Single generation cycles and delayed feedback cycles are not separate phenomena.

We study a simple model for generation cycles, which are oscillations with a period of one or a few generation times of the species. The model is formulated in terms of a single delay-differential equation for the population density of an adult stage, with recruitment to the adult stage depending on the intensity of competition during the juvenile phase. This model is a simplified version of a group of models proposed by Gurney and Nisbet, who were the first to distinguish between single-generation cycles and delayed-feedback cycles. According to these authors, the two oscillation types are caused by different mechanisms and have periods in different intervals, which are one to two generation times for single-generation cycles and two to four generation times for delayed-feedback cycles. By abolishing the strict coupling between the maturation time and the time delay between competition and its effect on the population dynamics, we find that single-generation cycles and delayed-feedback cycles occur in the same model version, with a gradual transition between the two as the model parameters are varied over a sufficiently large range. Furthermore, cycle periods are not bounded to lie within single octaves. This implies that a clear distinction between different types of generation cycles is not possible. Cycles of all periods and even chaos can be generated by varying the parameters that determine the time during which individuals from different cohorts compete with each other. This suggests that life-cycle features in the juvenile stage and during the transition to the adult stage are important determinants of the dynamics of density limited populations.

[Multidisciplinary health care needs of psychologically distressed cancer patients in a Comprehensive Cancer Center]. / Multidisziplinärer Versorgungsbedarf psychisch belasteter Tumorpatienten an einem Comprehensive Cancer Center.

BACKGROUND AND OBJECTIVE: Considering the prolonged life-expectancies and the resulting demands that are placed on cancer patients and their relatives, the importance of specific counseling and support services including psycho-oncology, social services, nutritional, and exercise counseling has profoundly increased. The main focus of the current study was to evaluate the multidisciplinary health care needs of emotionally distressed cancer patients whoe were treated in a Comprehensive Cancer Center. METHODS AND STUDYGROUP: 831 out-patients were evaluated with regard to their psychological distress level and their multidisciplinary health care needs for specialist services of psycho-oncology, social services, nutritional, and exercise counseling using a tablet-PC assisted screening questionnaire. Separate analyses were completed for patients with and without psychological distress. RESULTS: One third of the screened patients showed clinically relevant psychological distress. Health care needs for all specialist services were significantly greater among these patients compared to patients without psychological distress (all p-values < 0.005). The higher needs were foremost presented by the number of needed specialist services (p < 0.001): two thirds of the psychologically distressed patients demonstrated, besides the need for a psycho-oncological service, a need for two or three further specialist services, whereas among patients without psychological distress more than 70% showed a need for at most one specialist service. CONCLUSION: Multidisciplinary health care needs of psychologically distressed cancer patients should be systematically addressed in a Comprehensive Cancer Center, and patients should be offered a coordinated and integrated health care program.

[Effect of systematic information about psychosocial support services during outpatient radiotherapy. A controlled trial]. / Effekte systematischer Informationen über psychosoziale Angebote während der ambulanten Strahlentherapie. Eine kontrollierte Studie.

BACKGROUND: Up to 50 % of all cancer patients require psychosocial support during the course of their disease. However, only a proportion of these patients make use of the existing services. This is partly because patients are unaware that psychosocial support services are available to them. We investigated whether systematically providing printed information concerning psychosocial support can increase the knowledge and usage of these services, as well as health-related self-efficacy. MATERIALS AND METHODS: In a controlled trial, 108 breast cancer patients were assigned alternately to either an intervention- or a control group. At two predefined time points before and during radiotherapy, patients in the intervention group received correspondence informing them about psychosocial services (psycho-oncology, clinical social work and the Cancer Information Service).The control group received no systematic information. Using a standardized questionnaire, all patients were subsequently questioned about their knowledge of psychosocial support services, their perceived self-efficacy and their use of psychosocial support services. RESULTS: We found that systematic provision of information had a positive effect on the knowledge of psychosocial support services (p = 0.042; d = 0.45) and self-efficacy (p = 0.047; d = 0.42). However, no increase in the actual usage of these services was observed (p = 0.661; d = 0.10). CONCLUSION: The systematic provision of information in the form of written correspondence can easily be implemented into clinical routine and is an effective way to increase cancer patients' knowledge of psychosocial support services. Furthermore, providing information about the services had a positive impact on patients' perceived self-efficacy. However, simply making this information available did not increase the usage of psychosocial support services.

Quality of life after restorative proctocolectomy and ileal pouch-anal anastomosis in patients with familial adenomatous polyposis: a matter of adjustment.

AIM: Favourable outcomes for health-related quality of life (HRQL) have been reported in patients with familial adenomatous polyposis (FAP) after restorative proctocolectomy and ileal pouch-anal anastomosis (RPC). However, less is known about patients' subjective experience and adjustment to postoperative impairment. Using a multidimensional psychometric assessment, we investigated patient-reported HRQL to determine the impact of the patient's subjective experience together with medical, functional and psychosocial factors on HRQL. METHOD: In this cross-sectional study, 116 FAP patients who had undergone RPC on average 8 years earlier completed standardized and study-specific questionnaires and participated in a personal interview. The impact of medical, functional and psychosocial factors on patients' HRQL was determined by regression analyses. RESULTS: When using a generic psychometric measure, FAP patients' overall HRQL was comparable with that of the general population. Impaired HRQL, however, was found in patients reporting poor pouch function in contrast to those reporting good or moderate functional outcome. Findings from a personalized interview also suggested that a good functional result does not necessarily translate into good HRQL. Personal resources predicted patients' physical and psychological well-being, whereas little variance of HRQL was explained by medical factors and function. CONCLUSION: Patients' HRQL is, to a substantial degree, the result of adjustment to the adverse impact of RPC. By using personal resources the majority of patients may achieve satisfactory HRQL levels even when bowel function is impaired. A multidimensional assessment that comprises medical, functional and psychosocial aspects is required to ascertain an adequate evaluation of FAP patients after RPC.

Psychosocial outcome following genetic risk counselling for familial colorectal cancer. A comparison of affected patients and family members.

Few studies have reported prospective data on psychosocial outcomes after genetic counselling in families with suspected hereditary non-polyposis colorectal cancer (HNPCC). This prospective study examines the impact of multidisciplinary risk counselling on the psychosocial outcome of 139 affected cancer patients and 233 family members without cancer at risk for HNPCC. Participants completed questionnaires specific to HNPCC before and 8 weeks after attending the familial cancer clinic. Affected patients' levels of distress were closely related to their health status and exceeded that of unaffected individuals, as did worry regarding their relatives' risk. A significant reduction in general anxiety (Hospital Anxiety and Depression Scale), distress specific to familial CRC (Impact of Events Scale) and general cancer worry (Distress Hereditary Disorder) was demonstrated after counselling in both affected patients and unaffected individuals. Reduction in distress was more pronounced in affected patients given a high risk of HNPCC compared with those at intermediate risk. Among unaffected individuals, distress declined regardless of what clinical risk they were assigned. Their perceptions of risk and cancer-related threat declined, while confidence in effective surveillance increased. These results suggest the beneficial effects of multidisciplinary counselling even when high-risk information is conveyed. A patient's previous cancer experience is likely to contribute to clinically relevant distress (15% of those patients), indicating the need for appropriate counselling.

Exogenous cortisol exerts effects on the startle reflex independent of emotional modulation.

Exogenous cortisol's modulation of the acoustic startle reflex (ASR) was tested alone and during exposure to affectively valenced photographs in healthy men and women. During nonmodulated startle, oral hydrocortisone had a biphasic dose effect, with 5 mg increasing and 20 mg decreasing, eyeblink reflex magnitude compared to placebo. During emotion modulation, 20 mg of hydrocortisone reduced reflex magnitude without affecting the usual pattern of modulation across positive, neutral, and negatively affective slides. Gender differences were not found in either relationship. These findings illustrate dose-dependent effects of cortisol on the startle pathway independent of emotional state and consistent across genders.

Constitutive and modulated cytokine expression in two permanent human bone marrow stromal cell lines.

We present a detailed analysis of cytokine expression patterns of the two permanent human bone marrow stromal cell lines, L87/4 and L88/5. These cell lines, previously established in our laboratory, are highly radiotolerant without cell detachment and support long-term cultures of CD(34+)-enriched human cord blood cells. RT-PCR analysis of 22 different cytokines or cytokine receptor mRNAs showed an almost identical expression pattern in the two stromal cell lines compared to primary human Dexter-type stroma. Since stromal feeder lines employed in long-term cultures usually are irradiated and grown in media containing corticosteroids, we analyzed the impact of irradiation and dexamethasone on cytokine production in the two cell lines by RT-PCR, Northern blot analysis, bioassays, and RIAs. By RT-PCR analysis, constitutive mRNA expression of c-kit, G-CSF, GM-CSF, IL-1 beta, IL-6, IL-7, IL-8, IL-11, Kit ligand (KL), LIF, M-CSF, MIP-1 alpha, TGF-beta, and TNF-alpha was demonstrated in both cell lines, with L87/4 a more potent cytokine producer than L88/5. Northern blot data showed an increase in mRNA levels for GM-CSF, IL-1 beta, and LIF by irradiation and IL-1 alpha treatment in both cell lines. IL-1 alpha-induced GM-CSF, IL-1 beta, IL-6, IL-11, and LIF mRNA levels were reduced by the addition of dexamethasone, whereas dexamethasone had no influence on the amounts of IL-1 alpha-induced G-CSF mRNA. L87/4 and, to a lower extent, L88/5 cells showed dexamethasone-dependent increases in KL mRNA, while KL mRNA levels were not stimulated by IL-1 alpha.

Establishment of two permanent human bone marrow stromal cell lines with long-term post irradiation feeder capacity.

We describe the establishment of two permanent Simian virus 40-transformed human stromal cell lines, designated L87/4 and L88/5, derived from the bone marrow of a hematologically normal male patient. Both cell lines show a fibroblastoid morphology and do not express hematopoietic cell markers. L87/4 but not L88/5 expresses the macrophage marker CD68. The most remarkable feature of these new stromal cell lines is their ability to persist as growth-arrested adherent feeder cells after ionizing-irradiation at doses up to, and exceeding 20 Gy (L87/4). This renders them particularly useful for studying aspects of feeder dependence of hematopoietic cell development in long-term culture. Both cell lines are able to function as feeder cells, supporting the long-term proliferation of CD34+ human cord blood cells as well as the clonogenic growth of the human Burkitt lymphoma B-cell line BL70.