Daytime sleep in Parkinson's disease measured by episodes of immobility.

Excessive daytime sleepiness (EDS) is common in Parkinson's Disease (PD). Actigraphy uses periods of immobility as surrogate markers of nighttime sleep but there are no examples of its use in assessing EDS of PD. A commercial wrist worn system for measuring bradykinesia and dyskinesia also detects 2 min periods of immobility, which have a 85.2% concordance with the detection of sleep by ambulatory daytime polysomnography, (p < 0.0001 Chi Squared). High Epworth Sleepiness Scores (ESS) were associated with a proportion of time immobile (PTI) (p = 0.01 Mann-Whitney U). The median PTI between 0900 and 1800 h w in 30 age matched control subjects was 2%, representing 10 min and PTI at or above the 75th percentile (5% or 27 min) was taken as a high level. PD patients had higher PTI (median 4.8%) than controls (p < 0.0001, Mann-Whitney U). PD subjects with a high PTI had more bradykinesia, less dyskinesia and higher PDQ39 scores than those with low PTI. There was no relationship between PTI and dose or type of PD medications. However, in 53% of subjects, PTI increased in the 30-60 min after levodopa confirming that in some subjects levodopa results in increased sleepiness. In summary, immobility is a surrogate marker of daytime sleep in PD, confirmed by correlation with PSG and ESS. PD subjects measured this way are more likely to be sleepy and sleepy PD subjects are more likely to be bradykinetic and have a higher PDQ39. Levodopa leads to an increase in sleepiness in more than half of subjects post dosing.

Temperature-dependent expression of turtle Dmrt1 prior to sexual differentiation.

Vertebrates employ varied strategies, both chromosomal and nonchromosomal, to determine the sex of the developing embryo. Among reptiles, temperature-dependent sex determination (TSD) is common. The temperature of incubation during a critical period preceding sexual differentiation determines the future sex of the embryo, presumably by altering the activity or expression of a temperature-dependent regulatory factor(s). Here we examine the expression of the Dmrt1 gene, a candidate regulator of mammalian and avian sexual development, in the turtle. During the sex-determining period, Dmrt1 mRNA is more abundant in genital ridge/mesonephros complexes at male-promoting than at female-promoting temperatures. Dmrt1 is the first gene found to show temperature-dependent expression prior to sexual differentiation, and may play a key role in sexual development in reptiles. genesis 26:174-178, 2000.

Expression of Dmrt1 in the genital ridge of mouse and chicken embryos suggests a role in vertebrate sexual development.

Sex-determining mechanisms are highly variable between phyla. Only one example has been found in which structurally and functionally related genes control sex determination in different phyla: the sexual regulators mab-3 of Caenorhabditis elegans and doublesex of Drosophila both encode proteins containing the DM domain, a novel DNA-binding motif. These two genes control similar aspects of sexual development, and the male isoform of DSX can substitute for MAB-3 in vivo, suggesting that the two proteins are functionally related. DM domain proteins may also play a role in sexual development of vertebrates. A human gene encoding a DM domain protein, DMRT1, is expressed only in the testis in adults and maps to distal 9p24.3, a short interval that is required for testis development. Earlier in development we find that murine Dmrt1 mRNA is expressed exclusively in the genital ridge of early XX and XY embryos. Thus Dmrt1 and Sry are the only regulatory genes known to be expressed exclusively in the mammalian genital ridge prior to sexual differentiation. Expression becomes XY-specific and restricted to the seminiferous tubules of the testis as gonadogenesis proceeds, and both Sertoli cells and germ cells express Dmrt1. Dmrt1 may also play a role in avian sexual development. In birds the heterogametic sex is female (ZW), and the homogametic sex is male (ZZ). Dmrt1 is Z-linked in the chicken. We find that chicken Dmrt1 is expressed in the genital ridge and Wolffian duct prior to sexual differentiation and is expressed at higher levels in ZZ than in ZW embryos. Based on sequence, map position, and expression patterns, we suggest that Dmrt1 is likely to play a role in vertebrate sexual development and therefore that DM domain genes may play a role in sexual development in a wide range of phyla.

A region of human chromosome 9p required for testis development contains two genes related to known sexual regulators.

Deletion of the distal short arm of chromosome 9 (9p) has been reported in a number of cases to be associated with gonadal dysgenesis and XY sex reversal, suggesting that this region contains one or more genes required in two copies for normal testis development. Recent studies have greatly narrowed the interval containing this putative autosomal testis-determining gene(s) to the distal portion of 9p24.3. We previously identified DMRT1, a human gene with sequence similarity to genes that regulate the sexual development of nematodes and insects. These genes contain a novel DNA-binding domain, which we named the DM domain. DMRT1 maps to 9p24. 3 and in adults is expressed specifically in the testis. We have investigated the possible role of DM domain genes in 9p sex reversal. We identified a second DM domain gene, DMRT2, which also maps to 9p24.3. We found that point mutations in the coding region of DMRT1 and the DM domain of DMRT2 are not frequent in XY females. We showed by fluorescence in situ hybridization analysis that both genes are deleted in the smallest reported sex-reversing 9p deletion, suggesting that gonadal dysgenesis in 9p-deleted individuals might be due to combined hemizygosity of DMRT1 and DMRT2.

Epidemiology of giardiasis in Tasmania: a potential risk to residents and visitors.

BACKGROUND: Giardia infection is an ongoing problem in Tasmania and occurs throughout the state. It has been postulated that part of the problem is the reservoir of infection in native animals which is suggested to contribute to infections in humans. To date, however, no detailed study on the epidemiology of giardiasis in Tasmania has been carried out. METHODS: Information regarding the prevalence of Giardia infection in humans and the risk of intrafamilial transmission was obtained from the Department of Community and Health Services and from the direct examination of human or animal fecal samples. RESULTS: Giardia has been found to be present in a wide range of native and domestic animals and in humans of all ages from all over the state. CONCLUSIONS: Giardiasis is endemic in Tasmania and poses a risk to locals as well as to visitors to the state, especially those who participate in wilderness activities such as bushwalking. These people must be aware of the possible risk of Giardia infection and should take precautionary measures to avoid infection.

Giardiasis in native marsupials of Tasmania.

Tasmanian native marsupials were screened for the presence of Giardia spp. over a 3 yr period, revealing a 21% prevalence in the 295 animals tested. A pilot study of experimentally infected eastern barred bandicoots (Perameles gunnii) indicated susceptibility to infection with Giardia duodenalis from a human source.