Delusions associated with elevated muscarinic binding in dementia with Lewy bodies

The relation between disturbances of cholinergic neurotransmission and delusions (DELs) has not been investigated in degenerative dementias such as dementia with Lewy bodies (DLB). A cohort of dementia patients were assessed with standardized clinical evaluations (including the Columbia University Scale for Psychopathology in Alzheimer's Disease), which were repeated annually until death. DLB was confirmed neuropathologically in 21 patients. Neurochemical evaluation included M1 receptor autoradiography (pirenzepine binding), biochemical measurement of choline acetyltransferase (ChAT), and acetylcholinesterase (AChE) histochemistry in brain regions hypothesized to be involved in the genesis of psychosis. Compared with 11 age-matched controls, CHAT and pirenzepine levels were most extensively reduced in the temporal and parietal neocortex of DLB patients. In Brodmann area 36, DELs were significantly associated with elevated pirenzepine binding (131.0 vs 93.5, t = 2.7), whereas visual hallucinations were associated with significant reductions in ChAT (1.7 vs 2.5, t = 2.5). There were no significant associations with other areas or with cholinesterase. Although DELs and visual hallucinations were both linked with disturbances in cholinergic neurotransmission, the nature of the associations was different. Upregulation of the postsynaptic muscarinic receptor may be central in the genesis of DELs, with important treatment implications.

End of life treatment decisions in people with dementia: carers' views and the factors which influence them

OBJECTIVE

Treatment decisions in life threatening situations (TD) are poorly studied in people with dementia.

METHOD

The carers of people with dementia were asked four TD questions, pertaining to cardiac resuscitation, intravenous fluids, oral antibiotics and intravenous antibiotics. The impact of key variables (age, dementia severity, psychiatric co-morbidity, physical illness, family relationship of carer) on TD were evaluated.

RESULTS

Fifty carers participated, 46% wanted cardiac resuscitation, 60% wanted treatment with intravenous fluids, 52% wanted treatment with intravenous antibiotics and 60% wanted treatment with oral antibiotics. Agreement between questions was high (76 - 89%), suggesting that relatives were either for or against intervention. There was an association between more severe dementia and a reduced wish for intravenous antibiotics. None of the variables significantly influenced other TD.

CONCLUSION

The 'global' view of carers, was not influenced greatly by key disease variables. There are potential implications for the way in which carers are used as proxy decision makers.

Information theoretical probe selection for hybridisation experiments

MOTIVATION

The choice of probes is an important feature of hybridisation experiments. In this paper we present an algorithm that optimises probes with respect to a training set of sequences based on Shannon entropy as a quality criterion. The practical motivation for our algorithm is oligonucleotide fingerprinting, a method for the simultaneous identification of sequences (cDNA or genomic DNA) by their hybridisation tags according to a set of short probes such as octamers, although the algorithm is of course not restricted to that application.

RESULTS

We can show that our method is superior to the selection of probes according to their frequencies, which is a widely used strategy, and to randomly chosen probe sets. The quality of probe sets is assessed by a simulation pipeline that entails the set of probes as a simulation parameter. The performance of probe sets trained on sequences from different organisms shows additionally that probes should be chosen with regard to the organism under analysis. Case studies are presented on how constraints (G+C-content, complexity of the individual probes) influence the selection process.

AVAILABILITY

A description of the oligonucleotide fingerprinting pipeline is published on our web-page http://www.molgen.mpg.de/ approximately ag_onf/met.htm. An executable of the algorithm and probe lists designed for human and rodents can be downloaded from the ftp-site ftp://ftp.molgen.mpg.de/pub/mpimg/probe_design/.

When texture takes precedence over motion in depth perception

Both texture and motion can be strong cues to depth, and estimating slant from texture cues can be considered analogous to calculating slant from motion parallax (Malik and Rosenholtz 1994, report UCB/CSD 93/775, University of California, Berkeley, CA). A series of experiments was conducted to determine the relative weight of texture and motion cues in the perception of planar-surface slant when both texture and motion convey similar information. Stimuli were monocularly viewed images of planar surfaces slanted in depth, defined by texture and motion information that could be varied independently. Slant discrimination biases and thresholds were measured by a method of single-stimuli binary-choice procedure. When the motion and texture cues depicted surfaces of identical slants, it was found that the depth-from-motion information neither reduced slant discrimination thresholds, nor altered slant discrimination bias, compared to texture cues presented alone. When there was a difference in the slant depicted by motion and by texture, perceived slant was determined almost entirely by the texture cue. The regularity of the texture pattern did not affect this weighting. Results are discussed in terms of models of cue combination and previous results with different types of texture and motion information.

Investigation of the Alamar Blue (resazurin) fluorescent dye for the assessment of mammalian cell cytotoxicity

We show here the identity of Alamar Blue as resazurin. The 'resazurin reduction test' has been used for about 50 years to monitor bacterial and yeast contamination of milk, and also for assessing semen quality. Resazurin (blue and nonfluorescent) is reduced to resorufin (pink and highly fluorescent) which is further reduced to hydroresorufin (uncoloured and nonfluorescent). It is still not known how this reduction occurs, intracellularly via enzyme activity or in the medium as a chemical reaction, although the reduced fluorescent form of Alamar Blue was found in the cytoplasm and of living cells nucleus of dead cells. Recently, the dye has gained popularity as a very simple and versatile way of measuring cell proliferation and cytotoxicity. This dye presents numerous advantages over other cytotoxicity or proliferation tests but we observed several drawbacks to the routine use of Alamar Blue. Tests with several toxicants in different cell lines and rat primary hepatocytes have shown accumulation of the fluorescent product of Alamar Blue in the medium which could lead to an overestimation of cell population. Also, the extensive reduction of Alamar Blue by metabolically active cells led to a final nonfluorescent product, and hence an underestimation of cellular activity.

Motion processing in autism: evidence for a dorsal stream deficiency

We report that motion coherence thresholds in children with autism are significantly higher than in matched controls. No corresponding difference in form coherence thresholds was found. We interpret this as a specific deficit in dorsal stream function in autism. To examine the possibility of a neural basis for the perceptual and motor related abnormalities frequently cited in autism we tested 23 children diagnosed with autistic disorder, on two tasks specific to dorsal and ventral cortical stream functions. The results provide evidence that autistic individuals have a specific impairment in dorsal stream functioning. We conclude that autism may have common features with other developmental disorders and with early stages of normal development, perhaps reflecting a greater vulnerability of the dorsal system.

Tissue gene expression analysis using arrayed normalized cDNA libraries

We have used oligonucleotide-fingerprinting data on 60,000 cDNA clones from two different mouse embryonic stages to establish a normalized cDNA clone set. The normalized set of 5,376 clones represents different clusters and therefore, in almost all cases, different genes. The inserts of the cDNA clones were amplified by PCR and spotted on glass slides. The resulting arrays were hybridized with mRNA probes prepared from six different adult mouse tissues. Expression profiles were analyzed by hierarchical clustering techniques. We have chosen radioactive detection because it combines robustness with sensitivity and allows the comparison of multiple normalized experiments. Sensitive detection combined with highly effective clustering algorithms allowed the identification of tissue-specific expression profiles and the detection of genes specifically expressed in the tissues investigated. The obtained results are publicly available (http://www.rzpd.de) and can be used by other researchers as a digital expression reference.

History of breast prostheses

What material was available for breast augmentation 25 to 75 years ago? How has the development of today's breast implants evolved? These and other related issues are discussed in this article on the history of breast prostheses.

Anxiety, depression and psychosis in vascular dementia: prevalence and associations

BACKGROUND

Little is known about psychiatric symptoms in Vascular dementia (VaD).

METHOD

92 patients with VaD, and 92 patients with Alzheimer's disease (AD) are reported. The evaluation included standardised measures of mood and psychosis.

RESULTS

72% of VaD patients and 38% of those with AD had two or more anxiety symptoms. VaD patients with severe dementia (94%) were the most likely to be anxious. Depression was also significantly more common in VaD patients (19% vs. 8%) whereas psychotic symptoms were prevalent in both dementias.

CONCLUSION

Psychiatric symptoms are common in VaD, especially in patients with moderate or severe dementia. Rigorous assessment of psychiatric symptoms in VaD should be part of good clinical practice.

Immune function and vaccine responses in healthy advanced elderly patients

BACKGROUND

Decline in immune function has been reported to predictably accompany advancing age. However, to our knowledge, few studies have specifically characterized the rapidly expanding advanced elderly population or controlled adequately for concurrent diseases.

OBJECTIVE

To assess whether successfully reaching an advanced age in good health is associated with preserved immune function.

METHODS

We prospectively compared in vivo with in vitro variables of immune function in 29 healthy, independently living elderly subjects (mean age, 80 years; age range, 75-103 years) and in 21 healthy young control subjects (mean age, 29 years; age range, 25-35 years) in a Veterans Affairs Medical Center.

RESULTS

In vivo, among elderly and young subjects, numbers of total white blood cells, monocytes, lymphocytes, and lymphocyte subsets (CD4(+) and CD8(+) T lymphocytes and CD20(+) B cells) were similar, as were levels of total serum IgG and IgM. Only levels of serum IgA were higher in the elderly subjects (3.0 vs 1.7 g/L; P=.001). Functionally, both groups showed vigorous responses to protein (tetanus and diphtheria toxoids) and polysaccharide (23-valent pneumococcal) vaccines. Although levels varied, the fold increases in vaccine antigen-specific IgG were not significantly different in young and elderly subjects, and the avidities of IgG to pneumococcal polysaccharides 14 and 19F were similar before and after vaccination. In vitro, proliferative responses of blood mononuclear cells to T-lymphocyte and B-cell mitogens (pokeweed mitogen, Staphylococcus aureus Cowan strain I, and S aureus Cowan strain I plus interleukin 2), and lipopolysaccharide-induced production of tumor necrosis factor alpha, were comparable in elderly vs young subjects.

CONCLUSION

Successful aging, defined by reaching an advanced age with one's overall health intact, may be associated with preserved immune function and adequate responses to vaccines.

Depression in the carers of dementia sufferers: a comparison of the carers of patients suffering from dementia with Lewy bodies and the carers of patients with Alzheimer's disease

BACKGROUND

Depression has not previously been studied in the carers of patients suffering from dementia with Lewy Bodies (DLB).

METHOD

Twenty-five DLB carers were matched with 75 AD carers, according to carer characteristics. A standardised assessment incorporated measures of cognition, depression, psychosis and behavioural disturbance. DLB (consensus criteria), and AD (NINCDS ADRDA criteria) were diagnosed using operationalised clinical criteria. Carer depression was diagnosed using the Research Diagnostic Criteria.

RESULTS

The overall frequency of depression was similar in DLB and AD carers (28% vs. 31%). DLB carers were significantly more likely to experience a major depressive disorder (3/25 - 12% vs. 0/75 - 0% chi(2)=9.3, P=0.002, df 1), although the numbers were small. The severity of behavioural disturbance was associated with carer depression in the DLB carers and in the total sample.

CONCLUSION

The severity of behavioural disturbance was significantly associated with depression in DLB carers.

One year follow-up of parkinsonism in dementia with Lewy bodies

The progression of parkinsonism over 1 year was evaluated in a prospective cohort of patients (n = 338), suffering from dementia with Lewy bodies (DLB), Alzheimer's disease (AD) or vascular dementia (VaD). Parkinsonism was assessed using the modified Unified Parkinson's Disease Rating Scale. Significant parkinsonism was significantly commoner in DLB sufferers (71%) than amongst patients with AD (7%) or VaD (10%). DLB patients with established parkinsonism had an annual increase in severity of 9%, but progression was more rapid (49% in 1 year) in patients with early parkinsonism. Parkinsonism was frequent at all severities in DLB patients, but usually only present in other dementias when MMSE <10.

Guideline for the management of chronic asthma in adults--2000 update. South African Pulmonology Society Adult Asthma Working Group

OBJECTIVE

To make recommendations for the cost-effective management of asthma incorporating recent advances in the understanding and treatment of asthma since the last guideline statement in 1992. The guideline is applicable to adults and children over 12 years of age.

OPTIONS

Asthma should be graded according to standard severity criteria. The principle of 'hit early, hit hard' with corticosteroids to achieve rapid control is encouraged; thereafter treatment should be tailed down to the lowest dose of corticosteroids that maintains the aims of asthma treatment.

OUTCOMES

The aims of asthma management should be achieved; these include: (i) avoidance of causative and trigger factors; (ii) abolition of symptoms and ability to lead a normal lifestyle; (iii) restoration of normal (or best possible) lung function; (iv) reduction of the risk of severe attacks; and (v) optimisation of treatment with minimal side-effects.

EVIDENCE

Based on a selective review of randomised, controlled studies to support an evidence-based approach to treatment.

BENEFITS, HARMS AND COSTS

Appropriate management of asthma should lead to a reduction in morbidity and mortality of asthma and a consequent reduction in cost of asthma care. Side-effects of corticosteroids are placed in perspective together with a strategy to minimise these effects.

RECOMMENDATIONS

Asthma should be managed with inhaled corticosteroids as the most important anti-inflammatory treatment, except in the case of mild intermittent asthma which may be treated with beta 2 agonists on a pro re nata (prn) basis. It is preferable to add long-acting beta 2 agonists to low-dose inhaled corticosteroids before increasing corticosteroids. Leukotriene receptor antagonists are currently recommended for use in combination with inhaled corticosteroids pending further data on their long-term benefits. Differentiation of asthma from chronic obstructive pulmonary disease (COPD) is important. Early referral to a pulmonologist in difficult cases is encouraged.

VALIDATION

Endorsed by the South African Pulmonology Society, the Allergy Society of South Africa and the South African Medical Association. The guideline is compatible with those of other international societies.

Neurocardiovascular instability, hypotensive episodes, and MRI lesions in neurodegenerative dementia

We investigated whether carotid sinus hypersensitivity (CSH) and orthostatic hypotension (OH) were associated with a greater severity of hyperintensities on MRI scan in 30 patients with neurodegenerative dementia (17 dementia with Lewy bodies, 13 Alzheimer's disease), who had a detailed evaluation of OH and CSH during active standing and head-up tilt. Patients also underwent a 1.0 Tesla MRI scan, from which hyperintensities were rated on a standardized scale. A blood pressure (BP) drop > 30 mm Hg during carotid sinus massage or active standing was significantly associated with the severity of MRI hyperintensities in the deep white matter (OR 10.0, 95%; CI 1.8-55.7) and in the basal ganglia (OR 11.0, 95%; CI 1.2-99.5) but not in periventricular areas (OR 1.4, 95%; CI 0.3-1.8). Patients with the cardio-inhibitory form of CSH with the largest BP drops were the most at risk. Further longitudinal studies need to investigate the direction of causality to determine whether CSH or OH predispose to MRI hyperintensities and accelerate cognitive decline.

The association between white matter lesions on magnetic resonance imaging and noncognitive symptoms

A number of studies have suggested that cerebral changes, particularly deep white matter lesions (WML) visualized on magnetic resonance imaging (MRI), may be involved in the genesis of late life depression. This has been confirmed in a prospective study which also found a relationship between the presence of WML and poor 3-year outcome in elderly depressed subjects. Most studies find these lesions to predominate in frontal lobe and basal ganglia, supporting the hypothesis of "fronto-striatal" dysfunction in depression. To investigate whether WML are associated with mood disturbance in dementia, proton density and T2-weighted images were obtained in 80 subjects with dementia (dementia with Lewy bodies, n = 27; Alzheimer's disease, n = 28; vascular dementia, n = 25) and 26 age-matched normal controls. Periventricular lesions (PVL), white matter lesions (WML), and basal ganglia hyperintensities (BG) were visually rated blind to diagnosis using a semiquantitative scale. Frontal WML were associated with higher depression scores in patients with dementia, implying a common pathophysiology of depression irrespective of diagnosis. Further study of the neurobiological basis of WML is needed. This can best be achieved by serial clinical assessment combined with in vivo and in vitro MRI and neuropathological examination.

Design and development of selective muscarinic agonists for the treatment of Alzheimer's disease: characterization of tetrahydropyrimidine derivatives and development of new approaches for improved affinity and selectivity for M1 receptors

Cholinergic neurons degenerate in Alzheimer's disease, resulting in cognitive impairments and memory deficits, and drug development efforts have focused on selective M1 muscarinic agonists. 5-(3-Ethyl-1,2,4- oxadiazol-5-yl)-1,4,5,6-tetrahydropyrimidine trifluoroacetic acid (CDD-0102) stimulates M1 muscarinic receptors in rat brain [Messer, W.S., Jr., Abuh, Y.F., Liu, Y., Periyasamy, S., Ngur, D.O., Edgar, M.A., El-Assadi, A.A., Sbeih, S., Dunbar, P.G., Roknich, S., Rho, T., Fang, Z., Ojo, B., Zhang, H., Huzl, J.J., III, Nagy, P.I., 1997a. J. Med. Chem. 40, 1230-1246.] and improves memory function in rats with lesions of the basal forebrain cholinergic system. Moreover, CDD-0102 exhibits oral bioavailability, few side effects and low toxicity, and thus represents a viable candidate for clinical studies. Despite the development of functionally selective agonists such as xanomeline and CDD-0102, there is room for improvements in ligand affinity and selectivity. The high degree of amino acid homology within transmembrane domains has hindered the development of truly selective agonists. Site-directed mutagenesis, biochemical and molecular modeling studies have identified key amino acid residues such as Thr192 and Asn382 in the binding of agonist to M1 receptors [Huang, X.P., Nagy, P.I., Williams, F.E., Peseckis, S.M., Messer, W.S., Jr., 1999. Br. J. Pharmacol. 126, 735-745.]. Recent work has implicated residues at the top of transmembrane domain VI in the binding of muscarinic agonists and activation of M1 receptors [Huang, X.P., Williams, F.E., Peseckis, S.M., Messer, W.S., Jr., 1998. J. Pharmacol. Exp. Ther. 286, 1129-1139.]. Thus, residues such as Ser388 represent molecular targets for the further development of agonists with improved M1 receptor affinity, selectivity and activity.

Neuropathological substrates of dementia and depression in vascular dementia, with a particular focus on cases with small infarct volumes

The neuropathological substrates of dementia and depression were evaluated in 30 patients with cerebrovascular disease and significant cognitive impairment (VaD), with a particular focus on patients with small infarct volumes (<15 ml). VaD patients with small infarct volumes had a similar degree of cognitive impairment to those with larger infarct volumes (>15 ml) but were significantly more likely to be depressed and to have areas of microinfarction. A review of individual cases with small infarct volumes suggested that the combination of microinfarction, diffuse white matter disease and perivascular changes, or the overlap of neurodegenerative pathologies and microvascular changes were particularly important. Microinfarction was also significantly associated with major depression.

Dementia with Lewy bodies

OBJECTIVE

The aim of this paper is to summarise recent clinical and research findings with regard to dementia with Lewy bodies (DLB).

METHOD

A literature review (Medline) was carried out, as well as a review of reports of recent DLB symposia of international meetings and of other relevant papers and data known to the authors.

RESULTS

Dementia with Lewy bodies, as the disorder should be known, is the second commonest form of degenerative dementia, accounting for up to 20% cases in the elderly. It is characterised by fluctuating cognitive impairment, spontaneous parkinsonism and recurrent visual hallucinations. Consensus clinical and neuropathological criteria have been published. The clinical criteria have been shown to have high specificity, but may still lack sensitivity. Recognition of DLB is clinically important in view of the high incidence (60%) of adverse and life-threatening reaction to antipsychotics, the difference in prognosis and, possibly, the differential treatment response to cholinergic therapy. Neuroimaging changes have not been well described in DLB but some show promise as potential markers to differentiate DLB from AD. These include relative preservation of temporal lobe structures on magnetic resonance imaging and loss of pre- and postsynaptic dopaminergic markers on single photon emission tomography.

CONCLUSIONS

Dementia with Lewy bodies is a common cause of cognitive impairment in late life which appears to be clinically and neuropathologically distinct from AD. All clinicians should be aware of the typical triad of clinical features (fluctuating cognitive impairment, visual hallucinations and parkinsonism) which characterise the disorder and either avoid antipsychotics or prescribe them with extreme caution in such patients. Further research is likely to result in advances in diagnostic methods and therapeutics in the near future.

Ocular manifestations of systemic malignancies

Ocular manifestations of systemic malignancy are important for both the ophthalmologist and the internist to recognize because they may precede the diagnosis of cancer. This review of the current literature discusses the clinical manifestations, etiology, and potential therapeutic interventions for a group of visual paraneoplastic syndromes, including carcinoma-associated retinopathy and melanoma-associated retinopathy. These conditions are characterized by elevated serum levels of autoantibodies directed against tumor antigen that cross-react with retinal proteins, resulting in rod and cone dysfunction. The clinical presentation, site of origin, frequency, and intraocular distribution of tumors metastatic to the eye are also reviewed.

Ifosfamide, carboplatin, and etoposide: a highly effective cytoreduction and peripheral-blood progenitor-cell mobilization regimen for transplant-eligible patients with non-Hodgkin's lymphoma

PURPOSE

To evaluate a chemotherapy regimen that consisted of ifosfamide administered as an infusion with bolus carboplatin, and etoposide (ICE) supported by granulocyte colony-stimulating factor (G-CSF) for cytoreduction and stem-cell mobilization in transplant-eligible patients with primary refractory or relapsed non-Hodgkin's lymphoma (NHL).

PATIENTS AND METHODS

One hundred sixty-three transplant-eligible patients with relapsed or primary refractory NHL were treated from October 1993 to December 1997 with ICE chemotherapy at Memorial Sloan-Kettering Cancer Center. Administration of three cycles of ICE chemotherapy was planned at 2-week intervals. Peripheral-blood progenitor cells were collected after cycle 3, and all patients who achieved a partial response (PR) or complete response (CR) to ICE chemotherapy were eligible to proceed to transplantation. Event-free and overall survival, ICE-related toxicity, and the number of CD34(+) cells collected after treatment with ICE and G-CSF were evaluated.

RESULTS

All 163 patients were assessable for response, and there was no treatment-related mortality. A major response (CR/PR) was evident in 108 patients (66.3%); 89% of the responding patients underwent successful transplantation. Patient who underwent transplantation and achieved a CR to ICE had a superior overall survival to that of patients who achieved a PR (65% v 30%; P =.003). The median number of CD34(+) cells/kg collected was 8.4 x 10(6). The dose-limiting toxicity of ICE was hematologic, with 29.4% of patients developing grade 3/4 thrombocytopenia. There were minimal nonhematologic side effects.

CONCLUSION

ICE chemotherapy, with ifosfamide administered as a 24-hour infusion to decrease CNS side effects, and the substitution of carboplatin for cisplatin to minimize nephrotoxicity, is a very effective cytoreduction and mobilization regimen in patients with NHL. Furthermore, the quality of the clinical response to ICE predicts for posttransplant outcome.

Application of a loading wash-out method for investigating the hepatocellular efflux of a hepatically-generated metabolite, morphine-3-glucuronide

Previous studies using the rat isolated perfused liver demonstrated that the hepatic disposition of morphine-3-glucuronide is membrane permeability-rate limited, and that the movement of the metabolite across hepatic sinusoidal and canalicular membranes is partly via carrier-mediated transport systems. As a consequence of the membrane permeability-limitation, the biliary excretion of hepatically-generated morphine-3-glucuronide is much more efficient than that of morphine-3-glucuronide reaching the liver via the vasculature. We have quantitated the cellular efflux kinetics (cell-to-blood and cell-to-bile) of morphine-3-glucuronide in the rat isolated perfused liver using a loading wash-out design. In the 'loading' phase, morphine was infused into the liver (2.7 microM) and the biliary excretion and sinusoidal efflux of morphine-3-glucuronide was assessed under steady-state conditions. Subsequently, the infusion was stopped and the concentration vs time profile of morphine-3-glucuronide in outflow perfusate (the wash-out phase) was determined. A physiologically-based pharmacokinetic model was used to determine the rate-constants for the movement of hepatically-generated morphine-3-glucuronide into the sinusoidal and canalicular spaces of the liver, and the associated membrane permeability terms. The mean (+/-s.d.) rate constants for the biliary excretion and sinusoidal efflux of morphine-3-glucuronide were determined to be 0.160 +/- 0.043 and 0.169 +/- 0.068 min(-1), respectively, and the corresponding membrane permeability parameters were 1.12 and 1.18 mL min(-1), respectively. The sinusoidal membrane permeability term was significantly less than hepatic blood flow in the rat. The volume of distribution of hepatically-generated morphine-3-glucuronide (207.5 +/- 74.8 mL) was found to be approximately 50-times the intracellular space of the rat liver, suggesting that hepatically-generated morphine-3-glucuronide accumulates within hepatocytes. The results indicate that hepatically-generated morphine-3-glucuronide undergoes intracellular accumulation, probably as a consequence of poor membrane permeability.