Visuospatial functions in atypical parkinsonian syndromes.

OBJECTIVES: Visuospatial deficits have been occasionally reported but never systematically studied in atypical parkinsonian syndromes. The interpretation of existing studies is complicated by the possible influence of motor and frontal executive deficits. Moreover, no attempt has been made to distinguish visuoperceptual from visuospatial tasks. The aim of the present study was to assess visuoperceptual and visuospatial abilities in three atypical parkinsonian syndromes while minimising the influence of confounding variables. METHODS: Twenty patients with multiple system atrophy (MSA), 43 with progressive supranuclear palsy (PSP), and 25 with corticobasal degeneration (CBD) as well as 30 healthy age matched controls were examined with the Visual Object and Space Perception Battery (VOSP). RESULTS: Visuospatial functions were intact in MSA patients. PSP patients showed mild deficits related to general cognitive decline and the severity of oculomotor symptoms. The CBD group showed the most pronounced deficits, with spatial tasks more impaired than object based tasks. Performance on object based, but not spatial, tasks was related to general cognitive status. The extent of the visuospatial impairment could not be predicted from disease duration or severity. CONCLUSION: Visuospatial functions are not consistently impaired in atypical parkinsonian syndromes. The degree and pattern of impairment varies across the diseases, suggesting that the observed deficits could have a different neural basis in each condition. The distinction between the object based ("ventral stream") and the space oriented ("dorsal stream") processing might be useful in the interpretation of visuospatial deficits in parkinsonian syndromes, especially in CBD.

Subcortical dementia revisited: similarities and differences in cognitive function between progressive supranuclear palsy (PSP), corticobasal degeneration (CBD) and multiple system atrophy (MSA).

To examine the similarities and differences in cognitive function between three predominantly subcortical dementing disorders associated with parkinsonism we compared the profiles of cognitive performance in 39 patients with Progressive Supranuclear Palsy (PSP), 26 patients with Multiple System Atrophy (MSA) and 25 with Corticobasal Degeneration (CBD) with those of 30 patients with classic cortical dementia, Alzheimer's Disease (AD), using two different cognitive screening tests: Dementia Rating Scale (DRS) and Addenbrooke's Cognitive Examination (ACE). The cognitive profile on ACE and DRS subtests distinguished subcortical diseases from each other as well as from AD. All parkinsonian syndromes were characterized by a disproportionate impairment in verbal fluency, particularly letter fluency. The three diseases differed, however, in the degree of language, memory and visuospatial impairment. We conclude that similarities, as well as differences, between PSP, MSA and CBD can be detected using a brief, clinically applicable cognitive screening test. The pattern of cognitive impairment is likely to reflect a different distribution of pathology, in particular a higher degree of cortical involvement in PSP and CBD.

Cognitive bedside assessment in atypical parkinsonian syndromes.

BACKGROUND: Despite the growing recognition of the importance of cognitive symptoms for the diagnosis and management of atypical parkinsonian syndromes, the cognitive assessment of the patients in clinical practice often remains very limited. OBJECTIVES: To examine the ability of a brief and simple cognitive screening test to detect cognitive deficits in atypical parkinsonian syndromes. METHODS: Addenbrooke's cognitive examination (ACE), the mini-mental state examination (MMSE), and the dementia rating scale (DRS) were applied to 26 patients with multiple system atrophy (MSA), 39 with progressive supranuclear palsy (PSP), and 25 with corticobasal degeneration (CBD). The results were then compared with those obtained in 30 healthy age matched volunteers and 30 patients with Alzheimer's disease. RESULTS: In all four diseases the rate of detection of cognitive impairment on ACE was higher than on MMSE and comparable with DRS. The severity of cognitive impairment was most pronounced in the CBD group, which showed a similar degree of impairment to the Alzheimer group. In contrast, MSA patients were the least cognitively impaired. The PSP group took an intermediate position. CONCLUSIONS: Cognitive impairment in atypical parkinsonian syndromes can be detected using a brief and clinically applicable bedside test such as ACE.

Rapid identification of Candida dubliniensis with commercial yeast identification systems.

Candida dubliniensis is a newly described species that is closely related phylogenetically to Candida albicans and that is commonly associated with oral candidiasis in human immunodeficiency virus-positive patients. Several recent studies have attempted to elucidate phenotypic and genotypic characteristics of use in separating the two species. However, results obtained with simple phenotypic tests were too variable and tests that provided more definitive data were too complex for routine use in the clinical laboratory setting. The objective of this study was to determine if reproducible identification of C. dubliniensis could be obtained with commercial identification kits. The substrate reactivity profiles of 80 C. dubliniensis isolates were obtained by using the API 20C AUX, ID 32 C, RapID Yeast Plus, VITEK YBC, and VITEK 2 ID-YST systems. The percentages of C. dubliniensis isolates capable of assimilating or hydrolyzing each substrate were compared with the percentages from the C. albicans profiles in each kit's database, and the results were expressed as percent C. dubliniensis and percent C. albicans. Any substrate that showed >50% difference in reactivity was considered useful in differentiating the species. In addition, assimilation of methyl-alpha-D-glucoside (MDG), D-trehalose (TRE), and D-xylose (XYL) by the same isolates was investigated by the traditional procedure of Wickerham and Burton (L. J. Wickerham and K. A. Burton, J. Bacteriol. 56:363-371, 1948). At 48 h (the time recommended by the manufacturer for its new database), we found that the assimilation of four carbohydrates in the API 20C AUX system could be used to distinguish the species, i.e., glycerol (GLY; 88 and 14%), XYL (0 and 88%), MDG (0 and 85%), and TRE (15 and 97%). Similarly, results with the ID 32 C system at 48 h showed that XYL (0 and 98%), MDG (0 and 98%), lactate (LAT; 0 and 96%), and TRE (30 and 96%) could be used to separate the two species. Phosphatase (PHS; 9 and 76%) and alpha-D-glucosidase (23 and 94%) proved to be the most useful for separation of the species in the RapID Yeast Plus system. While at 24 h the profiles obtained with the VITEK YBC system showed that MDG (10 and 95%), XYL (0 and 95%), and GLY (26 and 80%) could be used to separate the two species, at 48 h only XYL (6 and 95%) could be used to separate the two species. The most useful substrates in the VITEK 2 ID-YST system were TRE (1 and 89%), MDG (1 and 99%), LAT (4 and 98%), and PHS (83 and 1%). While the latter kit was not yet commercially available at the time of the study, it would appear to be the most valuable for the identification of C. dubliniensis. Although assimilation of MDG, TRE, and XYL proved to be the most useful for species differentiation by the majority of commercial systems, the results with these carbohydrates by the Wickerham and Burton procedure were essentially the same for both species, albeit following protracted incubation. Thus, it is the rapidity of the assimilation achieved with the commercial systems that allows the differentiation of C. dubliniensis from C. albicans.

Complex chitinolytic system of Aspergillus fumigatus.

Native polyacrylamide gels incorporating a glycol chitin substrate were used to detect several chitinolytic enzymes in the culture filtrate and cell surface, wall and mixed membrane fractions of Aspergillus fumigatus during the exponential phase of growth. Much of the cellular chitinase activity did not bind to concanavalin A (Con A) matrix and was heat-sensitive. In contrast, almost all chitinases secreted appeared to be heat-stable glycoproteins. The heavily glycosylated molecules, in a Con A-binding fraction, were the most immunologically-reactive components, as judged by their binding to anti-Aspergillus antibodies, present in the serum of patients with aspergillosis. Most of the cellular chitinases of A. fumigatus mycelium bound to an insoluble chitin matrix while most of the secreted chitinases did not bind to chitin.

Analysis of peptidogalactomannans from the mycelial surface of Aspergillus fumigatus.

Peptidogalactomannans (pGMs) from mycelium of two strains of Aspergillus fumigatus were fractionated by Cetavlon precipitation and size exclusion chromatography and their carbohydrate structures analysed using methylation-fragmentation analysis, partial acetolysis and 13C-nuclear magnetic resonance spectroscopy. The most significant difference between the pGMs of the two strains was the degree of branching and the proportion of non-reducing ends of alpha-D-Manp and beta-D-Galf units. Methylation data showed that the pGM from AF 2109 contained alpha-D-Manp and beta-D-Galf non-reducing end units in a proportion of 3:1 while, in contrast, the proportion of these structures in pGM from AF 2140 was 7:1, resulting in a highly branched structure. The immunoreactivity of the pGM fractions was tested by indirect immunofluorescence. The fractions were also tested in an ELISA system with rabbit antiserum raised to whole cells of A. fumigatus NCPF 2140 and with serum from patients with either proven aspergilloma or ABPA. The carbohydrate moiety of the pGM appears to be responsible for the antigenicity. Periodate treatment, partial acid hydrolysis and beta-elimination removed most of the antibody binding capacity.

Effects of tunicamycin on glycoprotein antigens of Aspergillus fumigatus.

Tunicamycin, which inhibits N-glycosylation of proteins, was used as a tool to determine the type of linkage which occurs in glycoprotein antigens of Aspergillus fumigatus. When A. fumigatus extracts were electrophoretically separated and blotted then probed with anti-Aspergillus patients' sera, differences in antigenic profiles were noted when tunicamycin-treated samples were compared with controls. Tunicamycin had no detectable effect on the cellular proteinases of A. fumigatus, most of which are glycosylated. Some enzymatic components were lacking when extracellular proteinases were compared with those of control samples. The major catalase component of A. fumigatus is a concanavalin A (ConA)-binding glycoprotein. In cultures grown in the presence of tunicamycin, partially-deglycosylated catalase components were obtained which could be distinguished from the native catalase by altered mobilities in polyacrylamide gels. The effect of deglycosylation on catalase antigens was monitored using an antiserum raised to a ConA-binding fraction of A. fumigatus mycelium. These antibodies bound both to the native glycoprotein and the partially deglycosylated material. These latter two were largely unaffected when incubated with an antiserum raised to a non-ConA-binding fraction of A. fumigatus which is essentially carbohydrate free. The ability to produce partially-glycosylated antigens of A. fumigatus offers a model to study the effect of basic structural modifications on both the enzymatic and antigenic activities of these molecules.

Specific antibody detection in invasive aspergillosis by analytical isoelectrofocusing and immunoblotting methods.

Aspergillus fumigatus antigens have been tested to determine their potential as aids in the diagnosis of invasive aspergillosis (IA). Immunoglobulin G (IgG) antibodies to these antigens were detected by analytical isoelectrofocusing in conjunction with immunoblotting. A total of 12 antigenic fractions, including culture filtrates and surface and mycelial extracts of A. fumigatus, were investigated. Eleven were reactive with serum specimens from patients with aspergilloma, which served as positive controls for the evaluation of a specific IgG response. Eight of 12 antigens showed good responses with serum specimens from patients with allergic bronchopulmonary aspergillosis, which were used to assess the sensitivity of IgG detection. No measurable reactivity was detected in 18 negative control serum specimens, while 11 of 13 patients with proven, highly probable, or probable cases of IA had anti-Aspergillus IgG to multiple antigenic preparations. Patients with IA who were capable of mounting a substantial humoral response to Aspergillus antigens gave an antibody profile with five antigenic preparations which seemed to be characteristic of the disease. Data show that this method is highly sensitive and may allow the selection of fractions which are both highly antigenic and specific for the detection of antibodies to Aspergillus antigens. They also indicate that the use of a spectrum of antigenic molecules is advisable, given the variability observed in the immune responses of individual patients.

Chemical and immunological analysis of the Aspergillus fumigatus cell wall.

Hyphal-wall preparations of Aspergillus fumigatus have been analysed by sequential treatment with KOH, nitrous acid and again with KOH. By acidification of the alkali-soluble extract, a polyglucose was precipitated which showed an X-ray diffraction pattern similar to that of (1-->3)-alpha-glucan. The remainder of the alkali-soluble fraction was precipitated with ethanol; it contained all the mannose, galactose and protein of the wall and, in addition, 6.2% of the amino sugars. This wall-associated glycoprotein, following SDS-PAGE and immunoblotting, reacted with antisera raised against several mycelial extracts of A. fumigatus. Sera from patients with aspergilloma have antibodies which recognize components of this glycoprotein. The glycoprotein nature of these antigens was shown by their ability to bind Lens culinaris lectin. In addition, the antigen/antibody binding could be disrupted by exposure of antigen to periodate oxidation, hydrolysis with dilute acid or pretreatment with a large excess of an exo-beta-D-galactofuranosidase. The alkali-insoluble fraction consisted of a covalently linked glucan-chitin complex. Nitrous acid treatment, which specifically disrupts glycosidic linkages involving glucosamine, did not solubilize much material but changed the X-ray diffraction pattern from diffuse to a pattern showing the characteristic lines of crystalline (1-->3)-beta-glucan and chitin. Most of the glucan became alkali-soluble after this treatment, and the insoluble residue appeared to contain crystalline chitin.

Gelatinase activity of exoantigens from virulent and non-virulent isolates of Paracoccidioides brasiliensis.

Differences in the occurrence of components with gelatinase activity were detected among four isolates of Paracoccidioides brasiliensis: Pb339 and Pb18 (highly virulent), and Pb265 and Pb18AV (very low virulence). Culture filtrates from these isolates were electrophoresed in substrate gels and tested for gelatinase activity. Pb339 showed three enzyme bands of apparent molecular masses: 43, 53 and 78 kDa; Pb18 had two bands, one at 59 kDa and another with molecular mass higher than 78 kDa. Isolate Pb18AV showed only one band at 78 kDa and Pb265 exhibited a component of molecular mass which failed to enter the separating gel.

Fungal polysaccharides.

Fungal polysaccharides are cell wall components which may act as antigens or as structural substrates. As antigens, the role of mannans in Saccharomyces cerevisiae and Candida albicans, and of glycoproteins in Aspergillus fumigatus are discussed. Analyses on beta-glucan synthetase in Paracoccidioides brasiliensis and the inhibitory effect of Hansenula mrakii killer toxin on beta-glucan biosynthesis are also considered.

A study of the alkaline proteases secreted by different Aspergillus species.

Strains from several species of Aspergillus were grown in the presence of soluble collagen, and the major secreted proteins present in the culture fluid were examined for proteolytic activity. The possibility of relatedness among the alkaline proteases secreted by Aspergillus was studied by probing extracts from the various species with polyclonal antisera raised to the isolated alkaline proteases of A. fumigatus and A. oryzae. The pathogenic species A. flavus, A. terreus and A. nidulans hydrolyse collagen and were found to secrete an alkaline protease related to that of Aspergillus fumigatus. In contrast, A. niger and non-pathogenic species such A. glaucus, A. versicolor and A. clavatus were unable to degrade collagen in vitro. These findings suggest a possible pathogenic role for the secreted alkaline proteases of Aspergillus species.

The effect of sulconazole on the antigenic composition of two dermatophyte species.

Trichophyton rubrum and Trichophyton interdigitale have been grown in liquid culture in the presence of sulconazole. The antigenic activity of detergent extracts of intact organisms was analysed following SDS-PAGE and the probing of Western blots with homologous antisera raised in rabbits and with sera from patients with dermatophyte infections. Differences in protein-band patterns were noted; some bands present in control samples were absent in azole-treated samples and vice versa. These differences were reflected in antigenic band patterns, especially among components of approximate molecular weight of 30-40, 50-60 and 92-100 kDa.

Specific recognition pattern of IgM and IgG antibodies produced in the course of experimental paracoccidioidomycosis.

Specific IgM and IgG responses to Paracoccidioides brasiliensis produced in resistant and susceptible mice during experimental paracoccidioidomycosis were examined by the immunoblotting procedure. Sera from infected mice recognized 51 antigen bands with apparent molecular masses from 8 to 86 kD. Sixteen of these were defined as major antigen bands because of almost universal presence of antibodies to them, and their intense staining. All sera, including those from normal control mice, tested for both IgM and IgG antibody reacted with the major E antigen which appeared as a large diffuse band from 43 to 47 kD. Comparisons between resistant and susceptible mice showed some significant differences in IgM responses to many antigen bands. While IgG responses were quite similar for both strains, differences were apparent in the response to the antigens at 62 and 68 kD.

Analysis of Aspergillus fumigatus catalases possessing antigenic activity.

Analysis of Aspergillus fumigatus water soluble fractions by electrophoresis on non-denaturing polyacrylamide gels (PAGE) showed the presence of at least three catalase bands. They were designated F, S1 and S2 in order of descending electrophoretic mobility with respect to the anode. The multiple enzyme forms appear to be distinct in their physicochemical properties. Enzyme bands S1 and S2 were simple catalases; the F band had an additional peroxidase function. All of the components were antigenic and differed in their binding to specific antibodies raised in rabbits with separate fractions of A. fumigatus mycelium. When serum from patients with aspergilloma, allergic bronchopulmonary aspergillosis, cystic fibrosis and chronic asthma were pre-incubated with A. fumigatus antigens and analysed by PAGE, 17 of 26 samples either abolished or reduced catalase activity. Enzyme F was a non-Concanavalin A (ConA)-binding antigen; the S1 and S2 enzymes were ConA-binding glycoprotein antigens. The major catalase band present in A. niger preparations represented only a minor component in A. fumigatus.

The Homefinder service.

This paper describes the establishment of a Homefinder service for elderly patients at Charing Cross Hospital in 1985. The contribution made by this service over a five-year period in reducing acute medical bed occupancy by long-stay patients is discussed.

Immunolocalization of Aspergillus fumigatus mycelial antigens.

Specific immunoglobulin from the sera of patients with antibodies to Aspergillus and from antisera raised in rabbits to Aspergillus fumigatus fractions bound almost exclusively to the mycelial wall, as shown by immunogold labelling of ultra-thin sections. Different layers of the wall were labelled, depending on the source of the antigen used to produce antibody. Internal, cytoplasmic components were generally not labelled, except with antisera raised to crude wall material and to a Concanavalin A (ConA)-binding fraction of a water-soluble preparation.