Cost-effectiveness of early intervention in psychosis in low- and middle-income countries: economic evaluation from São Paulo, Brazil

AIMS

The effectiveness and cost-effectiveness of early intervention for psychosis (EIP) services are well established in high-income countries but not in low- and middle-income countries (LMICs). Despite the scarcity of local evidence, several EIP services have been implemented in LMICs. Local evaluations are warranted before adopting speciality models of care in LMICs. We aimed to estimate the cost-effectiveness of implementing EIP services in Brazil.

METHODS

A model-based economic evaluation of EIP services was conducted from the Brazilian healthcare system perspective. A Markov model was developed using a cohort study conducted in São Paulo. Cost data were retrieved from local sources. The outcome of interest was the incremental cost-effectiveness ratio (ICER) measured as the incremental costs over the incremental quality-adjusted life-years (QALYs). Sensitivity analyses were performed to test the robustness of the results.

RESULTS

The study included 357 participants (38% female), with a mean (SD) age of 26 (7.38) years. According to the model, implementing EIP services in Brazil would result in a mean incremental cost of 4,478 Brazilian reals (R$) and a mean incremental benefit of 0.29 QALYs. The resulting ICER of R$ 15,495 (US dollar [USD] 7,640 adjusted for purchase power parity [PPP]) per QALY can be considered cost-effective at a willingness-to-pay threshold of 1 Gross domestic product (GDP) per capita (R$ 18,254; USD 9,000 PPP adjusted). The model results were robust to sensitivity analyses.

CONCLUSIONS

This study supports the economic advantages of implementing EIP services in Brazil. Although cultural adaptations are required, these data suggest EIP services might be cost-effective even in less-resourced countries.

A cost effectiveness study into the detection of functionally significant coronary artery disease in patients with chronic coronary syndrome: a decision-analytic modelling approach

Background

ESC guidelines recommend functional or anatomical imaging for stable coronary artery disease (CAD) diagnosis. We investigated cost-effective diagnostic strategies for CAD detection with invasive coronary angiography (ICA) and fractional flow reserve (FFR) as reference standard [1,2], using NHS reference costs.

Methods

Deterministic and probabilistic decision-analytic models for diagnostic strategies in low (25%), intermediate (50%) and high (75%) risk CAD were devised. Strategies: standalone or combined testing with computed tomographic coronary angiography (CTCA), stress echocardiography (SE), CT-FFR, single-photon emission computed tomography (SPECT), cardiac magnetic resonance (CMR), positron emission tomography (PET), ICA, and ICA-FFR. Proportion of correct diagnosis served as measure of clinical effectiveness. Incremental cost-effectiveness ratios were calculated for dominant strategies. Cost-effectiveness acceptability curves (CEAC) tested variation of cost-effectiveness threshold (CET).

Results

Base case (Table 1) consistent with probabilistic analysis (Figure 1 left). CEACs (Figure 1 right).

Conclusions

Direct ICA is not cost-effective. Functional testing has significant role in low/intermediate risk. CMR is cost-effective in all risk and most likely cost-effective in CETs <£10,000. ICA-FFR yields highest correct diagnoses in all at highest cost. Future long-term follow-up studies with quality of life measures are needed.

References

1. Knuuti et al EHJ. 2018; 39(35):3322–30

2. Danad et al. EHJ. 2016; 38(13):991–8.

Figure 1. A: low, B: intermediate, C: high.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): The authors acknowledge financial support from the Department of Health through the National Institute for Health Research (NIHR) comprehensive Biomedical Research Centre award to Guy's & St Thomas' NHS Foundation Trust in partnership with King's College London and King's College Hospital NHS Foundation Trust and by the NIHR MedTech Co-operative for Cardiovascular Disease at Guy's and St Thomas' NHS Foundation Trust. This abstract presents independent research funded by the National Institute for Health Research (NIHR) under its Research for Patient Benefit (RfPB) Programme (Grant Reference Number PB-PG-0416-20008). This work was supported by the Wellcome/EPSRC Centre for Medical Engineering [WT 203148/Z/16/Z]. MSN was funded by the UK Medical Research Council under grant number MR/P01979X/1. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care, EPSRC, MRC or the Wellcome Trust.

Cost-Effectiveness Analysis of Stereotactic Ablative Body Radiation Therapy Compared With Surgery and Radiofrequency Ablation in Two Patient Cohorts: Metastatic Liver Cancer and Hepatocellular Carcinoma

AIMS

To compare the cost-effectiveness of stereotactic ablative body radiation therapy (SABR) with radiofrequency ablation and surgery in adult patients with metastatic liver cancer and hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Two patient cohorts were assessed: liver oligometastases and HCC. For each patient cohort, a decision analytic model was constructed to assess the cost-effectiveness of interventions over a 5-year horizon. A Markov process was embedded in the decision model to simulate the possible prognosis of cancer. Data on transition probabilities, survival, side-effects, quality of life and costs were obtained from published sources and the SABR Commissioning through Evaluation (CtE) scheme. The primary outcome was the incremental cost-effectiveness ratio with respect to quality-adjusted life-years. The robustness of the results was examined in a sensitivity analysis. Analyses were conducted from a National Health Service and Personal Social Services perspective.

RESULTS

In the base case analysis, which assumed that all three interventions were associated with the same cancer progression rates and mortality rates, SABR was the most cost-effective intervention for both patient cohorts. This conclusion was sensitive to the cancer progression rate, mortality rate and cost of interventions. Assuming a willingness-to-pay threshold of £20 000 per quality-adjusted life-year, the probability that SABR is cost-effective was 57% and 50% in liver oligometastases and HCC, respectively.

CONCLUSIONS

Our results indicate a potential for SABR to be cost-effective for patients with liver oligometastases and HCC. This finding supports further investigation in clinical trials directly comparing SABR with surgery and radiofrequency ablation.

Addressing low consumption of fruit and vegetables in England: a cost-effectiveness analysis

Background

Most adults do not meet the recommended intake of five portions per day of fruit and vegetables (F&V) in England, but economic analyses of structural policies to change diet are sparse. This study aimed to estimate (1) the health and economic burden attributable to the low intake of fruit and vegetables (F&V) by English adults, and (2) the cost-effectiveness of three policies promoting consumption of F&V in England - a universal 10% subsidy, a targeted 30% subsidy for low-income households, and a nationwide social marketing campaign (SMC).

Methods

Using published data from official statistics and meta-epidemiological studies, we estimated the deaths, years-of-life lost (YLL), and the healthcare costs attributable to consumption of F&V below the recommended five portions per day by English adults. Then, we estimated the cost-effectiveness from governmental and societal perspectives of three policies.

Results

Low consumption of F&V accounted for 16,321 [10,091-23,516] deaths and 238,767 [170,350-311,651] YLL due to cardiovascular diseases, type 2 diabetes and cancer in England in 2017, alongside £705,951 [398,761-1,061,559] million in healthcare costs. From a societal perspective, the incremental cost-effectiveness ratios were £22,891 [22,300-25,079], £16,860 [15,589-19,763], and £25,683 [25,237-28,671] per life-year saved for the universal subsidy, targeted subsidy and SMC, respectively. At a threshold of £20,000 per life-year saved, the likelihood that the universal subsidy, the targeted subsidy and the SMC were cost-effective was 84%, 19% and 5%, respectively. The targeted subsidy was the only policy that would also reduce inequalities.

Conclusions

Both a SMC and subsidies can significantly increase consumption of F&V and reduce the attributable burden of disease and healthcare costs, but their cost-effectiveness varies substantially. A targeted subsidy to low-income households is most likely cost-effective and can additionally reduce inequalities.

Key messages

Low intake of fruit and vegetables accounts for a substantial number of deaths and years of life lost and represents a heavy burden for the healthcare system in England. From a societal perspective, a targeted subsidy to low-income households was most likely cost-effective and it would reduce inequalities.

The impact of an epilepsy nurse competency framework on the costs of supporting adults with epilepsy and intellectual disability: findings from the EpAID study

BACKGROUND

The development of a nurse-led approach to managing epilepsy in adults with an intellectual disability (ID) offers the potential of improved outcomes and lower costs of care. We undertook a cluster randomised trial to assess the impact on costs and outcomes of the provision of ID nurses working to a designated epilepsy nurse competency framework. Here, we report the impact of the intervention on costs.

METHOD

Across the United Kingdom, eight sites randomly allocated to the intervention recruited 184 participants and nine sites allocated to treatment as usual recruited 128 participants. Cost and outcome data were collected mainly by telephone interview at baseline and after 6 months. Total costs at 6 months were compared from the perspective of health and social services and society, with adjustments for pre-specified participant and cluster characteristics at baseline including costs. Missing data were imputed using multiple imputation. Uncertainty was quantified by bootstrapping.

RESULTS

The intervention was associated with lower per participant costs from a health and social services perspective of -£357 (2014/2015 GBP) (95% confidence interval -£986, £294) and from a societal perspective of -£631 (95% confidence interval -£1473, £181). Results were not sensitive to the exclusion of accommodation costs.

CONCLUSIONS

Our findings suggest that the competency framework is unlikely to increase the cost of caring for people with epilepsy and ID and may reduce costs.

Cost-effectiveness of alternative changes to a national blood collection service

Objectives

To evaluate the cost‐effectiveness of changing opening times, introducing a donor health report and reducing the minimum inter‐donation interval for donors attending static centres.

Background

Evidence is required about the effect of changes to the blood collection service on costs and the frequency of donation.

Methods/Materials

This study estimated the effect of changes to the blood collection service in England on the annual number of whole‐blood donations by current donors. We used donors' responses to a stated preference survey, donor registry data on donation frequency and deferral rates from the INTERVAL trial. Costs measured were those anticipated to differ between strategies. We reported the cost per additional unit of blood collected for each strategy versus current practice. Strategies with a cost per additional unit of whole blood less than £30 (an estimate of the current cost of collection) were judged likely to be cost‐effective.

Results

In static donor centres, extending opening times to evenings and weekends provided an additional unit of whole blood at a cost of £23 and £29, respectively. Introducing a health report cost £130 per additional unit of blood collected. Although the strategy of reducing the minimum inter‐donation interval had the lowest cost per additional unit of blood collected (£10), this increased the rate of deferrals due to low haemoglobin (Hb).

Conclusion

The introduction of a donor health report is unlikely to provide a sufficient increase in donation frequency to justify the additional costs. A more cost‐effective change is to extend opening hours for blood collection at static centres.

The involvement of parents in healthcare decisions where adult children are at risk of lacking decision-making capacity: a qualitative study of treatment decisions in epilepsy

BACKGROUND

Patients with intellectual disabilities (ID) receive health care by proxy. It is family members and/or paid support staff who must recognise health problems, communicate with clinicians, and report the benefits, if any, of a particular treatment. At the same time international and national statutes protect and promote the right of people with disabilities to access the highest attainable standards of health on the basis of free and informed consent.

METHODS

To consider the role of parent-proxies in the management of epilepsy in adult children with ID who are at risk of lacking capacity to make decisions about their health care we interviewed 21 mothers.

FINDINGS

These mothers are not pursuing changes in treatment that might improve their son or daughter's epilepsy, nor are they willing to countenance changes in treatment. Clinicians concerned to build and sustain therapeutic alliances with these mothers, our evidence suggests, may well avoid going against their wishes.

DISCUSSION

Our research highlights the interactional contingencies of a hitherto neglected three-way clinical relationship comprising parent-proxy, an adult at risk of lacking decision-making capacity, and a treating clinician. This is a relationship, our findings suggest, where little importance is attached to either patient consent, or involvement in treatment decisions.

An evidence synthesis of qualitative and quantitative research on component intervention techniques, effectiveness, cost-effectiveness, equity and acceptability of different versions of health-related lifestyle advisor role in improving health

BACKGROUND

There is a need to identify and analyse the range of models developed to date for delivering health-related lifestyle advice (HRLA), or training, for effectiveness and cost-effectiveness in improving the health and well-being of individuals and communities in the UK, with particular reference to the reduction of inequalities.

OBJECTIVES

To identify the component intervention techniques of lifestyle advisors (LAs) in the UK and similar contexts, and the outcomes of HRLA interventions.

DATA SOURCES

Stakeholder views, secondary analysis of the National Survey of Health Trainer Activity, telephone survey of health trainer leads/coordinators. A search of a range of electronic databases was undertaken [including the Applied Social Sciences Index and Abstracts (ASSIA), EMBASE, NHS Economic Evaluation Database (NHS EED), MEDLINE, Psyc INFO, etc.], as well searching relevant journals and reference lists, conducted from inception to September 2008.

REVIEW METHODS

Identified studies were scanned by two reviewers and those meeting the following criteria were included: studies carrying out an evaluation of HRLA; those taking place in developed countries similar to the UK context; those looking at adult groups; interventions with the explicit aim of health improvement; interventions that involved paid or voluntary work with an individual or group of peers acting in an advisory role; advice delivered by post, online or electronically; training, support or counselling delivered to patients, communities or members of the public. After quality assessment, studies were selected for inclusion in the review. Data were abstracted from each study according to an agreed procedure and narrative, and realist and economic approaches were used to synthesise the data. Cost-effectiveness analysis of interventions was undertaken.

RESULTS

In total, 269 studies were identified but 243 were excluded. The 26 included studies addressing chronic care, mental health, breastfeeding, smoking, diet and physical activity, screening and human immunodeficiency virus (HIV) infection prevention. Overall, there was insufficient evidence to either support or refute the use of LAs to promote health and improve quality of life (QoL), and thus uncertainty about the interventions' cost-effectiveness. However, the economic analysis showed that LA interventions were cost-effective in chronic care and smoking cessation, inconclusive for breastfeeding and mental health and not cost-effective for screening uptake and diet/physical activity. LA interventions for HIV prevention were cost-effective, but not in a UK context.

LIMITATIONS

The wide variety of LA models, delivery settings and target populations prevented the reviewers from establishing firm causal relationships between intervention mode and study outcomes.

CONCLUSIONS

Evidence was variable, giving only limited support to LAs having a positive impact on health knowledge, behaviours and outcomes. Levels of acceptability appeared to be high. LAs acted as translational agents, sometimes removing barriers to prescribed behaviour or helping to create facilitative social environments. Reporting of processes of accessing or capitalising on indigenous knowledge was limited. Ambiguity was apparent with respect to the role and impact of lay and peer characteristics of the interventions. A future programme of research on HRLA could benefit from further emphasis on identification of needs, the broadening of population focus and intervention aims, the measurement of outcomes and the reviewing of evidence.

FUNDING

This study was funded by the Health Technology Assessment programme of the National Institute for Health Research.

Rehabilitation of older patients: day hospital compared with rehabilitation at home. A randomised controlled trial

OBJECTIVES

To test the hypotheses that older people and their informal carers are not disadvantaged by home-based rehabilitation (HBR) relative to day hospital rehabilitation (DHR) and that HBR is less costly.

DESIGN

Two-arm randomised controlled trial.

SETTING

Four trusts in England providing both HBR and DHR.

PARTICIPANTS

Clinical staff reviewed consecutive referrals to identify subjects who were potentially suitable for randomisation according to the defined inclusion criteria.

INTERVENTIONS

Patients were randomised to receive either HBR or DHR.

MAIN OUTCOME MEASURES

The primary outcome measure was the Nottingham Extended Activities of Daily Living (NEADL) scale. Secondary outcome measures included the EuroQol 5 dimensions (EQ-5D), Hospital Anxiety and Depression Scale (HADS), Therapy Outcome Measures (TOMs), hospital admissions and the General Health Questionnaire (GHQ-30) for carers.

RESULTS

Overall, 89 subjects were randomised and 42 received rehabilitation in each arm of the trial. At the primary end point of 6 months there were 32 and 33 patients in the HBR and DHR arms respectively. Estimated mean scores on the NEADL scale at 6 months, after adjustment for baseline, were not significantly in favour of either HBR or DHR [DHR 30.78 (SD 15.01), HBR 32.11 (SD 16.89), p = 0.37; mean difference -2.139 (95% CI -6.870 to 2.592)]. Analysis of the non-inferiority of HBR over DHR using a 'non-inferiority' limit (10%) applied to the confidence interval estimates for the different outcome measures at 6 months' follow-up demonstrated non-inferiority for the NEADL scale, EQ-5D and HADS anxiety scale and some advantage for HBR on the HADS depression scale, of borderline statistical significance. Similar results were seen at 3 and 12 months' follow-up, with a statistically significant difference in the mean EQ-5D(index) score in favour of DHR at 3 months (p = 0.047). At the end of rehabilitation, a greater proportion of the DHR group showed a positive direction of change from their initial assessment with respect to therapist-rated clinical outcomes; however, a lower proportion of HBR patients showed a negative direction of change and, overall, median scores on the TOMs scales did not differ between the two groups. Fewer patients in the HBR group were admitted to hospital on any occasion over the 12-month observation period [18 (43%) versus 22 (52%)]; however, this difference was not statistically significant. The psychological well-being of patients' carers, measured at 3, 6 and 12 months, was unaffected by whether rehabilitation took place at day hospital or at home. As the primary outcome measure and EQ-5D(index) scores at 6 months showed no significant differences between the two arms of the trial, a cost-minimisation analysis was undertaken. Neither the public costs nor the total costs at the 6-month follow-up point (an average of 213 days' total follow-up) or the 12-month follow-up point (an average of 395 days' total follow-up) were significantly different between the groups.

CONCLUSIONS

Compared with DHR, providing rehabilitation in patients' own homes confers no particular disadvantage for patients and carers. The cost of providing HBR does not appear to be significantly different from that of providing DHR. Rehabilitation providers and purchasers need to consider the place of care in the light of local needs, to provide the benefits of both kinds of services. Caution is required when interpreting the results of the RCT because a large proportion of potentially eligible subjects were not recruited to the trial, the required sample size was not achieved and there was a relatively large loss to follow-up.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN71801032.

Cholesterol embolization syndrome: cutaneous histopathological features and the variable onset of symptoms in patients with different risk factors

Cholesterol embolization syndrome (CES) may not only be due to direct dislodgement of cholesterol crystals from atherosclerotic plaques on the walls of arteries by surgery, angiogram or trauma, but may occur after anticoagulant and thrombolytic therapy. The latter two therapies both weaken the fibrin clot that stabilizes the atheromas in place; however, these two therapies commonly have different onsets of CES after their institution. We present three patients with different risk factors for CES who all presented with the pathognomonic triad of leg and/or foot pain, livedo reticularis and good peripheral pulses. In all three patients cholesterol emboli were demonstrated in cutaneous biopsy sections. In two patients there was associated renal involvement, which was fatal in one case. These cases illustrate that cutaneous biopsy may be diagnostic in patients with livedo reticularis, which progresses to necrosis and gangrene. In addition, they illustrate the problems and contradictions involved in treating patients with CES.

Selective blockade of T lymphocyte K(+) channels ameliorates experimental autoimmune encephalomyelitis, a model for multiple sclerosis

Adoptive transfer experimental autoimmune encephalomyelitis (AT-EAE), a disease resembling multiple sclerosis, is induced in rats by myelin basic protein (MBP)-activated CD4(+) T lymphocytes. By patch-clamp analysis, encephalitogenic rat T cells stimulated repeatedly in vitro expressed a unique channel phenotype ("chronically activated") with large numbers of Kv1.3 voltage-gated channels (approximately 1500 per cell) and small numbers of IKCa1 Ca(2+)-activated K(+) channels (approximately 50-120 per cell). In contrast, resting T cells displayed 0-10 Kv1.3 and 10-20 IKCa1 channels per cell ("quiescent" phenotype), whereas T cells stimulated once or twice expressed approximately 200 Kv1.3 and approximately 350 IKCa1 channels per cell ("acutely activated" phenotype). Consistent with their channel phenotype, [(3)H]thymidine incorporation by MBP-stimulated chronically activated T cells was suppressed by the peptide ShK, a blocker of Kv1.3 and IKCa1, and by an analog (ShK-Dap(22)) engineered to be highly specific for Kv1.3, but not by a selective IKCa1 blocker (TRAM-34). The combination of ShK-Dap(22) and TRAM-34 enhanced the suppression of MBP-stimulated T cell proliferation. Based on these in vitro results, we assessed the efficacy of K(+) channel blockers in AT-EAE. Specific and simultaneous blockade of the T cell channels by ShK or by a combination of ShK-Dap(22) plus TRAM-34 prevented lethal AT-EAE. Blockade of Kv1.3 alone with ShK-Dap(22), but not of IKCa1 with TRAM-34, was also effective. When administered after the onset of symptoms, ShK or the combination of ShK-Dap(22) plus TRAM-34 greatly ameliorated the clinical course of both moderate and severe AT-EAE. We conclude that selective targeting of Kv1.3, alone or with IKCa1, may provide an effective new mode of therapy for multiple sclerosis.

Heat-inducible vectors for use in gene therapy

The objectives of this study were to quantity and compare the activities of a minimal heat shock (HS) promoter and other promoters used in gene therapy applications, and to identify strategies to amplify the heat inducibility of therapeutic genes. Human tumour cells were transiently or stably transfected with the HS promoter driving expression of reporter genes. HS promoter activity was induced transiently, with maximum activity 16-24 h after HS, and was dependent on temperature. The activity of the minimal HS promoter was similar, after 42 degrees C HS for 1 h, to that of the cytomegalovirus (CMV) promoter. To determine if the HS promoter could be used to activate a second conditional promoter, cells were transiently transfected with vectors containing both the HS and human immunodeficiency virus type 1 (HIV1) promoters. When the IL-2 gene was placed downstream of the HIV1 promoter. IL-2 production was temperature-independent. The addition of the HIV tat gene downstream of the HS promoter caused IL-2 to be induced more than 3 fold after a single 42 degrees C HS. These data indicate that the minimal HS promoter, following activation by clinically attainable temperatures (< or = 42 degrees C), can drive expression of therapeutic genes at levels comparable to the CMV promoter and be used in conjunction with a second conditional promoter to drive temperature-dependent, gene expression.

Structural conservation of the pores of calcium-activated and voltage-gated potassium channels determined by a sea anemone toxin

The structurally defined sea anemone peptide toxins ShK and BgK potently block the intermediate conductance, Ca(2+)-activated potassium channel IKCa1, a well recognized therapeutic target present in erythrocytes, human T-lymphocytes, and the colon. The well characterized voltage-gated Kv1.3 channel in human T-lymphocytes is also blocked by both peptides, although ShK has a approximately 1,000-fold greater affinity for Kv1.3 than IKCa1. To gain insight into the architecture of the toxin receptor in IKCa1, we used alanine-scanning in combination with mutant cycle analyses to map the ShK-IKCa1 interface, and compared it with the ShK-Kv1.3 interaction surface. ShK uses the same five core residues, all clustered around the critical Lys(22), to interact with IKCa1 and Kv1.3, although it relies on a larger number of contacts to stabilize its weaker interactions with IKCa1 than with Kv1.3. The toxin binds to IKCa1 in a region corresponding to the external vestibule of Kv1.3, and the turret and outer pore of the structurally defined bacterial potassium channel, KcsA. Based on the NMR structure of ShK, we deduce the toxin receptor in IKCa1 to have x-y dimensions of approximately 22 A, a diameter of approximately 31 A, and a depth of approximately 8 A; we estimate that the ion selectivity lies approximately 13 A below the outer lip of the toxin receptor. These dimensions are in good agreement with those of the KcsA channel determined from its crystal structure, and the inferred structure of Kv1.3 based on mapping with scorpion toxins. Thus, these distantly related channels exhibit architectural similarities in the outer pore region. This information could facilitate development of specific and potent modulators of the therapeutically important IKCa1 channel.

Sensation Seeking Scales and consumer satisfaction with a substance abuse treatment program

Satisfaction of 119 addicts with an addiction treatment program was measured by an 11 item satisfaction scale. The scale's internal consistency was acceptable (Cronbach's alpha = .75). The total satisfaction score was weakly but significantly correlated with Zuckerman's Sensation Seeking scales: Those with higher scores on the Boredom Susceptibility scale (i.e., those easily bored) reported less satisfaction, whereas those with higher scores on Thrill and Adventure Seeking scale (i.e., risk, adventure, and thrill seekers) reported higher levels of treatment satisfaction. Older patients were more satisfied with the feedback they received from their psychological tests and also with staff's respect for their rights.

Tumor angiogenesis as a prognostic factor in laryngeal cancer

BACKGROUND

Lymph node metastasis is the single greatest predictor of recurrence in laryngeal cancer. Prognostic factors are needed to target patients who may benefit from adjuvant therapy. Tumor angiogenesis correlates with metastasis in breast, bladder, and oral cavity cancer and may have prognostic value in other tumors.

METHODS

In order to examine the relationship of tumor angiogenesis to recurrence, 51 patients with squamous cell carcinoma of the larynx were reviewed. In a blinded design, previously sectioned slides were chosen for advanced tumor and highest vessel concentration. Samples were cut and immunocytochemically stained for CD-31 (an endothelial marker). A computer image analyzer quantitated the percent area of staining. Variables were statistically examined against recurrence.

RESULTS

Patients were stratified by percent tumor staining. Nodal involvement was seen in 9 (36%) patients with tumor staining < or = 20% and in 20 (77%) with tumor staining > 20% (P = 0.003). Patients with < or = 20% staining and without metastasis had a 13% rate of recurrence whereas patients with > 20% staining and without metastasis had a 67% rate of recurrence (P = 0.025).

CONCLUSIONS

Though nodal status was suggestive of predictability, only angiogenesis is a statistically significant predictor of recurrence in node negative patients (P = 0.025). Angiogenesis shows strong correlation with regional recurrence and may be used as an independent prognostic indicator to determine clinically node negative patients who may be at higher risk for metastasis and require adjuvant therapy.

Antisocial personality traits and patients' satisfaction with treatment for addiction

The over-all satisfaction with treatment for addiction (sum of scores on 11 items of a questionnaire) by 50 addicts and their self-reported confidence in remaining abstinent were unrelated to scores on MMPI-2 scales (all classical clinical and validity scales, 15 content scales and 7 research scales) except to reports of shyness on the Social Discomfort Scale: patients characterizing themselves as shy gave the higher ratings of satisfaction with treatment (r = .33). We note that our previous finding using the MMPI-2, i.e., that less.socially responsible and more rebellious patients provided lower satisfaction ratings, was not replicated for this sample of addicts.

Polyamine-like actions of peptides derived from conantokin-G, an N-methyl-D-aspartate (NMDA) antagonist

Conantokins-T and -G are highly conserved polypeptides derived from Conus venoms. The N-methyl-D-aspartate (NMDA) antagonist properties of these compounds have been attributed to a potent noncompetitive inhibition of polyamine responses. Substitution of the highly conserved gamma-carboxyglutamate residues as well as modification of the N and C termini of conantokin-G abolished the inhibition of polyamine responses at the NMDA receptor complex. However, several of these modified polypeptides closely mimicked the neurochemical profile of polyamines at the NMDA receptor complex. One of these derivatives, Tyr0-conantokin-G, was found to be the most potent compound exhibiting polyamine-like actions at the NMDA receptor complex described to date, approximately 7-fold more potent than spermine. Circular dichroism studies demonstrate a significant alpha-helical content in conantokin-G (27% in aqueous medium). However, this alpha-helicity is not sufficient for the NMDA antagonist action of the parent peptide and is neither necessary nor sufficient for the polyamine-like behavior of several conantokin-G analogs. The modified conantokin-G derivatives described in this report should be useful probes for examining the role of both polyamines and the polyamine recognition site in the operation of the NMDA receptor complex.

Noncompetitive inhibition of N-methyl-D-aspartate by conantokin-G: evidence for an allosteric interaction at polyamine sites

Conantokins T and G are polypeptide toxins present in snails of the genus Conus. These substances were recently reported to act as N-methyl-D-aspartate (NMDA) antagonists. In the present study, we examined the possible mechanisms producing this antagonism. Conantokin-G inhibited spermine- and spermidine-stimulated [3H]MK-801 binding to extensively washed rat forebrain membranes in a noncompetitive manner with IC50 values of approximately 507 and approximately 946 nM, respectively. In contrast, glutamate-enhanced [3H]MK-801 binding was unaffected by conantokin-G concentrations of less than or equal to 20 microM. At concentrations greater than or equal to 5 microM, conantokin-G effected a modest, noncompetitive inhibition of glycine-stimulated [3H]MK-801 binding and also produced a small enhancement of basal [3H]MK-801 binding. Conantokin-G reduced (IC50 approximately 1.08 microM) the NMDA-stimulated accumulation of cyclic GMP in cerebellar granule cell cultures to basal values, but did not affect kainate-mediated increases in cyclic GMP. These findings indicate that conantokin-G acts as a noncompetitive NMDA antagonist through an allosteric inhibition of polyamine responses. The neurochemical profile of this polypeptide is distinct from previously described noncompetitive NMDA antagonists.