The parkin gene is not involved in late-onset Parkinson's disease.
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Adult↗
Biomedical subjects
H Jacobs
Publications and source records attributed to H Jacobs.
Fermentation of chicory fructo-oligosaccharides in mixtures of different degrees of polymerization by three strains of bifidobacteria.
We estimated and compared the action of three selected strains of bifidobacteria in a semi-synthetic medium for different degrees of polymerization of fructo-oligosaccharides contained in three commercial products derived from chicory inulin: Fibrulose F97 (shorter chains), Fibruline Instant (native chains), Fibruline LC (longer chains). Biomass and production of lactate and acetate were greater when the substrate contained mostly shorter chain fructo-oligosaccharides. Shorter chains were first to be consumed, and one strain could use longer chains. As the degree of polymerization increased, residual fructo-oligosaccharides increased after growth of the strains, and the rate of consumption of fructo-oligosaccharides decreased.
Acetates↗
Ordering of nitrogen in nickel nitride Ni(3)N determined by neutron diffraction.
The metallic interstitial nitride Ni(3)N was prepared from Ni(NH(3))(6)Cl(2) and NaNH(2) in supercritical ammonia (p(NH(3)) approximately 2 kbar) at 523 K. Its previously reported crystal structure, as determined from X-ray powder data, was confirmed by neutron powder diffraction: Ni(3)N crystallizes in the hexagonal epsilon-Fe(3)N-type structure (P6(3)22, Z = 2, a = 4.6224 A and c = 4.3059 A at room temperature). The N atoms on the octahedral sites of an hcp arrangement of Ni show virtually complete occupational order at ambient temperatures, which is preserved up to its thermal decomposition at T approximately 600 K. This behavior is in marked contrast to that of the isotypic iron nitride, epsilon-Fe(3)N, which shows reversible partial disordering within the same range of temperatures. Possible reasons for the different behaviors of the two nitrides epsilon-Fe(3)N and Ni(3)N are discussed.
Journal Article↗
Transdermal nicotine in PD: a randomized, double-blind, placebo-controlled study.
BACKGROUND: An inverse association between cigarette smoking and the risk of idiopathic PD has been found in many epidemiologic studies. The therapeutic and possible neuroprotective effects of nicotine formulations on parkinsonian symptoms are controversial. METHODS: In a 12-week, randomized, double-blind, placebo-controlled trial, the efficacy and tolerability of transdermal nicotine patches as an add-on treatment for cardinal symptoms were evaluated in 32 nonsmoking patients with PD. After a 1-week run-in phase, patients were randomized to receive nicotine patches (containing 17.5 mg nicotine in the first and 35.0 mg nicotine in the second and third weeks) or identically appearing placebo patches. After this treatment, 3 weeks without patch application followed. The same blinded examiner assessed the patients with the Columbia University Rating Scale, the Webster scale, the Schwab-England scale, a timed walking test, with an instrumental test for fine motor skills and hand tremor, and with the Hamilton Depression Scale. RESULTS: No significant drug effects between both groups were observed in any of the scores and quantitative tests. Side effects were mild and comparable in frequency between both groups. CONCLUSIONS: With the dosage and the period of treatment chosen, transdermal nicotine patches are not effective as an add-on treatment for symptoms of PD.
Administration, Cutaneous↗
Vaginal hyperalgesia in a rat model of endometriosis.
This study examined whether a rat model of surgically-induced endometriosis that reduces fertility also evokes vaginal hyperalgesia along with changes in vaginal compliance. In nine rats trained to escape vaginal distention, percent escape responses to different volumes of vaginal distention were measured for 2.5 months before and after endometriosis or sham surgery. Vaginal pressures were also measured simultaneously to provide an estimate of vaginal compliance. Endometriosis (or sham) was induced by autotransplantation of small pieces of uterus (or fat) on mesenteric cascade arteries, abdomen, and ovary. Escape responses were significantly increased only in rats whose autotransplants had formed cysts. Vaginal pressures, however, remained unchanged. This vaginal hyperalgesia may involve a process of viscero-visceral referred hyperalgesia.
Adipose Tissue↗
XAFS investigations of tin nitrides.
Tin nitrides (Sn3N4) prepared by the reaction of Sn-halides with KNH2 in liquid ammonia and a subsequent vacuum annealing procedure were investigated with transmission mode XAFS experiments. While the near edge data suggest the presence of a univalent Sn-compound with a valency close to +4, the analysis of the extended X-ray absorption fine structure proves the presence of two different local Sn sites in this crystal structure: While Sn(1) is surrounded by 4 nitrogen in a distance of 2.06 A, each Sn(2) ion is coordinated with 6 nitrogen at about 2.17 A radial distance.
Journal Article↗
Indirect and direct evidence for DNA double-strand breaks in hypermutating immunoglobulin genes.
The generation of a diverse antigen receptor repertoire is fundamental for the functionality of the adaptive immune system. While the V(D)J recombination process that generates the primary antigen receptor repertoire is understood in great detail, it is still unclear by which mechanism immunoglobulin (Ig) genes are further diversified by somatic hypermutation. Using mouse strains that carry a non-functional, pre-defined V(H)D(H)J(H) gene segment in their IgH locus we demonstrate DNA double-strand breaks (DSBs) in and around V(H)D(H)J(H) in B cells undergoing somatic hypermutation. The generation of these DSBs depends on transcriptional activity, and their distribution along the V(H)D(H)J(H) segment parallels that of point mutations in the hypermutation domain. Furthermore, similar to hot spots of somatic hypermutation, 50-60% of all DSBs occur preferentially at RGYW motifs. DSBs may transiently dissociate the Ig promoter from the intronic enhancer to block further transcription and to initiate an error-prone non-homologous DSB repair pathway. In accord with this model large deletions are frequently produced, along with point mutations, in a V(H)D(H)J(H) segment inserted together with its promoter into the IgH locus in inverted orientation. Our data suggest that DSBs are reaction intermediates of the mechanism underlying somatic hypermutation.
Animals↗
Novel mutation in the TOR1A (DYT1) gene in atypical early onset dystonia and polymorphisms in dystonia and early onset parkinsonism.
Dystonia is a movement disorder involving sustained muscle contractions and abnormal posturing with a strong hereditary predisposition and without a distinct neuropathology. In this study the TOR1A (DYT1) gene was screened for mutations in cases of early onset dystonia and early onset parkinsonism (EOP), which frequently presents with dystonic symptoms. In a screen of 40 patients, we identified three variations, none of which occurred in EOP patients. Two infrequent intronic single base pair (bp) changes of unknown consequences were found in a dystonia patient and the mother of an EOP patient. An 18-bp deletion (Phe323_Tyr328del) in the TOR1A gene was found in a patient with early onset dystonia and myoclonic features. This deletion would remove 6 amino acids close to the carboxy terminus, including a putative phosphorylation site of torsinA. This 18-bp deletion is the first additional mutation, beyond the GAG-deletion (Glu302/303del), to be found in the TOR1A gene, and is associated with a distinct type of early onset dystonia.
Adolescent↗
Towards an understanding of somatic hypermutation.
How germinal center (GC) B cells diversify their rearranged immunoglobulin genes by somatic hypermutation is unknown. However, the GC-specific activation-induced cytidine deaminase has been identified as a key factor controlling two central GC-specific events: somatic hypermutation and class-switch recombination of immunoglobulin genes. This factor may function as a catalytic subunit of an RNA-editing complex or, more directly, on DNA as a deoxy-cytidine deaminase in the hypermutation domain and class-switch region. Deamination of deoxy-cytidines on both strands may result in staggered DNA double-strand breaks (DSBs) that, in the hypermutation domain, become processed by member(s) of newly identified error-prone DNA polymerases. Direct evidence for DSBs in hot-spots of hypermutating immunoglobulin genes has been provided, implicating DSBs as reaction intermediates of an error-prone DSB-repair pathway acting specifically in GC B cells. These recent findings are key to the identification of the hypermutation mechanism.
Animals↗
Prenylated benzophenone derivatives from Clusia havetiodes var. stenocarpa.
Extracts of the fruit of Clusia havetiodes var. stenocarpa have yielded three new prenylated benzophenone derivatives, 28,29-epoxyplukenetione A (1), 33-hydroperoxyisoplukenetione C (2), and 15,16-dihydro-16-hydroperoxyplukenetione F (3), as well as four which have been previously described, plukenetiones C, F, and G and sampsonione G.
Benzophenones↗
New diterpenes from Jatropha divaricata.
Extracts of the stems of Jatropha divaricata have yielded the two new diterpenes ent-3 beta,14 alpha-hydroxypimara-7,9(11),15-triene-12-one (3) and the rearranged pimarane ent-15(13-->8)abeo-8 beta(ethyl)pimarane (4), which appears to be a new skeletal type. The rare cleistanthane diterpenes spruceanol (1) and cleistanthol (2) were also obtained.
Diterpenes↗
Personality traits in young patients with Parkinson's disease.
OBJECTIVES: It has been hypothesized that the dopaminergic deficit of older patients with Parkinson's disease (PD) is associated with a reduction in the dopamine-dependent personality trait "novelty seeking". It is unknown whether this may also be found in younger patients with PD whose dopaminergic deficit is considered to be purely motor. MATERIAL AND METHODS: We interviewed 122 patients below 51 years of age and 122 age- and sex-matched healthy controls with regard to clinical and sociodemographic data. Both groups had to fill out the Tridimensional Personality Questionnaire (TPQ) of Cloninger. Neuropsychological testing of formal intelligence and depression was also applied. RESULTS: "Novelty seeking" was not different between both groups. Patients were more often depressed than controls, explaining their difference in "harm avoidance" on the TPQ. "Persistence", a sub-scale of the third TPQ dimension "reward dependence", was significantly higher in patients. Neither sex, nor age, nor educational status were correlated with one of the three personality traits. CONCLUSIONS: The higher rate of depression explains our finding of more "harm avoidance" among young PD patients. According to a literature review the choice and performance of controls is crucial whether personality traits in PD patients may be assessed as abnormal.
Adult↗
Defining the specific physiological requirements for c-Myc in T cell development.
c-Myc is associated with cell growth and cycling in many tissues and its deregulated expression is causally implicated in cancer, particularly lymphomagenesis. However, the contribution of c-Myc to lymphocyte development is unresolved. We show here that the formation of normal lymphocytes by c-Myc-/- cells is selectively defective. c-Myc-/- cells are inefficient, in an age-dependent manner, at populating the thymus, and subsequent thymocyte maturation is ineffective: they fail to grow and proliferate normally at the late double-negative (DN) CD4-CD8- stage. Because N-Myc expression in thymocytes usually declines at the late DN stage, these results confirm that the nonredundant contributions of Myc family members to development are related to their distinct patterns of developmental gene expression.
Animals↗
Cycloartanes, protolimonoids, a pregnane and a new ergostane from Trichilia reticulata.
The new ergostane steroid ergosta-5,24(24')-diene-3beta,4beta,22R-triol (1), a pregnane, (E)-volkendusin, characterised as the diacetate (3), cycloartanes 4-6 and protolimonoids 7-9 were obtained from the leaves and twigs of Trichilia reticulata.
Chemical Phenomena↗
Attitudes of young patients with Parkinson's disease towards possible presymptomatic and prenatal genetic testing.
OBJECTIVE: To evaluate the opinions and attitudes of young patients with Parkinson's disease (PD) towards possible presymptomatic and prenatal genetic testing for their illness. BACKGROUND: With progress in understanding of the genetic component in the etiology of PD, presymptomatic genetic testing may become available in subgroups of patients. METHODS: During a survey on sociodemographic and risk factors 111 PD patients (mean age 45 years: mean age at PD onset 36 years) were given a questionnaire with six items about possible presymptomatic and prenatal genetic testing. RESULTS: Fifty-seven patients (5196) had knowledge about presymptomatic and prenatal testing. Eighty patients (72%) would take a presymptomatic test, if they had an autosomal dominant form of PD and if the test were available. The most Important reasons given for taking the test were planning of partnership (40%) and family (48%). When being identified as a carrier of a presumed "Parkinson gene", 78 patients (70%) would decide not to have children. Sixty-three patients (57%) would choose to have prenatal testing. Attitudes were largely independent of sociodemographic and disease variables. CONCLUSIONS: When addressed as hypothetical persons at genetic risk, young patients with PD support possible presymptomatic genetic testing and, to a lesser extent, prenatal testing. Attitudes and reasons to participate in such hypothetical testing do not grossly differ from those of at-risk persons in established single-gene autosomal dominant disorders of late onset.
Adult↗
Risk of Alzheimer's disease in relatives of Parkinson's disease patients with and without dementia.
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Alzheimer Disease↗
TCR-independent T cell development mediated by gain-of-oncogene function or loss-of-tumor-suppressor gene function.
The mechanisms that govern differentiation of T cell precursors during intrathymic development bridge an interdisciplinary research field of immunology, oncology and developmental biology. Critical checkpoints controlling early thymic T cell development and homeostasis are set by the proper signaling function of the IL-7 receptor, c-Kit receptor, and the pre-T cell antigen receptor (pre-TCR). Given the intimate link between cell cycle control and differentiation in T cell development, proto-oncogenes and tumor suppressors participate as physiological effectors downstream of these receptors not only to influence the cell cycle but also to determine differentiation and survival. Gain- or loss-of-function mutations of these downstream effectors uncouples partially or completely T cell precursors from these checkpoints, providing a selective advantage and enabling aberrant development. These effectors can be identified by provirus tagging in normal mice and more readily by complementation tagging in mice with a predefined block in T cell differentiation.
Animals↗
Degradation of short-chain alkyl- and alkanolamines by TiO2- and Pt/TiO2-assisted photocatalysis.
The photooxidation of C2H5NH2, (C2H5)2NH, HOC2H4NH2, (HOC2H4)2NH and (HOC2H4)3N using TiO2 and Pt/TiO2 as photocatalysts has been investigated. A laboratory set up was designed and a study on the influence of the concentration of the photocatalyst, the pH-value and the structure of the amine performed. The photocatalytic process was optimized with respect to the concentrations of the model substances during degradation. The decrease of the amine concentrations was found to be maximum at a pH of 10. The time-dependence of the formation of cationic breakdown products, such as NH3/NH4 and short-chain alkyl- and alkanolamines was studied by analyses with single column ion chromatography. The experimental data show that the photodegradation follows a Langmuir-Hinshelwood kinetic. The mineralization of the model substances also was monitored by measurements of the decrease of the TOC and of the formation of NO2 and NO3. The different mineralization efficiencies for the model substances studied are discussed with regard to their structure and adsorption behaviour on the photocatalyst. A possible breakdown mechanism involving the electrophilic attack of the hydroxyl radical is given. The applicability of the TiO2-assisted photocatalytic degradation of C2H5NH2 and (C2H5)2NH was tested at the pilot plant-scale with real solar radiation. The degradation rates and products obtained were similar to those found in the laboratory experiments.
Amines↗