Expression of TGFß-family signalling components in ageing cartilage: age-related loss of TGFß and BMP receptors.

OBJECTIVE: Ageing is the main risk factor for osteoarthritis (OA). We investigated if expression of transforming growth factor ß (TGFß)-family components, a family which is crucial for the maintenance of healthy articular cartilage, is altered during ageing in cartilage. Moreover, we investigated the functional significance of selected age-related changes. DESIGN: Age-related changes in expression of TGFß-family members were analysed by quantitative PCR in healthy articular cartilage obtained from 42 cows (age: ¾-10 years). To obtain functional insight of selected changes, cartilage explants were stimulated with TGFß1 or bone morphogenetic protein (BMP) 9, and TGFß1 and BMP response genes were measured. RESULTS: Age-related cartilage thinning and loss of collagen type 2a1 expression (∼256-fold) was observed, validating our data set for studying ageing in cartilage. Expression of the TGFß-family type I receptors; bAlk2, bAlk3, bAlk4 and bAlk5 dropped significantly with advancing age, whereas bAlk1 expression did not. Of the type II receptors, expression of bBmpr2 decreased significantly. Type III receptor expression was unaffected by ageing. Expression of the ligands bTgfb1 and bGdf5 also decreased with age. In explants, an age-related decrease in TGFß1-response was observed for the pSmad3-dependent gene bSerpine1 (P = 0.016). In contrast, ageing did not affect BMP9 signalling, an Alk1 ligand, as measured by expression of the pSmad1/5 dependent gene bId1. CONCLUSIONS: Ageing negatively affects both the TGFß-ALK5 and BMP-BMPR signalling routes, and aged chondrocytes display a lowered pSmad3-dependent response to TGFß1. Because pSmad3 signalling is essential for cartilage homeostasis, we propose that this change contributes to OA development.

TGF-ß is a potent inducer of Nerve Growth Factor in articular cartilage via the ALK5-Smad2/3 pathway. Potential role in OA related pain?

OBJECTIVE: Pain is the main problem for patients with osteoarthritis (OA). Pain is linked to inflammation, but in OA a subset of patients suffers from pain without inflammation, indicating an alternative source of pain. Nerve Growth Factor (NGF) inhibition is very efficient in blocking pain during OA, but the source of NGF is unclear. We hypothesize that damaged cartilage in OA releases Transforming Growth Factor-ß (TGF-ß), which in turn stimulates chondrocytes to produce NGF. DESIGN: Murine and human chondrocyte cell lines, primary bovine and human chondrocytes, and cartilage explants from bovine metacarpal joints and human OA joints were stimulated with TGF-ß1 and/or Interleukin-1 (IL-1)ß. We analyzed NGF expression on mRNA level with QPCR and stained human OA cartilage for NGF immunohistochemically. Cultures were additionally pre-incubated with inhibitors for TAK1, Smad2/3 or Smad1/5/8 signaling to identify the TGF-ß pathway inducing NGF. RESULTS: NGF expression was consistently induced in higher levels by TGF-ß than IL-1 in all of our experiments: murine, bovine and human origin, in cell lines, primary chondrocytes and explants cultures. TAK1 inhibition consistently reduced TGF-ß-induced NGF whereas it fully blocked IL-1ß-induced NGF expression. In contrast, ALK5-Smad2/3 inhibition fully blocked TGF-ß-induced NGF expression. Despite the large variation in basal NGF in human OA samples (mRNA and histology), TGF-ß exposure led to a consistent high level of NGF induction. CONCLUSION: We show for the first time that TGF-ß induces NGF expression in chondrocytes, in a ALK5-Smad2/3 dependent manner. This reveals a potential alternative non-inflammatory source of pain in OA.

Oxygen uptake kinetics in chronic heart failure: clinical and physiological aspects.

One of the hallmark symptoms of patients with chronic heart failure (CHF) is exercise intolerance. Therefore, exercise testing has become an important tool for the evaluation and monitoring of heart failure. Whereas the maximal aerobic capacity (peak VO(2)) is a reliable indicator of the severity and prognosis of heart failure, submaximal exercise parameters may be more closely related to the ability to perform daily activities. As such, oxygen (O(2)) uptake kinetics, describing the rate change of O(2) uptake during onset or recovery of submaximal constant-load exercise (O(2) onset and recovery kinetics, respectively), have been shown to be useful parameters for objectively evaluating the functional capacity of CHF patients. However, their evaluation in this population is not a routine part of daily clinical practice. Possible reasons for this include a lack of standardisation of the assessment methodology and a limited number of studies evaluating the clinical use of O(2) uptake kinetics in CHF patients. In addition, the pathophysiological mechanisms underlying the delay in O(2) uptake kinetics in these patients are not completely understood. This review discusses the current literature on the clinical potency and physiological determinants of O(2) uptake kinetics in CHF patients and provides directions for future research. (Neth Heart J 2009;17:238-44.Neth Heart J 2009;17:238-44.).

Regional implementation of the NWC guideline on ST-elevation myocardial infarction: Report from the Task Force Prehospital Triage Zuidoost Brabant (PHT ZoB).

BACKGROUND: The NVVC guideline on ST-elevation myocardial infarction forms the basis for the regional prehospital triage (PHT) project in Zuidoost Brabant. In this project diagnosis and treatment strategies are determined in the ambulance. AIM: To summarise quality assessment and clinical results after one year. METHODS: We evaluated the protocol and patient record form, the patient's call, assignment of tasks, diagnosis, treatment, time intervals, information to hospitals, cooperation and data transmission. Time delays were compared with time delays in a regional dry run before the start of the project and with time delays reported in the literature. RESULTS: Patients still wait over one hour before seeking medical attention. The GP received the majority (65%) of patient calls. In half of all cases (51%), GPs call the ambulance centre only after they have seen the patient. When the patient calls the ambulance centre (35%), information to the GP is either prompt or absent. In 77% of calls to 112 it remains unclear whether the GP was informed at all. The treatment strategy was correct in 97% of cases. Time between symptoms and call decreased in comparison with our local preliminary investigation. Quality assessment after one year shows protocol deviations that are either logical procedural improvements or correctable flaws with no substantial negative influence. CONCLUSION: Short-term clinical results are good, but structured follow-up is needed to reduce mortality in the long term, especially after thrombolysis. A guideline is a snapshot of a dynamic process. The PHT project allows rapid adaptations to be made to new paradigms.

Aortic root replacement with pulmonary autograft in children.

Between September 1988 and February 1993, 14 patients whose ages ranged from 3 months to 16 years (mean 11.1 +/- 4.3 years) underwent replacement of the aortic root with the autologous pulmonary root for aortic valve disease. The follow-up was 4 years (cumulative total of 25.2 patient-years). There was no early mortality. Late mortality (one patient) was 7.1% (95% confidence limits 0% to 21%). This patient had juvenile rheumatoid arthritis and died of consequent congestive heart failure with autograft failure 6 months after operation. Event-free survival after 4 years was 78.6% (95% confidence limits 50% to 95%). One patient was reoperated on because of autograft failure caused by a relapse of rheumatic fever. One patient operated on for critical neonatal aortic stenosis has subnormal exercise tolerance because of restrictive cardiomyopathy and pulmonary homograft regurgitation. The other 12 patients were in New York Heart Association functional class I at the end of follow-up. There was no prevalence of bacterial endocarditis. There were no signs of primary structural degeneration of the pulmonary autograft. During follow-up, in eight patients, increased anulus diameter of the pulmonary autograft could be demonstrated by precordial two-dimensional echocardiography, suggesting growth of the autograft. Our experience shows that aortic root replacement with the pulmonary autograft can be done with low mortality and morbidity in children with aortic valve disease. The operation seems to be contraindicated in children with juvenile rheumatoid arthritis because of the risk of recurrence of rheumatic disease in the autograft. The pulmonary autograft has also been shown to be susceptible to recurrence of rheumatic inflammation in children with a history of acute rheumatic fever. Despite pulmonary autograft replacement of the aortic valve in infants with critical valvular aortic stenosis and endocardial fibroelastosis, clinical results may be poor. Growth of the autograft is suggested by echocardiographic follow-up. We consider aortic root replacement with the pulmonary autograft the procedure of choice in children who require aortic valve replacement.

[Participants in movement programs for 55-year-olds and older. An exploratory study of 'More Movement for the Elderly' in Limburg]. / Deelnemers aan bewegingsprogramma's voor 55-plussers. Een exploratief onderzoek naar 'Meer Bewegen voor Ouderen' in Limburg.

In this article an exploratory study into a national exercise program for people of 55 years and older is reported. In order to gain more insight in the various characteristics of the participants, a questionnaire was completed by a sample of 839 persons. The studied aspects are background characteristics, medical characteristics, characteristics of daily activities, risk behaviour, way of acquaintance with and motive for participation in the program. The results of the research are, if possible, compared with a reference group. A comparison between the participants of the various types of the movement program, shows similarities on the dimensions ADL-problems and bad health. Differences are found on the dimensions gender, age and education. The conclusion is that the choice of the type of the movement program is probably made on the ground of these three characteristics. The comparison between the participants of the exercise program and the reference group shows that a selection within the population of people of 55 years and older is very likely. The majority of the participants is 65 to 74 years old (43%), female (80%) and of low educational level (85%). Positive differences in favour of the exercise participants are found on the variables hypertension, medicine usage. ADL problems and risk behaviour (smoking and drinking). It is, however, unclear whether these differences are the result of an effect of the program or the result of selection in the program population. A combination of these two factors is also not ruled out. An effect-study can give more evidence for one of the factors involved.

5-HT receptors mediating contractions of the isolated human coronary artery.

We investigated contractile responses of the isolated human coronary artery to 5-hydroxytryptamine (5-HT), washed human platelets, sumatriptan and ergotamine. 5-HT (pD2: 6.8 +/- 0.1, Emax: 47.7 +/- 6.8 mN) and platelets (effect 14.4 +/- 2.8 mN with 3.10(10) platelets/l) caused contractile responses which were attenuated by ketanserin (1 microM). In the presence of ketanserin (1 microM), both rauwolscine (1 and 10 microM) and cyanopindolol (1 and 10 microM) caused concentration-dependent additional antagonism against contractions induced by low (< or = 1 microM) concentrations of 5-HT. Sumatriptan-induced contractions (pD2: 6.2 +/- 0.1; Emax: 10.7 +/- 2.4 mN) were antagonized to a similar extent by both rauwolscine (1 microM) and cyanopindolol (1 microM) (pKB: 6.5 +/- 0.1 and 6.4 +/- 0.1, respectively) and also by metergoline (0.1 microM; pKB: 7.2 +/- 0.1). The order of potency of antagonists against sumatriptan resembles the order reported for the human saphenous vein 5-HT1D-like receptor. No significant additional antagonism by cyanopindolol (1 microM) or rauwolscine (1 microM) against platelet-induced contractile responses was observed. Ergotamine caused potent contractile responses (pD2: 8.4 +/- 0.3, Emax: 19.4 +/- 2.4 mN). It is concluded that although 5-HT2 receptors predominantly mediate 5-HT-induced contractions, the 5-HT1-like receptor seems to play a role in coronary vasospasm caused by low concentrations of 5-HT.

The significance of complete serological testing for hepatitis B in heart valve banking.

Allograft heart valves obtained from donor hearts have been cryopreserved in the Heart Valve Bank in Rotterdam for transplantation purposes. In contrast to hepatitis B screening of organ donors, which consists of only a rapid HBV surface antigen (HBsAg) assay, tissue donors can be screened more completely for hepatitis B virus (HBV) by HBsAg and antibodies against HBV core antigen (anti-HBc) tests, and when necessary, anti-HBs and HBV-DNA tests. The value of this complete HBV screening was investigated by evaluation of the HBV screening results of 676 donor sera. HBsAg was positive in 1 serum. Anti-HBc was positive in 63 sera, of which 52 also had positive antibodies against HBV surface antigen (anti-HBs) tests (no risk of transmission) and 10 had negative anti-HBs tests. In 3 cases with a negative anti-HBs test the HBV-DNA test was positive (risk of transmission). In 3 cases not enough serum was available to perform all tests, resulting in a total of 7 rejected donors. Single HBsAg testing would have resulted in the rejection of only 1 donor. In the presented group of selected donors, approximately 0.5% of the HBsAg-negative donors were lower-level chronic carriers of hepatitis B. Complete HBV screening decreases the risk of transmission of hepatitis B in allograft heart valve transplantation.