Lower extremity physical function and quality of life in patients with stroke: a longitudinal cohort study.

PURPOSE: Lower extremity physical function (LEPF) is a key component for mobility and is impacted in stroke-related disability. A reduction in LEPF can have a significant impact on an individual's Quality of Life (QoL). The aim of this study is to characterise the relationship between LEPF and QoL. METHODS: The MOBITEC-Stroke Study is a longitudinal cohort-study including patients with their first occurrence of ischaemic stroke. Using a linear mixed-effects model, the relationship between LEPF (timed up-and-go performance (TUG); predictor) and QoL (Stroke Specific Quality of Life scale (SS-QoL); outcome) at 3 and 12 months post stroke was investigated and adjusted for sex, age, Instrumental Activities of Daily Living (IADL), fear of falling (Falls Efficacy Scale-International Version, FES-I), and stroke severity (National Institute of Stroke Severity scale, NIHSS), accounting for the repeated measurements. RESULTS: Data of 51 patients (65 % males, 35% females) were analysed. The mean age was 71.1 (SD 10.4) years, median NIHSS score was 2.0. SS-QoL was 201.5 (SD 20.5) at 3 months and 204.2 (SD 17.4) at 12 months; the mean change was 2.7 (95% CI -2.4 to 7.7), p= 0.293. A positive association was found between baseline TUG performance (estimate log score -13.923; 95% CI -27.495 to -0.351; p=0.048) and change in SS-QoL score in multivariate regression analysis. CONCLUSION: Higher LEPF (i.e better TUG performance) at baseline, was associated with an improvement in QoL from 3- to 12-months post stroke. These results highlight the critical role of physical function, particularly baseline LEPF, in influencing the QoL of stroke survivors.

Self-reported life-space mobility in the first year after ischemic stroke: longitudinal findings from the MOBITEC-Stroke project.

BACKGROUND: Life-space mobility is defined as the size of the area in which a person moves about within a specified period of time. Our study aimed to characterize life-space mobility, identify factors associated with its course, and detect typical trajectories in the first year after ischemic stroke. METHODS: MOBITEC-Stroke (ISRCTN85999967; 13/08/2020) was a cohort study with assessments performed 3, 6, 9 and 12 months after stroke onset. We applied linear mixed effects models (LMMs) with life-space mobility (Life-Space Assessment; LSA) as outcome and time point, sex, age, pre-stroke mobility limitation, stroke severity (National Institutes of Health Stroke Scale; NIHSS), modified Rankin Scale, comorbidities, neighborhood characteristics, availability of a car, Falls Efficacy Scale-International (FES-I), and lower extremity physical function (log-transformed timed up-and-go; TUG) as independent variables. We elucidated typical trajectories of LSA by latent class growth analysis (LCGA) and performed univariate tests for differences between classes. RESULTS: In 59 participants (mean age 71.6, SD 10.0 years; 33.9% women), mean LSA at 3 months was 69.3 (SD 27.3). LMMs revealed evidence (p ≤ 0.05) that pre-stroke mobility limitation, NIHSS, comorbidities, and FES-I were independently associated with the course of LSA; there was no evidence for a significant effect of time point. LCGA revealed three classes: "low stable", "average stable", and "high increasing". Classes differed with regard to LSA starting value, pre-stroke mobility limitation, FES-I, and log-transformed TUG time. CONCLUSION: Routinely assessing LSA starting value, pre-stroke mobility limitation, and FES-I may help clinicians identify patients at increased risk of failure to improve LSA.

Toxicity and metabolism of the chloral-derived mammalian alkaloid 1-trichloromethyl-1,2,3,4-tetrahydro-beta-carboline (TaClo) in PC12 cells.

Chloral-derived beta-carbolines, which are structurally similar to the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, 5), are discussed to contribute to neuronal cell death in idiopathic Parkinson's disease. The cytotoxicity of 1-trichloromethyl-1,2,3,4-tetrahydro-beta-carboline (TaClo, 4) to neuronal-like clonal pheochromocytoma PC12 cells was examined by the determination of lactate dehydrogenase (LDH) release. After incubation for 48 h, 4 showed a strong dose-dependent cytotoxic activity towards PC12 cells with an ED50 value of 230 microM. In PC12 cells reductive dehalogenation of 4 was observed giving rise to the formation of 1-dichloromethyl-1,2,3,4-tetrahydro-beta-carboline (6) as a main TaClo metabolite exhibiting a cytotoxic potential comparable to that of TaClo. An X-ray structure analysis, performed for the trifluoroacetyl derivative of 6, revealed the N-substituent of such a highly chlorinated agent to be dramatically pushed out of the beta-carboline ring 'plane' due to the high steric demand of the huge dichloromethyl group at C(1).

Short and stereoselective synthesis of C-glycosylated glycine derivatives from glycals by radical addition and reduction.

Only three steps are required for the convenient synthesis of 2-C-branched glyco-amino acids from glycals with good yields and stereoselectivities.

Atropo-enantioselective total synthesis of knipholone and related antiplasmodial phenylanthraquinones.

The "lactone concept" has been efficiently employed for the first atropo-enantioselective synthesis of knipholone and related natural phenylanthraquinones. Besides the regio- and stereoselective construction of the biaryl axis, another important step was the "synthetically late" introduction of the C-acetyl group, either by a Friedel-Crafts type acetylation or by an ortho-selective Fries rearrangement first tested on simplified model systems and subsequently applied to the highly atroposelective preparation of the natural products and of simplified analogs thereof for biotesting. The synthetic availability of these natural biaryls, their precursors, and their unnatural analogs permitted a broader investigation of the antiplasmodial activities of these interesting biaryls.

1-Trichloromethyl-1,2,3,4-tetrahydro-beta-carboline (TaClo) and related derivatives: chemistry and biochemical effects on catecholamine biosynthesis.

1-Trichloromethyl-1,2,3,4-tetrahydro-beta-carboline (TaClo, 2) is a mammalian alkaloid that readily originates in the human organism, by Pictet-Spengler condensation of endogenously present tryptamine (Ta) and the non-natural hypnotic agent trichloroacetaldehyde (chloral, Clo). Due to its structural analogy to the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, 1), TaClo is discussed to possibly contribute to the pathogenesis of Parkinson's disease acting as an environmental toxin. Previous investigations on rats and neuronal cell cultures revealed 2 to be capable of inducing severe disturbances on the dopamine metabolism. In this paper, we report on the effects of 2 on the activity of tyrosine hydroxylase [L-tyrosine, tetrayhydropteridine/oxygen oxidoreductase (3-hydroxylating), EC 1.14,16.2; TH] in vitro using rat brain homogenates prepared from the TH-rich nucleus accumbens. TaClo (2) dose-dependently inhibited basal TH activity (IC(50)=3 microM), and after enzyme activation by pituitary adenylate cyclase-activating polypeptide (PACAP-27), it also reduced L-DOPA formation (IC(50)=15 microM). Moreover, two presumable TaClo metabolites, 2-methyl-TaClo (N-Me-TaClo, 3) and 1-dichloromethylene-1,2,3,4-tetrahydro-beta-carboline (1-CCl(2)-TH beta C, 4), which were synthesized in good yields, also proved to be potent inhibitors of TH, with the strongest effect on basal activity (similar to TaClo) being observed for 3 (IC(50)=3 microM). In contrast to TaClo, however, 3 and 4 showed biphasic effects after TH activation with PACAP-27, inducing a marked increase of enzyme activity in the nanomolar range (<0.1 microM), while TH activity was nearly completely blocked at high concentrations (IC(100)=0.1mM). An X-ray diffraction investigation on the 3-dimensional structure of the 1-CCl(2)-TH beta C-derived trifluoroacetamide 7 revealed the voluminous and quite rigid dichloromethylene substituent to be only moderately twisted out of the beta-carboline ring 'plane', thus resulting in an increased ring strain of the partially hydrogenated pyrido moiety accompanied by a strong steric hindrance of Cl(1), Cl(2), C(13), and N(2), which pushes the N-trifluoroacetyl group upwards to an even higher extent than for the TaClo-related trifluoroacetamide 8.

Addition of Bromine to Ketenes and Bisketenes: Electrophilic Attack at Carbonyl Carbon and Neighboring Group Participation.

Addition of bromine to bisketene (Me(3)SiC=C=O)(2) (1) gave the fumaryl dibromide E-7, whose stereochemistry was proven by X-ray structure determination. Upon warming, E-7 rearranged to the furanone 8, and this process was faster in the more polar CD(3)CN compared to CDCl(3), consistent with an ionization pathway for the rearrangement. The bromination of 1 in CH(2)ClCH(2)Cl followed second-order kinetics with a rate constant (2.1 +/- 0.1) x 10(4) M(-)(1) s(-)(1) at 25 degrees C. The first-order dependence of bromine addition to 1 on [Br(2)] is attributed to intramolecular nucleophilic assistance by the second ketenyl moiety in an initial complex of 1 and Br(2) to give E-7. A transition structure for this process has been calculated by ab initio methods. By contrast PhMe(2)SiCH=C=O 11 and gamma-oxoketene 16 underwent bromination by third-order kinetics, second order in [Br(2)], indicating the absence of neighboring group participation in the rate-limiting step. The bisketene Me(2)Si(CH=C=O)(2) (13) underwent bromination by mixed kinetics with both first- and second-order terms in [Br(2)].

5'-O-demethyldioncophylline A, a new antimalarial alkaloid from triphyophyllum peltatum.

From the root bark of Triphyophyllum peltatum, the new naphthylisoquinoline alkaloid 5'-O-demethyldioncophylline A has been isolated. Its otherwise difficult separation from the largely dominating main alkaloid, dioncophylline A, was greatly facilitated by a bromination-benzylation procedure. From the resulting derivative, a crystal structure analysis with an anomalous X-ray diffraction was achieved, allowing confirmation of the full absolute stereostructure of the new alkaloid. The structure was further corroborated by a partial synthesis from dioncopeltine A. The natural product was shown to exhibit antimalarial activity against erythrocytic forms of Plasmodium falciparum.

Dipolar Cycloaddition Reactions of Dihydropyrimidine-Fused Mesomeric Betaines. An Approach toward Conformationally Restricted Dihydropyrimidine Derivatives(1).

The bimolecular and intramolecular cycloaddition potential of various 4-aryldihydropyrimidine-fused mesomeric betaines was investigated. Dihydropyrimidine-fused isothiomünchnones and isomünchnones were found to undergo 1,3-dipolar cycloaddition reactions with electron-deficient dipolarophiles such as DMAD, methyl propiolate, methyl vinyl ketone, or N-methylmaleimide. In contrast, cross-conjugated mesomeric thiazinium betaines underwent 1,4-dipolar cycloaddition reaction with electron-rich dipolarophiles such as ynamines or ketene acetals. In general, these cycloadditions show a high degree of regioselectivity, facial selectivity, and exo/endo diastereoselectivity. Intramolecular variations of the above processes involving o-alkenylaryl-tethered dihydropyrimidine-fused isomünchnones lead to polycyclic dihydropyrimidine analogs that closely mimic the proposed receptor-bound conformation of dihydropyridine calcium channel modulators. These cycloadducts are the result of an endo-addition of the pi-bond to the carbonyl ylide dipole embedded in the isomünchnone system. The relative stereochemistry of these cycloadducts was established by single-crystal X-ray analysis.