Lateralized microstructural changes in early-stage Parkinson's disease in anterior olfactory structures, but not in substantia nigra.

Parkinson's disease (PD) is a progressive neurological disorder characterized by motor symptoms as well as severe deficits in olfactory function and microstructural changes in olfactory brain regions. Because of the evidence of asymmetric neuropathological features in early-stage PD, we examined whether lateralized microstructural changes occur in olfactory brain regions and the substantia nigra in a group of early-stage PD patients. Using diffusion tensor imaging (DTI) and the University of Pennsylvania Smell Identification Test (UPSIT), we assessed 24 early-stage PD patients (Hoehn and Yahr stage 1 or 2) and 26 healthy controls (HC). We used DTI and a region of interest (ROI) approach to study the microstructure of the left and right anterior olfactory structures (AOS; comprising the olfactory bulbs and anterior end of the olfactory tracts) and the substantia nigra (SN). PD patients had reduced UPSIT scores relative to HC and showed increased mean diffusivity (MD) in the SN, with no lateralized differences. Significant group differences in fractional anisotropy (FA) and MD were seen in the AOS, but these differences were restricted to the right side and were not associated with the primary side of motor symptoms amongst PD patients. No associations were observed between lateralized motor impairment and lateralized microstructural changes in AOS. Impaired olfaction and microstructural changes in AOS are useful for early identification of PD but asymmetries in AOS microstructure seem unrelated to the laterality of PD motor symptoms.

Faraday tilting of water-immersed granular beds.

Under low-frequency vertical vibration, a system of fine grains within a fluid is observed to tilt or to form piles, an effect studied by Faraday for grains in air. Here, we investigate the physical mechanisms behind Faraday tilting in a bed of vertically vibrated bronze spheres fully immersed in water. Experimental observations of surface tilting and bulk convection are compared with the results of molecular dynamics simulations in which the water is treated as an incompressible fluid. Our simulations reproduce the main features observed experimentally. Most tilt construction is shown to be due to horizontal fluid flow within the bed, principally occurring when the gap between the bed and the supporting platform is close to a maximum. Tilt destruction occurs by granular surface flow and in the bulk of the bed at times during each vibratory cycle close to and just later than bed impact. Destruction becomes more important for higher values of frequency and vibration amplitude, leading to lower tilt angles, partial tilting, or the symmetric domed geometry of Muchowski flow.

Olfactory identification ability in pre- and postmenopausal women with schizophrenia.

Previously we reported olfactory deficits in young male but not female patients with schizophrenia. In the present report, olfactory identification ability in pre- and postmenopausal women with schizophrenia and normal control subjects was assessed using the University of Pennsylvania Smell Identification Test (UPSIT). Additionally, serum estradiol levels were measured on the same 2 days as smell testing was completed. Olfactory deficits were observed in pre- and postmenopausal women with schizophrenia but were more pronounced in the postmenopausal patients. Regarding estradiol levels, women with schizophrenia had lower estradiol levels than did normal control subjects. The findings of this study indicate that olfactory deficits do exist in women with schizophrenia and may be accentuated by estrogen depletion.

Olfactory deficits in patients with schizophrenia and severe polydipsia.

BACKGROUND: The present study was designed to assess olfactory function in severely polydipsic/hyponatremic patients with schizophrenia who also had intermittent water intoxication. METHODS: The University of Pennsylvania Smell Identification Test and an olfactory acuity battery were administered to three groups of male subjects: 9 patients with schizophrenia and severe polydipsia/hyponatremia, 9 control nonpolydipsic/normonatremic patients with schizophrenia, and 9 normal controls. RESULTS: Male patients with severe polydipsia/hyponatremia and intermittent water intoxication had marked olfactory acuity and identification deficits when compared to the patient control group of similar age and age at illness onset, and to normal controls. CONCLUSIONS: The finding of deficient acuity (detection threshold) in the polydipsic/hyponatremic group but not the nonpolydipsic, normonatremic group suggests that for this subgroup, abnormalities of olfactory sensory function may occur in a pattern previously reported for other brain disorders such as Alzheimer's disease.

Impaired olfactory identification in relatives of patients with familial schizophrenia.

OBJECTIVE: Impaired olfactory identification ability has previously been demonstrated in patients with schizophrenia. This study assessed olfactory function in psychotic and nonpsychotic members of multigenerational families with familial schizophrenia to determine whether deficits were present in both groups. METHOD: The University of Pennsylvania Smell Identification Test was administered birhinally to three groups of subjects aged less than 65 years: 19 psychotic and 27 nonpsychotic members of families with familial schizophrenia and 43 age- and sex-matched healthy volunteers. RESULTS: Nonpsychotic family members had significantly higher mean University of Pennsylvania Smell Identification Test scores than psychotic family members but were impaired relative to the healthy volunteer group. These group differences could not be accounted for by age, sex, or smoking habit. Fifty-eight percent of the psychotic and 34% of the nonpsychotic family members performed in the microsmic (impaired) range, compared to 9% of the healthy volunteers. CONCLUSIONS: Impaired olfactory deficits may aggregate in families with schizophrenia and may be indicative of a genetic predisposition to psychosis.

Olfactory function in monozygotic twins discordant for schizophrenia.

OBJECTIVE: Abnormalities of olfactory identification ability have been proposed as a marker of cerebral dysfunction in schizophrenia. The authors studied the potential role of genetic factors in olfactory dysfunction by assessing monozygotic twins discordant for schizophrenia and matched comparison subjects. METHOD: The subjects were 12 pairs of monozygotic twins discordant for schizophrenia and 12 healthy subjects matched for sex and age. Each subject completed the University of Pennsylvania Smell Identification Test. RESULTS: The combined twin group scored significantly lower on smell identification than did the comparison group. The affected and unaffected twin groups did not differ from each other. CONCLUSIONS: Genetic factors may contribute to cerebral dysfunction as assessed by olfactory identification ability.

Olfactory deficits in schizophrenia are not a function of task complexity.

The purpose of the current study was to determine if olfactory identification deficits in patients with schizophrenia were related to task complexity. Given that we had previously reported that male patients with schizophrenia are the most impaired on olfactory identification tests (the University of Pennsylvania Smell Identification Test, UPSIT), we wished to determine whether a similar deficit would exist for this group on a task of similar format and complexity, the Colour Identification Test (CIT). Sixty-five neuroleptically medicated patients with a DSM-III-R diagnosis of schizophrenia and 30 normal control subjects participated. The dependent measures were scores on the UPSIT and CIT. Overall, patients with schizophrenia had significantly lower USPIT scores than did the normal control subjects whereas no mean difference was observed for colour identification. Male patients with schizophrenia had olfactory identification deficits but performed comparably to all other groups on the CIT. Furthermore, microsmic patients with schizophrenia had CIT scores that did not differ from normal control subjects. Finally, CIT and UPSIT scores were not significantly correlated for the study sample as a whole. The results of this study suggest that the olfactory identification deficits observed in patients with schizophrenia likely reflect abnormalities of brain areas involved in olfactory pathways and are not a function of task complexity.

Olfactory hallucinations and olfactory identification ability in patients with schizophrenia and other psychiatric disorders.

Olfactory identification ability and the prevalence of olfactory hallucinations were examined in 183 hospitalized patients from three diagnostic groups. One hundred and thirty-one patients with schizophrenia, 21 patients with major depression, 31 women with eating disorders along with 77 normal control subjects were examined using the University of Pennsylvania Smell Identification Test (UPSIT) and were questioned regarding the presence of olfactory hallucinations. Olfactory identification deficits were observed only in patients with schizophrenia. In contrast, olfactory hallucinations were reported by members of all psychiatric diagnostic categories (34.6% of patients with schizophrenia; 19% of depressed patients and 29% of eating disorders patients). For patients with schizophrenia, women were more likely to report olfactory hallucinations and had higher UPSIT scores than men.

Left nostril olfactory identification impairment in a subgroup of male patients with schizophrenia.

Abnormal structural brain asymmetries have been reported in schizophrenia in brain areas which overlap with olfactory processing regions, with abnormalities more often described within the left hemisphere. We attempted to determine whether the olfactory agnosia observed in some male patients with schizophrenia was more likely left-hemisphere based. We assessed unirhinal (single nostril) olfactory identification and detection threshold in 65 male patients who met DSM-IV criteria for the diagnosis of schizophrenia and 59 healthy male control subjects. A two-way, mixed-design ANCOVA with diagnosis as the between-group factor, nostril as the within-subject factor and age as covariate was used to compare olfactory identification ability. This analysis demonstrated that patients with schizophrenia performed more poorly than the healthy controls across nostrils, but no differences were observed in either group between nostrils. However, when patients were classified according to unirhinal olfactory status (impaired left < right, impaired right < left, normosmic left < right, normosmic right < left), impaired patients were more than twice as likely to be classified as having a left nostril disadvantage than right nostril disadvantage. In contrast, within the normosmic group of patients, this pattern was reversed. Moreover, when those patients whose unirhinal olfactory scores differed by less than two points were removed from the analysis, a 2:1 ratio of left < right versus right < left was observed in the impaired patients. These results suggest that for impaired male patients with schizophrenia, olfactory identification deficits are more likely found for the left nostril, perhaps indicative of abnormalities in olfactory processing within the left hemisphere.

Generalized lattice Boltzmann algorithm for the flow of a nematic liquid crystal with variable order parameter.

A lattice Boltzmann (LB) scheme is described, which recovers the equations developed by Qian-Sheng for the hydrodynamics of a nematic liquid crystal with a tensor order parameter. The standard mesoscopic LB scalar density is generalized to a tensor quantity and the macroscopic momentum, density, and tensor order parameter are recovered from appropriate moments of this mesoscopic density. A single lattice Boltzmann equation is used with a direction dependent Bhatnagar, Gross, and Krook (BGK) collision term, with additional forcing terms to recover the antisymmetric terms in the stress tensor. A Chapman-Enskog analysis is presented, which demonstrates that the Qian-Sheng scheme is recovered, provided a lattice with sixth-order isotropy is used. The method is validated against analytical results for a number of cases including flow alignment of the order tensor and the Miesowicz viscosities in the presence of an aligning magnetic field. The algorithm accurately recovers the predicted changes in the order parameter in the presence of aligning flow, and magnetic, fields. Preliminary results are given for an extension of the method to model the interface between isotropic and nematic fluids.

Lattice Boltzmann equation hydrodynamics.

By inserting position and time dependent "source" or "forcing" terms into the microscopic evolution equation of a lattice Boltzmann fluid and treating the generalized scheme within the usual Chapman-Enskog methodology, we show that the emergent dynamics of the lattice fluid may be usefully transformed. Our method of adjustment is demonstrated by implementing the cylindrical polar coordinate form of the continuity and momentum equations on a rectangular lattice and generating results for pipe flow. With straightforward systematic adjustment of the simulation, our approach produces results in excellent agreement with theory.

Improvement in cognitive functioning in patients with first-episode psychosis during treatment with quetiapine: an interim analysis.

BACKGROUND: The efficacies of second-generation antipsychotic medications in reducing symptoms are reasonably well-documented, but their effects on cognition are less clearly understood. AIMS: To under take an interim analysis of an open label, 2-year study examining the effects of quetiapine on cognition in patients with a first episode of schizophrenia and related disorders. METHOD: Cognitive testing was performed before quetiapine was initiated and repeated after 3, 6 and 12 months of treatment. To date, 13 patients have been fully assessed (mean dose 517.9 mg/day; s.d. = 225.8). RESULTS: Statistically significant improvement was noted on measures of attention (Continuous Performance Test; CPT), verbal productivity (Verbal Fluency Test) and executive function (Object Alternation Test) after 6 and 12 months of treatment. For the CPT, improvement was also noted after 3 months of treatment. CONCLUSIONS: During treatment for 1 year with quetiapine, cognitive performance was improved in young patients with psychosis. Continued controlled investigations of the effects of quetiapine on cognition are desirable.

Equine keratomycoses in California from 1987 to 2010 (47 cases).

REASONS FOR PERFORMING STUDY: Equine keratomycosis in the western USA has received little study, probably owing to its low prevalence. OBJECTIVES: To determine clinical features, predominant fungal isolates, treatment modalities and outcomes of horses with keratomycosis in California and compare these with results from different geographic regions. METHODS: Records of horses presented to the University of California-Davis Veterinary Medical Teaching Hospital (UCD-VMTH) with confirmed keratomycosis between 1987 and 2010 were reviewed for this retrospective study. Information retrieved from the record included background, ophthalmic examination findings, treatment prior to and following presentation, visual outcome, and ocular survival. RESULTS: A total of 48 eyes in 47 horses met the inclusion criteria and comprised 2% of cases presented to the UCD-VMTH ophthalmology service. Prior to presentation, 20 horses (43%) received at least one topically administered anti-inflammatory medication. Keratomycosis was confirmed by fungal culture in 38 horses (81%), by histopathology in 2 horses (4%) and by cytology in 7 horses (15%). Forty-four isolates were identified in the 38 horses cultured; Aspergillus was the most common isolate (64%) and a novel isolate, Papulospora, was identified in 2 horses. Treatment consisted of medication only (73%), medical and surgical treatment (25%), or immediate enucleation (2%). Globe retention was 77% and vision retention was 53%. Corneal perforation was significantly associated with loss of vision (P<0.001). CONCLUSIONS: Keratomycosis is relatively uncommon in horses presented for ophthalmic conditions at UCD-VMTH. Corneal perforation was a negative prognostic indicator for vision in this population of northern Californian horses.