Mild cognitive impairment represents early-stage Alzheimer disease

BACKGROUND

Mild cognitive impairment (MCI) is considered to be a transitional stage between aging and Alzheimer disease (AD).

OBJECTIVE

To determine whether MCI represents early-stage AD by examining its natural history and neuropathologic basis.

DESIGN

A prospective clinical and psychometric study of community-living elderly volunteers, both nondemented and minimally cognitively impaired, followed up for up to 9.5 years. Neuropathologic examinations were performed on participants who had undergone autopsy.

SETTING

An AD research center.

PARTICIPANTS

All participants enrolled between July 1990 and June 1997 with Clinical Dementia Rating (CDR) scores of 0 (cognitively healthy; n = 177; mean age, 78.9 years) or 0.5 (equivalent to MCI; n = 277; mean age, 76.9 years). Based on the degree of clinical confidence that MCI represented dementia of the Alzheimer type (DAT), 3 subgroups of individuals with CDR scores of 0.5 were identified: CDR 0.5/DAT, CDR 0.5/incipient DAT, and CDR 0.5/uncertain dementia.

MAIN OUTCOME MEASURE

Progression to the stage of CDR 1, which characterizes mild definite DAT.

RESULTS

Survival analysis showed that 100% of CDR 0.5/DAT participants progressed to greater dementia severity over a 9.5-year period. At 5 years, rates of progression to a score of CDR 1 (or greater) for DAT were 60.5% (95% confidence interval [CI], 50.2%-70.8%) for the CDR 0.5/DAT group, 35.7% (95% CI, 21.0%-50.3%) for the CDR 0.5/incipient DAT group, 19.9% (95% CI, 8.0%-31.8%) for the CDR 0.5/uncertain dementia group, and 6.8% (95% CI, 2.2%-11.3%) for CDR 0/controls. Progression to greater dementia severity correlated with degree of cognitive impairment at baseline. Twenty-four of the 25 participants with scores of CDR 0.5 had a neuropathologic dementing disorder, which was AD in 21 (84%).

CONCLUSIONS

Individuals currently characterized as having MCI progress steadily to greater stages of dementia severity at rates dependent on the level of cognitive impairment at entry and they almost always have the neuropathologic features of AD. We conclude that MCI generally represents early-stage AD.

Increased peripheral T cell reactivity to microbial antigens and collagen type II in rheumatoid arthritis after treatment with soluble TNFalpha receptors

OBJECTIVE

Peripheral T cells from patients with rheumatoid arthritis (RA) are hyporesponsive when stimulated with antigen or mitogen in vitro, possibly owing to increased production of proinflammatory cytokines such as tumour necrosis factor alpha (TNFalpha). This study sought to find out if and how RA T cell reactivity is affected during treatment with etanercept (Enbrel), a soluble TNFalpha receptor.

METHODS

Heparinised blood was collected from patients with RA at baseline, after four and eight weeks of etanercept treatment, and from healthy controls. After density separation spontaneous production of interferon gamma (IFNgamma), TNFalpha, interleukin 6 (IL6), and IL10 by peripheral blood mononuclear cells (PBMC) was detected by ELISPOT. For detection of T cell reactivity, PBMC were stimulated in vitro with mitogen (phytohaemagglutinin (PHA)), microbial antigens (purified protein derivative (PPD), influenza), or an autoantigen, collagen type II (CII). Supernatants were analysed for IFNgamma and IL2 content by enzyme linked immunosorbent assay (ELISA).

RESULTS

In RA the number of cells spontaneously producing IFNgamma was significantly increased after four, but not eight weeks' treatment with etanercept. T cell reactivity, as measured by IFNgamma production to PPD, influenza, and CII was significantly increased after four and sustained after eight weeks' treatment, whereas IFNgamma production induced by PHA remained unchanged. TNFalpha production was significantly higher in patients with RA than in controls and did not change during etanercept treatment.

CONCLUSION

Treatment of patients with RA with etanercept may lead to increased peripheral T cell reactivity both to microbial antigens and to self antigens such as CII. These findings indicate that TNFalpha blockade may not only suppress but also stimulate certain aspects of antimicrobial immune defence and autoimmunity.

Down-regulation of the T cell receptor CD3 zeta chain in rheumatoid arthritis (RA) and its influence on T cell responsiveness

T cells implicated in chronic inflammatory diseases such as RA respond weakly when stimulated in vitro with mitogen or antigen. The mechanism behind this hyporesponsiveness is unclear, but a depressed expression of the T cell receptor (TCR)-associated CD3zeta chain has been suggested. In the present work we describe a low expression of CD3zeta in synovial fluid (SF) T cells from RA patients compared with peripheral blood (PB) T cells, but no difference in CD3zeta expression between RA and healthy control PB T cells. In vitro studies demonstrated that granulocytes but not SF macrophages are able to down-regulate the expression of CD3zeta. Through stimulation with anti-CD3 antibodies we demonstrated that the TCR-dependent proliferative response was decreased in SF T cells compared with PB T cells. Stimulation with phorbol ester and ionomycin also resulted in a low proliferative response of SF T cells, indicating that both signal transduction through the TCR (stimulation with anti-CD3) and events further downstream in the signalling pathways (stimulation with phorbol ester and ionomycin) are affected. A similar depression of T cell activity was observed when induction of IL-2 and IL-4 was measured. However, SF T cells were not defective in the induction of interferon-gamma (IFN-gamma) when stimulated with phorbol myristate acetate (PMA)/ionomycin, in contrast to the diminished IFN-gamma response observed after stimulation with anti-CD3. This indicates that the hyporesponsiveness of SF T cells can not be generalized to all T cell functions. The differential response to external stimuli is likely to be of importance for the capacity of SF T cells to influence inflammatory reactions.

Interferon-gamma production in response to in vitro stimulation with collagen type II in rheumatoid arthritis is associated with HLA-DRB1(*)0401 and HLA-DQ8

INTRODUCTION

Despite much work over past decades, whether antigen-specific immune reactions occur in rheumatoid arthritis (RA) and to what extent such reactions are directed towards joint-specific autoantigens is still questionable. One strong indicator for antigenic involvement in RA is the fact that certain major histocompatibility complex (MHC) class II genotypes [human leucocyte antigen (HLA)-DR4 and HLA-DR1[ predispose for the development of the disease [1]. In the present report, collagen type II (CII) was studied as a putative autoantigen on the basis of both clinical and experimental data that show an increased frequency of antibodies to CII in RA patients [2-4] and that show that CII can induce experimental arthritis [5]. It is evident from the literature that RA peripheral blood mononuclear cells (PBMCs) respond poorly to antigenic stimulation [6-8], and in particular evidence for a partial tolerization to CII has been presented [9]. The strategy of the present work has accordingly been to reinvestigate T-cell reactivity to CII in RA patients, to relate it to the response to commonly used recall antigens and to analyze interferon (IFN)-gamma responses as an alternative to proliferative responses.

AIMS

To study cellular immune reactivity to CII in patients with RA and in healthy control individuals and to correlate this reactivity to HLA class II genotypes and to the presence of antibodies to CII in serum.

METHODS

Forty-five patients who met the 1987 American college of Rheumatology classification criteria for RA [10] and 25 healthy control individuals of similar age and sex were included. Twenty-six of these patients who had low levels of anti-CII in serum were randomly chosen, whereas 19 patients with high anti-CII levels were identified by enzyme-linked immunosorbent assay (ELISA)-screening of 400 RA sera. Heparinized blood was density gradient separated and PBMCs were cultured at 1 x 10(6)/ml in RPMI-10% fetal calf serum with or without antigenic stimulation: native or denatured CII (100 microgram/ml), killed influenza virus (Vaxigrip, Pasteur Merieux, Lyon, France; diluted 1:1000) or purified protein derivative (PPD; 10 microgram/ml). CII was heat-denatured in 56 degrees C for 30 min. Cell supernatants were collected after 7 days and IFN-gamma contents were analyzed using ELISA. HLA-DR and HLA-DQ genotyping was performed utilizing a polymerase chain reaction-based technique with sequence-specific oligonucleotide probe hybridization. Nonparametric statistical analyses were utilized throughout the study.

RESULTS

PBMCs from both RA patients and healthy control individuals responded with IFN-gamma production to the same degree to stimulation with native and denatured CII (Fig. 1a), giving median stimulation indexes with native CII of 4.6 for RA patients and 5.4 for health control individuals, and with denatured CII of 2.9 for RA patients and 2.6 for healthy control individuals. RA patients with elevated levels of anti-CII had a weaker IFN-gamma response to both native and denatured CII that did healthy control individuals (P-).02 and 0.04, respectively). Stimulation with the standard recall antigens PPD and killed influenza virus yielded a median stimulation index with PPD of 10.0 for RA patients and 51.3 for healthy control individuals and with influenza of 12.3 for RA patients and 25.7 for healthy, control individuals. The RA patients displayed markedly lower responsiveness to both PPD and killed influenza virus than did healthy control individuals (Fig. 1b). IFN-gamma responses to all antigens were abrogated when coincubating with antibodies blocking MHC class II. The low response to PPD and killed influenza virus in RA patients relative to that of healthy control individuals reflects a general downregulation of antigen-induced responsiveness of T cells from RA patients [6-8]. That no difference between the RA group and the control group was recorded CII-induced IFN-gamma production therefore indicates that there may be an underlying increased responsiveness to CII in RA patients, which is obscured by the general downregulation of T-cell responsiveness in these patients. In order to address this possibility, we calculated the fraction between individual values for the CII-induced IFN-gamma production and the PPD-induced and killed influenza virus-induced IFN-gamma production and the PPD-induced and killed influenza virus-induced IFN-gamma production, and compared these fractions. A highly significant difference between the RA and health control groups was apparent after stimulation with both native CII and denatured CII when expressing the response as a fraction of that with PPD (Fig. 2a). Similar data were obtained using killed influenza virus-stimulated IFN-gamma values as the denominator (Fig. 2b).When comparing the compensated IFN-gamma response to denatured CII stimulation between RA patients with different HLA genotypes, highly significant differences were evident, with HLA-DRB1*0401 patients having greater CII responsiveness than patients who lacked this genotype (Fig. 3a). HLA-DQ8 positive patients also displayed a high responsiveness to CII as compared with HLA-DQ8 negative RA patients (Fig. 3b). These associations between the relative T-cell reactivity to denatured CII and HLA class II genotypes were not seen in healthy control individuals. Similar results were achieved using influenza as denominator (P = 0.02 for HLA-DRB1*0401 and P = 0.01 for HLA-DQ8).

DISCUSSION

No reports have previously systematically taken the general T-cell hyporesponsiveness in RA into account when investigating specific T-cell responses in this disease. In order to address this issue we used the T-cell responses to PPD and killed influenza virus as reference antigens. This was made on the assumption that exposure to these antigens is similar in age-matched and sex-matched groups of RA patients and healthy control individuals. The concept of a general hyporesponsiveness in RA T cells has been documented in several previous reports, in which both nominal antigens [6,7,8] and mitogens [11,12,13] have been used. The fact that a similar functional downregulation in RA PBMCs was obtained with both PPD and killed influenza virus as reference antigens strengthens the validity of our approach. We identified an association between the IFN-gamma response to CII and HLA-DRB1*0401 and HLA-DQ8 in the RA patient group, which is of obvious interest because both these MHC class II alleles have been associated with high responsiveness to CII in transgenic mice that express these human MHC class II molecules [14,15]. There was no association between high anti-CII levels and shared epitope (HLA-DRB1*0401 or HLA-DRB1*0404).

CONCLUSION

CII, a major autoantigen candidate in RA, can elicit an IFN-gamma response in vitro that is associated with HLA-DRB1*0401 and HLA-DQ8 in RA patients. This study, with a partly new methodological approach to a classical problem in RA, has provided some additional support to the notion that CII may be a target autoantigen of importance for a substantial group of RA patients. Continued efforts to identify mechanisms behind the general hyporesponsiveness to antigens in RA, as well as the mechanisms behind the potential partial anergy to CII, may provide us with better opportunities to study the specificity and pathophysiological relevance of anti-CII reactivity in RA.

Factors associated with residents' attitudes toward dying patients

BACKGROUND AND OBJECTIVES

Management of the dying patient often elicits anxiety in physicians. This study identified the association of physicians' personal fear of death, tolerance of uncertainty, and attachment style with physician attitudes toward dying patients.

METHODS

Four psychological scales were distributed to family practice residents located in Texas, Missouri, and Maine. The scales were "Death Anxiety," "Death Attitudes," "Physicians' Reactions to Uncertainty," and "Experiences in Close Relationships." The scores from the measures and demographic data were used to determine which factors were associated with physician attitudes toward caring for terminally ill patients.

RESULTS

Completed surveys were received from 157 residents. Younger residents (< 30 years) reported more stress from uncertainty and were more uncomfortable with the care of dying patients. Residents who reported higher death anxiety were also more uncomfortable with caring for dying patients. In a multivariate analysis, uncertainty, death anxiety, and age predicted 26% of the total outcome variance of the death attitudes score.

CONCLUSIONS

Physician tolerance of uncertainty plays a significant role in physician attitudes toward the dying patient. Our findings suggest that decreasing physicians' stress from uncertainty by educating them in the management of the dying patient may improve their attitude toward death and may better prepare them to provide end-of-life care.

Increased serum levels of immunoglobulins, C-reactive protein, type 1 and type 2 cytokines in patients with mixed connective tissue disease

It is controversial whether mixed connective tissue disease (MCTD) should be regarded as a distinct disease entity. In the present study, we investigated immunological parameters in patients with MCTD by studying serum levels of immunoglobulins, C-reactive protein (CRP) and cytokines and compared the results to the corresponding values in systemic lupus erythematosus (SLE), in rheumatoid arthritis (RA) patients and in healthy controls. Using the ELISA technique, serum levels of the cytokines interferon-gamma (IFN-gamma), interleukin-10 (IL-10) and tumour necrosis factor-alpha (TNF-alpha) were investigated. Cytokine levels in SLE and MCTD were correlated to disease activity as assessed by systemic lupus activity measure (SLAM). They were also correlated to serum levels of CRP, IgG, IgA and IgM in the three patient groups. The MCTD patients had the highest levels of immunoglobulins, followed by the SLE patients. In contrast, the highest CRP levels were observed in RA patients, followed by the MCTD patients. The MCTD patients had the highest serum levels of IL-10, but also had elevated IFN-gamma and TNF-alpha levels similar to the RA patients. There was no correlation between the investigated cytokine levels and disease activity, as assessed by SLAM. We conclude that MCTD patients have high immunoglobulin levels as well as high CRP levels and that this situation is compatible with the observed increase in both type 1 and type 2 cytokine levels. The findings imply that MCTD shares some distinct immunological properties with both RA and SLE and that MCTD may also be considered as a separate disease entity according to these properties.

A prospective study of cognitive function and onset of dementia in cognitively healthy elders

OBJECTIVE

To examine the earliest cognitive changes associated with the onset of dementia as well as changes associated with normal aging.

DESIGN

Longitudinal evaluation of participants with annual clinical and psychometric examinations for up to 15 1/2 years.

SETTING AND PARTICIPANTS

Elderly volunteers (n = 82) enrolled with a Clinical Dementia Rating of 0 (cognitively intact) in longitudinal studies.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Clinical Dementia Rating and results of a 1 1/2-hour psychometric battery.

RESULTS

As estimated with survival analysis, 40% of participants had a Clinical Dementia Rating greater than 0 (cognitive decline) within 12 years of enrollment; 59% of these were judged to have dementia of the Alzheimer type or incipient dementia. Participants with poorer performance on psychometric testing at enrollment were at higher risk for cognitive decline subsequently. The rate of change in psychometric performance before clinically detectable cognitive change occurred was not significantly different between those who eventually developed dementia and those who remained stable, except for performance on the Logical Memory subtest of the Wechsler Memory Scale. When subtle cognitive decline was clinically detected, however, an abrupt deterioration in performance on independently administered psychometric tests was observed.

CONCLUSIONS

Cognitively healthy elderly people maintain stable cognitive performance when measured longitudinally by both careful clinical evaluation and repeated psychometric testing. This stability is maintained unless and until they develop a dementing illness, at which time a sharp decline in performance is observed.

Clinicopathologic studies in cognitively healthy aging and Alzheimer's disease: relation of histologic markers to dementia severity, age, sex, and apolipoprotein E genotype

OBJECTIVE

To study differences between subjects with Alzheimer disease (AD) and cognitively intact control subjects, with respect to brain histologic markers of AD, and the relationship of those markers in the AD group to severity of dementia, age at death, sex, and apolipoprotein E genotype.

SETTING

Washington University Alzheimer's Disease Research Center, St Louis, Mo.

DESIGN AND SUBJECTS

Consecutive neuropathologic series of 224 prospectively studied volunteer research subjects, 186 with dementia of the Alzheimer type (DAT) or "incipient" DAT and confirmed to have AD by postmortem examination and 13 cognitively intact subjects, confirmed to lack postmortem findings of AD.

MAIN OUTCOME MEASURES

Brain densities (number per square millimeter) of senile plaques and neurofibrillary tangles, extent of cerebral amyloid angiopathy, cortical Lewy bodies, and apolipoprotein E genotype.

RESULTS

Neocortical neurofibrillary tangle densities were substantially correlated with dementia severity, and to a greater degree than was true for senile plaque densities. When infarcts, hemorrhages, and Parkinson disease changes coexisted with AD, neurofibrillary tangle and senile plaque densities were lower. Plaque-predominant AD was found in a greater proportion of subjects with milder than more severe dementia. Entorhinal cortical Lewy bodies were no more frequent in plaque-predominant AD than in the remaining AD cases. Increasing age at death was negatively correlated with dementia severity and densities of senile plaques and neurofibrillary tangles. The apolipoprotein E epsilon4 allele frequency was greater in AD than in control subjects but decreased with increasing age. After controlling for dementia severity, senile plaque densities were only weakly related to epsilon4 allele frequency, and only in hippocampus. However, the degree of cerebral amyloid angiopathy was clearly related to epsilon4 allele frequency. Among subjects diagnosed during life as having DAT or incipient DAT, only 7% were found to have a neuropathologic disorder other than AD causing their dementia.

CONCLUSIONS

(1) The order of the strength of relationships between densities of histologic markers and dementia severity in AD is neurofibrillary tangles greater than cored senile plaques greater than total senile plaques. (2) Advanced age at death is associated with somewhat less severe dementia and fewer senile plaques and neurofibrillary tangles. (3) Plaque-predominant AD may represent a developmental stage in AD. (4) Despite a substantial effect of apolipoprotein E epsilon4 as a risk factor for AD, on decreasing the age at AD onset, and increasing the amount of cerebral amyloid angiopathy, its effect on senile plaque densities is variable and complex, being confounded with age, dementia severity, and methodologic differences. (5) Stringent clinical diagnostic criteria for DAT, even in the very mild stage, and senile plaque-based neuropathologic criteria for AD are highly accurate.

A molecular analysis of hyalin--a substrate for cell adhesion in the hyaline layer of the sea urchin embryo

The hyaline layer of echinoderm embryos is an extraembryonic matrix that functions as a substrate for cell adhesion through early development. The major constituent of the hyaline layer is the protein hyalin, a fibrillar glycoprotein of approximately 330 kDa that multimerizes in the presence of calcium. Here we provide a molecular characterization of hyalin and identify a region of the protein that is important for its function in cell adhesion. Partial hyalin cDNAs were identified from two sea urchin species, Strongylocentrotus purpuratus and Lytechinus variegatus, by screening expression libraries with monoclonal antibodies to hyalin. The cDNAs each encode a tandemly arranged series of conserved repeats averaging 84 amino acids. These hyalin repeats are as similar between the two species as they are to repeats within each species, suggesting a strong functional conservation. Analysis of this repeat shows that it is a unique sequence within the GenBank database with only weak similarity to mucoid protein sequences. The hyalin mRNA is approximately 12 kb in length and is present in developing oocytes coincident with the appearance of cortical granules, the vesicle in which the hyalin protein is specifically packaged. The mRNA is present throughout oogenesis but is rapidly lost at oocyte maturation so that eggs and early embryos have no detectable hyalin mRNA. The hyalin protein, however, remains at relatively constant levels throughout development. Thus, all the hyalin protein present during early development, when no RNA is detectable, is maternally derived and exocytosed from cortical granules at fertilization. Hyalin mRNA reaccumulates in embryos beginning at the mesenchyme blastula stage; a RNA gel blot and in situ hybridization analysis of gastrulae and larvae shows a progressive confinement of hyalin mRNA to the aboral ectoderm. Recombinant hyalin containing the tandem repeat region of the protein was expressed in bacteria and is shown to serve as an adhesive substrate, almost equal to that of native hyalin, in cell adhesion assays. This adhesive activity is partially blocked by dilute hyalin monoclonal antibody Tg-HYL to the same extent as that for native hyalin. Thus, this hyalin repeat region appears to contain the ligand for the hyalin cell surface receptor. These data help explain some of the classic functions ascribed to the hyalin protein in early development and now enable investigators to focus on the mechanisms of cell interactions with the hyaline layer.

Production of T-cell cytokines at the single-cell level in patients with inflammatory arthritides: enhanced activity in synovial fluid compared to blood

We used a newly developed, sensitive ELISPOT technique in order to estimate the number of cells producing interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) in synovial fluid mononuclear cells (SFMC) and peripheral blood mononuclear cells (PBMC) in patients with rheumatoid arthritis (RA) and other inflammatory arthritides, and to correlate the results with clinical and laboratory parameters of disease activity. SFMC and PBMC were cultured either without stimuli or with a standardized dose of phytohaemagglutinin (PHA) for 6 h. Twenty-nine patients, 16 with RA and 13 with other inflammatory joint diseases, were investigated and compared to PBMC from 25 healthy controls. The mean number of IFN-gamma-producing cells was 37.1/10(5) plated SFMC (range 0-121.5). The corresponding value for PBMC was 5.1 (0-39). The difference was highly significant (P = 0.0033 for RA patients, P = 0.0050 for non-RA patients and P < 0.0001 for all patients). Forty-five per cent of SFMC samples (range for all samples 0-38.5 SFC/10(5) MNC) and 25% of PBMC samples (0-20.5) exhibited spontaneous IL-4 production, yielding a significant difference for all patients treated collectively (P = 0.021). Although the cells that spontaneously secrete these cytokines are relatively few, quantification of these cells thus shows increased functional T-cell activation and decreased ratio of cells spontaneously producing IL-4 vs IFN-gamma in the joint fluid as compared to blood of arthritis patients.

Sphingomyelinase and phospholipase A2 regulate type I deiodinase expression in FRTL-5 cells

We have previously reported (Mol. Cell. Endocrinol. (1994) 101, R31-R35) that the proinflammatory cytokines, tumor necrosis factor-alpha (TNF), interleukin-1 beta (IL-1 beta), and interferon-gamma (IFN-gamma), have a marked inhibitory effect on the expression and activity of type I iodothyronine deiodinase (D1) in FRTL-5 rat thyroid cells, while the anti-inflammatory cytokine, transforming growth factor-beta 1 (TGF-beta 1) had no effect. These three proinflammatory cytokines utilize a number of intracellular second messenger systems including the pathways beginning with activation of sphingomyelinase and phospholipase A2. We have studied the time-dependent and dose-dependent effects of sphingomyelinase, ceramide, phospholipase A2 (PLA2), and arachidonic acid on the expression and activity of D1 in FRTL-5 cells. Sphingomyelinase (0.3 U/mL) inhibited D1 activity 55% and reduced D1 mRNA levels 70% to 90% by 8 hours. Similar treatment with 10 U/mL PLA2 inhibited D1 activity 54%. Treatment with 15 microM 5, 8, 11-eicosatriynoic acid (ETI), a nonmetabolizable analog of arachidonic acid, or 15 microM ceramide for 3 hours reduced D1 activity with a half-time of disappearance (t1/2) of 4.2 hours and 3.7 hours, respectively, but ETI and ceramide did not alter the D1 immunoreactivity or mRNA levels. Treatment for 8 hours with cycloheximide (5 or 10 micrograms/mL) had no effect on the D1 mRNA level, but blocked the TNF-induced reduction of this mRNA. We conclude that proinflammatory cytokines inhibit D1 expression and activity in FRTL-5 cells, in part, by activation of sphingomyelinase and PLA2 that results in (1) competitive inhibition of D1 activity by the enzymatic products ceramide and arachidonic acid and (2) reduction of D1 mRNA stability by protein synthesis-dependent mechanisms.

Growth inhibition of new human thyroid carcinoma cell lines by activation of adenylate cyclase through the beta-adrenergic receptor

In normal thyroid cells, the TSH-adenylate cyclase system plays a pivotal role in controlling growth and differentiation. However, the role of this system in the growth of thyroid carcinoma is not well understood. To investigate this subject, we have established four new human thyroid carcinoma cell lines, designated BHP 2-7, 7-13, 10-3, and 18-21, from different patients. Northern gel analysis revealed that all of these cell lines expressed Pax-8 messenger ribonucleic acid; additionally, only BHP 18-21 cells expressed TTF-1 messenger ribonucleic acid. These cells were treated with various concentrations of 8-bromo-cAMP, forskolin, TSH, and adrenergic receptor agonist (norepinephrine, epinephrine, and isoproterenol). Cell proliferation was assessed by [3H]thymidine incorporation and cell number. In these human thyroid carcinoma cell lines, the addition of 8-bromo-cAMP reduced [3H]thymidine incorporation at a concentration of 10 mumol/L. Forskolin (0.1-10 mumol/L) significantly induced cAMP accumulation, decreased [3H]thymidine incorporation, and reduced cell number in a dose-dependent manner. Conversely, TSH (0.01-1 mU/ mL) did not affect the accumulation of cAMP or cell growth. We found that adrenergic receptor agonists induced the accumulation of cAMP and inhibited cell growth. The rank of potency was isoproterenol > epinephrine > > norepinephrine. The binding studies of [3H]CGP-12177, a specific beta-adrenergic agonist, revealed that these new thyroid carcinoma cells had beta-adrenergic receptors. These results indicate that cAMP inhibits the growth of some human thyroid carcinoma cells, and that cAMP production is regulated through beta-adrenergic receptor-mediated pathways, but not through TSH receptor-mediated pathways.

A model for quality assessment in primary health care using the tracer condition technique with insulin treated diabetes as one of the tracers

OBJECTIVE

To find a method for quality assessment in primary health care and to apply this method on a defined disease.

DESIGN

General practitioners and hospital doctors worked out a programme for evaluating the quality of outpatient care of patients with insulin treated diabetes as one of five tracers. An expert committee comprising experienced general practitioners and hospital doctors compared two health centres with one outpatient medical department. Data were collected during a defined period combined with a one-year retrospective view, official statistics on medical care, and a questionnaire completed by the patients.

SETTING

Two primary health care centres and one outpatient medical department in southwestern Sweden.

PATIENTS

243 insulin treated diabetic patients attending the hospital and 87 insulin treated patients attending the health centres.

MAIN RESULTS

There were no difficulties for the expert panel to agree on which indicators were to be studied. The expert panel concluded that there was no difference between the quality of the two levels of care studied.

CONCLUSIONS

Medical audit was a useful method for evaluating medical quality. Co-operation between hospital doctors and general practitioners was of great value for evaluation of the quality of primary health care.

Tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta 1 (TGF-beta 1) inhibit the expression and activity of Na+/K(+)-ATPase in FRTL-5 rat thyroid cells

We recently reported that tumor necrosis factor-alpha (TNF-alpha) induction of the synthesis and secretion of transforming growth factor (TGF)-beta 1 by FRTL-5 cells is a thyroid-stimulating hormone (TSH)-dependent and age-dependent process. TNF-alpha is only cytotoxic to aged (> 40 passages) FRTL-5 cells grown in TSH-containing medium, whereas TGF-beta induces programmed cell death (apoptosis) in epithelial cells but not in FRTL-5 cells, which otherwise retain many properties of normal thyroid follicular cells. This cell line is, therefore, a convenient model for studies on the TSH-dependent and age-dependent inhibitory effects of these cytokines on epithelial cell growth, viability, and function. One prominent effect of TNF-alpha (and TGF-beta 1) on FRTL-5 cell function is suppression of iodide uptake, which is markedly stimulated by TSH. In aged FRTL-5 cells, iodide uptake is only about 10% that of young control cells. Na+/K(+)-ATPase activity, which drives iodide uptake by thyroid cells, is inhibited by TNF-alpha and TGF-beta. The following experiments quantitate the effects of TSH, aging, TNF-alpha, and TGF-beta 1 on the expression and activity of Na+/K(+)-ATPase activity in FRTL-5 cells. Young (< 20 passages) and aged (> 40 passages) FRTL-5 cells were treated with various doses (0-100 ng/ml) of recombinant human TNF-alpha or TGF-beta 1 for various times (0-3 days) with and without 2 U/liter TSH. These treatments reduced the rate-limiting Na+/K(+)-ATPase beta 1 mRNA level and Na+/K(+)-ATPase activity in parallel in a dose-dependent and time-dependent fashion. Aged FRTL-5 cells were more sensitive to the inhibitory effects of TNF-alpha, whereas young cells were more sensitive to the suppressive effects of TGF-beta 1 on the expression and activity of Na+/K(+)-ATPase. We conclude that inhibition of Na+/K(+)-ATPase activity by TNF-alpha and TGF-beta in FRTL-5 cells is differentially affected by aging and that this inhibitory effect can be dissociated from effects on cell viability.

Cross-national interrater reliability of dementia diagnosis in the elderly and factors associated with disagreement

Thirteen researchers from five centers in Australia, Germany, the Netherlands, United Kingdom, and United States applied DSM-III-R and Clinical Dementia Rating (CDR) syndrome-level dementia criteria to written vignettes of 100 elderly people identified in clinics or community surveys. Subjects ranged in type from cognitively intact to severely demented and many were also frail, partially sighted, or deaf. This paper concerns reliability within and between centers, and the relationship between reliability and factors such as diagnostic criteria, dementia severity, and respondents' clinical characteristics. Within-center interrater reliability was high, more so for "yes-no" DSM-III-R diagnoses than the multi-level CDR. Between-center rates were lower but still moderate to good. Concordance was lower for intermediate dementia levels than for no dementia and severe dementia. Physical disability made an additional contribution to uncertainty but deafness, poor vision, anxiety, and depression had no discernible effects. Reliability levels are likely to be lower in representative aged populations than in carefully selected clinical groups.

Induction of cytotoxic T-cell response by optimal-length peptides does not require CD4+ T-cell help

In several experimental models, synthetic peptides were shown to activate efficiently cytotoxic T-lymphocyte (CTL) responses and therefore represent an attractive strategy to develop new vaccines. However, the mechanisms by which they induce CTL responses are not yet fully understood. Several studies using 15 16-mer peptides previously demonstrated that CD4 helper T cells are required to induce optimal CTL responses with synthetic peptides. However, recently it was suggested that shorter 8 12-mer peptides could have an increased in vivo immunogenicity. In the present study, we therefore investigated if such optimal-length peptides still require CD4+ T-cell help to activate CTL responses. To address this question three synthetic peptides containing different viral CTL epitopes were injected into mice depleted of CD4+ or CD8+ T cells using specific monoclonal antibodies or into mice genetically deficient in those T-cell populations. Our results clearly established that activation of CTL responses by those short optimal peptides does not require CD4+ T-cell help and therefore suggested that high-density binding of peptides to major histocompatibility complex class I molecules on the surface of antigen-presenting cells is required for direct activation of CD8+ T cells, independently of CD4+ T-cell help.

Antitumor actions of cytokines on new human papillary thyroid carcinoma cell lines

To investigate the in vitro effects of cytokines on the growth of human papillary thyroid carcinoma (PTC) cells, we established six new PTC cell lines, designated BHP 5, 14, 15, 17, 18, and 19, from different patients. We studied the antiproliferative actions of cytokines by using BHP cells, NP cells (PTC cell line), and ARO cells (anaplastic thyroid carcinoma cell line). These cells were treated with various concentrations of tumor necrosis factor-alpha (TNF alpha), interferon-gamma (IFN gamma), interleukin-1 beta (IL-1 beta), and transforming growth factor-beta 1 (TGF beta 1), alone and in combination. Cell proliferation was assessed by [3H]thymidine incorporation and cell number measurement. In BHP cell lines, IFN gamma, IL-1 beta, and TGF beta 1 inhibited [3H]thymidine incorporation and decreased cell number, but TNF alpha stimulated [3H]thymidine incorporation. In NP cells, treatment with each cytokine decreased [3H]thymidine incorporation and cell number. In contrast, the proliferation of ARO cells was either stimulated by or resistant to TNF alpha, IL-1 beta, and TGF beta 1. The effects of these cytokines on [3H]thymidine incorporation were additive in these cell lines. The results suggest that IL-1 beta and TGF beta 1 play a pivotal role in growth inhibition of PTC cells, and the escape from negative control of IL-1 beta and TGF beta 1 may be a step toward anaplastic changes. The additive effects of these cytokines suggest that they act through different pathways.

Staging methods for the assessment of dementia: Perspectives

Most dementias in old age are characterized by a progressive course with interindividual variability in pattern and rate of progression. Developing a system for staging such dementia poses a challenge in capturing this variability in a system that will afford comparisons among individuals and predictions of future change. Several core questions underlie the development of such systems: (1) Is there a definable order in which abilities are lost? (2) Which skills and functions should be considered essential for the staging of dementia and what is their relative weight? (3) Can the different skills be captured within one staging system? (4) How is the whole range of function captured, and are the differences between stages clearly defined? (5) Which populations can be rated with each staging system? The determination of this last question is based on understanding which other medical conditions may interfere with the course of dementia and how prior characteristics, such as education, affect ratings on specific scales for the staging of dementia. Several systems for staging dementia in older adults are described. These include the Clinical Dementia Rating, the Global Deterioration Scale/Brief Cognitive Rating Scale/Functional Assessment Staging System, the Six Clinical Phases of Cognitive Decline, the Hierarchic Dementia Scale, and the Functional Capacity Scale. Some aspects of the utility of these systems are reviewed, and the issues for further research are discussed.

Immunization with glycosylated Kb-binding peptides generates carbohydrate-specific, unrestricted cytotoxic T cells

Cytotoxic T cells (CTL) recognize target proteins as short peptides presented by major histocompatibility complex (MHC) class I restriction elements. However, there is also evidence for peptide-independent T cell receptor (TCR) recognition of target proteins and non-protein structures. How such T cell responses are generated is presently unclear. We generated carbohydrate (CHO)-specific, MHC-unrestricted CTL responses by coupling di- and trisaccharides to Kb- or Db-binding peptides for direct immunization in mice. Four peptides and three CHO have been analyzed with the CHO either in terminal or central position on the carrier peptide. With two of these glycopeptides, with galabiose (Gal alpha 1-4Gal; Gal2) bound to a homocysteine (via an ethylene spacer arm) in position 4 or 6 in a vesicular stomatitis virus nucleoprotein-derived peptide (RGYVYQGL binding to Kb), CTL were generated which preferentially killed target cells treated with glycopeptide compared to those treated with the core peptide. Polyclonal CTL were also found to kill target cells expressing the same Gal2 epitope in a glycolipid. By fractionation of CTL, preliminary data indicate that glycopeptide-specific Kb-restricted CTL and unrestricted CHO-specific CTL belong to different T cell populations with regard to TCR expression. The results demonstrate that hapten-specific unrestricted CTL responses can be generated with MHC class I-binding carrier peptides. Different models that might explain the generation of such responses are discussed.