanogaster during prepupal development

A central function of the Drosophila salivary glands (SGs), historically known for their polytene chromosomes, is to produce and then release during pupariation the secretory glue used to affix a newly formed puparium to a substrate. This essential event in the life history of Drosophila is regulated by the steroid hormone ecdysone in the late‐larval period. Ecdysone triggers a cascade of sequential gene activation that leads to glue secretion and initiates the developmentally‐regulated programmed cell death (PCD) of the larval salivary glands, which culminates 16 h after puparium formation (APF). We demonstrate here that, even after the larval salivary glands have completed what is perceived to be one of their major biological functions – glue secretion during pupariation – they remain dynamic and physiologically active up until the execution phase of PCD. We have used specific metabolic inhibitors and genetic tools, including mutations or transgenes for shi, Rab5, Rab11, vha55, vha68‐2, vha36‐1, syx1A, syx4, and Vps35 to characterize the dramatic series of cellular changes occurring in the SG cells between pupariation and 7–8 h APF. Early in the prepupal period, they are remarkably active in endocytosis, forming acidic vacuoles. Midway through the prepupal period, there is abundant late endosomal trafficking and vacuole growth, which is followed later by vacuole neutralization and disappearance via membrane consolidation. This work provides new insights into the function of Drosophila SGs during the early‐ to mid‐prepupal period.     

Genetic variation for domestication-related traits revealed in a cultivated rice,Nipponbare (<Emphasis Type="Italic">Oryza sativa ssp. japonica</Emphasis>) × ancestral rice, <Emphasis Type="Italic">O. nivara</Emphasis>, mapping population

Oryza nivara is the ancestral species of cultivated rice (Oryza sativa). It has been the source of novel alleles for resistance to biotic and abiotic stresses, as well as yield improvement, lost during the course of domestication. To determine the molecular changes that occurred during domestication, the O. sativa ssp. japonica variety, Nipponbare, from which a reference sequence (RefSeq) was developed, was crossed with the O. nivara accession (IRGC100897), from which BAC-end sequences (BES) were derived. The mapping population composed of 279 F₂ progeny lines derived from this cross was phenotyped for 19 traits important to domestication and yield improvement, including basal sheath and culm color, culm angle, days to heading, plant height, seed shattering, flag leaf length and width, panicle type and length, awn length and color, pericarp color, and seed color, length, width, length to width ratio, volume and surface area. The population was genotyped using 95 SSR markers and 114 single nucleotide variation (SNV) markers, selected by comparing the Nipponbare RefSeq and O. nivara BES. At least one major QTL was identified for each trait evaluated, and for 28 of the 46 QTL, the trait increase was attributed to the allele contributed by the O. nivara parent. Candidate genes were identified in 37 of the QTL regions. This study validated SNV markers that can be used for mapping in populations with a wild species parent. In the future, SNVs could be used for marker-assisted selection to incorporate desirable, novel alleles for stress resistance and yield improvement, identified in rice wild species like O. nivara into elite, adapted O. sativa varieties.     

Molecular mapping of the Oregon Wolfe Barleys: a phenotypically polymorphic doubled-haploid population

A phenotypically polymorphic barley (Hordeum vulgare L.) mapping population was developed using morphological marker stocks as parents. Ninety-four doubled-haploid lines were derived for genetic mapping from an F₁ using the Hordeum bulbosum system. A linkage map was constructed using 12 morphological markers, 87 restriction fragment length polymorphism (RFLP), five random amplified polymorphic DNA (RAPD), one sequence-tagged site (STS), one intron fragment length polymorphism (IFLP), 33 simple sequence repeat (SSR), and 586 amplified fragment length polymorphism (AFLP) markers. The genetic map spanned 1,387 cM with an average density of one marker every 1.9 cM. AFLP markers tended to cluster on centromeric regions and were more abundant on chromosome 1 (7H). RAPD markers showed a high level of segregation distortion, 54% compared with the 26% observed for AFLP markers, 27% for SSR markers, and 18% for RFLP markers. Three major regions of segregation distortion, based on RFLP and morphological markers, were located on chromosomes 2 (2H), 3 (3H), and 7 (5H). Segregation distortion may indicate that preferential gametic selection occurred during the development of the doubled-haploid lines. This may be due to the extreme phenotypes determined by alleles at morphological trait loci of the dominant and recessive parental stocks. Several molecular markers were found to be closely linked to morphological loci. The linkage map reported herein will be useful in integrating data on quantitative traits with morphological variants and should aid in map-based cloning of genes controlling morphological traits. Received: 23 August 2000 / Accepted: 15 December 2000     

Einige interessante Blätter- und Blütenabnormitäten anAdoxa Moschatellina L.

Ohne Zusammenfassung     

Reduced Accumulation of ABA during Water Stress in a Molybdenum Cofactor Mutant of Barley

A barley (Hordeum vulgare L.) mutant (Az34) has been identified with low basal levels of abscisic acid (ABA) and with reduced capacity for producing ABA in response to water stress. The mutation is in a gene controlling the molybdenum cofactor resulting in a pleiotropic deficiency in at least three molybdoenzymes, nitrate reductase, xanthine dehydrogenase, and aldehyde oxidase. The mutant was found to lack aldehyde oxidase activity with several substrates including: (a) ABA aldehyde, a putative precursor of ABA; (b) an acetylenic analog of ABA aldehyde; and (c) heptaldehyde. Elevating the growth temperature from 18 to 26°C caused mutant leaves to wilt and brown. Desiccation of mutant leaves was prevented by applying ABA. These results indicate that ABA biosynthesis at some developmental stages is dependent upon a molybdoenzyme which may be an aldehyde oxidase.     

Nucleotide pools and regulation of ribonucleic acid synthesis in yeast.

Nucleotide pools were measured in growing and amino acid-starved Saccharomyces cerevisiae. During amino acid starvation there are neither significant changes in the endogeneous nucleoside triphosphate pool levels nor measurable synthesis of guanosine 5'-diphosphate, 3'-diphosphate. Stable ribonucleic acid synthesis does not appear to be regulated by changes in the triphosphate pools or by the unusual nucleotide guanosine 5'-diphosphate, 3'-diphosphate.     

Chloramphenicol stimulation of lysogeny by lambda regulatory mutants.

Inhibition of protein synthesis in Escherichia coli by amino acid starvation or chloramphenicol addition increases the frequency of lysogeny by lambda phage two- to fourfold. Lambda cIII mutants, which normally lysogenize at very low frequencies, lysogenize at very high frequencies in the presence of chloramphenicol.     

EFFECT OF CORTISONE AND THYROXINE ON ACID GLYCOSIDASES IN RAT FOREBRAIN AND CEREBELLUM DURING EARLY POSTNATAL DEVELOPMENT

Abstract— l -Thyroxine (200 μg/100 g B.W.) or cortisone-acetate (5 mg/100 g B.W.), administered for 4 consecutive days, affected several lysosomal enzymes in forebrain and cerebellum of rats during various periods of the first month of postnatal development; their effect was age dependent as well as organ specific. Extending thyroxine or cortisone treatment to 7 days (from day 2 to 9) affected enzyme activity more than the 4-day treatment period.