Prion protein immunocytochemistry--UK five centre consensus report

Creutzfeldt-Jakob disease (CJD) and other prion diseases are associated with the deposition of insoluble prion protein (PrPCJD) in the central nervous system (CNS). Antibodies raised against PrPCJD also react with its precursor protein, a soluble form of PrP (PrPC), which is widely distributed in the normal CNS. This cross-reactivity has in the past raised doubts as to the specificity and diagnostic reliability of PrP immunolocalization, especially in familial cases which are atypical clinically and which lack characteristic pathology findings. Following an MRC-funded workshop which focused on this problem, a multicentre prospective study was set up to identify a reliable protocol for PrPCJD immunocytochemistry. Five UK centres took part in this study and demonstrated consistent staining of plaques, vacuolar deposits in severe spongiform change, and perineuronal deposits using a variety of antibodies and enhancement procedures. A protocol using formic acid, guanidine thiocyanate, and hydrated autoclaving pre-treatment in conjunction with a monoclonal PrPCJD antibody produced the clearest immunochemical results and is presented as the consensus UK recommendation for PrPCJD immunocytochemical procedures.

The role of the knee brace in the prevention of anterior knee pain syndrome

Our prospective study evaluates the use of a knee brace with a silicon patellar support ring as a method of preventing anterior knee pain from developing in young persons undergoing strenuous physical exercise. We studied 60 young athletes, who qualified for a strenuous physical training course and who had not suffered from anterior knee pain previously. Twenty-seven subjects were in the brace group and 33 were in the nonbrace control group. The incidence of anterior knee pain syndrome increased with the intensity of exertion as the study progressed; i.e., subjects ran 6 km in the 1st week, gradually increasing each week up to 42 km/week at the 8th week. Yet, there was a significant reduction in the incidence of the syndrome at the end of the study in male athletes who had applied the braces before exercise sessions and in the brace group as a whole, compared with the control group. Prophylactic use of the brace, as described, did not reduce the ability of the athletes who wore braces to improve their physical fitness parameters in response to exercise. These data indicate that the use of a brace may be an effective way to prevent the development of anterior knee pain syndromes in persons participating in strenuous and intensive physical exercise.

Role of P-glycoprotein in chemoresistant superficial bladder tumours

OBJECTIVE

The drug resistance at cellular level is mediated by P-glycoprotein (P-G), which is variably expressed in bladder tumours. The effect of intravesical chemotherapy on P-G status was studied in chemoresistant and recurrent superficial tumours which progressed to metastasis or needed further treatment.

METHODS

Archival histological materials of 14 patients who received intravesical epirubicin for recurrent superficial transitional cell carcinoma of the bladder were studied for the presence of P-G using monoclonal antibody JSB-1.

RESULTS

Four patients showed complete absence of P-G following chemotherapy although only 2 patients were recurrence-free. In 4 patients with extravesical metastasis, there was no evidence of increased P-G expression.

CONCLUSIONS

The P-glycoprotein expression is not related to histological grading or clinical progression of bladder tumours.

Microsatellite polymorphism of the alpha 1-antichymotrypsin gene locus associated with sporadic Alzheimer's disease

A variant of the apolipoprotein E gene, APOE*4, is associated with both sporadic Alzheimer's disease (AD) and a subset of familial AD and this association is stronger with early as opposed to late onset AD. Both APOE*4 and alpha 1-antichymotrypsin (ACT) will accelerate the rate of amyloid filament formation and are major constituents of the plaques associated with AD. We now show that a dinucleotide microsatellite allele in the 5'-flanking sequence of the ACT gene, designated A10, in association with APOE*4 significantly increases the risk of developing sporadic AD, which accounts for the majority of AD cases.

Motor neurone disease-inclusion dementia

We describe nine patients, five women and four men (age at death 58-83 years), who developed isolated progressive frontotemporal dementia over 4 to 12 years. These cases represent nine of the 385 (2.3%) cases from a series of autopsy cases of dementia in a large teaching hospital. One had a mother with a history of frontotemporal dementia and marked frontal lobe atrophy. Another had multiple affected family members with frontotemporal dementia, motor neurone disease or both. None of the nine had clinical evidence of either an upper or lower motor neurone disorder. In each case neuropathological examination revealed cortical pathology identical to that described previously as typical of dementia associated with motor neurone disease. There was variable macroscopic atrophy and neuronal loss in the frontal and temporal lobes. All cases had cortical microvacuolation, in seven limited to cortical layer II, and transcortical in two. There was variable cortical and subcortical gliosis. Intraneuronal ubiquitin-immunoreactive inclusions, characteristic of the extra-motor involvement of motor neurone disease, were found in the hippocampal dentate granule cells and residual neurones in layer II of the frontotemporal cortex of all cases. Similar inclusions were also seen in the nucleus ambiguus of three cases. The hypoglossal nuclei showed no neuronal loss, gliosis or ubiquitin-immunoreactive inclusions. Ubiquitin-immunoreactive dystrophic neurites were detected within affected cortex, being most conspicuous in layer II in areas containing microvacuolation. Dystrophic neurites were not detected in subcortical structures. Spinal cords were unavailable for examination because of limited autopsy consent. The finding of intraneuronal ubiquitin-immunoreactive inclusions characteristic of motor neurone disease in patients with frontotemporal dementia, without clinical or pathological evidence of motor system degeneration, extends the clinical spectrum of diseases associated with such inclusions. We propose the term motor neurone disease-inclusion dementia (MNDID) for these cases.

Extraction and protein sequencing of immunoglobulin light chain from formalin-fixed cerebrovascular amyloid deposits

Substantial amounts of a single protein have been extracted into electrophoresis sample buffer from archived formalin-fixed brain blood vessels, taken from a case of cerebral amyloidosis. Cyanogen bromide cleavage and tryptic digestion of the protein on Western blots allowed amino acid sequences from three resultant peptides to be determined. Comparison of these peptides with database sequences identified the extracted protein as being derived from an immunoglobulin light chain. This is the first demonstration of amino acid sequencing of a polypeptide extracted from formalin-fixed tissue. This case also appears to be unique, since primary cerebrovascular amyloidosis involving immunoglobulin light chains has not been previously described. The amyloid protein had clearly resisted formalin fixation; it is possible that this resistance occurred because the protein was deposited in large amounts as insoluble densely packed aggregates, which may exclude infiltration of the formalin. This technique may therefore have applications in the post-mortem diagnosis of amyloidoses and in the purification of other amyloids.

Pathological lesions of Alzheimer's disease and dementia with Lewy bodies brains exhibit immunoreactivity to an ATPase that is a regulatory subunit of the 26S proteasome

MS73 is one of a family of ATPases that act as regulatory subunits of the 26S proteasome. Localisation of this ATPase in histological sections of hippocampus from Alzheimer's disease (AD) and in cingulate gyrus sections of dementia with Lewy bodies (DLB) brains was examined immunohistochemically. In all cases of AD (n = 10) neurofibrillary tangles (NFT), plaque neurites and neuropil threads were immunoreactive for MS73. In seven out of the nine cases of DLB, distinctive MS73-positive structures were detected within cortical Lewy bodies. The association of MS73 with these neuronal abnormalities provides further evidence that proteolytic processing involving the 26S proteasome occurs in lesions of AD and DLB.

Consensus guidelines for the clinical and pathologic diagnosis of dementia with Lewy bodies (DLB): report of the consortium on DLB international workshop

Recent neuropathologic autopsy studies found that 15 to 25% of elderly demented patients have Lewy bodies (LB) in their brainstem and cortex, and in hospital series this may constitute the most common pathologic subgroup after pure Alzheimer's disease (AD). The Consortium on Dementia with Lewy bodies met to establish consensus guidelines for the clinical diagnosis of dementia with Lewy bodies (DLB) and to establish a common framework for the assessment and characterization of pathologic lesions at autopsy. The importance of accurate antemortem diagnosis of DLB includes a characteristic and often rapidly progressive clinical syndrome, a need for particular caution with neuroleptic medication, and the possibility that DLB patients may be particularly responsive to cholinesterase inhibitors. We identified progressive disabling mental impairment progressing to dementia as the central feature of DLB. Attentional impairments and disproportionate problem solving and visuospatial difficulties are often early and prominent. Fluctuation in cognitive function, persistent well-formed visual hallucinations, and spontaneous motor features of parkinsonism are core features with diagnostic significance in discriminating DLB from AD and other dementias. Appropriate clinical methods for eliciting these key symptoms are described. Brainstem or cortical LB are the only features considered essential for a pathologic diagnosis of DLB, although Lewy-related neurites, Alzheimer pathology, and spongiform change may also be seen. We identified optimal staining methods for each of these and devised a protocol for the evaluation of cortical LB frequency based on a brain sampling procedure consistent with CERAD. This allows cases to be classified into brainstem predominant, limbic (transitional), and neocortical subtypes, using a simple scoring system based on the relative distribution of semiquantitative LB counts. Alzheimer pathology is also frequently present in DLB, usually as diffuse or neuritic plaques, neocortical neurofibrillary tangles being much less common. The precise nosological relationship between DLB and AD remains uncertain, as does that between DLB and patients with Parkinson's disease who subsequently develop neuropsychiatric features. Finally, we recommend procedures for the selective sampling and storage of frozen tissue for a variety of neurochemical assays, which together with developments in molecular genetics, should assist future refinements of diagnosis and classification.

Neurofibrillary tangles of Alzheimer's disease brains contain 14-3-3 proteins

The localisation of 14-3-3 proteins compared to that of tau and ubiquitin-protein conjugates in sections of hippocampus from Alzheimer's disease (AD) brains was examined by immunohistochemistry. In all cases (n = 10), anti-14-3-3 stained a proportion of neurofibrillary tangles (NFT). In general, NFT stained by anti-14-3-3 were smaller than those stained by anti-tau or anti-ubiquitin-protein conjugates and were more confined to the neuronal cell body. Occasionally, cortical Lewy bodies in cases of Lewy body dementia were also found to be 14-3-3-positive. Since 14-3-3 proteins are central to MAP kinase signalling, the results support the proposal that this pathway is in part responsible for the hyperphosphorylation of tau, which leads to the formation of the paired helical filaments seen in AD brains.

In vivo characterization of a specific cannabinoid receptor antagonist (SR141716A): inhibition of delta 9-tetrahydrocannabinol-induced responses and apparent agonist activity

SR141716A has been described as a cannabinoid receptor antagonist. This study was conducted to determine whether SR141716A was capable of antagonizing the pharmacological effects of the prototypical cannabinoid agonist delta 9-THC. The AD50 (+/- 95% confidence limits) obtained after a 10 min i.v. pretreatment with SR141716A in measures of hypoactivity, hypothermia, and antinociception were: 0.12 (0.02-0.66), 0.087 (0.037-0.201), and 0.16 (0.03-1.01) mg/kg, respectively. The effect of SR141716A lasted up to 1 hr (antinociception, 10 mg/kg), 4 hr (locomotion, 1 and 3 mg/kg), or 24 hr (hypothermia, 3 mg/kg). Further evaluation revealed an AD50 value of 2.7 mg/kg (1.7-4.4) in the PPQ-stretch procedure. Additionally, the ED50 (+/- S.E.) of morphine in the tail-flick antinociception procedure was increased by SR141716A (30 mg/kg, i.v.) from 3.2 (+/- 0.3) to 5.3 (+/- 0.6) mg/kg. Finally, SR141716A produced direct effects on locomotor activity at doses greater than 3 mg/kg. Locomotion was stimulated to more than 200% of control (20 mg/kg), with an ED50 value of 4.7 (+/- 1.5) mg/kg. The ED50 value represents stimulation to levels approximately 150% of control. It is not clear whether this pharmacological activity represents an uncharacterized action of SR141716A, or an index of tonic activity of an endogenous cannabinergic system. SR141716A will be useful in establishing the biochemical events responsible for the in vivo effects of exogenous cannabinoids, as well as in establishing the existence of a putative endogenous cannabinergic system.

Five conversations: reflections of stakeholders on the impact of the ethnocultural communities facing AIDS study

This paper reports on issues identified in conversations held between one of the Ethnocultural Communities Facing AIDS Study (ECFA) investigators and five stakeholders associated with this experiment in collaborative and participatory research. The stakeholders reflect on their experiences in partnering with university-based researchers, resistance in ethnocultural communities to being researched, and the next steps implicated by the research in question. The problem of HIV/AIDS in ethnocultural communities in Canada is, relative to the mainstream, also viewed as a symbol of disadvantage in these communities. The stakeholders suggest that to address these deeper concerns, there must be vital, dynamic, and enduring communication between researchers, community representatives, and government at all levels, in the process of identifying solutions and implementing them in the present.

The new neuropathology of degenerative frontotemporal dementias

The clinical features and recent developments in the neuropathology of frontotemporal dementia are reviewed. The five main neurodegenerative disorders that underlie the clinical syndrome of frontotemporal dementia are distinguished using immunohistochemistry with antisera to ubiquitin and tau proteins. Motor neuron disease-type dementia is characterised by ubiquitin-immunoreactive intraneuronal inclusions in cortical layer II and the hippocampal dentate granule cells. A diagnosis of Alzheimer's disease changes is based upon the presence of neurofibrillary tangles, which immunostain with antibodies to tau and ubiquitin, and many associated neuritic plaques. Corticobasal degeneration is diagnosed by the presence of tau-immunoreactive, but ubiquitin-non-reactive intraneuronal inclusions in cortical layer II and the substantia nigra. Pick's disease is restricted to cases with tau- and ubiquitin-immunoreactive spherical cortical intraneuronal inclusions (Pick bodies), best seen in the hippocampal dentate gyrus and frontotemporal cortex. Dementia of frontal type is the preferred term for cases in which no intraneuronal inclusions are seen with antisera to tau and ubiquitin. A practical approach to the pathological diagnosis of frontotemporal dementia and the differential diagnosis of the five disorders using immunohistochemical studies is provided.

Endosome-lysosomes, ubiquitin and neurodegeneration

Before the advent of ubiquitin immunochemistry and immunogold electron microscopy, there was no known intracellular molecular commonality between neurodegenerative diseases. The application of antibodies which primarily detect ubiquitin protein conjugates has shown that all of the human and animal idiopathic and transmissible chronic neurodegenerative diseases, (including Alzheimer's disease (AD), Lewy body disease (LBD), amyotrophic lateral sclerosis (ALS), Creutzfeldt-Jakob disease (CJD) and scrapie) are related by some form of intraneuronal inclusion which contains ubiquitin protein conjugates. In addition, disorders such as Alzheimer's disease, CJD and sheep scrapie, are characterised by deposits of amyloid, arising through incomplete breakdown of membrane proteins which may be associated with cytoskeletal reorganisation. Although our knowledge about these diseases is increasing, they remain largely untreatable. Recently, attention has focused on the mechanisms of production of different types of amyloid and the likely involvement within cells of the endosome-lysosome system, organelles which are immuno-positive for ubiquitin protein conjugates. These organelles may be 'bioreactor' sites for the unfolding and partial degradation of membrane proteins to generate the amyloid materials or their precursors which subsequently become expelled from the cell, or are released from dead cells, and accumulate as pathological entities. Such common features of the disease processes give new direction to therapeutic intervention.

Cost-benefit and cost-effectiveness analyses of behavioral marital therapy as an addition to outpatient alcoholism treatment

Thirty-six newly abstinent married male alcoholics, who had recently begun outpatient individual alcoholism counseling, were randomly assigned to a no-marital-therapy control group or to 10 weekly sessions of a behavioral marital therapy (BMT) or an interactional couples group. The cost-benefit analysis of BMT plus individual alcoholism counseling showed (a) decreases in health care and legal costs in the 2 years after as compared to the year before treatment, (b) a positive cost offset, and (c) a benefit-to-cost ratio greater than 1 indicating that health and legal system cost savings (i.e., benefits) exceeded the cost of delivering the BMT treatment. None of the positive cost-benefit results observed for BMT were true for participants given interactional couples therapy plus individual alcoholism counseling for which posttreatment utilization costs increased. Thus, adding BMT to individual alcoholism counseling produced a positive cost benefit, whereas the addition of interactional couples therapy did not. Individual counseling both alone and with BMT added showed substantial and significant cost savings from reduced utilization that substantially and significantly exceeded the cost of delivering the treatment; and the two treatments did not differ significantly on these cost savings and cost offsets. Individual counseling alone did have a significantly more positive benefit-to-cost ratio than BMT plus individual counseling due to the lower cost of delivering the individual counseling which was about half the cost of delivering BMT plus individual counseling. Cost-effectiveness analyses indicated that BMT plus individual counseling was less cost effective than individual counseling alone and modestly more cost effective than interactional therapy in producing abstinence from drinking. When marital adjustment outcomes were considered, the three treatments were equally cost effective except during the active treatment phase when BMT was more cost effective than interactional couples therapy. Study limitations are discussed.

Follicular fluid levels of midazolam, fentanyl, and alfentanil during transvaginal oocyte retrieval

OBJECTIVE

To investigate the time course of changes in follicular fluid (FF) concentrations of midazolam (Roche Products Ltd., Welwyn Garden City, United Kingdom), fentanyl (Janssen Pharmaceuticals Ltd., Wantage, United Kingdom), and alfentanil (Janssen Pharmaceuticals Ltd.) during ultrasound-guided transvaginal oocyte collection.

STUDY DESIGN

Forty-five patients with tubal infertility were randomized to receive a bolus IV dose of midazolam, fentanyl, or alfentanil for sedation during ultrasound-guided transvaginal oocyte collection. Paracervical block with lignocaine was given for analgesia. Simultaneous blood and FF samples were drawn at 5-minute intervals after the bolus dose for analysis of drug levels.

RESULTS

Data were obtained on 15 women receiving midazolam and fentanyl and on 13 women receiving alfentanil. Plasma levels of all agents rose to a peak and then fell in an exponential fashion as was expected. The FF levels of the agents continued to rise significantly to 25 minutes after the bolus dose, although the absolute level was low when compared with the blood level. There were no significant differences in fertilization or pregnancy rates in the three groups, but patient numbers were small.

CONCLUSION

We conclude that midazolam, fentanyl, and alfentanil are found in FF after a single IV dose, but further investigation needs to be undertaken to investigate any potential influence on fertilization and implantation rates.

Tau, ubiquitin, and alpha B-crystallin immunohistochemistry define the principal causes of degenerative frontotemporal dementia

OBJECTIVE

We investigated the use of immunostaining with antibodies to tau, ubiquitin, and alpha B-crystallin in defining a protocol for the staged neuropathologic examination of brains from patients with a progressive frontotemporal dementia.

DESIGN

Brains obtained from 50 patients dying with the clinical diagnosis of frontotemporal dementia were examined histopathologically to define pathologic distinctions.

SETTING

Two university hospital neuropathology departments.

RESULTS

Anti-tau immunostaining defined corticobasal degeneration, Alzheimer's disease, and Pick's disease; antiubiquitin defined motor neuron disease with dementia. The remaining brains have frontal lobe degeneration: the use of alpha B-crystallin immunostaining, on these, to detect ballooned neurons may help to define two groups of patients, one of which we believe may represent a variant of Pick's disease.

CONCLUSION

These findings indicate that immunostaining with these antibodies is essential for the evaluation of frontal dementia.

An anatomical, histological and magnetic resonance imaging study of the nasal septum

Considerable variations are present in the thickness of the normal nasal septum. These were studied and measured in cadavers and from MRI scans. In addition, a histological analysis was performed to determine whether cavernous tissue is present at any point in the septum. The nasal septum reaches maximum thickness antero-superiorly where the mucosa may be as thick a 5.0 mm (average 3.5 mm) and the minimum thickness lies inferiorly where the mucosa is often thinner than 0.5 mm. The area of maximum septal thickness lies at the region of the nasal valve and its contribution towards nasal airway resistance must be significant. No cavernous tissue was identified in the nasal septum.

Immunohistochemical localization of ubiquitin cross-reactive protein in human tissues

Ubiquitin cross-reactive protein (UCRP) is an interferon-inducible ubiquitin homologue which is constitutively present in cells and can be conjugated to other proteins. Using a characterized polyclonal antiserum to UCRP, immunohistochemical localization of UCRP was performed on paraffin-processed normal human tissues and in human tissues known to contain ubiquitinated intracellular inclusions. The antibody to UCRP immunostained lymphoid cells, striated and smooth muscle, several epithelia, and neurons. The level of staining varied greatly between tissues but was in a consistent punctate pattern. Localization to neuromuscular junctions and striations is similar to that described for antisera to ubiquitin-protein conjugates. Inclusion bodies characterized by immunoreactivity to anti-ubiquitin were not detected by the antibody to UCRP. Importantly, because UCRP may also be detected by antisera to conjugated ubiquitin, future studies on the distribution of ubiquitin in tissue sections must now take account of possible cross-reactivity with UCRP.

Allergen-induced histamine release in rat mast cells transfected with the alpha subunits of Fc epsilon RI

A rat mast cell histamine assay (RMCHA) has been developed to quantitate the biological activity of a recombinant humanized, monoclonal anti-IgE antibody (rhuMAbE25). Rat mast cells (RBL 48), transfected with the alpha subunit of the high affinity human IgE receptor (Fc epsilon RI), were presensitized for 2 h with human plasma containing IgE specific for ragweed and challenged with ragweed allergen in the presence of 50% D2O. Histamine release plateaus at 0.1 micrograms/ml of ragweed. The release of histamine was time, temperature and Ca2+ dependent. This ragweed-induced histamine release could be inhibited by rhuMAbE25 in a dose-dependent fashion with an IC50 of 1.19 +/- 0.31 micrograms/ml (n = 25). Other humanized MAbs and recombinant human growth factors neither trigger histamine release nor inhibit ragweed-induced histamine release. This RMCHA correlates well with the human basophil histamine assay (HBHA) (Fei et al., 1994) with a correlation coefficient of 0.93 (n = 59, p < 0.0001). Histamine was also released when the cells were presensitized with human plasma containing the respective allergen-specific IgE and then challenged with standardized mite, D. farinae, house dust mix, standardized cat pelt, or Alternaria tenuis. Comparison of allergen-induced histamine release showed a good correlation between RMCHA and HBHA with a correlation coefficient of 0.69 (n = 37, p = 0.0001). We conclude that RMCHA provides a useful tool to confirm allergen-specific IgE in allergic patients and can be used to evaluate the biological activity of any anti-IgE monoclonal antibody. Moreover, RMCHA provides an unique opportunity to study the mechanism of IgE-mediated histamine release in the absence of interfering proteins and growth factors normally present in whole blood.

Once weekly intravenous calcitriol suppresses hyperparathyroidism in hemodialysis patients

Although thrice weekly intravenous calcitriol therapy suppresses parathyroid hormone in end-stage renal disease patients, the efficacy of once weekly administration is not known. Sixty-three patients hemodialyzed for a mean duration of 44 +/- 4 months were treated with once weekly intravenous calcitriol at a mean dose of 2.8 +/- 1 microgram/week. Parathyroid hormone was significantly suppressed from a mean baseline level of 471 +/- 38 to 342 +/- 46 at 5 months and 220 +/- 40 pg/ml at 7 months of therapy. Plasma calcium levels rose from 9.0 +/- 0.1 to 9.4 +/- 0.1 and 9.9 +/- 0.2 mg/dl, respectively. Plasma phosphate level was unchanged. No untoward side effects were observed. The same mean dose of calcitriol achieved a comparable degree of parathyroid hormone suppression regardless of whether patients were on prior thrice weekly or no prior therapy. In patients who had been treated with thrice weekly bolus injections, switching to a once weekly bolus injection achieved a comparable suppression with a 36% reduction in the cumulative dose. Thus, once weekly intravenous bolus administration of calcitriol resulted in a rapid and marked suppression of parathyroid hormone, similar in adequacy to thrice weekly boluses but at a considerably lower cumulative weekly dose. Results were particularly impressive in patients recently starting dialysis, suggesting that once weekly administration is safe, cost effective, and should become standard therapy.

Lewy body dysphagia

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