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Biomedical subjects

J Ott

Publications and source records attributed to J Ott.

At least 271 records · Page 15Linked to original sources
PubMedDate not supplied

Spastic paraplegia with iron deposits in the basal ganglia: a new X-linked mental retardation syndrome.

We report on a family with X-linked mental retardation (XLMR) and severe spastic paraplegia. Appearance is normal but there is severe involvement of the lower limbs (affected relatives never walked), with minimal involvement of the upper limbs and unusual MRI findings including macrogyria, white matter hypoplasia, lack of myelination and a markedly increased paramagnetic signal suggestive of iron deposition. Linkage studies documented possible linkage, with no recombination, between the disease locus and DXS424. A 7-point linkage analysis yielded a maximum LOD score of 1.9, (theta = 0.00) for three loci spanning Xq22-q25. The combination of the unusual clinical and MRI findings and the tentative localization to a region different than other XLMR syndromes with spastic paraplegia, provide good evidence that this is a new XLMR syndrome.

Adult↗
PubMedDate not supplied

First-stage autosomal genome screen in extended pedigrees suggests genes predisposing to low bone mineral density on chromosomes 1p, 2p and 4q.

Osteoporosis is characterized by low bone density, and osteopenia is responsible for 1.5 million fractures in the United States annually. In order to identify regions of the genome which are likely to contain genes predisposing to osteopenia, we genotyped 149 members of seven large pedigrees having recurrence of low bone mineral density (BMD) with 330 DNA markers spread throughout the autosomal genome. Linkage analysis for this quantitative trait was carried out using spine and hip BMD values by the classical lod-score method using a genetic model with parameters estimated from the seven families. In addition, non-parametric analysis was performed using the traditional Haseman-Elston approach in 74 independent sib pairs from the same pedigrees. The maximum lod score obtained by parametric analysis in all families combined was +2.08 (theta = 0.05) for the marker CD3D on chromosome 11q. All other combined lod scores from the parametric analysis were less than +1.90, the threshold for suggestive linkage. Non-parametric analysis suggested linkage of low BMD to chromosomes 1p36 (Zmax = +3.51 for D1S450) and 2p23-24 (Zmax = +2.07 for D2S149). Maximum multi-point lod scores for these regions were +2.29 and +2.25, respectively. A third region with associated lod scores above the threshold of suggestive linkage in both single-point and multi-point non-parametric analysis was on chromosome 4qter (Zmax = +2.95 for D4S1539 and Zmax = +2.48 for D4S1554). Our data suggest the existence of multiple genes involved in controlling spine and hip BMD, and indicate several candidate regions for further screening in this and other independent samples.

Bone Density↗
PubMedDate not supplied

Entheogens.

Explore the source record for details and available documents.

Hallucinogens↗
PubMedDate not supplied

Pharmahuasca: human pharmacology of oral DMT plus harmine.

A summary is presented of human self-experiments or psychonautic bioassays of pharmahuasca--capsules containing crystalline N,N-dimethyltryptamine (DMT) plus harmine, as well as combinations of other psychoactive tryptamines with other beta-carbolines. The 1967 Holmstedt-Lindgren hypothesis of the ayahuasca effect--oral psychoactivity of DMT consequent to monoamine-oxidase (MAO) inhibition from simultaneous ingestion of beta-carbolines--has been confirmed by eight self-experimenters. Results of a total of some 70 bioassays are summarized and the literature on this subject is reviewed (with 66 references and one table).

Administration, Oral↗
PubMedDate not supplied

Pharmepéna-Psychonautics: Human intranasal, sublingual and oral pharmacology of 5-methoxy-N,N-dimethyl-tryptamine.

Summarized are psychonautic bioassays (human self-experiments) of pharmepéna--crystalline 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT; O-Me-bufotenine), at times combined with crystalline beta-carbolines (harmaline or harmine). These substances were administered via intranasal, sublingual and oral routes, by way of pharmacological modeling of diverse South American shamanic inebriants (principally the snuffs epéna/nyakwana, prepared from barks of diverse species of Virola.) Intranasal, sublingual and oral psychoactivity of 5-MeO-DMT, and the 1967 Holmstedt-Lindgren hypothesis of the paricá-effect--intranasal potentiation of tryptamines by concomitant administration of monoamine-oxidase-inhibiting (MAOI) beta-carbolines from stems of Banisteriopsis caapi admixed with the snuffs--have been confirmed by some 17 psychonautic bioassays. Salient phytochemical and psychonautic literature is reviewed.

Administration, Intranasal↗
PubMedDate not supplied

Pharmañopo-psychonautics: human intranasal, sublingual, intrarectal, pulmonary and oral pharmacology of bufotenine.

Summarized are psychonautic bioassays (human self-experiments) of pharmañopo--crystalline bufotenine (5-HO-DMT; 5-hydroxy-N,N-dimethyltryptamine; dimethylserotonine), at times combined with harmaline or harmine-via intranasal, sublingual, intrarectal, pulmonary (inhaled vapor) and oral routes. This is done by way of pharmacological modeling of diverse South American shamanic inebriants, principally the snuffs ñopolyopo and cebílhaáj, prepared from seeds of Anadenanthera peregrina var. peregrina and A. colubrina var. Cebil, respectively. Psychoptic (visionary) activity of bufotenine has been established and the 1967 Holmstedt-Lindgren hypothesis of the paricá effect-intranasal potentiation of tryptamines by concomitant administration of monoamine-oxidase-inhibiting (MAOI) beta-carbolines from stems of Banisteriopsis caapi admixed with the snuffs-has been confirmed by 25 psychonautic bioassays. Salient phytochemical and psychonautic literature is reviewed, and isolation of bufotenine from Anadenanthera seeds detailed (with one table and eight references).

Administration, Inhalation↗
PubMedDate not supplied

Methods of analysis and resources available for genetic trait mapping.

Methods of genetic linkage analysis are reviewed and put in context with other mapping techniques. Sources of information are outlined (books, web sites, computer programs). Special consideration is given to statistical problems in canine genetic mapping (heterozygosity, inbreeding, marker maps).

Animals↗
PubMedDate not supplied

Establishing appropriate genome-wide significance levels for canine linkage analyses.

A threshold of 3.3 for a genome-wide maximum LOD score (MAXLOD) has been demonstrated in human linkage studies as corresponding to a type I error rate of 5%. Generalization of this work to other species assumes the presence of an infinitely dense marker map. While this assumption is increasingly realistic for the human genome, it may be unrealistic for the dog genome. In this study we establish the analytic and empirical thresholds for MAXLOD in canine linkage studies corresponding to type I error rates of 5% and 1% for autosomal traits. Empirical thresholds are computed via simulation assuming a 10 cM map with no fine mapping performed. Pedigree structures for simulations were drawn from two canine disease studies. Five thousand replicates of genome-wide null genotype data were simulated and analyzed for each disease. We determined that MAXLOD thresholds of 3.2 and 2.7 correspond to analytic and empirical type I error rates of 5%, respectively. In all cases, the MAXLOD thresholds from simulations were always at least 0.5 LOD units below the corresponding analytic thresholds. We therefore recommend that a threshold of 3.2 be used for canine linkage studies when fine mapping is performed, and that researchers perform their own simulation studies to assess genome-wide empirical significance levels when no fine mapping is performed.

Animals↗
PubMedDate not supplied

Linkage of autosomal recessive primary congenital glaucoma to the GLC3A locus in Roms (Gypsies) from Slovakia.

The autosomal recessive form of primary congenital glaucoma (gene symbol GLC3) has been recently mapped to two different loci, GLC3A (at 2p21), and GLC3B (at 1p36), respectively, on families of Turkish and Saudi Arabian provenance. This disorder is known to occur with an extremely high incidence in Roms (Gypsies) in Slovakia. We performed a standard linkage analysis on a sample of 7 Slovak Gypsy families comprising 18 affected members, and found significant linkage with four STR markers from the chromosomal region of 2p21 (D2S1788, D2S1346, D2S2328, and D2S1356), without heterogeneity. This finding demonstrates that in the Rom population of Slovakia, primary congenital glaucoma is due to the locus GLC3A, and consequently, to the mutation(s) in the cytochrome P4501B1 gene, which has been recently identified as the principal cause of the disease. Roms represent the third population, in which the disorder has been mapped to GLC3A.

Chromosome Mapping↗