[Pilot study to investigate sleep disorders in the blind and persons with relevant visual impairment]. / Pilotstudie zur Erfassung von Schlafstörungen bei Erblindung oder relevanter Sehbeeinträchtigung.

BACKGROUND: Sleep disorders are associated with serious health problems in blind and visually impaired persons. Loss of light perception may result in a shift of sleep-wake pattern, which may lead to significant impairments in daily life--the so-called non-24-hour sleep-wake disorder. To date, epidemiologic data on non-24 only exist for the USA. This pilot study was conducted to provide first epidemiologic data for the prevalence of non-24 and other sleep disorders among blind and visually impaired persons in Germany. METHODS: Recruited were 111 blind and visually impaired subjects (36 subjects without light perception; male [m] = 56, 27-85 years, average [Mx] = 59.53, standard deviation [SD] = 14.69) and 111 sighted controls (m = 41, 27-88 years, Mx = 58.32, SD = 14.21), who answered a set of validated questionnaires referring to general health status (SF-36), sleep characteristics (PSQI), and daytime sleepiness (ESS). In addition, a questionnaire to predict non-24-hour sleep-wake disorder, which is not yet validated in German, was provided. RESULTS: The prevalence of 72.2% for the non-24-hour sleep-wake disorder in blind people is in accordance with results from the USA. In contrast, our results indicated non-24 in only 21.3% of the subjects with residual light perception. Furthermore, other sleep disorders like problems falling asleep (100% vs. 79.9%), maintaining sleep (90% vs. 88.1%), sleep-disordered breathing (19.4% vs. 32%), or sleep-related movement disorders (28.1% vs. 32.9%) were also common in the group of blind or visually impaired persons. DISCUSSION: The non-24-hour sleep-wake disorder is a frequent problem among people with no light perception, associated with problems falling asleep, maintaining sleep, and daytime sleepiness. The perception of light as an external cue for our circadian rhythm plays a key role. However, sleep disruption is not fully explained by non-24, making a detailed sleep history essential.

The behaviour of 226Ra in high-volume environmental water samples on TK100 resin.

Accurate, low-level measurement of 226Ra in high volume water samples requires rapid pre-concentration and robust separation techniques prior to measurement in order to comply with discharge limits and drinking water regulations. This study characterises the behaviour of 226Ra and interfering elements on recently developed TK100 (Triskem International) extraction chromatography resin. Distribution coefficients over a range of acid concentrations are given, along with an optimised procedure that shows rapid pre-concentration and separation of 226Ra on TK100 resin is achievable for high volume (1 L) water samples without the need for sample pre-treatment.

Feline Pit2 functions as a receptor for subgroup B feline leukemia viruses.

Different subgroups of feline leukemia virus (FeLV) use different host cell receptors for entry. Subgroup A FeLV (FeLV-A) is the virus that is transmitted from cat to cat, suggesting that cells expressing the FeLV-A receptor are important targets at the earliest stages of infection. FeLV-B evolves from FeLV-A in the infected cat through acquisition of cellular sequences that are related to the FeLV envelope gene. FeLV-Bs have been shown to infect cells using the Pit1 receptor, and some variants can infect cells at a lower efficiency using Pit2. Because these observations were made using receptor proteins of human or rodent origin, the role that Pit1 and Pit2 may play in FeLV-B replication in the cat is unclear. In this study, the feline Pit receptors were cloned and tested for their ability to act as receptors for different FeLV-Bs. Some FeLV-Bs infected cells expressing feline Pit2 and feline Pit1 with equal high efficiency. Variable region A (VRA) in the putative receptor-binding domain (RBD) was a critical determinant for both feline Pit1 and feline Pit2 binding, although other domains in the RBD appear to influence how efficiently the FeLV-B surface unit can bind to feline Pit2 and promote entry via this receptor. An arginine residue at position 73 in VRA was found to be important for envelope binding to feline Pit2 but not feline Pit1. Interestingly, this arginine is not found in endogenous FeLV sequences or in recombinant viruses recovered from feline cells infected with FeLV-A. Thus, while FeLV-Bs that are able to use feline Pit2 can evolve by recombination with endogenous sequences, a subsequent point mutation during reverse transcription may be needed to generate a virus that can efficiently enter the cells using the feline Pit2 as its receptor. These studies suggest that cells expressing the feline Pit2 protein are likely to be targets for FeLV-B infection in the cat.

Many nonmammalian cells exhibit postentry blocks to transduction by gammaretroviruses pseudotyped with various viral envelopes, including vesicular stomatitis virus G glycoprotein.

Previous studies have suggested that Moloney murine leukemia virus (MoMLV)-based vectors pseudotyped with the vesicular stomatitis virus G glycoprotein (VSV-G) have extensive ability to transduce nonmammalian cells. However, we have identified multiple cell lines from fish (FHM), mosquitoes (Mos-55), moths (Sf9 and High-5), flies (S2), and frogs (XPK2) that are not efficiently transduced by MoMLV-based vectors pseudotyped with many different viral envelope proteins, including VSV-G, while the same vectors are functional in these cells following transfection. A comparison of MoMLV-based vector transduction in mammalian and nonmammalian cells shows that the nonmammalian cells exhibit blocks at either entry, reverse transcription, or integration. Additionally, VSV-G-pseudotyped MoMLV-based vector transduction is attenuated in the zebrafish cell line ZF4 at entry and/or reverse transcription, whereas other transduction processes are unaffected. We show that the variation of transduction by MoMLV-based vectors in mammalian and nonmammalian cells is not due to differences in culture conditions or cell division rate but is likely the result of divergence in cellular factors required for retroviral transduction.

Terpenoid indole alkaloid profile changes in Catharanthus pusillus during development.

The terpenoid indole alkaloid content of Catharanthus pusillus was investigated during development from young to old plants. Different plant organs were assessed showing that the new leaves were the main repository site with vindoline ( approximately 4.8 mg/g DW) and catharanthine ( approximately 2.2 mg/g DW) being the major metabolites with the highest yields at the second and third sampling time (51 and 70 days, respectively). The other samples analysed, from old, oldest and yellow leaves followed in accumulation levels. The roots and stems were the least accumulative organs, although for the case of tubotaiwine the root was the most important organ. It appeared that the alkaloid content changed coinciding with the different developmental stages of the plants, particularly at flowering and fruiting stages. Moreover, this species seems to constitute a precious source of the monomerics, vindoline and catharanthine, intermediates in the synthesis of the two important antitumor dimerics vincristine and vinblastine, which did not accumulate in this species.

CNS infection with clostridium septicum.

We present an unusual case of Clostridium septicum brain infection in a 72-yr-old woman who had no underlying malignant disease. The infection spread from a localized sit to the CNS causing gas formation. The patient died rapidly.

Learning leadership: students' experiences of a midwifery mentoring practicum.

A leadership mentoring practicum is described wherein nurse-midwifery students are placed with leader/mentors at the state, regional, and national levels of organizations. Logs are kept by the students and discussions at student-faculty seminars focus on linking leadership theory to observations of leadership qualities and behaviours in the mentors. A profile of a "composite leader" derived from the students' experience experiences is presented.