Remifentanil as an adjunct to anaesthesia for electroconvulsive therapy fails to confer long-term benefits.

BACKGROUND: Adding the µ-opioid receptor agonist remifentanil to agents used to induce general anaesthesia in electroconvulsive therapy (ECT) can reduce the required doses of induction agents and their unfavourable effects on seizure threshold and quality. However, whether remifentanil has favourable long-term treatment effects in terms of response and remission rates, speed of response and remission, and side-effects has not been studied. METHODS: This retrospective, register-based cohort study involved patients with major depression consecutively treated at two units at different hospitals in Norway with the same ECT procedure. Both units used thiopental for ECT anaesthesia, but only one unit added remifentanil (R+; n=47; 541 sessions), whereas the other did not (R-; n=119; 1166 sessions). A Cox proportional hazards model for interval-censored data was conducted to examine the effects of remifentanil on the time to response and remission from depressive symptoms, whilst adjusting for age, sex, and baseline depression score. RESULTS: Both R+ and R- patients showed substantial reductions of depressive symptoms, with no difference in the response (76% in both groups) or remission (63% vs 65%) rate. However, R+ patients responded (hazard ratio=0.59; 95% confidence interval: 0.4-0.8) and remitted (hazard ratio=0.72; 95% confidence interval: 0.5-1.0) more slowly, and reported more often side-effects of nausea (30% vs 8%; P<0.001), dizziness (22% vs 8%; P=0.027), and headache (48% vs 23%; P=0.004). CONCLUSIONS: The use of adjunctive remifentanil was associated with more short-term side-effects and no favourable long-term clinical outcomes. The practice of routinely adding remifentanil to barbiturate anaesthesia should therefore be reconsidered.

[Medical rehabilitation by general practitioners in patients with chronic mental disorders]. / Rehabilitationsbedarf bei Hausarztpatienten mit psychischen Störungen.

BACKGROUND: Rehabilitation medicine is the medical specialty for the prevention, diagnosis and treatment of chronic disorders. This is especially relevant in mental disorders. Treatment of chronic disorders requires a complex and multidisciplinary long-term-treatment which is regularly done by general practitioners. However, concepts for rehabilitation-medicine in outpatient settings are until now by and large insufficient. METHODS: 40 general practitioners were asked to give an estimate on how many patients with chronic psychological disorders were among their patients.Next, 1 451 patients between 18 and 60 years filled in the WHO-5 wellbeing-rating, the IMET scale on participation disorders, the Burvill scale on multimorbidity and answered questions on their mental and work status. RESULTS: The general practitioners estimated that on average 41,9% (SD=18,2; Range 15-90%) were suffering from chronic mental disorders. 46,5% of the patients said that they suffered from mental problems, 38,3% had mental problems longer than 6 months, i. e., chronic, and in 26,9% even persistent. 29,7% of the patients suffered from chronic mental problems with relevant participation disorders. CONCLUSION: Patients with chronic mental disorders and participation problems are frequent in general practice. Rehabilitation medicine is an important part the daily activities of general practitioners, including diagnosis, treatment, treatment coordination, and sociomedical interventions like sick leave certificates, or initiating inpatient rehabilitation. General practitioners should get more scientific attention when concepts of rehabilitation are discussed.

Sex-specifics of ECT outcome.

OBJECTIVE: Electroconvulsive therapy (ECT) is the most effective treatment for patients with severe major depressive disorder (MDD). Given the known sex differences in MDD, improved knowledge may provide more sex-specific recommendations in clinical guidelines and improve outcome. In the present study we examine sex differences in ECT outcome and its predictors. METHODS: Clinical data from 20 independent sites participating in the Global ECT-MRI Research Collaboration (GEMRIC) were obtained for analysis, totaling 500 patients with MDD (58.6 % women) with a mean age of 54.8 years. Severity of depression before and after ECT was assessed with validated depression scales. Remission was defined as a HAM-D score of 7 points or below after ECT. Variables associated with remission were selected based on literature (i.e. depression severity at baseline, age, duration of index episode, and presence of psychotic symptoms). RESULTS: Remission rates of ECT were independent of sex, 48.0 % in women and 45.7 % in men (X2(1) = 0.2, p = 0.70). In the logistic regression analyses, a shorter index duration was identified as a sex-specific predictor for ECT outcome in women (X2(1) = 7.05, p = 0.01). The corresponding predictive margins did show overlapping confidence intervals for men and women. CONCLUSION: The evidence provided by our study suggests that ECT as a biological treatment for MDD is equally effective in women and men. A shorter duration of index episode was an additional sex- specific predictor for remission in women. Future research should establish whether the confidence intervals for the corresponding predictive margins are overlapping, as we find, or not.

A simple presurgical necrotizing enterocolitis-mortality scoring system.

OBJECTIVE: To assess the relationship between early laboratory parameters, disease severity, type of management (surgical or conservative) and outcome in necrotizing enterocolitis (NEC). STUDY DESIGN: Retrospective collection and analysis of data from infants treated in a single tertiary care center (1980 to 2002). Data were collected on disease severity (Bell stage), birth weight (BW), gestational age (GA) and pre-intervention laboratory parameters (leukocyte and platelet counts, hemoglobin, lactate, C-reactive protein). RESULTS: Data from 128 infants were sufficient for analysis. Factors significantly associated with survival were Bell stage (P<0.05), lactate (P<0.05), BW and GA (P<0.01, P<0.001, respectively). From receiver operating characteristics curves, the highest predictive value resulted from a score with 0 to 8 points combining BW, Bell stage, lactate and platelet count (P<0.001). At a cutoff level of 4.5 sensitivity and specificity for predicting survival were 0.71 and 0.72, respectively. CONCLUSION: Some single parameters were associated with poor outcome in NEC. Optimal risk stratification was achieved by combining several parameters in a score.

Perturbation of C6 glial cells by acetate leads to modulation of [125I]IGF-II binding to the IGF-II/M6P receptor: implications for ligand internalization studies.

Acid washes are used as an experimental tool to differentiate between cell-surface bound and internalized radioligands. We have observed that washes with acid buffers containing 100 mM acetate can modulate [125I]IGF-II binding to rat C6 glial cells in an unexpected manner: when cells in monolayer culture were prewashed with phosphate buffered saline (pH 7.3) (PBS), [125I]IGF-II binding was characteristic of the IGF-II/mannose-6-phosphate (M6P) receptor. Importantly, IgG 3637, which is purified from an antiserum directed against the rat IGF-II/M6P receptor, blocked binding of [125I]IGF-II whereas nonimmune IgG did not. Affinity crosslinking studies using DSS as the crosslinking agent and Western blotting experiments using antiserum 3637 confirmed the presence of the IGF-II/M6P receptor in C6 glial cells. Prewashes of C6 cell monolayers with acid buffers (pH 4-4.5) which contained 100 mM sodium acetate and which have been used in internalization studies reduced [125I]IGF-II binding by 40-60%. Affinity crosslinking studies using C6 cells showed that the formation of the 250 kDa radioligand-receptor complex was not prohibited by IgG 3637 after acid washes with buffers containing high acetate concentrations, while acid washes with buffers containing no acetate did not cause a loss in the blocking ability of IgG 3637. However, acid washes with 100 mM acetate did not alter the recognition of IGF-II/M6P receptors by IgG 3637 in Western blotting experiments. In addition, in a subset of experiments acid prewashes with acetate also decreased binding of [125I]IGF-I to the IGF-I receptor by 20%. We conclude that acid washes with acetate buffers lead to decreased [125I]IGF-I and [125I]IGF-II binding. In addition, the capability of anti-receptor IgG to block radioligand binding to the IGF-II/M6P receptor also declines. We hypothesize that alteration of ligand binding might be partially caused by perturbation of the cell membrane and hence a conformational change in IGF receptors. These data imply that the use of acetate buffers in acid wash experiments in ligand internalization studies--particularly in studies involving the IGF-II/M6P receptor--should be avoided.

The effect of substrate binding on the conformation and structural stability of Herpes simplex virus type 1 thymidine kinase.

The structure of Herpes simplex virus type 1 thymidine kinase (TK(HSV1)) is known at high resolution in complex with a series of ligands and exhibits important structural similarities to the nucleoside monophosphate (NMP) kinase family, which are known to show large conformational changes upon binding of substrates. The effect of substrate binding on the conformation and structural stability of TK(HSV1), measured by thermal denaturation experiments, far-UV circular dichroism (CD) and fluorescence is described, and the results indicate that the conformation of the ligand-free TK(HSV1) is less ordered and less stable compared to the ligated enzyme. Furthermore, two crystal structures of TK(HSV1) in complex with two new ligands, HPT and HMTT, refined to 2.2 A are presented. Although TK(HSV1):HPT does not exhibit any significant deviations from the model of TK(HSV1):dT, the TK(HSV1):HMTT complex displays a unique conformationally altered active site resulting in a lowered thermal stability of this complex. Moreover, we show that binding affinity and binding mode of the ligand correlate with thermal stability of the complex. We use this correlation to propose a method to estimate binding constants for new TK(HSV1)substrates using thermal denaturation measurements monitored by CD spectroscopy. The kinetic and structural results of both test substrates HPT and HMTT show that the CD thermal denaturation system is very sensitive to conformational changes caused by unusual binding of a substrate analog.

Identification and in situ localization of the insulin-like growth factor-II/mannose-6-phosphate (IGF-II/M6P) receptor in the rat gastrointestinal tract: comparison with the IGF-I receptor.

In the present study we investigated pharmacological, biochemical, and immunological characteristics as well as the tissue distribution of the insulin-like growth factor-II/mannose-6-phosphate (IGF-II/M6P) receptor in the rat gastrointestinal tract, and compared the data with those from corresponding experiments for the IGF-I receptor. Competitive binding and affinity cross-linking studies with [125I]IGF-II, and [125I]IGF-I respectively, in rat jejunum yielded results analogous to those previously obtained for IGF-II/M6P and IGF-I receptors in intestinal epithelial membranes and other tissues. Furthermore, the IGF-II/M6P receptor antibody no. 3637 completely inhibited the association of [125I]IGF-II with receptor protein but nonimmune antibody did not, providing additional evidence for the presence of the IGF-II/M6P receptor in the rat gut. Also, analysis of the IGF-II/M6P receptor by immunoblotting using antiserum no. 3637 identified a specific band of mol wt 220.000 throughout the gastrointestinal tract with the highest content of immunoreactivity being present in colon and ileum. Autoradiographic mapping of the distribution of IGF-receptors in the rat gut showed that the expression of IGF-II/M6P receptors was in general 2-3 times greater than that of IGF-I receptors. IGF-II/M6P receptors were found 1) in greatest densities in colon and ileum, 2) more abundantly in the mucosa than in the muscularis propria, and 3) predominantly in the luminal part of the mucosal epithelial cells. Radioimmunocytochemistry employing anti-IGF-II/M6P receptor antibody no. 3637 and [125I]protein A demonstrated an IGF-II/M6P receptor distribution analogous to that shown by autoradiography with [125I]IGF-II). IGF-I receptors were present 1) in greatest densities in ileum and colon, 2) more abundantly in the muscularis propria than in the mucosa, and 3) within the mucosa in greater densities in the lamina propria than in the surface epithelium. For both receptor types densities were greater in crypt than in villous epithelial cells. We conclude: 1) the presence of IGF-II/M6P receptors throughout the rat gastrointestinal tract points to an important role for IGF-II in this organ, 2) the finding of different patterns of distribution for IGF-II/M6P and IGF-I receptors supports the concept of their different principal functions, 3) a high degree of expression of both receptor types in crypt epithelium suggests an essential role for both IGF receptors in the regulation of cell mitogenesis and growth.

Identification and characterization of insulin-like growth factor receptors on adult rat cardiac myocytes: linkage to inositol 1,4,5-trisphosphate formation.

Cultured cardiac myocytes from adult Sprague-Dawley rats express both insulin-like growth factor-I (IGF-I) receptors and insulin-like growth factor-II/mannose 6-phosphate (IGF-II/Man6P) receptors and respond to IGF-I with a dose-dependent accumulation of inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] and inositol 1,4-bisphosphate [Ins(1,4)P2]. Specific binding of [125I]IGF-I to isolated membranes from cultured cardiac myocytes amounted to 1-1.2%. Binding of [125I]IGF-I was inhibited by unlabeled IGF-I at nanomolar concentrations and insulin at much higher concentrations. These data suggest that IGF-I binds to its own receptor on rat cardiac myocytes. Competitive binding studies using isolated membranes from cardiac myocytes and [125I]IGF-II showed 2-4% specific binding. Binding of [125I]IGF-II was inhibited by IGF-II and much less potently by IGF-I and insulin. Immunoglobulin G (IgG) 3637 (an IgG directed against the IGF-II/Man6P receptor) partially inhibited binding of [125I]IGF-II whereas nonimmune IgG did not. Affinity cross-linking studies with [125I]IGF-II and cardiac myocyte membranes and subsequent analysis of the ligand-receptor complex using SDS-PAGE and autoradiography showed a radiolabeled band of approximately 250 kilodalton (kDa). The formation of the [125I]IGF-II-receptor complex was inhibited by incubation with IGF-II and IgG 3637 but not by insulin or nonimmune IgG. Western blotting of protein extracts from cultured cardiac myocytes was performed using IgG 3637 and an immunoperoxidase technique for the visualization of the IGF-II/Man6P receptor protein. A specific band at 220 kDa under nonreducing conditions was detected on the blots, providing further evidence for the expression of the IGF-II/Man6P receptor by cardiac myocytes. The effect of IGFs on the accumulation of inositol phosphates was measured by HPLC analysis of perchloric acid extracts from myo-[3H]inositol-labeled cultured cardiac myocytes. IGF-I (50 ng/ml) stimulated the accumulation both of Ins(1,4,5)P3 and Ins(1,4)P2 after 30 sec by 43% and 63%. IGF-II (up to 500 ng/ml) had no significant effect on inositol phosphate accumulation under the same conditions. However, in the presence of millimolar concentrations of Man6P, IGF-II (500 ng/ml) also increased Ins(1,4,5)P3 accumulation by 59%. We conclude that cardiac myocytes from adult rats express IGF receptors and respond to IGFs with the accumulation of Ins(1,4,5)P3 and Ins(1,4)P2. This effect seems to be mediated by an IGF-I receptor-specific pathway.

Expression of the insulin-like growth factor-II/mannose-6-phosphate receptor in multiple human tissues during fetal life and early infancy.

The insulin like growth factor-II/mannose-6-phosphate (IGF-II/M6P) receptor has been detected in many cells and tissues. In the rat, there is a dramatic developmental regulation of IGF-II/M6P receptor expression, the receptor being high in fetal and neonatal tissues and declining thereafter. We have systematically studied the expression of the human IGF-II/M6P receptor protein in tissues from 10 human fetuses and infants (age 23 weeks gestation to 24 months postnatal). We have asked 1) whether there is differential expression among different organs, and 2) whether or not the human IGF-II/M6P receptor is developmentally regulated from 23 weeks gestation to 24 months postnatal. Protein was extracted from human tissues using a buffer containing 2% sodium dodecyl sulfate and 2% Triton X-100. Aliquots of the protein extracts were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting using an anti-IGF-II/M6P receptor antiserum (no. 66416) and 125I-protein A or an immunoperoxidase stain. IGF-II/M6P receptor immunoreactivity was detected in all tissues studied with the highest amount of receptor being expressed in heart, thymus, and kidney and the lowest receptor content being measured in brain and muscle. The receptor content in ovary, testis, lung, and spleen was intermediate. The apparent molecular weight of the IGF-II/M6P receptor (220,000 kilos without reduction of disulfide bonds) varied among the different tissues: in brain the receptor was of lower molecular weight than in other organs. Immunoquantitation experiments employing 125I-protein A and protein extracts from human kidney at different ages revealed a small, albeit not significant, difference of the receptor content between fetal and postnatal tissues: as in other species, larger amounts of receptor seemed to be present in fetal than in postnatal organs. In addition, no significant difference of the receptor content between human fetal liver and early postnatal liver was measured employing 125I-protein A-immunoquantitation in three fetal and five postnatal liver tissue samples. The distribution of IGF-binding protein (IGEBP) species, another abundant and major class of IGF binding principles, was also measured in human fetal and early postnatal lung, liver, kidney, muscle, and brain using Western ligand blotting with 125I-IGF-II: as with IGF-II/M6P receptor immunoreactivity there was differential expression of the different classes of IGFBPs in the various organs.(ABSTRACT TRUNCATED AT 400 WORDS)

Insulin-like growth factor (IGF)-I and -II and IGF-binding proteins-1, -2, and -3 in children and adolescents with diabetes mellitus: correlation with metabolic control and height attainment.

The putative effects of diabetes and metabolic control on circulating levels of insulin-like growth factors (IGFs) and their binding proteins (IGFBPs) remain controversial. In the present study, serum levels of IGF-I and IGF-II and IGFBP-1, -2, and -3 were measured in 58 patients (age, 0.8-17 yr) with treated (51 subjects) or untreated (7 subjects) insulin-dependent diabetes mellitus (IDDM) and were compared with the levels in normal subjects. In the untreated patients IGF-I and IGF-II were decreased as compared with the healthy controls. In the treated diabetics IGF-I and IGF-II were reduced; IGFBP-2 (only in prepubertal subjects) and IGFBP-3 were increased. Furthermore, age-adjusted values of IGF-I, IGF-II, and IGFBP-3 were lower in prepubertal than in pubertal patients. Regression analysis revealed a negative correlation between hemoglobin (Hb)A1c and standard deviation scores (SDS) of IGF-I and a positive association between HbA1c and IGFBP-1 SDS or IGFBP-2 SDS. In the treated patients HbA1c was positively related to IGFBP-1 SDS and IGFBP-2 SDS when applying simple regression analysis and to IGFBP-2 SDS when using a multiple regression model. Strong correlations were observed between height SDS and IGF-I SDS, IGF-II SDS, and IGFBP-3 SDS in prepubertal subjects who had had IDDM for at least 2 yr, but not in adolescents. Such correlations have also been found in healthy children and adolescents. In conclusion; 1) IDDM is associated with alterations of the IGF-IGFBP system, which are partially accounted for by differences in metabolic control and pubertal status; 2) the lower plasma concentrations of serum IGF-I may play a role in the pathogenesis of growth impairment of poorly controlled prepubertal, but not pubertal, children and adolescents with IDDM; and 3) in addition, a potential role of the altered IGF-IGFBP system for the development of diabetic late complications is hypothesized.

Biosynthetic labeling of beta-hexosaminidase B: inhibition of the cellular uptake of lysosomal secretions containing [3H]hexosaminidase B by insulin-like growth factor-II in rat C6 glial cells.

The insulin-like growth factor-II/mannose-6-phosphate receptor binds two classes of ligands, IGF-II and lysosomal enzymes containing the mannose-6-phosphate recognition marker. To study the interaction of the two classes of ligands at the receptor level, we have isolated 'high uptake' forms of lysosomal enzymes containing mannose-6-phosphate that had been radiolabeled biosynthetically using a tissue culture model: Tay-Sachs disease fibroblasts were incubated in medium containing [3H]mannose, ammonium chloride and mannose-6-phosphate. Under the conditions of these experiments, the Tay-Sachs disease fibroblasts synthesized and secreted radiolabeled hexosaminidase B, as confirmed by measuring enzymatic activity of cell-conditioned medium. The enzyme secreted was recognized by antibodies raised against purified hexosaminidase A and B but not by nonimmune control sera in Western blotting and immunoprecipitation experiments. The radiolabeled cell-conditioned medium was partially purified by ion-exchange chromatography on a DEAE-Sephadex column. When partially purified [3H]hexosaminidase B was incubated with rat C6 glial cells which express large numbers of IGF-II/mannose-6-phosphate receptors, the enzyme was taken up specifically via the IGF-II/mannose-6-phosphate receptor as evidenced by carbohydrate competition experiments. The specific uptake of the radiolabeled lysosomal enzyme was partially inhibited by IGF-II and an antibody against the IGF-II/mannose-6-phosphate receptor (No. 3637). We conclude that the cellular uptake of a biosynthetically labeled lysosomal enzyme, hexosaminidase B, is partially inhibited by IGF-II. We hypothesize that IGF-II might be capable of modulating lysosomal pathways in vivo.

Human colon carcinoma cells (CaCo-2) synthesize IGF-II and express IGF-I receptors and IGF-II/M6P receptors.

The IGFs have been implicated in the development of the intestinal tract. We have studied the human colon carcinoma cell line CaCo-2 to gain more insight into the function of the IGFs in the gut. [125I]IGF-I and -II bound specifically to CaCo-2 cells as measured in competitive binding experiments. The existence of IGF-I receptors was further demonstrated by affinity crosslinking studies using DSS as the crosslinking agent. Western blotting of CaCo-2 cell extracts using an anti IGF-II/M6P receptor antiserum provided additional evidence for the expression of the IGF-II/M6P receptor. In addition, Northern blotting experiments showed specific IGF-I receptor and IGF-II/M6P receptor gene expression in CaCo-2 cells. An 11 kb band was visualized with a 614 bp PstI IGF-I receptor probe on autoradiographs. Hybridization with a 663 bp IGF-II/M6P receptor probe yielded a 9 kb RNA species. Analysis of CaCo-2 cell RNA using solution hybridization/RNase protection assays yielded two protected fragments, approximately 379 bases in length, with a 394 base IGF-I receptor riboprobe and a 250 base protected fragment with a 260 base IGF-II/M6P receptor riboprobe. In a subset of experiments a PstI 700 base fragment of the IGF-I cDNA and a 554 base SalI fragment of the IGF-II cDNA were used for hybridization: no hybridization was detected with the IGF-I probe. However, using the [32P]IGF-II probe bands at 6.0 and 5.0 kb were labeled in Northern blotting experiments. Analysis of CaCo-2 cell RNA using solution hybridization/RNase protection assays yielded a 289 base protected fragment and a faint 534 base species with a 556 base human IGF-II riboprobe. In addition, IGF-II immunoreactivity was measured in CaCo-2 cell-conditioned medium using an IGF-binding protein blocked radioimmunoassay. CaCo-2 cell-conditioned medium contained 5-15 ng/ml IGF-II immunoreactivity. In conclusion, (1) CaCo-2 cells express both IGF-I receptor mRNA and IGF-II/M6P receptor mRNA and contain functional IGF-I receptor and IGF-II/M6P receptor protein. (2) CaCo-2 cells express IGF-II mRNA and secrete IGF-II immunoreactivity. We hypothesize that in human colon carcinoma cells IGF-II could act as an autocrine growth factor or alternatively could serve as a regulatory factor during differentiation.

Circulating insulin-like growth factor II/mannose-6-phosphate receptor and insulin-like growth factor binding proteins in fetal sheep plasma are regulated by glucose and insulin.

We have reported previously that levels of insulin-like growth factor I (IGF-I) and IGF-II in fetal sheep plasma decrease with maternal starvation and increase following an infusion of glucose to the starved fetus, while a fetal infusion of insulin elevates UGF-I alone. We now report the changes in the circulating IGF-II/M6P receptor and plasma IGF binding proteins (IGFBPs), as measured by western blotting and ligand blotting, respectively, in fetus and mother during this study. In fetal plasma, the circulating IGF-II/mannose-6-phosphate (M6P) receptor, IGFBP-3 and IGFBP-4 were reduced during starvation. While circulating IGF-II/M6P receptor and IGFBP-4 levels were increased following the fetal insulin or glucose infusion, IGFBP-3 was unchanged and increased only after 48 h of maternal refeeding. Both IGFBP-1 and IGFBP-2 increased with starvation but while IGFBP-1 levels returned to control values following both insulin and glucose infusion, levels of IGFBP-2 were not reduced significantly by either infusion or by refeeding. In maternal plasma, levels of IGFBP-3 and IGFBP-4 decreased while IGFBP-1 and IGFBP-2 increased after 48 h of starvation. Levels of each IGFBP were unaltered following the fetal infusions but returned to values obtained during the control period after refeeding. These data show that each of the IGF carrier proteins is sensitive of changes in nutrition, either acutely, such as IGFBP-1, or chronically, as for IGFBP-3. This suggests that the circulating IGF-II/M6P receptor and the IGFBP's may modulate IGF activity in the fetus during different nutritional states.

Identification and characterization of insulin-like growth factor I (IGF-I) and IGF-II/mannose-6-phosphate (IGF-II/M6P) receptors in bovine adrenal cells.

We have identified and characterized insulin-like growth factor I (IGF-I) and IGF-II/mannose-6-phosphate (IGF-II/M6P) receptors in bovine adrenal cells. Iodine-125-labeled IGF-I ([125I]IGF-I) binding was characteristic of the IGF-I receptor, and binding kinetics as well as receptor densities were similar in cortical and medullary membranes. Scatchard analysis of [125I]IGF-I binding to cultured adrenocortical cells showed a single class of high-affinity binding sites with a Kd of 1.4 nmol/l and an average of 150,000 binding sites/cell. Affinity cross-linking experiments displayed a band at an apparent molecular weight of 135 kD, corresponding to the size of the alpha-subunit of the IGF-I receptor. In analogy, the binding of [125I]IGF-II to bovine adrenal membranes was characteristic of the IGF-II/M6P receptor and no differences between cortical and medullary membrane fractions were found. Scatchard analysis revealed a single class of high-affinity binding sites in adrenocortical cells with a Kd of 1.1 nmol/l and an average of 280,000 binding sites/cell. The identity of the IGF-II/M6P receptor was confirmed by western blotting of adrenocortical membranes with an anti-IGF-II/M6P receptor antibody and by affinity cross-linking of adrenocortical cells with labeled IGF-II. In conclusion, we have identified and characterized IGF-I and IGF-II/M6P receptors in bovine adrenocortical as well as medullary cells. In both regions of the bovine adrenal gland the IGF-II/M6P receptor is much more abundant than the IGF-I receptor.

Pertussis toxin sensitive G-proteins are not involved in the mitogenic signaling pathway of insulin-like growth factor-I in normal rat kidney epithelial (NRKE) cells.

There is controversy as to whether or not a pertussis toxin sensitive G-protein is involved in the signaling pathway of insulin-like growth factor-I. We have used normal rat kidney epithelial (NRKE) cells to ask whether or not a pertussis toxin sensitive G-protein was involved in IGF-I stimulated DNA synthesis. NRKE cells express both IGF and IGF-II/M6P receptors and respond to IGF-I with increased thymidine incorporation into DNA. Under many circumstances incubation of cells/cell membranes with GTP analogues will inhibit binding of ligands that are linked to a G-protein-receptor pathway. However, when NRKE membrane preparations were incubated with 125I-IGF-I or 125I-IGF-II in the presence or absence of GTP gamma S, ATP and GTP, binding of the radioligands was not affected by the GTP-analogue. IGF-I and factors from serum of hypophysectomized rats (HRS) stimulated [3H]thymidine incorporation into DNA of NRKE cells. Under serum-free conditions in the presence of EGF (2 ng/ml) and PDGF (1 ng/ml) pertussis toxin over a wide range of doses had no effect upon IGF-I stimulated [3H]thymidine incorporation into DNA of NRKE cells. In addition, PT at a dose of 100 ng/ml had no effect on IGF-I(0.2-50 ng/ml) stimulated DNA synthesis of NRKE cells. However, PT at doses of 5, 50, 500, 5000 and 50,000 ng/ml was capable to ADP-ribosylate a 40 kDa protein in NRKE cell plasma membrane preparations corresponding to known PT-sensitive G-proteins. We conclude, that (1) PT-sensitive G-proteins and both IGF-I and IGF-II/M6P receptors are present in NRKE cell plasma membrane preparations, and most importantly, that (2) PT-sensitive G-proteins are not involved in the mitogenic signaling pathway of IGF-I in NRKE cells.

Human IM-9 lymphoblasts as a model of the growth hormone-insulin-like growth factor axis: gene expression, and interactions of ligands with receptors and binding proteins.

Human IM-9 lymphoblasts bind growth hormone (hGH) and insulin-like growth factors (IGFs). We have systematically examined the IM-9 cells as a valuable model of the interaction of hGH and the IGFs at the cellular level. Cells were cultured in medium with 10% serum and for a subset of experiments cultured in serum-free medium. Binding of [125I]hGH and [125I]IGF-I and -II to intact IM-9 cells was measured: unlabeled hGH inhibited binding of [125I]hGH (half max. 20 ng/ml). Binding of [125I]IGF-I was inhibited by IGF-I (half max. 7.5 ng/ml), IGF-II (half max. 60 ng/ml), and insulin and anti IGF-I receptor antibody (alpha IR3). [125I]IGF-II was inhibited by IGF-II (half max. 15 ng/ml), IGF-I (half max. 500 ng/ml), insulin (half max. 250 ng/ml) but not by alpha IR3. Crosslinking experiments with [125I]IGF-II and DSS as the crosslinking agent and analysis of radioligand-receptor complexes by SDS-PAGE under reducing conditions revealed that [125I]IGF-II bound to a 250 kDa and a 135 kDa receptor species. The latter possibly represents an insulin-type receptor whereas the 250 kDa species had the characteristics of the IGF-II/M6P receptor. When IM-9 cell conditioned medium was analyzed in ligand blotting experiments with either [125I]IGF-I or -II a 30 kDa IGFBP species was detected on the autoradiographs. Also, IGF-II immunoreactivity (approx. 1 ng/ml medium) was measured in the cell conditioned medium using an IGF-BP blocked RIA employing [125I]IGF-II. In a subset of experiments IM-9 cells were homogenized in 4 M guanidinium-thiocyanate and RNA extracted in 5.7 M CsCl. Denatured RNA was electrophoresed on 0.8% agarose gels and transferred to a nylon membrane, fixed and the blots hybridized with cDNA probes. Probes were labeled with [32P]dCTP using a random prime labeling procedure: a Pst I 700 bp fragment of the human IGF-I cDNA, a 554 bp Pst I-Sal I fragment of the IGF-II cDNA, a 614 bp Pst I fragment of the IGF-I receptor cDNA and a 663 bp Pst I fragment of the IGF-II/M6P receptor. Autoradiographs of Northern blots showed specific hybridization with the IGF-I probe at 3.7 kb and with the IGF-II probe at 5.3 kb. No signal was detected with the IGF-I receptor cDNA probe. Hybridization with the IGF-II/M6P receptor probe yielded a 9 kb RNA species.(ABSTRACT TRUNCATED AT 400 WORDS)

Interleukin-10 expression: is there a neglected contribution of CD8+ T cells in rheumatoid arthritis joints?

OBJECTIVE: To search for RA specific processes among T cell accumulation, T cell activation, or cytokine expression in CD4+ and CD8+ synovial fluid (SF) T cells. METHODS: Flow cytometry of CD4+, CD8+, CD45RA+, CD45RO+, CD69 double or triple stained peripheral blood (PB) and SF T cells. IL-2, IL-10, and IFN-gamma expression was determined in PMA + ionomycin stimulated T cells on the single cell level. Concentrations of secreted IL-2, IL-4, IL-10, and IFN-gamma were quantified in the sera and synovial fluids by enzyme linked immunosorbent assay (ELISA). RESULTS: A preferential recruitment of CD45RO+ memory T cells was found for CD4+ helper T cells, and in similar also for CD8+ suppressor T cells. An elevated CD69 expression was detected in memory, but also in CD45RA+ naive CD4+ and CD8+ SF T cells, whilst IL-2 expression was only demonstrable in a minor proportion of T cells populations. Preferential recruitment of memory T cells, but incomplete activation of naive and memory, CD4+ and CD8+ T cells were in similar found in RA and control patients. In RA but not in the control patients, a relevant proportion of CD4+ and CD8+ PB and SF T cells expressed IL-10 and IFN-gamma. High concentrations of IL-10, that were correlated with the amounts of secreted TNF-alpha, were only detected in RA joints. CONCLUSION: Memory and naive T cell state of CD4+ and CD8+ T cell accumulates in the joints, and early T cell activation occur in similar patterns in RA and control patients. High IL-10 SF concentrations in contrast, and elevated percentages of IFN-gamma and IL-10 expressing CD4+ and CD8+ T cells in the PB and SF were characteristic for RA. Here, CD8+ T cells may contribute to high IL-10 concentrations in RA joints.

The insulin-like growth factor-II/mannose-6-phosphate receptor is present in fetal bovine tissues throughout gestation.

The insulin-like growth factor-II (IGF-II) and the IGF-II/mannose-6-phosphate (M6P) receptor are thought to play an important role in fetal growth and development. We have studied the expression of the IGF-II/M6P receptor in fetal bovine tissues from 5 through 36 weeks' gestation. Tissues from bovine fetuses were extracted in buffer containing 2% Triton-X-100 and 2% sodium dodecyl sulfate (SDS). Aliquots of the protein extracts were analyzed by SDS polyacrylamide gel electrophoresis and the protein bands were transferred onto nitrocellulose. Immunoblotting was performed with anti-bovine IGF-II/M6P receptor antiserum. In a subset of experiments, ligand blotting was carried out with radiolabeled IGF-II and subsequent autoradiography. IGF-II/M6P receptors were expressed in all tissues examined, with the highest amount of receptor being present in fetal lung and liver. Low amounts of receptors were measured in fetal brain. The amount of receptor was developmentally regulated throughout fetal life. The developmental regulation of receptor expression varied among the different tissues. In conclusion, the IGF-II/M6P receptor is present in all fetal bovine tissues examined. The presence of the IGF-II/M6P receptor seems to be developmentally regulated during bovine fetal life. We hypothesize that this receptor exerts important biologic effects during fetal growth and tissue and organ development.

The Making Cases Count intiative.

Given the challenges faced, how can homeopaths communicate the power and scope of the therapeutic system of homeopathy? Homeopaths need to communicate to patients, the public and media, other healthcare professionals, healthcare researchers, and funders of healthcare (healthcare insurers, those who commission healthcare services either in publicly funded healthcare systems such as the NHS or charities). Effective communication with these stakeholders requires information that is: (a) easily understood, (b) credible, and (c) relevant. The patient's voice is the trusted, indisputable and easily understood common ground in homeopathy. Yet, the experiences of patients are rarely heard outside the profession of homeopathy. Homeopaths are in a unique position to make these voices heard by disseminating the results of their routine practice cases incorporating their patients' voices. The 'Making Cases Count' initiative has been created in order to bring about a culture where easily understood, trusted and salient information is regularly made available to all stakeholders in homeopathy. The Making Cases Count initiative supports, guides and incentives homeopaths to collect routine data with the aim of bringing about a culture where a significant proportion of homeopaths collect routine data from their patients in a format which will then be able to be transformed (i.e. anonymised, summarised and counted). This routine data requires numbers and categories to report the behavior and the perspective of patients receiving homeopathic treatment. This can be strengthened through the use of validated outcome measures in hearing patients' voices. When transformed, this routine data will then be able to inform homeopaths and more importantly other key stakeholders. It is now time to make patient cases count.