Subtle temperature-induced changes in small molecule conformer dynamics - observed and quantified by NOE spectroscopy.

NOE-distance relationships are shown to be sufficiently accurate to monitor very small changes in conformer populations in response to temperature (<0.5%/10 °C) - in good agreement with Boltzmann-predictions, illustrating the effectiveness of accurate NOE-distance measurements in obtaining high quality dynamics as well as structural information for small molecules.

Dissociation of hemi-spatial and hemi-motor impairments in a unilateral primate model of Parkinson's disease.

Monkeys with unilateral lesions of nigrostriatal dopamine projections were tested on a series of spatial tasks. One task, in which monkeys were required to use one or the other arm to retrieve food rewards from different positions, allowed separate assessment of the use of each arm in each hemi-space in order to distinguish hemi-spatial and hemi-motor impairments. The lesioned monkeys exhibited a persistent neglect of contralesional space when using either arm which could be dissociated from a motor impairment in the contralesional arm alone. Another task allowed free use of either arm across peri-personal space and demonstrated an ipsilesional bias in the monkeys' self-determined attention (orientation) to a task which they were trying to perform. It is argued that the tendency for monkeys with this lesion to rotate ipsilesionally is due to an ipsilesional deviation of the 'centre of interest' (determined by telencephalic circuitry) relative to 'straight ahead' (determined by brainstem circuitry). The dopamine projections may contribute to cortico-subcortical circuits which determine the spatial layout of mental representation, attention and intention. The results in this primate model of unilateral Parkinson's disease (PD) support the view that patients with left-sided Parkinsonian symptoms exhibit a unilateral deficit in spatial mental representation as well as their well-recognised motor symptoms. Patients with bilateral Parkinson's symptoms may exhibit bilateral deficits in mental representation.

Serial MRI, functional recovery, and long-term infarct maturation in a non-human primate model of stroke.

We have examined the effects of permanent middle cerebral artery occlusion (pMCAO) in marmoset monkeys over 5 months, using behavioural and magnetic resonance imaging (MRI) techniques. Three marmosets were trained on behavioural tests before pMCAO. Shortly after surgery, these marmosets were scanned with T2-weighted (T2W) and diffusion-weighted (DW) MRI. Three, 10 and 20 weeks after surgery, these marmosets were re-tested on the behavioural tasks and had further MRI sessions to monitor lesion development. This was followed by histological analysis. All these marmosets had a persistent contralesional motor deficit and a spatial neglect which resolved over the 20 weeks of testing. Percentage infarct volume assessed by MRI on the day of surgery and at 20 weeks matched the percentage infarct volume measured histologically at 20 weeks. However, the apparent infarct size at 3 weeks was considerably less than that measured by histological analysis or that measured at the other MRI time points. Additional histological analysis of the brains of two further marmosets removed 3 weeks after pMCAO found considerable infiltration by lipid filled macrophages into the ischaemic zone which may have caused an MRI "fogging" effect leading to an apparent reduction in infarct volume.

Contralesional neglect in monkeys with small unilateral parietal cortical ablations.

Transient contralesional spatial neglect, in addition to motor impairment in the contralesional arm, is sometimes seen in patients following cerebral infarction in the right hemisphere and is seen following experimental occlusion of the right middle cerebral artery in primates. To test whether contralesional visuospatial neglect arises from a disruption of the forward flow of information from the striate cortex through the dorsal territory of the middle cerebral artery, we made a small strip suction ablation in the right parietal cortex from the medial edge of the dorsal cortical surface to the posterior ventral edge of the superior temporal gyrus in marmoset monkeys. These monkeys did not exhibit a motor impairment, or misreaching, with the contralesional arm. When they were unrestrained and free to use either arm, they were impaired at finding rewards in their contralesional space and in choosing the nearer of two rewards hidden in ipsilesional space (i.e. they had an ultra-ipsilesional bias in ipsilesional space). Comparison of performance under four conditions in a task in which the monkeys were constrained to reach into each hemispace with each arm separately indicated that they were impaired at reaching into contralesional, but not ipsilesional, space with either arm but they did not exhibit any impairment confined to the contralesional arm. These impairments in contralesional space were transient suggesting that the monkeys were able to re-align their egocentric spatial coordinates to obviate these deficits.

Genetic characterization of Pseudomonas 'NZI7'--a novel pathogen that results in a brown blotch disease of Agaricus bisporus.

AIMS: To characterize a novel pseudomonad isolate capable of causing brown blotch disease of Agaricus bisporus. METHODS AND RESULTS: Using the white-line-in-agar (WLA) assay, fluorescent pseudomonads isolated from a New Zealand mushroom farm were screened for the lipodepsipeptide tolaasin, a characteristic marker of Pseudomonas tolaasii. One isolate, NZI7, produced a positive WLA assay and caused brown lesions of A. bisporus comparable with those produced by Ps. tolaasii. However, genetic analysis suggested that Ps. tolaasii and NZI7 were genetically dissimilar, and that NZI7 is closely related to Pseudomonas syringae. Nucleotide sequence analyses of a gene involved in tolaasin production indicated that similar genes are present in both NZI7 and Ps. tolaasii. CONCLUSION: NZI7 represents a novel Pseudomonas species capable of causing brown blotch disease of A. bisporus. SIGNIFICANCE AND IMPACT OF THE STUDY: Phenotypic identification of Ps. tolaasii based on A. bisporus browning and positive WLA may have limited specificity.

Characterization by 16S rRNA sequence analysis of pseudomonads causing blotch disease of cultivated Agaricus bisporus.

Bacterial blotch of Agaricus bisporus has typically been identified as being caused by either Pseudomonas tolaasii (brown blotch) or Pseudomonas gingeri (ginger blotch). To address the relatedness of pseudomonads able to induce blotch, a pilot study was initiated in which pseudomonads were selectively isolated from mushroom farms throughout New Zealand. Thirty-three pseudomonad isolates were identified as being capable of causing different degrees of discoloration (separable into nine categories) of A. bisporus tissue in a bioassay. These isolates were also identified as unique using repetitive extragenic palindromic PCR and biochemical analysis. Relationships between these 33 blotch-causing organisms (BCO) and a further 22 selected pseudomonad species were inferred by phylogenetic analyses of near-full-length 16S rRNA gene nucleotide sequences. The 33 BCO isolates were observed to be distributed throughout the Pseudomonas fluorescens intrageneric cluster. These results show that in addition to known BCO (P. tolaasii, P. gingeri, and Pseudomonas reactans), a number of diverse pseudomonad species also have the ability to cause blotch diseases with various discolorations. Furthermore, observation of ginger blotch discoloration of A. bisporus being independently caused by many different pseudomonad species impacts on the homogeneity and classification of the previously described P. gingeri.

A phylogenetic analysis of the SSU rRNA from members of the Plasmodiophorida and Phagomyxida.

The Plasmodiophorida and Phagomyxida are orders of zoosporic eukaryotes of uncertain phylogenetic affinities. We have obtained ribosomal DNA sequence information from several species in these groups. Phylogenetic analyses of these sequences have confirmed that they form a monophyletic grouping that clusters most closely with a rhizopod assemblage consisting of sarcomonads and chlorarachneans. The Phagomyxida sequences appear distant enough from those of the Plasmodiophorida to justify a separate order. The relationships between the Plasmodiophorida remain unclear, with species from the same genus showing significant degrees of divergence.

NXY-059, a free radical--trapping agent, substantially lessens the functional disability resulting from cerebral ischemia in a primate species.

BACKGROUND AND PURPOSE: NXY-059 is a novel nitrone with free radical-trapping properties that has a considerable neuroprotective effect in rats. We have now examined the efficacy of this drug at reducing long-term functional disability in a primate model of stroke. METHODS: Twelve monkeys were trained and tested on a variety of behavioral tasks used to dissociate and quantify motor and spatial deficits. Five minutes after permanent occlusion of the right middle cerebral artery, monkeys received a 1-mL intravenous infusion of either saline or NXY-059 (28 mg x kg(-1)), and osmotic minipumps, model 2001D, were implanted subcutaneously to provide continuous drug or saline infusion for 48 hours. Drug-filled pumps released NXY-059 at 16 mg x kg(-1) x h(-1). The monkeys were retested 3 and 10 weeks after surgery to assess functional disability. Surgery, behavioral testing, and histology were all done blinded to treatment condition. RESULTS: NXY-059-treated monkeys were significantly better at reaching with their hemiparetic arm than were saline-treated monkeys when retested 3 weeks (P:<0.01) and 10 weeks (P:<0.01) after surgery. Drug treatment also significantly lessened the degree of spatial perceptual neglect (P:<0.01), a debilitating though ameliorating consequence of this infarct. NXY-059 treatment reduced the overall amount of brain damage by >50% of saline-treatment values, with similar levels of protection afforded to both white and gray matter. CONCLUSIONS: This novel drug has a substantial protective effect, lessening the disability caused by an experimentally induced stroke in a primate species. These findings provide considerable encouragement for the clinical development of NXY-059.

Clomethiazole protects against hemineglect in a primate model of stroke.

Permanent occlusion of the M1 segment of the middle cerebral artery (pMCAO) in the marmoset, a New World species of monkey, produces unilateral functional deficits, including motor neglect with the contralesional arm and contralesional spatial hemineglect. In this study we examined whether clomethiazole, a drug which modulates the gamma-aminobutyric acid(A) receptor, reduced the severity of the hemineglect and other deficits in this primate model of stroke. Nine monkeys received pMCAO; 1 h later four of the nine were administered clomethiazole by intraperitoneal injection and subcutaneous implantation of osmotic mini-pumps, which released clomethiazole for 48 h. The monkeys had been trained and tested on a number of behavioral tasks prior to surgery and were re-tested 3 and 10 weeks later. Three weeks after pMCAO, monkeys treated with clomethiazole had a significantly reduced degree of spatial neglect compared to untreated controls. Clomethiazole was not effective against the severe contralesional motor impairment in the current study, although it ameliorated a somewhat less severe motor deficit in a previous study in which the more distal, M2 segment of the middle cerebral artery had been occluded. Postmortem analysis of the brains showed that clomethiazole treatment had significantly reduced the area of damage in part of the parietal cortex. These data suggest that clomethiazole may reduce the neglect that can be a debilitating consequence of right-sided stroke in man.

Intraocular metastases of cutaneous malignant melanoma: a case report and review of the literature.

Cutaneous malignant melanoma metastatic to the eye is rare but has been documented. The usual presentation is after the diagnosis of disseminated metastases. A 40-year-old Caucasian man presented with floaters and hazy vision due to ocular metastasis. He developed painful intractable rubeotic glaucoma leading to enucleation. Histopathological examination confirmed anterior segment tumour adherent to the iris that was consistent histopathologically with the primary cutaneous melanoma.

Functional benefit from clomethiazole treatment after focal cerebral ischemia in a nonhuman primate species.

Clomethiazole (CMZ) (Zendra) is neuroprotective in rodents following focal and global ischemia. However, its neuroprotective effects in other species, particularly on functional outcome, have not been reported. We have therefore examined the ability of CMZ to ameliorate the functional deficits produced by a focal cerebral ischemic lesion in the marmoset, a New World primate. Six monkeys received permanent middle cerebral artery occlusion (pMCAO); six further monkeys received pMCAO with administration of CMZ, 5 min after the arterial occlusion, by intraperitoneal bolus injection and by subcutaneous implantation of an osmotic minipump, which released CMZ for 24 h. The monkeys were trained and tested preoperatively on a number of behavioral tasks which were repeated 3 and 9 weeks after surgery. CMZ-treated monkeys were better than non-drug-treated monkeys at using the disabled arm contralateral to the lesion and also showed a reduction in contralateral spatial hemineglect. Postmortem histopathological analysis at several stereotaxic levels showed a significant reduction in the area of ischemic damage in CMZ-treated monkeys compared to that in untreated animals. CMZ treatment reduced the overall volume of damage by 31.8% (MCA group, 370.8 +/- 37.4 mm3 of damage; CMZ group, 253.0 +/- 38.0 mm3 of damage). This study demonstrates that CMZ is neuroprotective in a nonhuman primate species and is able to ameliorate the level of functional disability and reduce the size of infarct produced by focal cerebral ischemia.

Assessment of functional impairment following permanent middle cerebral artery occlusion in a non-human primate species.

The purpose of the present study was to examine and quantify the functional consequence of a focal cerebral ischaemic lesion in a primate species, the marmoset. Following craniotomy and retraction of the frontal and temporal lobes, the middle cerebral artery was permanently occluded by means of electrocoagulation. Three and eight weeks after surgery, various behavioural tests were used to give a quantifiable measure to the neurological deficits produced. These tests required the monkeys to reach into tubes for foodbits, retrieve rewards from the steps of two designs of 'staircases', respond to one of two simultaneously presented rewarded tubes, remove adhesive labels attached to their feet, and respond to sensory stimuli. Unilateral motor impairment of the contralateral forelimb and neglect of contralateral tactile stimuli were seen in all subjects, and spatial neglect was also present in some monkeys. Subsequent histological analysis revealed unilateral cortical damage in all subjects with varying amounts of injury to the caudate and the putamen in some animals. These results demonstrate the potential for the use of this species in future investigations to examine the effect of neuroprotective treatment on functional outcome after a focal ischaemic insult.

Studies of ventilation efficiency in a protective isolation room by the use of a scale model.

OBJECTIVE: To assess the ability of a protective isolation room ventilation system to reduce patient exposure to airborne infectious agents, using a small-scale model that permits cost-effective and unobtrusive study of relevant indices of performance. DESIGN: A one-half scale model of a protective isolation room at the University of Minnesota Hospital was constructed and equipped for tracer gas experiments to assess ventilation efficiency. MEASUREMENTS: Tracer gas (SF6) was injected into the model supply air. Tracer gas concentration was recorded over time and analyzed to determine local and room mean age of air. Age of air is a direct measurement of ventilation efficiency and can be used to predict patient exposure to contamination. RESULTS: Although for the room taken as a whole, ventilation efficiency was close to 50% (a value corresponding to perfect mixing), the experimental results for the local mean age of air indicate that some parts of the model were ventilated much better than others. CONCLUSION: Room air exchange rate is only one parameter useful in assessing ventilation in patient areas. Effective distribution of ventilation air also is critical to the control of airborne contamination. Areas of the room with poor ventilation would be expected to have higher concentrations of airborne infectious agents and other contaminants. Patient exposure can be minimized by placing the patient in well-ventilated areas of the room. Improved ventilation designs may reduce patient exposure further without increasing actual airflow rate.

Patient care decisions and employer liability.

The foregoing discussion has raised numerous issues respecting potential liability for home health care providers resulting from utilization management entity activities and related provider, employee, and subcontractor decisions made in the patient care process. Knowledge of these issues without corrective action by providers is fraught with risk. The development and maintenance of written policies and procedures along the lines suggested will not only minimize employer and employee liability arising from these activities, but will also facilitate effective patient advocacy.