[The relationship between posttraumatic stress disorder and metabolic syndrome: an overview]. / De relatie tussen posttraumatische stressstoornis en metabool syndroom.

BACKGROUND: In this article we discuss the relationship between posttraumatic stress disorder (PTSD) and metabolic syndrome (MbS). AIM: To assess the prevalence of MbS in patients with PTSD, establish which factors are involved and to consider what the implications are for clinical practice. METHOD: We performed a systematic search of the literature, using Medline, Embase Psychiatry and PsycINFO covering the period January 1990 up to and including October 2014. RESULTS: We found 12 studies including one meta-analysis which showed large variations in the prevalence of MbS in patients with PTSD; these variations ranged between 7.7% to 73.0%. The PTSD and its severity as well as the comorbid depression and the use of antipsychotics all played a role in the wide discrepancies of the results. Furthermore, the reported results seem to indicate that many methodologies were used in these studies. The reasons for the large differences found in the prevalence of MbS in PTSD patients are complex: the variations are probably due mainly to the different methodologies that were used. The prevalence of MbS which stood out in a positive sense varied between 31.9% and 47.8%. CONCLUSION: To obtain greater clarity, more quantitative and descriptive studies are needed, in which the screening is performed on a PTSD-subgroup with severe PTSD, a severe comorbid depression and/or antipsychotic use. The studies should use method control for diagnoses of PTSD, depression, severity of both and of MbS.

Use of the conditional marketing authorization pathway for oncology medicines in Europe.

Conditional marketing authorization (CMA) in the European Union (EU) is an early access pathway for medicines that show promising therapeutic effects, but for which comprehensive data are not available. Using a mixed quantitative-qualitative research design, we evaluated how CMA has been used in marketing authorization of oncology medicines in the period 2006 to 2013. We show that compared to full marketing authorization, CMA is granted based on less comprehensive data. However, this is accompanied by significantly longer assessment times and less consensus among regulators about marketing authorization. Moreover, development time from first-in-human testing to marketing authorization did not differ between full marketing authorization and CMA, but was significantly longer for CMA compared to accelerated approved products in the United States (US). Results indicate that CMA is not used by companies as a prospectively planned pathway to obtain early access, but as a "rescue option" when submitted data are not strong enough to justify full marketing authorization.

Odd and even Kondo effects from emergent localization in quantum point contacts.

A quantum point contact (QPC) is a basic nanometre-scale electronic device: a short and narrow transport channel between two electron reservoirs. In clean channels, electron transport is ballistic and the conductance is then quantized as a function of channel width with plateaux at integer multiples of 2e(2)/h (where e is the electron charge and h is Planck's constant). This can be understood in a picture where the electron states are propagating waves, without the need to account for electron-electron interactions. Quantized conductance could thus be the signature of ultimate control over nanoscale electron transport. However, even studies with the cleanest QPCs generically show significant anomalies in the quantized conductance traces, and there is consensus that these result from electron many-body effects. Despite extensive experimental and theoretical studies, understanding these anomalies is an open problem. Here we report that the many-body effects have their origin in one or more spontaneously localized states that emerge from Friedel oscillations in the electron charge density within the QPC channel. These localized states will have electron spins associated with them, and the Kondo effect--related to electron transport through such localized electron spins--contributes to the formation of the many-body state. We present evidence for such localization, with Kondo effects of odd or even character, directly reflecting the parity of the number of localized states; the evidence is obtained from experiments with length-tunable QPCs that show a periodic modulation of the many-body properties with Kondo signatures that alternate between odd and even Kondo effects. Our results are of importance for assessing the role of QPCs in more complex hybrid devices and for proposals for spintronic and quantum information applications. In addition, our results show that tunable QPCs offer a versatile platform for investigating many-body effects in nanoscale systems, with the ability to probe such physics at the level of a single site.

The prevalence of mental health problems in Rwandan and Burundese refugee camps.

OBJECTIVE: We examined the prevalence of mental health problems in refugees living in camps that emerged in Tanzania during the Rwanda crisis that started in 1994. METHOD: Using the 28-item version of the General Health Questionnaire (GHQ-28), we examined two samples: a random sample (n = 854) and a sample of clients of a psychosocial support programme in these camps (n = 23). Sensitivity, specificity and positive- and negative predictive values were estimated for several cut-off scores of the GHQ-28. RESULTS: The prevalence of serious mental health problems was estimated at 50% (SE 12%). When using the GHQ-28 as a screener, a cut-off score of 14 is recommended. CONCLUSION: Given the high prevalence of mental health problems, psychosocial programmes for large refugee populations should aim at strengthening community structures and supporting groups instead of focusing at individuals. The screening capacity of the GHQ-28 could be used to identify mentally vulnerable groups.

A monoclonal antibody (ER-HR3) against murine macrophages. I. Ontogeny, distribution and enzyme histochemical characterization of ER-HR3-positive cells.

We describe ER-HR3, a monoclonal antibody directed against bone marrow-derived haemopoietic reticulum cells. ER-HR3-positive cells have the electron-microscopic and enzyme-histochemical characteristics of macrophages. Additionally, they are able to phagocytoze. The ER-HR3 antigen is expressed by a majority of blood monocytes and is present on a subpopulation of resident macrophages in multiple organs. ER-HR3-positive cells are abundant in the bone marrow, the splenic red pulp, the mesenteric lymphoid paracortex and the interfollicular areas of the Peyer's patch. Few ER-HR3-positive cells have been observed in the thymic cortex and the connective tissues of the gastro-intestinal tract, the dermis and the renal medulla. Moreover, epidermal Langerhans cells express the antigen. No cross-reactivity with other cell types has been found. It is concluded that ER-HR3 has a unique distribution pattern distinct from other macrophage-specific antibodies.

A monoclonal antibody (ER-HR3) against murine macrophages. II. Biochemical and functional aspects of the ER-HR3 antigen.

We describe the purification and intracellular distribution of an antigen present on a subpopulation of murine macrophages and recognized by monoclonal antibody ER-HR3 against bone marrow-derived haemopoietic reticulum cells. Using the ER-HR3 antibody as an immobilizing ligand, two proteins were isolated as determined by SDS polyacrylamide gel electrophoresis. Under non-reducing conditions, there was a major band with an apparent molecular mass of 69 kDa and a minor band of 55 kDa. Under reducing conditions, the apparent molecular mass of each band was estimated as 76 kDa and 67 kDa, respectively. Intracellularly, these proteins occurred in close association with membranous structures, as demonstrated with gold-labelled protein A in an electron-microscopic study of the ER-HR3-positive cell line AP284. Some of the antigen was present in vesicles. To gain further insight into the possible function of the ER-HR3 antigen, its tissue distribution was investigated under distinct experimental conditions. In mice infected with Bacillus Calmette Gurèrin, ER-HR3-positive cells were observed in many, but not all, granulomata of the spleen, the lung and the liver. The ER-HR3 reactivity in these mice clearly differed from that of other antimacrophage monoclonal antibodies, such as F4/80, M5/114 and M1/70. Furthermore, phenylhydrazine-induced extramedullary erythropoiesis in the liver was accompanied by ER-HR3 expression on a subpopulation of macrophages. Finally, the addition of ER-HR3 to an antigen-specific T cell proliferation assay did not inhibit T cell proliferation.

Improved fixation of frozen lympho-haemopoietic tissue sections with hexazotized pararosaniline.

In this study, a simple single-step fixation method for frozen tissue sections is introduced using the hexazotized salt of Pararosaniline as preservative agent. Tissue preservation by this method was shown to be superior to the commonly-used fixation with acetone. Fixation with hexazotized Pararosaniline caused a minimal loss of antigenicity as demonstrated using twenty-three monoclonal antibodies directed against lympho-haemopoietic and stromal cells.

Marrow repopulating cells, but not CFU-S, establish long-term in vitro hemopoiesis on a marrow-derived stromal layer.

We have studied the ability of subpopulations of hemopoietic stem cells, obtained from murine bone marrow using elutriation and multiparameter sorting, to establish and maintain hemopoiesis following their deposition on irradiated stromal layers of long-term bone marrow cultures. Two fractions were obtained that differed in their mitochondrial activity as indicated by the retention of Rhodamine-123 dye. The Rhodamine-bright cell fraction, containing the majority of day-8 and day-12 spleen colony-forming units (CFU-S) and in vitro clonable progenitors, showed hemopoiesis only in the first weeks. In contrast, the Rhodamine-dull fraction, which was depleted for day-8 CFU-S and which contained the majority of cells with marrow-repopulating ability, maintained hemopoiesis for a prolonged time after an initial week of delay. These data fully support and extend previously published in vivo data, indicating that CFU-S have low capability to generate new CFU-S and granulocyte-macrophage colony-forming units (CFU-GM), and that cells responsible for long-term generation of hemopoietic precursors and for maintenance of hemopoiesis both in vivo and in vitro are the precursors of CFU-S and of in vitro clonable progenitor cells. In addition, the present findings form the basis for an in vitro assay for a primitive precursor of CFU-S, namely the marrow-repopulating cell.

Murine macrophage cell line AP284 presents antigen to cloned MT4+, Lyt-2- T cells in vitro and in vivo.

A murine macrophage cell line AP284 that appeared to be mature in phenotype was isolated. After repeated cloning, the cell line expressed the markers Mac-1, Mac-2, Mac-3, 2.4G2, F4/80 as well as Ia antigens. Moreover, it was positive for the enzymes nonspecific esterase and acid phosphatase, negative for alkaline phosphatase and was able to phagocytize latex beads. We studied whether this cell line was able to present antigen to cloned MT4+, Lyt-2- T cells specific for methylated bovine serum albumin (mBSA) or ovalbumin (OVA). The in vitro proliferative response of the cloned T cells specific for mBSA or OVA was found to be effectively supported by AP284. This proliferation could be blocked by monoclonal antibodies against Ia determinants. AP284 also effectively presented antigen in vivo as was shown in a foot swelling assay measuring delayed type hypersensitivity (DTH) to mBSA caused by specific cloned T cells with the helper phenotype. This offers a unique model system for studying the process of antigen presentation in which both the antigen presenting cells and the T cells are monoclonal.

Effects of cis-diamminedichloroplatinum (II) upon haemopoietic progenitors and the haemopoietic microenvironment in mice.

We studied the short- and long-term effects of a fractionated injection of cis-diamminedichloroplatinum (II) (CDDP) upon the haemopoietic stroma and the haemopoietic precursor cell compartment of young and adult mice. The integrity of the stromal microenvironment was investigated using three different assays including quantification of (a) the fibroblastoid progenitor cell compartment, (b) the regenerative capacity after subcutaneous implantation of spleen and femur, and (c) the growth of normal bone marrow progenitors in lethally irradiated CDDP-treated mice. CDDP treatment induced a slight anaemia which lasted for the observation period of 1 year, and could not be restored by infusion of normal bone marrow cells. The population size of haemopoietic progenitors was severely decreased immediately after CDDP treatment and the CFU-S recovery in the bone marrow was slow and temporary. Stromal function was significantly decreased and normalization occurred within approximately 40 d, depending on the stromal parameter measured. Subsequently, the regenerative capacity of the stroma showed a second decrease which was still detected at 1 year. This pattern of stromal damage has not been reported for any other cystostatic agent. Since the other two assays did not detect a second decrement in stromal integrity it is implied that the three stromal assays used detect different stromal functions. We conclude that CDDP treatment of both young and adult mice results in severe short-term damage and a late occurring secondary regenerative defect of the haemopoietic organ stroma.

Radiation sensitivity of hemopoietic stroma: long-term partial recovery of hemopoietic stromal damage in mice treated during growth.

We studied the ability of the hemopoietic organ stroma to recover from damage inflicted by 5 or 7 Gy gamma radiation administered during a period of stromal growth in 4-week-old mice. Irradiation resulted in an immediate depletion of femoral colony-forming fibroblastic progenitors (CFU-F) down to 10-20% of age-matched control values. A full recovery to normal numbers occurred between 120 and 240 days after irradiation and was followed by a secondary decrease 1 year after irradiation. This secondary decrease was accompanied by a decrease in the femoral CFU-S and CFU-C content. Femoral CFU-F attained normal numbers and it was demonstrated to occur from surviving CFU-F and could not be enhanced or prolonged following infusion of unirradiated bone marrow cells after irradiation. During the transient CFU-F recovery the hemopoietic stroma remained severely damaged as judged by the regenerative capacity of spleen and femur stroma after subcutaneous implantation, and the ability of the spleen to accumulate CFU-S in response to lipopolysaccharide injection. We have reported earlier that in similarly irradiated adult mice, no restoration of femoral CFU-F was observed. This difference between 4-week-old and adult mice could not be explained by a difference in in vitro radiosensitivity of CFU-F or in their in vivo regeneration kinetics following irradiation and subsequent lipopolysaccharide injection. We conclude from these observations that the recovery kinetics of the CFU-F population is different in young and adult irradiated mice, infused CFU-F do not contribute to CFU-F regeneration in an irradiated femur, CFU-F are not the sole determinants of stromal regeneration in femur and spleen following irradiation.

Long-term effects of cytostatic agents on the hemopoietic stroma: a comparison of four different assays.

We have compared four assays to detect hemopoietic stromal damage induced by various cytostatic agents in young (4-week old) and adult (12-week old) mice. These assays included: (a) quantitation of the hemopoietic stem cell content of subcutaneously implanted spleens and femurs, (b) quantitation of fibroblastic colony-forming units per femur and spleen, (c) quantitation of the growth of normal hemopoietic progenitor cells in irradiated cytostatic drug-treated mice, and (d) measurement of splenic hemopoietic stem cell accumulation in response to bacterial lipopolysaccharide-induced hemopoietic stress. Busulfan caused a short- and long-term hemopoietic stromal defect. However, the four assays used showed different kinetics and severity of the stromal damage. Cyclophosphamide treatment resulted in a short-term stromal damage which was repaired within one week to three months, depending on the assay used. Methotrexate and vincristine did not cause long-term stromal damage as measured by the four assays used, whereas a short-term splenic stromal damage was detected using the subcutaneous implantation technique. No significant differences in stromal sensitivity to drug treatment were observed between young and adult mice. The presented data suggest that the four assays used to study stromal integrity measure different components of the hemopoietic microenvironment, and indicate that the use of a single assay may well lead to erroneous interpretations.

Hemopoiesis on purified bone-marrow-derived reticular fibroblast in vitro.

Murine bone-marrow-derived reticular fibroblast cultures were tested for the ability to support hemopoiesis and release hemopoietic growth factors in vitro. The reticular fibroblast cultures employed in these studies were 95%-100% pure on the basis of Mac-1, F4/80, MIV-51, T200, antifactor VIII and ER-TR7 monoclonal antibody staining. Further support for the fibroblastic nature of these cells was obtained from collagen and laminin analyses. Addition of stromal cell-depleted bone marrow cell suspensions to flasks of confluent reticular fibroblasts resulted in production and release of granulocytes, monocyte-macrophages, and granulocyte-monocyte progenitors from the adherent layer for 4-8 weeks. Pluripotent spleen colony-forming units were detected during the first four weeks. Assay of reticular fibroblast conditioned medium for hemopoietic growth factors demonstrated production of granulocyte-macrophage colony-stimulating activity and stem-cell-activating factor. We did not detect any erythroid burst-promoting activity. These results suggest that reticular fibroblasts may play a role in the maintenance of pluripotent stem cells and in the proliferation and differentiation of cells committed to the granulocyte-monocyte lineage.

How to quantify an arterial stenosis: a study on the femoral arteries of dog and man.

The blood supply to the femoral bed was studied in anaesthetised dogs before and after producing arterial stenoses. The blood supply system consisted of the vessels proximal to the site of measurement in the femoral artery and was characterised by a supply graph, which related mean perfusion pressure to mean flow. The different pressures and flows were obtained using an artificial periphery, the impedance of which was changed from beat to beat. The supply graph was approximated by a parabola with two parameters: the intercepts with the pressure and flow axes, the latter indicating the maximum mean flow. For constant aortic pressure the maximum mean flow appeared to be linearly related to the cross sectional area of the stenosed section (r = 0.98). Maximum mean flow was already considerably reduced before the stenosis became critical--that is, before physiological flow was measurably diminished. The change in maximum mean flow was therefore used to quantify the haemodynamic effects of stenoses that were less than critical. Blood supply graphs of the superficial femoral arteries were determined also in seven patients undergoing a femoropopliteal bypass operation. The maximum mean flow correlated well with the degree of obstruction determined from the preoperative angiograms (r = 0.90).

Comparative in vitro effects of cyclophosphamide derivatives on murine bone marrow-derived stromal and hemopoietic progenitor cell classes.

We investigated the in vitro effects of ASTA-Z-7595, ASTA-Z-7557, ASTA-Z-7654, and 4-hydroperoxycyclophosphamide (4HC) on murine stromal fibroblastoid colony-forming units, committed hemopoietic progenitors (erythroid burst-forming units and granulocyte/macrophage colony-forming units), and pluripotent hemopoietic stem cells assayed by the spleen colony-forming unit (CFU-s) assay. In general, the drugs showed a time-and dose-dependent effect on colony-forming unit survival, and the relative toxicities were in the order in which the drugs are listed above. We found a relative sparing of day 12 CFU-s compared with day 7 CFU-s and committed hemopoietic and stromal progenitors, although colony size of day 12 CFU-s was reduced. Our results support two possible mechanisms for delayed or inadequate hemopoietic reconstitution in clinical studies using bone marrow purged with 4-hydroperoxycyclophosphamide or ASTA-Z-7557, i.e., damage to (a) transplantable stromal cells or (b) the hemopoietic stem cells.