[Predictors of participation in medical rehabilitation follow-up in working patients with chronic back pain]. / Prädiktoren der Teilnahme an einer Nachsorge nach ambulanter Rehabilitation bei erwerbstätigen Rehabilitanden mit chronischen Rückenschmerzen1.

BACKGROUND AND AIM: Outpatient follow-up programmes aim to increase the sustainability of rehabilitation. However, the factors influencing participation in follow-up programmes are still unclear. The aim of this study was to examine participation in the MERENA follow-up programme of the Rhineland-Palatinate German Pension Fund. METHOD: The study was conducted in 12 outpatient rehabilitation centres with 192 working patients who were being treated for chronic back pain at the time the survey was conducted. Both patients and physicians completed a written survey at the outset of rehabilitation, on completion, and again (if applicable) at the end of the follow-up programme. The data collected mainly concerned the patients' health and factors related to their occupational situation (e. g. functional capacity, working capacity) and reasons for refusing to participate in the MERENA follow-up programme. Predictors for participation in the follow-up programme were determined using binary logistic regression analysis. RESULTS: On completion of rehabilitation, nearly all patients were given the recommendation to participate in the follow-up programme. Half of these patients took advantage of the programme. The most frequently given reason for refusal to participate was that participation in the programme was not compatible with their duties at work. Low functional capacity and continued work disability increased the probability that a patient would take part in a follow-up programme after rehabilitation. In contrast, a longer commute to the centre was an obstacle to participation. Women were more likely to participate in the programme than men. CONCLUSIONS: The results indicate that participation in a follow-up programme is often not compatible with employment. We could not satisfactorily explain why women were more likely to participate in the programme. This result could have been related to women's more flexible time schedules. An improvement of the current situation could be achieved by having follow-up programmes closer to the home, by flexible follow-up offerings, alternative follow-up services (e. g. in certified physiotherapy centres and sport clubs) as well as by integrating companies in follow-up planning and implementation.

Illness representations in women with fibromyalgia.

OBJECTIVE: In the US population, the prevalence of fibromyalgia is about 3.4% in women. For those who are affected, fibromyalgia is associated with significant limitations relating to quality of life, activity, and participation. Furthermore, fibromyalgia leads to serious socio-economic costs. The objective of the present paper is to describe the cognitive illness representations of women with fibromyalgia and to analyse their relationship to rehabilitation outcomes. METHODS: The outcome was measured using the SF-36 and fibromyalgia impact questionnaire. The illness perceptions were assessed using the Illness Perception Questionnaire - revised. The prediction of outcome was done using hierarchical multiple regression analyses. RESULTS: N=245 patients are included in the sample. The patients attribute a multitude of symptoms to fibromyalgia and name numerous triggering factors. Illness representations are correlated with the illness impact at the beginning of rehabilitation and predict the outcome after the end of rehabilitation. CONCLUSION: The fact that illness representations turn out to be predictors of outcome, even when the baseline health status is statistically controlled, highlights the relevance of the illness representations of patients with fibromyalgia. Therefore, effective and efficient methods should be developed for integrating patient's illness beliefs into the management of the illness as early as possible.

Re-processing strategies for biologicals API manufacturing processes.

During the past 10 years, the production of biotechnological products has reached large scale starting from fermentor volumes of several thousand litres. Due to this large scale production, the value of a single batch has significantly increased. Sometimes even in routine production, technical or human failures occur. Without a re-processing procedure in place, such a failed batch has to be discarded leading to a waste of raw materials, time, energy and to a waste of money. This can be avoided by a well-defined re-processing strategy. On the other hand re-processing always raises concerns regarding product quality and stability. Therefore, re-processing should be adequately validated to exclude a negative impact on the product. An example for such a validation study is discussed.

[Coping with illness by young diabetic patients: a comparison from the viewpoint of patients, their parents and personal physicians]. / Krankheitsanpassung jugendlicher Diabetiker: ein Vergleich der Sicht der Patienten, ihrer Eltern und der behandelnden Arzte.

108 adolescents with type 1 diabetes as well as their parents and physicians in charge were studied in a prospective longitudinal design. Most of the juvenile patients were of good metabolic control. The results from different questionnaires of coping are presented. The opinions of the patients, their parents and the physicians in charge differ in some important aspects. Furthermore there are significant differences between the patients of best versus worst metabolic control as far as the extent of self reported psychosocial problems related with the disease is concerned.

Pharmacokinetic and thrombolytic properties of unglycosylated recombinant tissue-type plasminogen activator (BM 06.021) produced in Escherichia coli.

Recombinant tissue-type plasminogen activator (rt-PA) was produced in Escherichia coli cells in order to obtain an unglycosylated rt-PA (BM 06.021) with increased thrombolytic potency due to altered pharmacokinetic properties. The pharmacokinetics were studied in rabbits upon intravenous infusion of 200 kU/kg over 30 min. The thrombolytic dose-response effects were evaluated in a rabbit model with 125I-labeled venous thrombi upon intravenous infusion over 4 h. The thrombolytic effects after intravenous bolus injection of 200 kU/kg BM 06.021 were investigated in a canine model of coronary artery thrombosis. All studies were performed comparing BM 06.021 with glycosylated rt-PA (alteplase). BM 06.021 demonstrated a longer (p less than 0.05) half-life (5.6 +/- 2.6 vs. 2.1 +/- 0.3 min) and a lower (p less than 0.05) clearance rate (7.5 +/- 0.8 vs. 22.2 +/- 3.1 ml.min-1.kg-1) than alteplase in rabbits upon intravenous infusion. The dose-response curve of BM 06.021 for thrombolysis in a rabbit model of jugular vein thrombosis was located to the left of that for alteplase with a 2.1-fold lower effective dose of 50% thrombolysis (ED50) of BM 06.021 (207 vs. 436 kU/kg). Intravenous bolus injection of 200 kU/kg BM 06.021 induced the same reperfusion rate (4/6) as intravenous infusion of 800 kU/kg alteplase over 90 min in a canine model of coronary artery thrombosis. The residual thrombus wet weight did not significantly differ between BM 06.021 and alteplase (5.7 +/- 1.8 vs. 6.3 +/- 1.1 mg). The results indicate that unglycosylated rt-PA (BM 06.021) has a higher in vivo thrombolytic potency than glycosylated rt-PA (alteplase).(ABSTRACT TRUNCATED AT 250 WORDS)

Biochemical properties of the kringle 2 and protease domains are maintained in the refolded t-PA deletion variant BM 06.022.

BM 06.022 is a t-PA deletion variant which comprises the kringle 2 and the protease domain. Production of BM 06.022 in Escherichia coli leads to the formation of inactive inclusion bodies, which have to be refolded by an in vitro refolding process to achieve activity and proper structure of the domains. We analysed the biochemical properties of BM 06.022 to obtain some information about the structure of kringle 2 and the protease as compared with the structure of these domains in the intact t-PA molecule. The kinetic analysis of the amidolytic activity of BM 06.022 and CHO-t-PA yielded similar values for kcat (13.9 s-1 and 11.4 s-1 for the single chain forms and 33.9 s-1 and 27.1 s-1 for the two chain forms of BM 06.022 and CHO-t-PA, respectively) and for Km (2.5 mM and 2.1 mM for the single chains forms and 0.5 mM and 0.3 mM for the two chain forms of BM 06.022 and CHO-t-PA, respectively). BM 06.022 and CHO-t-PA have the same plasminogenolytic activity in the absence of CNBr fragments of fibrinogen. However, BM 06.022 has a lower plasminogenolytic activity in the presence of CNBr fragments of fibrinogen and a lower affinity to fibrin as compared with CHO-t-PA. The affinity of BM 06.022 for fibrin is completely suppressed by 0.3 mM epsilon-aminocaproic acid, while the intact t-PA has a residual affinity of approximately 30%. The dissociation constants for the interaction with the lysine analogue epsilon-aminocaproic acid are 0.10 mM and 0.09 mM for BM 06.022 and the intact t-PA, respectively. Furthermore, BM 06.022 and CHO-t-PA are inhibited by PAI-1 in a similar manner.

Thrombolysis with an Escherichia coli-produced recombinant plasminogen activator (BM 06.022) in the rabbit model of jugular vein thrombosis.

The recombinant plasminogen activator BM 06.022 consists of the kringle 2 and the protease domains of human t-PA and is unglycosylated because of the expression in Escherichia coli. The thrombolytic and pharmacokinetic properties as well as the hemostasis effects of BM 06.022 were investigated in the rabbit model of jugular vein thrombosis. The thrombi were 125I-fibrin labeled. Intravenous bolus injection of 50, 100, 200, and 400 kU/kg BM 06.022 or 400, 800, and 1600 kU/kg alteplase over 15 s to six rabbits/dose produced a dose-dependent increase of thrombolysis determined 2 h post injection. The dose-response curve of BM 06.022 was located left compared with that of alteplase. The effective dose of 50% thrombolysis (ED50) obtained by half-logarithmic regression analysis was 163 kU/kg (= 0.28 mg/kg) for BM 06.022 and 871 kU/kg (= 1.09 mg/kg) for alteplase. At equipotent doses (50% thrombolysis), the residual concentration of fibrinogen was 74.2% and 76.5%, that of plasminogen 66.7% and 69.4%, and that of alpha 2-antiplasmin 47.3% and 46% for BM 06.022 and alteplase, respectively. Pharmacokinetic analysis for plasma activity at a dose of 400 kU/kg revealed a half-life of 18.9 +/- 1.5 min for BM 06.022, whereas alteplase was distributed with a half-life of 2.1 +/- 0.1 min, accounting for 86.7 +/- 1.9% of the total AUC, followed by a beta-phase with a half-life of 13.8 +/- 0.9 min. Plasma clearance of BM 06.022 was 4.7 +/- 0.7 ml min-1 kg-1 compared with 20 +/- 1.2 ml min-1 kg-1 for alteplase.(ABSTRACT TRUNCATED AT 250 WORDS)

Proteolytic dimers of porcine muscle lactate dehydrogenase: characterization, folding, and reconstitution of the truncated and nicked polypeptide chain.

Lactate dehydrogenase from porcine skeletal muscle is a "dimer of dimers" that is stabilized in its tetrameric state by an N-terminal "arm" of approximately 20 amino acid residues. Due to the low dissociation constant of the tetramer, the dimer is inaccessible to direct analysis. Limited proteolysis during reconstitution (after dissociation at pH 2.3) yields stable "dimers". As suggested by affinity chromatography, these inactive dimers contain the dinucleotide fold of native LDH. In the presence of structure-making ions, approximately 40% activity is restored in the dimeric state [Girg, R., Jaenicke, R., & Rudolph, R. (1983) Biochem. Int. 7, 443-444]. The cleavage yields about equal amounts of three fragments, F 34, F 21, and F 14 (Mr 33.5K, 21.4K, and 13.5K, respectively). F 34 represents the intact chain lacking the N-terminal 10-11 amino acid residues; its C-terminus is heterogeneous, varying in the range between residues 326 +/- 5. F 21 contains residues 11/12 to 200 +/- 3; F 14 is a mixture of three subfragments: residues 11/12 to approximately 133, 38 to approximately 163, and 208 to approximately 327. After solubilization in 6 M guanidine hydrochloride, F 34 can be reconstituted to partially active dimers. Reactivation is determined by slow subunit refolding with subsequent diffusion-controlled dimerization, in accordance with the monomer-dimer transition in the reconstitution mechanism of the intact tetramer. Reconstitution of F 21 and F 14 is concentration dependent and leads to partially active "nicked dimers", indicating that separate domains are able to reassociate correctly to yield the native subunit arrangement.

Monoclonal antibodies detecting plasminogen activators on the membrane of leukemic lymphoid cells of T-cell origin.

The specificities of six monoclonal antibodies produced against plasminogen activator of the human Bowes melanoma cell line are described. They have been used to detect membrane-bound plasminogen activator on cultured human lymphoid cell lines and in neoplastic human lymphocytic and myeloid cells of leukemic patients. These studies indicate that only certain phenotypic subsets of the T-cell lineage derived from patients with chronic lymphocytic leukemia or with Szezary syndrome express plasminogen activator on their surface membrane.

Cutaneous infiltrates of histiocytosis X contain plasminogen activator-bearing epidermotropic dendritic cells different from Langerhans cells.

Plasminogen activators (PA) play an important role in cell migration and tissue degradation. Considering the strong epidermotropism of atypical mononuclear cells in histiocytosis X (HX) skin infiltrates leading to intraepidermal abscess formation, it was the purpose of this study to look for tissue-type PA (t-PA) and/or urokinase-type PA (u-PA) on HX cells. Four monoclonal antibodies against PA were used, employing the alkaline phosphatase anti-alkaline phosphatase (APAAP) technique on cryostat sections from four patients with HX. Twenty percent to 40% of infiltrating cells in the epidermis expressed the t-PA antigen. t-PA+ cells were present in the follicular centers of human tonsil, absent in normal epidermis and scanty in cutaneous infiltrates from mycosis fungoides and lupus erythematosus. Double labeling with anti-PA and T6 (CD1) or S100 protein revealed some of the HX cells to express both antigens (t-PA+ CD1+ or t-PA+ S100+). We conclude that cutaneous infiltrates of HX contain PA+ dendritic cells which are different from normal Langerhans cells and which may be responsible for the strong epidermal alterations in HX.

Administration of silica or monoclonal antibody to Thy-1 prevents low-dose streptozotocin-induced diabetes in mice.

Multiple injections of low doses of streptozotocin induce an experimental diabetes in mice. We have analyzed in two inbred strains whether the development of hyperglycaemia can be influenced by administration of macrophage-toxic silica particles or by a monoclonal antibody to Thy-1.2. Mice received streptozotocin (30 or 40 mg/kg) on five consecutive days (day 0-day 4) and in addition either silica particles (starting at day 0) or anti-Thy-1.2 (starting at day -2 or -3). In both strains mice receiving streptozotocin alone became hyperglycaemic within two weeks. Additional treatment with silica almost fully prevented diabetes development. Anti-Thy-1.2 administration was similarly effective in C57B1/Ks and partially protective in C57BL/6 mice. Histological analysis of pancreatic islets showed that a large fraction of beta cells had been spared from destruction by this treatment. The data indicate a role for both macrophages and Thy-1 positive cells in the pathogenesis of low-dose streptozotocin-induced diabetes.

Injection of anti-thy-1.2 serum breaks genetic resistance of mice against herpes simplex virus.

Nude mice have been shown to be as resistant to intraperitoneal infection with herpes simplex virus type 1 (HSV) as their heterozygous littermates. Here we document that both activation of natural killer (NK) cells and interferon induction were normal in nu/nu mice after injection of HSV. Injection of silica caused increased mortality by HSV in C57BL/6 mice. Silica, in addition, led to a significant reduction of NK cell activity but had no effect on the interferon response. Treatment of C57BL/6 mice with anti-asialo GM1 (an antiserum with a predominant effect on NK cells) caused complete abolition of the NK cell response, but had no effect on interferon induction or virus-induced mortality. In further studies a monoclonal anti-thy-1.2 antibody was utilized which possessed high activity in vivo in depleting T cell responses in mice. Injection of anti-thy-1.2 decreased NK cell activation but was without effect on the interferon response. Unexpectedly, in view of the data in nu/nu mice, this antibody increased HSV-induced mortality in C57BL/6 mice. Similar data were obtained when anti-thy-1.2 was injected into nu/nu mice. Our results are compatible with the hypothesis that T cell precursors sensitive to anti-thy-1.2 present in homozygous nude mice play a role in resistance against HSV. Furthermore, the data in the euthymic mice may indicate a role of T cells in the primary resistance of mice against HSV.

A new model for investigations of T-cell functions in mice: differential immunosuppressive effects of two monoclonal anti-Thy-1.2 antibodies.

Two monoclonal anti-Thy-1.2 antibodies were investigated for their activity in eliminating T cells in vitro and in vivo. Both antibodies exert a complement-dependent cell cytotoxicity in vitro. Antibody B that belongs to the IgM class shows a 100-fold higher complement-dependent cytotoxic activity than antibody C, which is of IgG2a class. However, administration of antibody C into Balb/c mice results in the elimination of T cells as determined by the failure of different T-cell functions. Within 24 hours after administration of antibody C, the reactivity of spleen of lymph-node cells to T-cell mitogens, the antibody response to the T-cell-dependent antigen SRBC and the SRBC-induced delayed-type hypersensitivity are completely abolished. These effects are dose-dependent in a dose range of 0.1-1.0 mg Ig protein per animal and affects only T cells in the peripheral lymphoid organs. The Thy-1.2-bearing cells residing in the thymus are not impaired by the treatment of the animals with this monoclonal antibody and are able to repopulate the peripheral lymphoid organs within 30 to 60 days. Investigations into the mode of action of the removal of peripheral T cells revealed that antibody-C-coated Thy-1.2-bearing cells are rapidly phagocytosed by macrophages, while antibody-B-coated Thy-1.2-bearing cells are not. This might be the reason for the differential in-vivo activities of the two monoclonal antibodies. A model with new qualities for the study of functions and the regeneration of T cells in vivo has been established.

Normal and Friend virus specific cell compartments in Friend leukemia characterized by their sensitivity to actinomycin D in vivo.

DBA/2 mice were infected with the polycythemia inducing Friend Virus (F-MuLV-P) and treated with different doses of Actinomycin D (Act D) when the whole erythroid cell system, as measured by the CFU-E technique with and without addition of erythropoietin (Ep), had been transformed into Ep-independence. During and after this therapy the different stem cell pools CFU-S, CFU-C, BFU-E and CFU-E (with and without Ep) were studied and their sensitivity to Act D in bone marrow and spleen was compared to that of normal mice, recently published by other authors. There seemed to be no difference in the Act D sensitivity between normal erythropoiesis and Ep-independent erythropoiesis caused by F-MuLV-P. Furthermore a cell called ICPC (infectious centers producing cell) was studied. This cell system, detected by spleen colony formation due to high local virus production in an unirradiated host, proved to be Act D sensitive in the spleen but not in the marrow. When the erythroid cell system regenerated after Act D chemotherapy, all erythroid colony growth was Ep-independent. This means that Act D did not induce normal erythropoiesis as seen with hydroxyurea treatment.

Effects of tilorone on hemopoietic stem cells and on the development of Friend leukemia.

Hematological effects of tilorone, an interferon inducer, on the hematopoietic cell system of normal CBA/Ca mice and on the development of Friend virus (FV-P)-induced polycythemia in DBA/2 mice were studied. In normal mice 80 mg/kg IP had a marked depressive effect on pluripotent (CFU-s), granuloid committed (CFU-C), and erythroid committed (CFU-E) stem cells with regeneration between days 5 and 12. In bone marrow smears only lymphopenia was detected. Treatment of mice before FV-P infection caused a slight retardation in the development of the splenomegaly and the transformation of bone marrow cells to Ep independence. Repeated treatment after FV-P infection also reduced the increase in spleen weight and the development of reticulocytosis, but the Ep independence of bone marrow and spleen cells was not influenced. In vitro exposure of normal cells and cells from FV-P-infected animals to the drug showed the same sensitivity of colony growth in normal as well as in Ep-independent CFU-E. The action of the drug on Friend leukemia is at least in part considered a toxic effect on the hematopoietic stem cell system.

Effects of ribavirin on the development of the Friend leukemia.

Ribavirin (300 and 250 mg/kg i.p., respectively) had a toxic effect on hemopoietic stem cells in normal mice CFU-S, CFU-C, and especially CFU-E were reduced after a single treatment. The drug was further studied in mice infected with the polycythemia-inducing strain of the Friend virus (FV-P). In these mice a specific erythropoietin-independent CFU-E population (CFU-EI) replaces the normal erythropoiesis and can be considered a tumor cell population. With the in vitro technique for CFU-E, CFU-EI can easily be quantified and used as a sensitive marker for the development of the disease. Repeated doses of ribavirin reduced the increase of spleen weight after FV-P infection and the progressive transformation of normal CFU-E into CFU-EI was delayed. The further development of the disease remained unaltered. In vitro CFU-E and CFU-EI were inhibited at the same concentrations when the drug was added to the culture medium. In mice pretreated with multiple doses of hydroxyurea, ribavirin delayed the recurrence of Friend leukemia as seen from the spleen weight increase, but the CFU-E population was predominantly Ep-independent. It is concluded that the effects of the drug were due to its cytotoxicity rather than to a specific antiviral effect.

Erythroid stem cell regeneration in normal and plethoric mice treated with hydroxyurea.

Hydroxyurea (4 x 500 mg/kg at 6 hour intervals) was used to study hemopoietic regeneration in normal and in hypertransfused mice. All recognizable granuloid and erythroid cells, most granulopoietic (CFU-C) and all erythroid (CFU-E) precursors and about 80% of the pluripotent stem cells were eliminated after this treatment. Regeneration started between days 2 and 3 in the marrow and 1 day later in the spleen. An overshoot in CFU-C and CFU-E per femur was seen at day 4. In parallel to their committed precursors granulopoietic cells reappeared between days 2 and 4, erythroblasts between days 3 and 5. In the spleen a maximum CFU-S and CFU-C concentration was seen at day 7. The early increase of CFU-E in the marrow was followed by a fall to low levels, then the CFU-E concentration in the spleen increased. The regeneration was further studied in hypertransfused mice. CFU-S and also CFU-E in the marrow regenerated in exactly the same way as in normal mice and erythroblasts were found in marrow smears. The further maturation of erythroblasts to reticulocytes was impaired in hypertransfused mice, but not in normal mice. The role of erythropoietin (Ep) in the regulation of the CFU-E regeneration is discussed; early differentiation steps seem to be possible without Ep.

Hematopoietic stem cells in Friend murine leukemia virus-infected mice undergoing chemotherapy: remission and relapse of erythropoietin-independent erythropoiesis induced by hydroxyurea.

Hydroxyurea (HU), given ip four times, each time at 500 mg/kg in 6-hour intervals, was used to treat DBA/2 mice with Friend murine leukemia virus-induced polycythemia (F-MuLV-P). In these mice a new cell type, found after virus infection, gave rise to erythropoietic colonies in vitro without addition of erythropoietin (Ep) and completely replaced Ep-dependent normal erythropoietic colonies in vitro. The colony-forming units in the spleen (CFUs), the colony-forming units in culture (CFUc), and the erythropoietic colony-forming units (CFUE) were studied. Two days after treatment, CFUs were reduced to about 20% in controls and F-MuLV-P-infected animals, and CFUc were reduced to 6-11% in controls and F-MuLV-P-infected animals. CFUE were not detectable. At day 4 after the first HU dose, when CFUs has regenerated to about normal levels, a sharp rise in Ep-dependent CFUE was seen in the marrow; this rise was not present before HU treatment. The subsequent fall at day 7 coincided with a regeneration of CFUE in the spleen, but in the spleen these CFUE were all Ep-independent. Possibly, the normal Ep-dependent CFUE during regeneration in the marrow might have derived from previously resting CFUs that were not killed by HU. The subsequent conversion to Ep independency could have been due to reinfection by F-MuLV-P persisting in the animal.

Studies on the target cell for the Friend virus (FV-P strain) using the CFU-E technique.

In order to characterize the target cell for the polycythemia inducing Friend virus (FV-P) in vivo, mice were treated by induction of plethorism, bleeding, Actinomycin D, and Busulfan before virus infection. The development of the Friend leukemia was then studied mainly using the CFUE technique for erythroid colony growth in vitro. This technique allows the quantification of a new cell type, an erythropoietin (Ep) independent colony forming cell. These Ep independent colonies were taken as marker for the disease. Their number with time after infection was correlated with the compartment size of pluripotent, granuloid committed and erythroid stem cells at the time of infection. The results indicate that the development of the Friend leukemia does not require the actual presence of CFUE, as seen using Actinomycin D, and is not correlated with the number of pluripotent or granuloid stem cells, as seen after Busulfan. It is, however, dependent on the erythropoietic state of the animal, as seen in plethoric mice and mice after bleeding. It is, therefore, concluded that the target cell for FV-P is located within the Ep-responsive cell compartment, between early (BFUE) and late (CFUE) erythroid precursor cells.