Alterations in mucosal neuropeptides in patients with irritable bowel syndrome and ulcerative colitis in remission: a role in pain symptom generation?

BACKGROUND

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder characterized by chronic abdominal pain. The transient receptor potential vanilloid 1 (TRPV1) channel, which is involved in visceral pain signalling, has been shown to be up-regulated in IBS. Activation of TRPV1 leads to the release of neuropeptides, such as somatostatin and substance P (SP). We hypothesized that increased pain perception in IBS could be explained by increased transcription in TRPV1 and/or altered levels of neuropeptides. We therefore assessed the transcription of TRPV1 and the mucosal concentration of somatostatin and SP in IBS in comparison to healthy volunteers and patients with ulcerative colitis (UC) in remission as disease controls, and to ascertain their relationship to pain symptoms.

METHOD

Sigmoid colonic mucosal samples were collected from 12 patients with IBS, 34 patients with UC in remission and 9 healthy volunteers, in which groups TRPV1 mRNA levels were determined using quantitative polymerase chain reaction and neuropeptide concentrations by radioimmunoassay. Pain symptom intensity was determined by questionnaires.

RESULTS

Transcription of TRPV1 as well as the concentration of neuropeptides were significantly higher in IBS, but only the former correlated with pain symptom severity.

CONCLUSION

Increased transcription of TRPV1 may provide a possible explanation for pain generation in IBS. While the neuropeptides SP and somatostatin were both found to be increased in IBS, these changes are not sufficient to explain pain generation. Pain generation in IBS is probably explained by a complex redundancy in the regulation of local nociceptive mechanisms, which remains a subject of intensive investigation.

[The aftermath of the reduction in inpatient care and treatment II: cross-sectional study relating to the health, the need for care, the quality of life, social functioning and the integration in society of chronic mental patients in Amsterdam]

BACKGROUND

The move from less hospital care to more community-based care was expected to have positive results for long-term mental patients. It was believed that independent living would improve the quality of life and promote better social functioning and better integration into society. The basic idea was that the needs of patients would be better served by outpatient care.

AIM

To map particulars relating to illness symptoms, functioning, care needs, quality of life, extent and features of the social network and social integration of a group of long-term psychiatric patients in Amsterdam 15 years after the closure of the Santpoort psychiatric hospital.

METHOD

Interviews and questionnaires were used to obtain information from a stratified sample of long-term mental patients in the care of the mental health organisations in Amsterdam.

RESULTS

323 patients and those who were treating them were interviewed. Most group members were fairly elderly and one-third suffered from schizophrenia. More than half of the group had long-term psychiatric problems. Most of the patients were in poor health, half of the group had somatic symptoms and a quarter abused alcohol or drugs. Patients and doctors had varying views on whether patients’ needs had been met. Patients had few social contacts. About one-third of these social contacts were with fellow-patients. Patients living independently caused few or no problems in the city. However, these patients were more often victim of discrimination, social exclusion and criminality.

CONCLUSION

Many patients with long-term mental illness considered their current quality of life to be reasonably good and were satisfied with the health care they received. However, the limited number of social contacts, inadequate integration into society and the poor health of many patients are matters that still give cause for concern.

The course of limitations in activities over 5 years in patients with knee and hip osteoarthritis with moderate functional limitations: risk factors for future functional decline

OBJECTIVE

To describe the course of limitations in activities over 5 years follow-up and identify predictors of future limitations in activities in elderly patients with osteoarthritis (OA) of the hip or knee with moderate functional limitations.

METHOD

A longitudinal cohort study with 5 years follow-up was conducted. Patients (n=288) were recruited at rehabilitation centers and hospitals. The main outcome measures were self-reported and performance-based limitations in activities. Prognostic factors were demographic and clinical data, body functions, comorbidity, cognitive functioning, avoidance of activity and social support. Measurements were conducted at baseline, 1, 2, 3 and 5 years follow-up.

RESULTS

Both in patients with knee and hip OA, the course of limitations in activities remained fairly stable over a period of 5 years. Avoidance of activity, increased pain, more comorbidity, a higher age, a longer disease duration, a reduced muscle strength and range of joint motion at baseline predicted more future limitations in activities in patients with knee OA. In patients with hip OA, avoidance of activity, increased pain, more comorbidity, a higher age, a higher educational level and a reduced range of motion at baseline predicted more future limitations in activities.

CONCLUSIONS

The course of limitations in activities remains fairly stable over a period of 5 years in elderly patients with hip or knee OA. However, at individual level there is considerable variation. Predictors of more future limitations in activities include avoidance of activity, increased pain, higher morbidity count, reduced range of motion, and a higher age.

A multidisciplinary and multidimensional intervention for patients with hand osteoarthritis

Background: Although several guidelines recommend that treatment programmes in patients with hand osteoarthritis should be both multidisciplinary and multidimensional, currently no such treatment programme for hand osteoarthritis has been described. Therefore the aim of this study was to systematically develop a multidisciplinary and multidimensional non-pharmacological treatment programme and to give a detailed description on the content of this treatment programme.

Development of the treatment programme: The programme was developed in phases. In a preclinical theoretical phase, disease-specific problems, current evidence and the influence of patient characteristics on the benefit of interventions were explored. In a modelling phase, the treatment programme was designed.

Treatment programme: The programme contains an individual intake, four weekly nurse and occupational therapist-led group sessions and a booster session after six months. Treatment components of the programme are self-management, daily home exercises to enhance joint mobility and grip strength and education about ergonomic principles. The treatment programme is tailored to the needs of individual patients with hand osteoarthritis.

Conclusions: A non-pharmacological multidisciplinary and multidimensional treatment programme for patients with hand osteoarthritis was developed. Further research is necessary to investigate the effectiveness of this treatment programme. Currently, the programme is being evaluated in an ongoing randomized clinical trial.

Prevalence and risk factors for recurrence of depression five years after short term psychodynamic therapy

BACKGROUND

Follow-up research concerning the efficacy of treatment for depression is scarce and varies widely in clinical and methodological terms. Aim was to conduct a five-year follow-up study of recurrence of depression after short supportive Psychodynamic Treatment (PDT) alone or in combination with pharmacotherapy.

METHODS

Patients who had been treated five years previously for major depressive disorder in a randomised control trial comparing short supportive PDT alone or in combination with pharmacotherapy, were traced. Patients who completed treatment were included. Recurrent episodes in the past five years were identified using CIDI. Severity of symptoms after five years was measured with the Hamilton Rating Scale for Depression and sub-scales Depression, Anxiety and Somatisation of the self-report Symptom Checklist 90.

RESULTS

52 (37%) patients of the original sample were localised. 42% had suffered from one or more recurrences during the follow-up period. There was no significant difference between the group who had received psychotherapy and the group who had received combined therapy during the acute phase. Young women and patients with more residual depressive symptoms and less somatic symptoms directly after treatment, were more at risk for recurrence.

LIMITATIONS

Relatively small study population. Furthermore it was not known if patients received other treatment during the follow-up period.

CONCLUSIONS

The long-term efficacy of PDT (with or without antidepressants) seemed to be comparable with other psychotherapies for depression. But the high recurrence rate urges us to shift the focus of depression treatment to improving long-term outcome and to the prevention of recurrence, in particular for young women and patients with residual symptoms of depression.

Physiotherapy in hip and knee osteoarthritis: development of a practice guideline concerning initial assessment, treatment and evaluation

BACKGROUND

An update of a Dutch physiotherapy practice guideline in Hip and Knee Osteoarthritis (HKOA) was made, based on current evidence and best practice.

METHODS

A guideline steering committee, comprising 10 expert physiotherapists, selected topics concerning the guideline chapters: initial assessment, treatment and evaluation. With respect to treatment a systematic literature search was performed using various databases, and the evidence was graded (1-4). For the initial assessment and evaluation mainly review papers and textbooks were used. Based on evidence and expert opinion, recommendations were formulated. A first draft of the guideline was reviewed by 17 experts from different professional backgrounds. A second draft was field-tested by 45 physiotherapists.

RESULTS

In total 11 topics were selected. For the initial assessment, three recommendations were formulated, pertaining to history taking, red flags, and formulating treatment goals. Concerning treatment, 7 recommendations were formulated; (supervised) exercise therapy, education and self management interventions, a combination of exercise and manual therapy, postoperative exercise therapy and taping of the patella were recommended. Balneotherapy and hydrotherapy in HKOA, and thermotherapy, TENS, and Continuous Passive Motion in knee OA were neither recommended nor discouraged. Massage therapy, ultrasound, electrotherapy, electromagnetic field, Low Level Laser Therapy, preoperative physiotherapy and education could not be recommended. For the evaluation of treatment goals the following measurement instruments were recommended: Lequesne index, Western Ontario and McMaster Universities osteoarthritis index, Hip disability and Osteoarthritis Outcome Score and Knee injury and Osteoarthritis Outcome Score, 6-minute walktest, Timed Up and Go test, Patient Specific Complaint list, Visual Analoge Scale for pain, Intermittent and Constant OsteoArthritis Pain Questionnaire, goniometry, Medical Research Council for strength, handheld dynamometer.

CONCLUSIONS

This update of a Dutch physiotherapy practice guideline on HKOA included 11 recommendations on the initial assessment, treatment and evaluation. The implementation of the guideline in clinical practice needs further evaluation.

Instruments to assess physical activity in patients with osteoarthritis of the hip or knee: a systematic review of measurement properties

OBJECTIVE

There is no consensus on the best approach for measuring physical activity in patients with osteoarthritis (OA) of the hip or knee. The aims of this study were (1) to identify all physical activity measures that have been validated in patients with OA of the hip or knee and to systematically review their measurement properties, and (2) to give recommendations on which instrument is most suitable for what purpose.

DESIGN

A search was performed in PubMed, Embase, and Sportdiscus (complete databases until November 10, 2010). Three reviewers independently evaluated the quality of the included studies, using the Consensus-based Standards for the selection of health Measurement Instruments (COSMIN) checklist. Subsequently, the reviewers independently evaluated the quality of the included physical activity instruments, using the recently developed QAPAQ checklist for appraising the qualitative attributes and measurement properties of physical activity questionnaires.

RESULTS

Nine studies were included, in which 12 measurement instruments were evaluated: five single-item rating scales, six multi-item questionnaires, and one pedometer. In general, the methodological quality of the studies was poor to moderate. Only the Lower-Extremity Activity Scale (LEAS) and the pedometer received positive ratings for content validity. The LEAS and Baecke questionnaire received positive ratings for reliability. The University of California at Los Angeles (UCLA), the Tegner score, and the LEAS received positive ratings for construct validity. The Daily Activity Questionnaire (DAQ) received a positive rating for criterion validity. Responsiveness was not evaluated for any of the included instruments.

CONCLUSION

For monitoring physical activity levels of populations the UCLA or LEAS seem most useful. For studies measuring physical activity as a risk factor for developing OA or as a protective factor against functional decline there is not enough evidence for any instrument to conclude that it has adequate measurement properties. For follow-up studies on wear in joint replacement patients we recommend to use accelerometers. However, more validation studies of adequate quality are needed for all included instruments.

Proprioception in knee osteoarthritis: a narrative review

OBJECTIVE

To give an overview of the literature on knee proprioception in knee osteoarthritis (OA) patients.

METHOD

A literature search was performed and reviewed using the narrative approach.

RESULTS

(1) Three presumed functions of knee proprioception have been described in the literature: protection against excessive movements, stabilization during static postures, and coordination of movements. (2) Proprioceptive accuracy can be measured in different ways; correlations between these methods are low. (3) Proprioceptive accuracy in knee OA patients seems to be impaired when compared to age-matched healthy controls. Unilateral knee OA patients may have impaired proprioceptive accuracy in both knees. (4) Causes of impaired proprioceptive accuracy in knee OA remain unknown. (5) There is currently no evidence for a role of impaired proprioceptive accuracy in the onset or progression of radiographic osteoarthritis (ROA). (6) Impaired proprioceptive accuracy could be a risk factor for progression (but not for onset) of both knee pain and activity limitations in knee OA patients. (7) Exercise therapy seems to be effective in improving proprioceptive accuracy in knee OA patients.

CONCLUSIONS

Recent literature has shown that proprioceptive accuracy may play an important role in knee OA. However, this role needs to be further clarified. A new measurement protocol for knee proprioception needs to be developed. Systematic reviews focusing on the relationship between impaired proprioceptive accuracy, knee pain and activity limitations and on the effect of interventions (in particular exercise therapy) on proprioceptive accuracy in knee OA are required. Future studies focusing on causes of impaired proprioceptive accuracy in knee OA patients are also needed, taking into account that also the non-symptomatic knee may have proprioceptive impairments. Such future studies may also provide knowledge of mechanism underlying the impact of impaired proprioceptive accuracy on knee pain and activity limitations.

[The aftermath of the reduction in inpatient care and treatment; a retrospective study that considers the extent to which a group of chronic psychiatric patients made use of the Amsterdam mental health services]

BACKGROUND

The move towards less hospital care and more community care for psychiatric patients began in the eighties. Chronic patients possibly have not really benefited from the new procedures.

AIM

To find out whether chronic psychiatric patients in Amsterdam were receiving adequate care and made good use of the available psychiatric services.

METHOD

We amalgamated the registration details of three mental health care institutions in Amsterdam over the period 1-1-2000 to 1-1-2005.

RESULTS

In 2005 4576 patients met the criteria for chronic mental illness. In five years, the number of patients in mental health care had risen by 50%. Most of these patients had received care via specialised programmes. 38% of chronic patients had no access to specialised programmes, many of which had waiting lists. Only 6.5% of chronic patients received long-term inpatient care. Not many long-term psychiatric patients used the acute psychiatric services. Each year only 10% of long-term psychiatric patients were admitted to a psychiatric hospital. If admitted, they spent a much longer time in hospital. The average number of days spent in hospital rose from 86 in 2000 to 131 in 2004. Crisis contacts increased in line with the increase in the numbers of chronic patients in care, but these crisis contacts were registered mainly with the patient treatment team and not with the municipal acute psychiatric service.

CONCLUSION

Only a small proportion of long-term psychiatric patients make use of the acute psychiatric services.

First rehabilitation consultation in patients of non-native origin: factors that lead to tension in the patient-physician interaction

PURPOSE

To explore which factors lead to tension in the patient-physician interaction in the first consultation by rehabilitation physicians of patients with chronic non-specific low back pain of Turkish and Moroccan origin.

METHOD

In-depth semi-structured, face to face interviews were conducted with 12 patients of Moroccan and Turkish origin and four native Dutch rehabilitation physicians. Interviews were transcribed and/or summarised. All interviews were subsequently coded and analysed according to themes.

RESULTS

Factors that lead to tension in the patient-physician interaction were as follows: differences in expectations regarding the aim of treatment, symptom presentation, views on responsibilities with regard to rehabilitation treatment, lack of trust, contradicting views of physicians from patients' country of origin with regard to the cause and treatment of pain and communication problems.

CONCLUSION

Sources of tension were identified during the interaction between Dutch physicians and patients of Turkish and Moroccan origin. These factors potentially are associated with future drop-out. Future research should clarify whether these factors indeed are associated with drop-out.

Reasons for drop-out in rehabilitation treatment of native patients and non-native patients with chronic low back pain in the Netherlands: a medical file study

AIM

Drop-out of rehabilitation treatment in non-native patients with chronic low back pain has been reported to be higher than in native Dutch patients. It was expected that drop-out in non-native patients would be due to different expectations on the content of rehabilitation treatment and due to language or communication problems. Aim of this study was to determine differences in reasons for drop-out between native patients and non-native patients with chronic non-specific low back pain participating in a rehabilitation program.

METHODS

A retrospective study in medical files (N.=99) of patients who dropped out of treatment was performed in two rehabilitation centers and two rehabilitation departments of general hospitals. Patient files were checked for diagnosis, status of origin, gender, age and reason for drop-out. The differences in frequency in reasons for drop-out between native and non-native patients were tested by Chi-square tests.

RESULTS

Withdrawal due to different expectations on the content of rehabilitation treatment occurred significantly more frequently in non-native patients (P=0.035). Withdrawal due to refusal to participate (no further reason given) occurred more often (P=0.008) in native Dutch patients than in non-native patients. No significant differences between non-native patients and native Dutch patients were reported regarding withdrawal due to language or communication problems, and no show (patient did not show up at consultation sessions without informing about the reason and without making an appointment for a new consultation).

CONCLUSION

The present study provided evidence that drop-out in non-native patients is often related to different expectations regarding the content of rehabilitation treatment.

Validity and responsiveness of the ankle function score after acute ankle injury

The purpose of this study was to examine prognostic validity, concurrent validity and responsiveness of ankle function score (AFS) for patients with acute ankle injury. In a prospective cohort study, AFS was compared with Olerud and Molander ankle score (OMAS), patient-specific complaints (PSC), and global perceived effect. Sensitivity and specificity were calculated to estimate prognostic validity; correlation was calculated for concurrent validity. Effect Size, Standardized Response Mean, and Responsiveness Ratio were calculated to estimate responsiveness. The sensitivity of AFS was 76% and the specificity was 57%. Correlation between AFS and OMAS at baseline, end of treatment and difference was 0.82, 0.70 and 0.79, respectively. Outcomes for responsiveness of AFS were comparable to outcomes for OMAS and PSC. This study found limited evidence for the AFS as a prognostic and evaluative instrument. The AFS is a simple instrument based on basic functional outcomes (pain, stability, weight bearing, swelling and gait) and may be used in addition to subjective clinical judgment as a prognostic and evaluative tool for recovery after acute ankle injury.

Quality indicators indicate good adherence to the clinical practice guideline on "Osteoarthritis of the hip and knee" and few prognostic factors influence outcome indicators: a prospective cohort study

BACKGROUND

Evaluation with quality indicators of adherence to the clinical practice guideline on "Osteoarthritis of the hip and knee" and of treatment outcomes.

AIM

Furthermore to determine prognostic factors for outcome indicators.

DESIGN

Prospective cohort study.

POPULATION

Twenty-seven well informed physical therapists recorded patient and treatment characteristics of 103 community-dwelling patients referred by a general practitioner diagnosed with osteoarthritis of hip or knee.

METHODS

With selected process and outcome indicators adherences to the guideline and treatment outcomes were assessed. Prognostic factors were calculated for Algofunctional Index (AI) and Visual Analogue Scale (VAS) for pain (decreases of ≤25% indicating "poor outcome"), number of sessions (>12) and duration of treatment (>6 weeks), using multivariate logistic regression models.

RESULTS

Process indicators showed that information & advice was given to 95% of the patients and functions and activities were exercised in 97% respectively 87%. Aftercare was arranged for 46% of the patients, that was clearly lower than the benchmark of 90%. Outcome indicators VAS-pain and AI decreased by 45% and 36%, respectively. The combination ">12 months" duration of complaints and age ≥65" was associated with a "poor outcome" on AI (OR 2.53; 95% CI 1.01-6.38). Co-morbidity (OR 2.8; 95% CI 1.17-6.88), and "VAS-pain at baseline ≥51 mm" (OR 3.1; 95% CI 1.34-7.23) were associated with a higher number of treatment sessions.

CONCLUSION AND CLINICAL REHABILITATION IMPACT

and Quality indicators showed that a group of well-informed physical therapists could to a large extent adhere to key recommendations of the guideline and that clinically relevant improvements were obtained in terms of pain and physical functioning. Prognostic factors for poorer outcome on outcome indicators were comorbidity, a higher pain score at baseline and the combination ">12 months' duration of complaints and age ≥65".

The current status of urban-rural differences in psychiatric disorders

OBJECTIVE

Reviews of urban-rural differences in psychiatric disorders conclude that urban rates may be marginally higher and, specifically, somewhat higher for depression. However, pooled results are not available.

METHOD

A meta-analysis of urban-rural differences in prevalence was conducted on data taken from 20 population survey studies published since 1985. Pooled urban-rural odds ratios (OR) were calculated for the total prevalence of psychiatric disorders, and specifically for mood, anxiety and substance use disorders.

RESULTS

Significant pooled urban-rural OR were found for the total prevalence of psychiatric disorders, and for mood disorders and anxiety disorders. No significant association with urbanization was found for substance use disorders. Adjustment for various confounders had a limited impact on the urban-rural OR.

CONCLUSION

Urbanization may be taken into account in the allocation of mental health services.

Fat distribution influences the cardio-metabolic profile in a clinically healthy European population

BACKGROUND AND AIMS

Waist and hip circumferences are largely influenced by Fat Mass and several other determinants. To evaluate the specific effects of a preferential fat distribution, we corrected the waist and hip circumferences for all their determinants. We then examined the association between fat distribution and several cardio-metabolic parameters in a clinically healthy population.

SUBJECTS AND METHODS

In a subgroup of 625 females (F) and 490 males (M) from the RISC (Relationship between Insulin Sensitivity and Cardiovascular Disease) study, we evaluated insulin sensitivity by hyperinsulinaemic euglycaemic clamp and intima-media thickness (IMT) of the common (CCA) and internal (ICA) carotid artery by ultrasound imaging. Waist and hip circumferences were adjusted for age, height, fat and fat-free mass; in males, waist was also adjusted by hip and vice versa.

RESULTS

Both F and M with enlarged waist showed significantly increased plasma insulin, C-peptide, total cholesterol, non-high density lipoprotein-cholesterol, low density lipoprotein cholesterol and triglycerides, when compared with subjects with a smaller waist circumference. Males also showed lower glucose uptake and higher heart rate and ICA-IMT. A larger hip in both females and males was linked to a significantly greater inhibition of free fatty acids during the clamp test.

CONCLUSION

Adjustment of waist circumference for its determinants permits the detection of early impairment of cardiovascular function and of glucose and lipid metabolism in a clinically healthy population, in particular in normal body weight subjects. Enlarged hip adjusted values are associated with greater insulin sensitivity.

Involuntary admission of emergency psychiatric patients: report from the Amsterdam Study of Acute Psychiatry

OBJECTIVE

This brief report presents initial data from the Amsterdam Study of Acute Psychiatry (ASAP-I) about factors associated with the decision to admit patients compulsorily (involuntarily) to emergency psychiatric services in the Amsterdam region of the Netherlands.

METHODS

The study was a prospective cohort study of 1,970 consecutive patients who came into contact with the Psychiatric Emergency Service Amsterdam.

RESULTS

A history of more than 14 outpatient contacts the previous year was associated with a low risk of compulsory admission (OR=.3). An involuntary admission in the previous five years was associated with a higher risk (OR=3.7). Referral by a general practitioner was associated with a low risk compared with referral by police (OR=2.4) or by mental health services (OR=2.3).

CONCLUSIONS

The hypothesis that outpatient treatment may help to prevent compulsory admission found some support in this study. More research is needed to understand the mechanisms of the associations so that an intervention study can be developed to test this hypothesis.

Psychometric properties of an interviewer-administered version of the Kessler Psychological Distress scale (K10) among Dutch, Moroccan and Turkish respondents

The Kessler Psychological Distress scale (K10) is an instrument that is widely used to screen for mental disorders, but information is lacking on its psychometric qualities in non-Western samples. This study used a population-based sample (N = 725) to assess the reliability and validity of the K10 across ethnic groups in an urban area. The results were generally supportive of the K10 as a reliable and valid instrument to screen for anxiety and depression in all three groups. Cronbach's alpha was high (0.93) and the results indicated the existence of a solid single factor structure. Item bias in relation to ethnic background was minor. In each group, there was good criterion validity with respect to one-month DSM-IV diagnosis for depressive and/or anxiety disorder. The results nevertheless highlight the importance of cross-cultural validation, as we found different cut-off values for ethnic subgroups to obtain optimal sensitivity and specificity for detecting depressive and/or anxiety disorders.

Recreational exercise in rheumatic diseases

The purpose of this study was to evaluate changes in health-related quality of life after eight to twelve months of recreational exercise in patients with rheumatic diseases (inflammatory joint disease, osteoarthritis, fibromyalgia and other generalized pain syndromes), and to determine whether patient (age, sex, diagnosis) and exercise characteristics (follow-up time, type of activity, frequency of participation) are related to health-related quality of life change. Health-related quality of life was assessed twice in 138 patients with rheumatic diseases. 1) At enrolment in a centre for outpatient recreational exercise and 2) following eight to twelve months of recreational exercise. Health-related quality of life was measured using the Short-Form Health Survey 36 and three numeric rating scales for pain, fatigue and general condition. Multiple linear regression was used to analyze the influence of patient and exercise characteristics on follow-up HRQoL-score. Patients showed significant improvements in pain and general condition, and reported a positive change in health. A diagnosis of inflammatory joint disease (e. g. rheumatoid arthritis, polyarthritis, spondylitis) or osteoarthritis, participating in sports activities two to three times per week, and following land-based fitness classes were associated with the most improvement in health-related quality of life. Regular participation in recreational exercise contributes to improved health-related quality of life in patients with rheumatic diseases.