On the correlation between outcome indicators and the structure and process indicators used to proxy them in public health care reporting

Hospital quality indicators provide valuable insights for quality improvement, empower patients to choose providers, and have become a cornerstone of value-based payment. As outcome indicators are cumbersome and expensive to measure, many health systems have relied on proxy indicators, such as structure and process indicators. In this paper, we assess the extent to which publicly reported structure and process indicators are correlated with outcome indicators, to determine if these provide useful signals to inform the public about the outcomes. Quality indicators for three conditions (breast and colorectal cancer, and hip replacement surgery) for Dutch hospitals (2011-2018) were collected. Structure and process indicators were compared to condition-specific outcome indicators and in-hospital mortality ratios in a between-hospital comparison (cross-sectional and between-effects models) and in within-hospital comparison (fixed-effects models). Systematic association could not be observed for any of the models. Both positive and negative signs were observed where negative associations were to be expected. Despite sufficient statistical power, the share of significant correlations was small [mean share: 13.2% (cross-sectional); 26.3% (between-effects); 13.2% (fixed-effects)]. These findings persisted in stratified analyses by type of hospital and in models using a multivariate approach. We conclude that, in the context of compulsory public reporting, structure and process indicators are not correlated with outcome indicators, neither in between-hospital comparisons nor in within-hospital comparisons. While structure and process indicators remain valuable for internal quality improvement, they are unsuitable as signals for informing the public about hospital differences in health outcomes.

FRI0096 CLINICAL BENEFITS REPORTED IN AMPLE TRIAL OBSERVED IN A REAL-WORLD (RW) COHORT OF US RHEUMATOID ARTHRITIS (RA) PATIENTS

Background:

Efficacy observed in controlled trials may not reflect RW effectiveness, given documented differences in patient populations and management.1

Objectives:

This study aimed to assess disease measures over time as measured in a trial setting (AMPLE) and in a separate RW observational setting, both among patients with RA treated with abatacept.

Methods:

The RW cohort comprised retrospective patient-level data abstracted by 31 community rheumatologists for adult RA patients treated with abatacept who had an anti-cyclic citrullinated peptide-2 titer ≥250 AU/mL. AMPLE was a phase III, randomized controlled trial of RA patients treated with abatacept that assessed disease measures over a 2-year follow-up. Data included demographics, treatments, labs, and disease measures (tender and swollen joint counts (TJC, SJC), C-reactive protein (CRP), American College of Rheumatology-20 (ACR20) and ACR50 at baseline and 3 and 6 months) and were summarized descriptively. Disease measures were evaluated across AMPLE and RW cohorts.

Results:

Of the 291 RW patients and 318 AMPLE patients, the majority were female (70%, 81%), white (72%, 81%), and RF-positive (91%, 76%), respectively (Table 1). The mean ages at abatacept initiation were 54.7 and 51.4 years old in RW and AMPLE, respectively. Concomitant corticosteroids (45%, 65%) and methotrexate (62%, 100%) were common in RW and AMPLE, respectively. All patients in AMPLE were biologic naïve, whereas 83% of RW patients had prior biologic use. AMPLE administered abatacept subcutaneously (SC), while 37% of RW patients received abatacept SC. Patients had median SJC and TJC of 6 and 8 in RW and 13 and 22 in AMPLE at abatacept initiation, respectively (Table 2). SJC (TJC) improved a median of 65% (60%) and 68% (66%) at 3 months and 75% (67%) and 76% (75%) at 6 months in RW and AMPLE, respectively (Fig 1). The majority of patients achieved ACR20 at 3 months (79% and 60%) and 6 months (88% and 66%) in RW and AMPLE, respectively, while 58% and 32% achieved ACR50 at 3 months and 67% and 45% at 6 months, respectively (Fig 2).

Table 1:

Patient Characteristics.

RW cohort(n=291)AMPLE cohort(n=318)Female (n, %)205 (70%)259 (81%)White (n, %)209 (72%)257 (81%Age at abatacept initiation, years (mean, SD)54.7 (14.8)51.4 (12.6)RF-positive* (n, %)249 (91%)240 (76%)Concomitant medications (n, %) Corticosteroids†132 (45%)207 (65%) Methotrexate179 (62%)318 (100%)Prior biologic use (n, %)241 (83%)0 (0%)Route of administration (n, %) Intravenous183 (63%)0 (0%) Subcutaneous108 (37%)318 (100%)

LEGEND: *among 274 with known RF status;†corticosteroids in AMPLE cohort at any time in the 2-year study period

Table 2.

Changes in Disease Activity.

RW cohort(n=291)AMPLE cohort(n=318)SJC (median) Baseline value613 3-month value24 6-month value13TJC (median) Baseline value822 3-month value37 6-month value25CRP, mg/dL (mean) Baseline value1.081.6 3-month value0.470.8 6-month value0.300.8ACR20 achieved (n, %) 3-month value194 (79%)191 (60%) 6-month value78 (88%)209 (66%)ACR50 achieved (n, %) 3-month value144 (58%)103 (32%) 6-month value60 (67%)144 (45%)

LEGEND: values soonest after 3 months and value between 6-9 months used for RW cohort; values at days 85 and 197 used for AMPLE cohort.

Conclusion:

Despite differences in patient characteristics, improvements in SJC and TJC, as well as high rates of ACR20 and ACR50, were observed in both trial setting and RW settings. These improvements in disease activity were observed at similar magnitudes in both settings, demonstrating that trial efficacy is achievable in RW clinical practice with abatacept treatment.

References:

[1]Kilcher G, Hummel N, Didden EM, et al. Rheumatoid arthritis patients treated in trial and real-world settings: comparison of randomized trials with registries.Rheumatology. 2018;57(2):354-369.

Disclosure of Interests:

Andrew Klink Employee of: I am employed by Cardinal Health., Xue Han Employee of: BMS, Francis Lobo Shareholder of: Bristol-Myers Squibb (US), Employee of: Bristol-Myers Squibb (US), Rick Szymialis Shareholder of: BMS, Employee of: BMS, Jenny Lam Shareholder of: A few shares in Gilead in IRA account, Grant/research support from: Currently, a BMS fellowship (not a full-time employee), Bruce Feinberg Employee of: I am employed by Cardinal Health.

Information and communication technology enabling partnership in person-centred diabetes management: building a theoretical framework from an inductive case study in The Netherlands

OBJECTIVES

The aim of this paper is to construct a theoretical framework for information and communication technology (ICT)-enabled partnership towards diabetes management.

DESIGN

We conducted an inductive case study and held interviews on the development and use of an artificial pancreas (AP) system for diabetes management.

SETTING

The study was carried out in the Netherlands with users of an AP system.

PARTICIPANTS

We interviewed six patients with type 1 diabetes, five healthcare professionals (two medical specialists and three diabetes nurses), and one policy advisor from the Ministry of Health, Welfare and Sport.

RESULTS

We built a new theoretical framework for ICT-enabled person-centred diabetes management, covering the central themes of self-managing the disease, shared analysing of (medical) data and experiencing the partnership. We found that ICT yielded new activities of data sharing and a new role for data professionals in the provision of care as well as contributed to carefree living thanks to the semiautomated management enabled by the device. Our data suggested that to enable the partnership through ICT, organisational adjustments need to be made such as the development of new ICT services and a viable financial model to support these services.

CONCLUSION

The management of diabetes through ICT requires an adjustment of the partnership between persons with the chronic condition and the healthcare professional(s) in such a way that the potential for self-managing the condition by analysing the newly available (medical) data (from the AP system) together leads to an experience of partnership between patients and healthcare professionals.

Cure for increasing health care costs: The Bernhoven case as driver of new standards of appropriate care

Containing costs is a major challenge in health care. Cost and quality are often seen as trade-offs, but high quality and low costs can go hand-in-hand as waste exists in unnecessary and unfounded care. In the Netherlands, two healthcare insurers and a hospital collaborate to improve quality of care and decrease healthcare costs. Their aim is to reduce unnecessary care by shifting the business model and culture from a focus on volume to a focus on quality. Key drivers to support this are taking time for integrated diagnosis ('first time right'), the right care at the right place and shared decision making between doctor and patient. Conditions to realize this are 1) contract innovation between the hospital and insurers to move away from fee-for-service reimbursement, 2) a culture change within the organization with emphasis on collaboration and empowerment of medical leadership and physicians to change daily practice, and 3) a reorganization of the hospital organization structure from a large number of medical departments to four business units related to the fundamental underlying patient need (acute care, solution shop, intervention unit and chronic care). Results from this whole-system-approach experiment show it is possible to provide better care (as experienced by patients) with lower volumes (16% lower DRG claims after 3 years) and provides valuable lessons for further healthcare reform.

ParkinsonNet: A Low-Cost Health Care Innovation With A Systems Approach From The Netherlands

ParkinsonNet, a low-cost innovation to optimize care for patients with Parkinson disease, was developed in 2004 as a network of physical therapists in several regions in the Netherlands. Since that time, the network has achieved full national reach, with 70 regional networks and around 3,000 specifically trained professionals from 12 disciplines. Key elements include the empowerment of professionals who are highly trained and specialized in Parkinson disease, the empowerment of patients by education and consultation, and the empowerment of integrated multidisciplinary teams to better address and manage the disease. Studies have found that the ParkinsonNet approach leads to outcomes that are at least as good as, if not better than, outcomes from usual care. One study found a 50 percent reduction in hip fractures and fewer inpatient admissions. Other studies suggest that ParkinsonNet leads to modest but important cost savings (at least US$439 per patient annually). These cost savings outweigh the costs of building and maintaining the network. Because of ParkinsonNet's success, the program has now spread to several other countries and serves as a model of a successful and scalable frugal innovation.

Maldistribution or scarcity of nurses? The devil is in the detail

AIMS

The goal of this paper was to improve our understanding of nursing shortages across the variety of health care sectors and how this may affect the agenda for addressing nursing shortages. A health care sector comprises a number of health care services for one particular type of patient care, for example, the hospital care sector.

BACKGROUND

Most Western countries are shifting health care services from hospital care towards community and home care, thus increasing nursing workforce challenges in home and community care. In order to implement appropriate policy responses to nursing workforce challenges, we need to know if these challenges are caused by maldistribution of nurses and/or the scarcity of nurses in general.

EVALUATION

Focusing on the Netherlands, we reviewed articles based on data of a labour market research programme and/or data from the Dutch Employed Persons' Insurance Administration Agency. The data were analysed using a data synthesis approach.

KEY ISSUES

Nursing shortages are unevenly distributed across the various health care sectors. Shortages of practical nurses are caused by maldistribution, with a long-term projected surplus of practical nurses in hospitals and projected shortages in nursing/convalescent homes and home care. Shortages of first-level registered nurses are caused by general scarcity in the long term, mainly in hospitals and home care.

CONCLUSIONS

Nursing workforce challenges are caused by a maldistribution of nurses and the scarcity of nurses in general. To implement appropriate policy responses to nursing workforce challenges, integrated health care workforce planning is necessary.

IMPLICATIONS FOR NURSING MANAGEMENT

Integrated workforce planning models could forecast the impact of health care transformation plans and guide national policy decisions on transitioning programmes. Effective transitioning programmes are required to address nursing shortages and to diminish maldistribution. In addition, increased recruitment and retention as well as new models of care are required to address the scarcity of nurses in general.

Information and Communication Technologies to Support Chronic Disease Self-Management: Preconditions for Enhancing the Partnership in Person-Centered Care

Objective

In order to alleviate the pressure on health care systems exerted by the growing prevalence of chronic diseases, information and communication technologies (ICT) are being introduced to enable self-management of chronic diseases by supporting partnerships between patients and health care professionals. This move towards chronic disease self-management is accompanied by a shift in focus on integrating the patient with his or her perceptions on the chronic disease as a full-fledged partner into the health care system. This new perspective has been described as “person-centered care” (PCC). To date, information and communication technologies only partially build on the principles of PCC. This paper examines the preconditions of ICT to enable a person-centered approach to chronic disease management.

Methods

Using cancer treatment as a case study for ICT-enabled PCC, we conducted a comparative analysis of thirteen scientific studies on interventions presented as ICT-enabled PCC for cancer treatment, to answer the research question: What are the preconditions of ICT-enabled PCC in chronic disease management? Based on the intended and actual outcomes, we distilled in several analytic steps the preconditions of ICT-enabled PCC for chronic disease self-management.

Results

We distinguished four user-related preconditions of ICT-enabled PCC: (shared) decision making, personalized ICT, health-related quality of life, and efficiency.

Conclusions

We argue that these four preconditions together can improve people’s self-management of chronic diseases by strengthening the partnership between the patient and the healthcare professional. Moreover, the study revealed a discrepancy between intended and reported actual outcomes in terms of realizing person-centered care.

The arduous quest for translating health care productivity gains into cost savings. Lessons from their evolution at economic scoring agencies in the Netherlands and the US

We analyze the assessments of recent health reforms by the Congressional Budget Office (CBO) in the United States and the Bureau for Economic Policy Analysis (CPB) in the Netherlands. Both reforms aim to capitalize on productivity gains, which is appealing for policymakers because of the potential for cost savings while maintaining - or enhancing - quality and access. These measures however generally translate into more health care, rather than care that is affordable and appropriate. Scoring agencies therefore have rightfully been reluctant to assign significant savings to these measures. Thus with regard to cost savings, both agencies instead have favored more traditional policy measures in the past. They are however increasingly mapping out loose ends and dilemmas for payers, including information asymmetries, reputation issues and provider business models that contradict the goals of policymakers. This calls for further exploring this avenue and the development of more integrated agendas that might commit actors and the spread of best practices.

[Hospitals as vital links]

The reform of the system in 2006 aimed at reducing waiting lists in an efficient manner. Performance-linked funding and regulated competition did indeed lead to improved efficiency. The other side of the coin is overtreatment, and expensive and not infrequently damaging growth in volume. In order to control costs, three strategies have been determined: agreements with an annual cap on volume; (b) collaboration of regional health-care providers with the mission of improving results in health care (with profit-sharing if costs fall); and (c) fusions reducing the number of hospitals which reduces the burden of injuries (supply no longer creates its own demand). This article comments on these strategies. The author argues for a fourth approach: if the quality of health care improves, the number of complications will fall, overtreatment will decline and the outcome will be a decrease in burden of injuries. This requires the health care insurers to modify the way they manage their contracts and methods of payment, and stimulates competition based on quality.

The role of the ACTH receptor in adrenal tumors: identification of a novel microsatellite marker

In vitro, the growth inhibiting effect of ACTH on adrenocortical cells is well documented, even though there are reports of opposite effects under defined cell culture conditions. In vivo, activation of the ACTH receptor (ACTHR) has a trophic effect on the adrenal cortex, while the effects on proliferation are still under discussion, especially since other POMC derived peptides have been characterized. However, ACTH is thought to act as a differentiation factor with inhibiting effects on tumor growth. In undifferentiated adrenocortical carcinomas, ACTHR expression is frequently lost, which is associated with extensive tumor growth. We describe a new microsatellite marker within the intron of the ACTHR gene termed ACTHRint1. In a series of 114 patients with various adrenal and non-adrenal tumors, the rate of heterozygosity was 100 %. Only one out of 57 patients with adrenocortical adenoma showed LOH at the ACTHR locus, whereas 4 of 10 carcinomas had loss of one allele. Patients suffering from tumors with LOH showed a more aggressive disease course and had earlier recurrences with poor prognosis. These data confirm earlier findings that adrenocortical carcinomas frequently show loss of ACTHR expression, which is associated with a more aggressive tumor growth. However, whether the ACTHR is directly involved in tumor growth or acts a marker of differentiation that is lost in more advanced tumor stages is still not clear.

Nationalism and patriotism: national identification and out-group rejection

It is argued that the differentiation between nationalism and patriotism proposed in the literature can be seen as analogous to judgments based on different types of comparisons: intergroup comparisons with other nations are associated with intergroup behaviour that corresponds to nationalism, whereas temporal or standard comparisons are linked with behaviour that corresponds to patriotism. Four studies (N = 103, 107, 96 and 105) conducted in Germany and Britain examined the hypothesis that national identification and in-group evaluation only show a reliable relationship with out-group rejection under an intergroup comparison orientation. Participants were primed with either an intergroup comparison, a temporal comparison or no explicit comparison orientation. A subsequent questionnaire assessed in-group (own country) identification, in-group evaluation (i.e. national pride) and rejection of national out-groups. Across all four studies, both in-group identification and in-group evaluation show a stronger correlation with out-group derogation if participants were primed with an intergroup comparison orientation compared to temporal and control conditions. Results are discussed with regard to nationalism and patriotism as well as Hinkle and Brown's (1990) model on relational vs. autonomous orientations.

ACTH-receptor expression, regulation and role in adrenocortial tumor formation

The regulation of the ACTH-receptor gene is unique in that it is up-regulated by its own ligand, ACTH. Ligand-induced up-regulation of ACTH-receptor expression may be an important adaptive process directed towards optimizing adrenal responsiveness to ACTH in the context of physiological stress and the maintenance of metabolic homeostasis in which the adrenals play a pivotal role. Whereas enhancement by ligand-induced up-regulation permits a more efficient and rapid glucocorticoid response, negative feedback regulation of glucocorticoids in the hypothalamus and pituitary inhibits ACTH secretion and allows a balanced adrenal response to stress. Since the cloning of the promoter region of the ACTH receptor, considerable progress in the understanding of the regulatory processes has been made. The effects of ACTH on ACTH-receptor expression is dependent on cAMP, probably mediated through AP-1. The profound effect of three SF-1-binding sites in the ACTH-receptor promoter was demonstrated by deletion experiments. Conversely, ACTH-receptor expression can be suppressed by adrenal-specific transcription factors,like DAX-1. Despite an extensive search, no activating ACTH-receptor mutations have been found in adrenal tumors,excluding the ACTH receptor as a relevant oncogene in adrenal tumorigenesis. However, the ACTH receptor may act as a differentiation factor as suggested by LOH in adrenal carcinomas with an undifferentiated tumor type. In benign adrenal tumors, a strong correlation between ACTH-receptor expression and expression of P450 steroidogenic enzymes is evident. This close regulative relationship is lost in adrenal carcinoma, probably as a result of tumor dedifferentiation. Down-regulation of ACTH-receptor expression in normal and neoplastic tissue can be achieved by adrenostatic compounds such as aminoglutethimide and metyrapone.

New mechanisms of adrenostatic compounds in a human adrenocortical cancer cell line

BACKGROUND

Adrenostatic compounds are frequently used in the treatment of patients with Cushing's syndrome and act via direct inhibition of steroidogenic enzymes. However, additional mechanisms may be involved in the blockade of adrenal steroid secretion. We therefore investigated the effects of aminoglutethimide (AG), metyrapone (MTP) and etomidate (ETO) in the human NCI-h295 adrenocortical carcinoma cell line.

MATERIALS AND METHODS

Cells were incubated with increasing doses of the adrenostatic compounds. Steroid hormone secretion (cortisol, 17-OH-progesterone, DHEA-S) and cAMP synthesis were determined and Northern blot analysis and cell proliferation experiments were performed.

RESULTS

ETO was the most potent adrenostatic compound inhibiting P450c11 hydroxylase at low concentrations (IC50 15 nM), and also blocking P450 side-chain cleavage (scc) enzyme (IC50 400 nM) at higher concentrations. The pattern of enzyme inhibition was similar for MTP with an IC50 of 3-5 microM for P450c11 and 17 microM for P450scc, while AG blocked P450scc with an IC50 of 10 microM. AG significantly suppressed the baseline ACTH-R mRNA expression in a dose-dependent fashion (300 microM AG: 5% +/- 1%; 30 microM AG: 64% +/- 1%; 3 microM AG: 108% +/- 19% compared with control cells: 100% +/- 11%) but increased glucocorticoid receptor mRNA. The reduced ACTH-R mRNA was paralleled by low ACTH-induced cAMP accumulation indicating reduced expression of ACTH-R protein. The simultaneous incubation of hydrocortisone together with AG reversed the inhibitory effect of AG on the ACTH-R expression. AG and ETO inhibited cell proliferation in the NCI-h295 cells, but ETO was much more potent and showed antiproliferative effects at concentrations of 6 microM. The growth inhibition was not reversed by administration of hydrocortisone.

CONCLUSIONS

Our data demonstrate that adrenostatic compounds not only act by suppression of steroidogenic enzymes but can also influence both ACTH-R expression and cell proliferation in adrenal cells. As these effects occur in vitro at concentrations that are reached during treatment with these drugs in patients, they are probably also of clinical relevance. Particularly the antiproliferative activity of ETO may be useful in Cushing's syndrome due to adrenocortical cancer. The interaction of steroidogenesis, ACTH-R and glucocorticoid receptor expression as well as cell proliferation provides a new concept of the intra-adrenal response to stress in humans.

CT-guided transthoracic needle biopsy using an ipsilateral dependent position

OBJECTIVE

We postulated that the pneumothorax rate of transthoracic needle biopsy might improve with an ipsilateral dependent position of the affected side. We tried to determine the feasibility, effectiveness, and safety of CT-guided biopsy with the patient in this position.

SUBJECTS AND METHODS

CT-guided needle biopsy with the patient in an ipsilateral dependent position was performed in 23 patients with 17 lung lesions (15 posterior and two anterior) and six mediastinal lesions. Fine-needle aspiration was used in all patients, and core biopsy was also used in six patients. The technical difficulty of the procedure was classified into three grades compared with a routine transthoracic needle biopsy as follows: grade I, no more difficult; grade II, somewhat more difficult; and grade III, much more difficult.

RESULTS

Adequate samples were obtained in 22 (96%) of 23 patients. A small asymptomatic pneumothorax occurred in two patients (8.7%). Difficulty was rated grades I, II, and III in 18 (78%), two (9%), and three (13%) procedures, respectively. Four of the five grades II and III procedures were biopsies of anterior lesions. Traversing the pleura was avoided in three of six mediastinal masses.

CONCLUSION

Transthoracic needle biopsy of selected lung and mediastinal lesions using an ipsilateral dependent position is feasible, effective, and safe. The role of this technique for reducing the rate of pneumothorax as a result of the biopsy requires further investigation.

A mammalian germ cell-specific RNA-binding protein interacts with ubiquitously expressed proteins involved in splice site selection

RNA-binding motif (RBM) genes are found on all mammalian Y chromosomes and are implicated in spermatogenesis. Within human germ cells, RBM protein shows a similar nuclear distribution to components of the pre-mRNA splicing machinery. To address the function of RBM, we have used protein-protein interaction assays to test for possible physical interactions between these proteins. We find that RBM protein directly interacts with members of the SR family of splicing factors and, in addition, strongly interacts with itself. We have mapped the protein domains responsible for mediating these interactions and expressed the mouse RBM interaction region as a bacterial fusion protein. This fusion protein can pull-down several functionally active SR protein species from cell extracts. Depletion and add-back experiments indicate that these SR proteins are the only splicing factors bound by RBM which are required for the splicing of a panel of pre-mRNAs. Our results suggest that RBM protein is an evolutionarily conserved mammalian splicing regulator which operates as a germ cell-specific cofactor for more ubiquitously expressed pre-mRNA splicing activators.

[Multiorgan surgery in rectal cancer--extended therapy or improvement of prognosis?]

About 10% of rectal cancers have to be treated by a multivisceral resection. Within a period of 14 years we performed 103 of these operations, 60 for primary cancers, 43 for recurrent cancers with a significant increase in the latter. The total or partial removal of 204 extra-rectal organs allowed for a R0 resection in 67% of cases. 69% were confirmed as being pT4 by histologic examination. In comparison with conventional rectal resection morbidity is higher at 32% while mortality is identical with 4%. A significant benefit (p < 0.05) in terms of survival is found for primary cancers as opposed to recurrences, R0 resections compared to R1 or R2 resections, lymphnode negative compared to lymphnode positive patients and patients who underwent IORT. The number of additionally removed organs did not influence survival. Compared with the natural course even palliative resections carry a survival benefit and allow the treatment of the often devastating specific morbidity of the disease. Despite adjuvant multimodal therapies the high rate of local and distant recurrences after multivisceral resection of the rectum still poses a major problem.

Strategies to cope with negative social identity: predictions by social identity theory and relative deprivation theory

Predictions by social identity theory (SIT) and relative deprivation theory (RDT) concerning preferences for strategies to cope with a negative in-group status position were tested. The focus of the present research was a comparison of the theories regarding their differential patterns of prediction. For this purpose, a natural sample within a specific historical situation was investigated: East Germans after the German unification. First, the predictive power of SIT and RDT variables was tested separately. In a second step, a possible integration of the theories was addressed. Combining the SIT variables and RDT variables led to an integrated model indicating a differential pattern of prediction for intergroup strategies. The RDT components explained the collective responses, whereas SIT constructs were related to individual strategies.

Strategies to cope with negative social identity: predictions by social identity theory and relative deprivation theory

Predictions by social identity theory (SIT) and relative deprivation theory (RDT) concerning preferences for strategies to cope with a negative in-group status position were tested. The focus of the present research was a comparison of the theories regarding their differential patterns of prediction. For this purpose, a natural sample within a specific historical situation was investigated: East Germans after the German unification. First, the predictive power of SIT and RDT variables was tested separately. In a second step, a possible integration of the theories was addressed. Combining the SIT variables and RDT variables led to an integrated model indicating a differential pattern of prediction for intergroup strategies. The RDT components explained the collective responses, whereas SIT constructs were related to individual strategies.

The human protein kinase gene PKX1 on Xp22.3 displays Xp/Yp homology and is a site of chromosomal instability

We have isolated a gene, PKX1, by virtue of its position within the candidate region for chondrodysplasia punctata in Xp22.3. Although data from one patient render it unlikely that PKX1 is the CDPX gene, this gene shows several interesting features. First, PKX1 appears to encode a novel type of human protein kinase that is related to the catalytic subunit of cAMP-dependent protein kinases and has striking homology to the DC2 protein kinase from Drosophila melanogaster. Second, PKX1 is part of a family of at least four genes or pseudogenes, of which three map to the human sex chromosomes. In contrast to all other genes from the X-specific region of Xp22.3, PKX1 has a homologue on Yp rather than Yq. This is intriguing as it indicates that the single pericentric inversion event hypothesized to have occurred during primate evolution is not sufficient to explain the present X/Y-homology pattern of Xp22.3. Third, we have characterized patients with different chromosomal rearrangements in Xp22.3 or Yp and show that a high proportion of these have occurred within the PKX1 locus. This suggests that the PKX1 gene, besides harbouring a previously described hot-spot for illegitimate Xp/Yp-recombination, contains additional sequences predisposing to chromosomal breakage events.

Refinement of the locus for X-linked recessive chondrodysplasia punctata

Although the locus for X-linked recessive chondrodysplasia punctata (CDPX1) has been mapped to the region between PABX and DXS31 (the critical region is about 3 Mb long), the precise location within the critical region has not been determined. In this paper, we describe a boy with a 46,Y,der(X)t(X;Y)(p22.3;q11)mat karyotype and review the genotype-phenotype correlations in three male patients with the combination of apparent lack of clinical features of CDPX1 and a partial deletion of the critical region. The results suggest that the region defined by the two BssHII sites at 3180 and 3570 kb from the Xp telomere may be the target region for the CDPX1 locus.

High-density physical mapping of a 3-Mb region in Xp22.3 and refined localization of the gene for X-linked recessive chondrodysplasia punctata (CDPX1)

The study of patients with chromosomal rearrangements has led to the mapping of the gene responsible for X-linked recessive chondrodysplasia punctata (CDPX1; MIM 302950) to the distal part of the Xp22.3 region, between the loci PABX and DXS31. To refine this mapping, a yeast artificial chromosome (YAC) contig map spanning this region has been constructed. Together with the YAC contig of the pseudo-autosomal region that we previously established, this map covers the terminal 6 Mb of Xp, with an average density of 1 probe every 100 kb. Newly isolated probes that detect segmental X-Y homologies on Yp and Yq suggest multiple complex rearrangements of the ancestral pseudoautosomal region during evolution. Compilation of the data obtained from the study of individuals carrying various Xp22.3 deletions led us to conclude that the CDPX disease displays incomplete penetrance and, consequently, to refine the localization of CDPX1 to a 600-kb interval immediately adjacent to the pseudoautosomal boundary. This interval, in which 12 probes are ordered, provides the starting point for the isolation of CDPX1.

Double crossover in the human Xp/Yp pseudoautosomal region and its bearing on interference

Most models on crossover and crossover interference have assumed that the intensity of interference depends inversely on the physical distance separating the respective intervals. The possibility, however, also exists that interference depends on genetic rather than on physical distance. As the human pseudoautosomal region (PAR) on Xp/Yp is physically small, yet genetically a hot spot of recombination in male meiosis, studies on the existence of multiple crossover events may be particularly useful in addressing the question of interference. Our results demonstrate for the first time a double crossover during male meiosis in the human PAR on Xp/Yp. The occurrence of a single obligatory recombination event in this region can, therefore, no longer be taken as a dogma. However, double crossover events seem to remain exceptional and, thus, the model originally suggested by Burgoyne remains globally correct. As both recombination events can be localized within a narrow range of physical distance, theories describing interference due to steric hindrance may have to be reconsidered. This finding may, therefore, have general implications for our understanding of the mechanism of positive and negative crossover interference in mammalian genomes and may be interesting especially for linkage mapping where double recombinations in small intervals tend to be considered as genotyping errors.

A patient with an interstitial deletion in Xp22.3 locates the gene for X-linked recessive chondrodysplasia punctata to within a one megabase interval

A male patient carrying an interstitial deletion in Xp22.3 and affected by Kallmann syndrome, X-linked ichthyosis and mental retardation, but without chondrodysplasia punctata or short stature, was investigated with molecular probes from the distal Xp22.3 region. By means of a novel probe, M115, from the relevant region, the distal deletion breakpoint was shown to be between 3.18 and 3.57 Mb from Xptel. As the patient is not affected by X-linked recessive chondrodysplasia punctata, the gene for this disease can therefore be located to within an interval of less than one megabase proximal to the pseudoautosomal boundary. If the chondrodysplasia punctata gene is associated with a CpG island, this leaves only two islands at 2760 and 3180 kb from the Xp telomere as the most promising candidate sites for this gene.

Is correction for lung density in radiotherapy treatment planning necessary?

From 1978-981 a series of 30 patients with cancer of the esophagus were treated at the National Cancer Institute. Each of these patients had a CT scan of the chest taken in the treatment position, but prior to any treatment being given. Using these scans a retrospective analysis of the effect of lung density on delivered dose was performed. This indicated that failure to correct for tissue inhomogeneity results in a much higher dose being delivered than is prescribed. This effect is dependent on the energy of the beam being used for treatment; it may exceed 30% for 60Co. It also showed that there is wide patient to patient variation in lung density and that this variation is non-randomly distributed. The average lung density in his group of patients was 0.21 compared to the standard estimate of 0.35 but some had densities substantially lower than this, these being the patients with the largest lung volumes. This variability acts to further increase the discrepancy between prescribed and delivered dose even in a very homogeneous group of patients being treated under identical conditions for the same malignancy. The implications of this for future clinical trials in thoracic malignancies are discussed.