[Flexible assertive community treatment (FACT) as part of a community (health) network]. / FACT als onderdeel van wijkgerichte zorg in het (zorg)netwerk.

BACKGROUND: Community-based care for people with severe mental illness increasingly requires far-reaching cooperation between different domains. This cooperation must always be unique and local, and at the same time provide an answer to generic and nationally set goals.
AIM: Offering new insights on collaboration within and between domains.
METHOD: Reflection on developments in the social domain and specialist mental healthcare using relevant literature and recent (inter)national experiences.
RESULTS: It seems possible to provide better integral care by allowing FACT-teams to network together with Social Support partners (e.g. by sharing financial and/or human resources). In this process, networks of care for people with serious mental illness (SMI), develop over various phases and realize new partnerships. The model fidelity scale for FACT-teams was adjusted to facilitate that process. CONCLUSIONS The new FACT model fidelity scale is ready to allow FACT-teams to explore flexible local solutions for partnerships to realize the much-needed multi-domain integrated community care for people with SMI.

[Development of the renewed Flexible ACT scale: F-ACT fidelity 2017]. / De ontwikkeling van de vernieuwde Flexible ACT-schaal: F-ACT-s 2017.

BACKGROUND: An important model for the organisation of care for people with severe mental illness is flexible assertive community treatment (F-ACT). F-ACT combines case management with assertive crisis intervention. Quality control was implemented in 2008 using a model fidelity scale. Research has shown that the norms used for the F-ACT fidelity scale no longer correspond with current norms concerning restorative and evidence-based care, as established in treatment guidelines.
AIM: To develop a new model fidelity scale for F-ACT teams.
METHOD: Using knowledge of experts, relevant articles and feedback from professionals, researchers, interest groups and family members, a new model fidelity scale was developed: the F-ACTs 2017. The revised scale was tested by trained auditors in 21 F-ACT teams and adjusted in two pilot rounds.
RESULTS: In 2017 the final version was presented to the stakeholders and was approved by the board of auditors; the final version is currently in use. CONCLUSIONS With the availability of F-ACTs 2017, the (research) field has state-of-the-art instrument to monitor the quality of care of persons with severe mental illness. It uses field standards to evaluate the degree of model fidelity of teams that focus on patients with severe mental illness in a rapidly changing context.

[Model fidelity of flexible assertive community treatment (F-ACT) teams: five years of audit results]. / Modelgetrouwheid van flexible assertive community treatment(F-ACT)-teams: resultaten van vijf jaar auditeren.

BACKGROUND: The Flexible act (f-act) has been introduced in the Netherlands since 2004, alongside the Assertive Community Treatment (act) model. An estimate of 400 (f-)act teams concurrently provide care to approximately 70.000 people with serious mental illness. The ccaf has been assessing the model fidelity of act and f-act teams since 2009 to promote the quality and transparency of healthcare for clients with serious mental illness. OBJECTIVE To describe the state of implementation of f-act and associated trends in the Netherlands.
METHOD: Analysis of the ccaf database, which holds the data of audits conducted between 2009 and 2014.
RESULTS: The audits conducted by ccaf between 2009 and 2014 indicated an adequate implementation of f-act. The team foundations were well organized, featuring a multidisciplinary team structure, management of medication, practical support and investment in healthcare continuity, including during an admission. However, the results regarding participation and recovery were unsatisfactory. Furthermore, the results depicted a decline in the scores concerning a number of areas, including outreach and support of participation and recovery. CONCLUSIONS Although the data indicates an on average satisfactory implementation of f-act in the Netherlands, there are signs that the implementation of f-act is under pressure with relatively fewer home visits, a rising caseload and a reduced investment in recovery and participation. The findings are in accordance with the signs and arguments to adjust the emphasis on reducing hospital admissions, prioritizing the consolidation of outpatient care instead.

[Functional remission of people with serious mental illness (SMI): psychometric properties of a new ROM-instrument]. / Functionele remissie bij mensen met een ernstige psychiatrische aandoening; psychometrische eigenschappen van een nieuw ROM-instrument.

BACKGROUND: Instruments are used for routine outcome monitoring of patients with severe mental illness in order to measure psychiatric symptoms, care needs and quality of life. By adding an instrument for measuring functional remission a more complete picture can be given of the complaints, the symptoms and general functioning, which can give direction to providing care for patients with severe mental illness. AIM: To describe the development and testing of a new instrument of functional remission (FR) among people with a psychotic disorder or another serious mental disorder (SMI) as an addition to the symptomatic remission (SR), according to international criteria. METHOD: The FR-assessment involves assessment by a mental health professional who conducts a semi-structured interview with the patient and his or her family and/or uses patient files relating to the three areas of functioning: daily living and self-care; work, study and housekeeping; and social contacts. These areas are rated on a three-point scale of 0: independent; 1: partially independent; 2: dependent. The assessment covers a period of six months, in accordance with the measurement of symptomatic remission and should be part of regular routine outcome monitoring (ROM) procedures. The FR-instrument was used in 2012 with 840 patients from eight Dutch mental care institutions and included a one-year follow-up among 523 patients (response 62%). RESULTS: The results showed that the instrument is relatively easily to complete. It was also relevant for clinical practice, although further research is needed because of the raters' low response. Intra- and inter-rater reliability, discriminating and convergent validity, and sensitivity to change were rated sufficient to good. CONCLUSION: If the FR-instrument becomes part of regular ROM-procedures and is used as a measure of societal participation, it could be a useful addition to current measures of symptomatic remission.

[Development of a fidelity scale for function assertive community treatment (FACT)]. / Ontwikkeling van een modelgetrouwheidsschaal voor functie-assertive community treatment (FACT).

BACKGROUND: Assertive community treatment (ACT) is one of the most important models for the care and treatment, in the community, of people with severe mental illness (SMI). ACT is concerned primarily with smi-patients who have the most complex problems and it provides care by means of intensive assertive outreach. Function act (FACT) provides care for the entire group of SMI - patients and combines the principles of case management and ACT. For a long time it has been possible to measure the degree of ACT model reliability using the facts reliability scale. Throughout this time, however, a reliability scale for FACT was not available. AIM: To develop a reliability scale for fact teams. METHOD: Using the knowledge of experts and feedback from fact teams it has been possible to develop a reliability scale for fact teams. The scale was tested and subsequently adapted as a result of 10 pilot trials performed by 10 fact teams. RESULTS: The definitive version of the scale was confirmed in 2008 and is currently used in the field. CONCLUSION: With the ACT and FACT reliability scales the research field now have two instruments with which teams working with SMI - patients can measure model reliability. The DACTS and FACTS provide opportunities for quality improvement and transparency.

A 99mTc(I)-postlabeled high affinity bombesin analogue as a potential tumor imaging agent.

The overexpression of neuropeptide receptors observed in many cancers provides an attractive target for tumor imaging and therapy. Bombesin is a peptide exhibiting a high affinity for the gastrin releasing peptide (GRP) receptor, which is overexpressed by a variety of tumors such as breast or prostate cancer. In the present study, we have evaluated if the bombesin analogue [N(alpha)-histidinyl acetate]bombesin(7-14), radiolabeled with the novel [99mTc(OH(2))(3)(CO)(3)]+, has the potential to be used as a diagnostic radiopharmaceutical. Receptor saturation studies, carried out on the GRP receptor-expressing PC-3 human prostate cancer cell line, revealed for [99mTc(CO)(3)-N(alpha)-histidinyl acetate]bombesin(7-14) K(d) values in the subnanomolar range. Competitive binding assays, using the cold rhenium(I)-labeled analogue as a surrogate for the 99mTc-conjugate, also showed high affinity binding. Incubation of the radioconjugate with PC-3 cells resulted in a rapid temperature- and time-dependent specific internalization. At 37 degrees C more than 70% was internalized within the first 15 min and remained constant up to 2 h. Despite the weak proteolytic stability of [99mTc(CO)(3)-N(alpha)-histidinyl acetate]bombesin(7-14) in vitro, biodistribution studies, performed in PC-3 tumor-bearing mice, showed low uptake in the tumor (0.89 +/- 0.27% ID/g 30 min pi) but high uptake into the pancreas (7.11 +/- 3.93% ID/g 30 min pi), a GRP receptor-positive organ. Blockade experiment (coinjection of 300 microg bombesin/mouse with the radioligand) showed specificity of the uptake. Despite the low tumor uptake, tumor-to-blood ratios of 2.0 and 2.7 and tumor-to-muscle ratios of 8.9 and 8.0 were obtained at 30 min and 1.5 h postinjection, respectively. The promising results merit the future in vivo investigation of 99mTc/188Re-tricarbonyl-labeled bombesin analogues.

Myosin-I nomenclature.

We suggest that the vertebrate myosin-I field adopt a common nomenclature system based on the names adopted by the Human Genome Organization (HUGO). At present, the myosin-I nomenclature is very confusing; not only are several systems in use, but several different genes have been given the same name. Despite their faults, we believe that the names adopted by the HUGO nomenclature group for genome annotation are the best compromise, and we recommend universal adoption.

Myosin vb is associated with plasma membrane recycling systems.

Myosin Va is associated with discrete vesicle populations in a number of cell types, but little is known of the function of myosin Vb. Yeast two-hybrid screening of a rabbit parietal cell cDNA library with dominant active Rab11a (Rab11aS20V) identified myosin Vb as an interacting protein for Rab11a, a marker for plasma membrane recycling systems. The isolated clone, corresponding to the carboxyl terminal 60 kDa of the myosin Vb tail, interacted with all members of the Rab11 family (Rab11a, Rab11b, and Rab25). GFP-myosin Vb and endogenous myosin Vb immunoreactivity codistributed with Rab11a in HeLa and Madin-Darby canine kidney (MDCK) cells. As with Rab11a in MDCK cells, the myosin Vb immunoreactivity was dispersed with nocodazole treatment and relocated to the apical corners of cells with taxol treatment. A green fluorescent protein (GFP)-myosin Vb tail chimera overexpressed in HeLa cells retarded transferrin recycling and caused accumulation of transferrin and the transferrin receptor in pericentrosomal vesicles. Expression of the myosin Vb tail chimera in polarized MDCK cells stably expressing the polymeric IgA receptor caused accumulation of basolaterally endocytosed polymeric IgA and the polymeric IgA receptor in the pericentrosomal region. The myosin Vb tail had no effects on transferrin trafficking in polarized MDCK cells. The GFP-myosin Va tail did not colocalize with Rab11a and had no effects on recycling system vesicle distribution in either HeLa or MDCK cells. The results indicate myosin Vb is associated with the plasma membrane recycling system in nonpolarized cells and the apical recycling system in polarized cells. The dominant negative effects of the myosin Vb tail chimera indicate that this unconventional myosin is required for transit out of plasma membrane recycling systems.

Are class III and class IX myosins motorized signalling molecules?

Myosins exist that are fused to domains that harbour signalling activities. Class III myosins (NINAC) are protein kinases that play important roles in phototransduction. Class IX myosins inactivate the small G-protein Rho that acts as molecular switch. Because these myosins interact via their myosin head domain with actin filaments, they link signal transduction to the actin cytoskeleton. The exact motor properties of these myosins, however, remain to be determined.

Functional role for the class IX myosin myr5 in epithelial cell infection by Shigella flexneri.

Efficient control of Shigella-induced, rho-dependent cytoskeletal rearrangements seems to be required to shape the delicate cellular structures associated with bacterial invasion of epithelial cells. We therefore studied a class IX myosin and rho antagonist, the GTPase-activating protein (GAP) myr5, for a potential role in the bacterial entry process. We show that myr5 is recruited into bacterial entry spots. The recruitment pattern resembled that of rhoC or ezrin, but not rhoA, rac or CDC42, while in vitro GAP activity of myr5 was similar for rhoA, B or C. Analysis of myr5 mutants suggested that GTPase- or ATP-binding activites are not required for Shigella-induced recruitment of this atypical myosin to the bacterial entry site. Functional studies revealed a potential dual role of the myosin functions and the GAP module of myr5 for bacterial internalization.

Both calmodulin and the unconventional myosin Myr4 regulate membrane trafficking along the recycling pathway of MDCK cells.

In epithelial cells, endocytosed transferrin and its receptor, which cycle basolaterally, have been shown to transit through recycling endosomes which can also be accessed by markers internalized from the apical surface. In this work, we have used an in vitro assay to follow transfer of an endocytosed marker from apical or basolateral early endosomes to recycling endosomes labeled with transferrin. We show that calmodulin (CaM) function is necessary for transfer and identified myr4, a member of the unconventional myosin superfamily known to use CaM as a light chain, as a possible target protein for CaM. Since myr4 is believed to act as an actin-based mechanoenzyme, we tested the role of polymerized actin in the assay. Our data show that conditions which either prevent actin polymerization or induce the breakdown of existing filaments strongly inhibit interactions between recycling endosomes and either set of early endosomes. Altogether, our data indicate that trafficking at early steps of the endocytic pathway in Madin-Darby Canine Kidney cells depends on the actin-based mechanoenzyme myr4, its light chain CaM, and polymerized actin.

Unconventional myosins.

Myosins constitute a large superfamily of F-actin-based motor proteins found in many organisms from yeast to humans. A phylogenetic comparison of their head sequences has allowed them to be grouped into 15 different classes. Unconventional myosins can be monomeric or dimeric, but are thought not to form filaments, unlike conventional myosin. The double-headed class-V myosins are good candidates for transporting vesicles, organelles and (mRNA) particles along actin filaments. Class-I myosins are involved in membrane dynamics and actin organization at the cell cortex, thus affecting cell migration, endocytosis, pinocytosis and phagocytosis. A class-III myosin from Drosophila is required for phototransduction and maintenance of the rhabdomere. Class-IX myosins negatively regulate the small G-protein Rho, a signalling molecule that regulates the organization of the actin cytoskeleton. Protein kinases that are regulated by members of the Rho small G-protein family regulate the motor activities of different myosins.

Myr 7 is a novel myosin IX-RhoGAP expressed in rat brain.

Rho family GTPases are important regulators of neuronal morphology, but the proteins directly controlling their activity in neurons are still poorly defined. We report the identification of myr 7, a novel unconventional myosin IX-RhoGAP expressed in rat brain. Myr 7 is a multidomain protein related to myr 5, the first class IX myosin to be characterized. It exhibits a myosin head domain with an N-terminal extension and a large insertion at loop 2, an actin contact site and regulator of myosin ATPase rate. The myosin head domain is followed by a neck domain consisting of six unevenly spaced consecutive IQ motifs representing light chain binding sites. The tail domain contains a C6H2-zinc binding motif and a region that specifically stimulates the GTPase-activity of Rho followed by a short stretch predicted to adopt a coiled-coil structure. Five alternatively spliced regions, one in the 5'-noncoding region, two in the myosin head and two in the tail domain, were noted. Analysis of myr 7 and myr 5 expression in different tissues revealed that myr 7 is expressed at high levels in developing and adult brain tissue whereas myr 5 is expressed only at moderate levels in embryonic brain tissue and at even further reduced levels in adult brain tissue. Myr 5 is, however, highly expressed in lung, liver, spleen and testis. Myr 7 is expressed in all brain regions and is localized in the cytoplasm of cell bodies, dendrites and axons. Myr 5 exhibits an overlapping, but not identical cellular distribution. Finally, a myr 7 fusion protein encompassing the GAP domain specifically activates the GTPase-activity of Rho in vitro, and overexpression of myr 7 in HtTA1-HeLa cells leads to inactivation of Rho in vivo. These results are compatible with a role for myr 7 (and myr 5) in regulating Rho activity in neurons and hence in regulating neuronal morphology and function.

Targeting of the myosin-I myr 3 to intercellular adherens type junctions induced by dominant active Cdc42 in HeLa cells.

Myr 3, a member of the myosin-I family from rat, is shown in this study to be localized at adherens-type intercellular junctions in epithelial and nonepithelial tissues. Formation of intercellular junctions and the accompanying recruitment of myr 3 to these junctions involves signaling by the Rho subfamily of small GTP-binding proteins. This conclusion is based on studies with HtTA-1 HeLa cells that were induced by overexpression of constitutively active Cdc42Hs to form typical adherens-type intercellular junctions enriched in cadherins (N-cadherin), beta-catenin, filamentous actin and myr 3. Recruitement of myr 3 to Cdc42-induced adherens junctions in HeLa cells was dependent on a short region of the tail domain and a functional myosin motor domain, but was independent of its myosin-I tail homology and SH3 regions. Overexpression of constitutively active Rac1 induced a distinct type of adherens junction in HeLa cells that was characterized by elaborate intercellular interdigitations enriched in N-cadherin, beta-catenin and F-actin. Myr 3 was often present, but not specifically enriched in the intercellular junctions induced by constitutively active Rac1.

The ATPase activity of Myr3, a rat myosin I, is allosterically inhibited by its own tail domain and by Ca2+ binding to its light chain calmodulin.

We purified Myr3 (third unconventional myosin from rat), a mammalian "amoeboid" subclass myosin I, from rat liver. The heavy chain of purified Myr3 is associated with a single calmodulin light chain. Myr3 exhibits K/EDTA-ATPase and Mg-ATPase activity. The Mg-ATPase activity is stimulated by increasing F-actin concentrations in a complex triphasic manner similar to the Mg-ATPase activity of myosin I molecules from protozoa. Although purified Myr3 was observed to cross-link actin filaments, it bound in an ATP regulated manner to F-actin, and no evidence for a nucleotide-independent high affinity actin binding site that could explain the triphasic activation pattern was obtained. Micromolar concentrations of free Ca2+ reversibly inhibit the Mg-ATPase activity of Myr3 by binding to its light chain calmodulin, which remains bound to the Myr3 heavy chain irrespective of the free Ca2+ concentration. Polyclonal antibodies and Fab fragments directed against the tail domain were found to stimulate the Mg-ATPase activity. A similar stimulation of the Myr3 Mg-ATPase activity is observed upon proteolytic removal of the very C-terminal SH3 domain. These results demonstrate that Myr3 is subject to negative regulation by free calcium and its own tail domain and possibly positive regulation by a tail-domain binding partner.

Characterization and cloning of a Dictyostelium Ste20-like protein kinase that phosphorylates the actin-binding protein severin.

After receiving an external stimulus Dictyostelium amoebae are able to rearrange their actin cytoskeleton within seconds, and phosphorylation is a prime candidate for quick modification of cytoskeletal components. We isolated a kinase from cytosolic extracts that specifically phosphorylated severin, a Ca2+-dependent F-actin fragmenting protein. In gel filtration chromatography severin kinase eluted with a molecular mass of about 300 kDa and contained a 62-kDa component whose autophosphorylation caused a mobility shift in SDS-polyacrylamide gel electrophoresis and stimulated phosphorylation of severin. Severin kinase activity could be specifically precipitated with antibodies raised against the 62-kDa polypeptide. Phosphorylation of severin was strongly reduced in the presence of Ca2+, indicating additional regulation at the substrate level. Peptide sequencing and cloning of the cDNA demonstrated that the 62-kDa protein belongs to the Ste20p- or p21-activated protein kinase family. It is most closely related to the germinal center kinase subfamily with its N-terminal positioned catalytic domain followed by a presumptive regulatory domain at the C terminus. The presence of a Ste20-like severin kinase in Dictyostelium suggests a direct signal transduction from the plasma membrane to the cytoskeleton by phosphorylation of actin-binding proteins.

The rat myosin myr 5 is a GTPase-activating protein for Rho in vivo: essential role of arginine 1695.

myr 5 is an unconventional myosin (class IX) from rat that contains a Rho-family GTPase-activating protein (GAP) domain. Herein we addressed the specificity of the myr 5 GAP activity, the molecular mechanism by which GAPs activate GTP hydrolysis, the consequences of myr 5 overexpression in living cells, and its subcellular localization. The myr 5 GAP activity exhibits a high specificity for Rho. To achieve similar rates of GTPase activation for RhoA, Cdc42Hs, and Rac1, a 100-fold or 1000-fold higher concentration of recombinant myr 5 GAP domain was needed for Cdc42Hs or Rac1, respectively, as compared with RhoA. Cell lysates from Sf9 insect cells infected with recombinant baculovirus encoding myr 5 exhibited increased GAP activity for RhoA but not for Cdc42Hs or Rac1. Analysis of Rho-family GAP domain sequences for conserved arginine residues that might contribute to accelerate GTP hydrolysis revealed a single conserved arginine residue. Mutation of the corresponding arginine residue in the myr 5 GAP domain to a methionine (M1695) virtually abolished Rho-GAP activity. Expression of myr 5 in Sf9 insect cells induced the formation of numerous long thin processes containing occasional varicosities. Such morphological changes were dependent on the myr 5 Rho-GAP activity, because they were induced by expression the myr 5 tail or just the myr 5 Rho-GAP domain but not by expressing the myr 5 myosin domain. Expression of myr 5 in mammalian normal rat kidney (NRK) or HtTA-1 HeLa cells induced a loss of actin stress fibers and focal contacts with concomitant morphological changes and rounding up of the cells. Similar morphological changes were observed in HtTA-1 HeLa cells expressing just the myr 5 Rho-GAP domain but not in cells expressing myr 5 M1695. These morphological changes induced by myr 5 were inhibited by coexpression of RhoV14, which is defective in GTP hydrolysis, but not by RhoI117. myr 5 was localized in dynamic regions of the cell periphery, in the perinuclear region in the Golgi area, along stress fibers, and in the cytosol. These results demonstrate that myr 5 has in vitro and in vivo Rho-GAP activity. No evidence for a Rho effector function of the myr 5 myosin domain was obtained.

Ras-binding domains: predicting function versus folding.

Ras interacts with a number of effector molecules to achieve its prolific signalling. Based on iterative sequence profile and motif searches of databases a novel family of Ras-binding domains was recently identified (Ponting and Benjamin, Trends Biochem. Sci. 21: 422-425, 1996). Among them the rat unconventional myosin and Rho-GTPase-activating protein myr 5 was predicted to contain a Ras-binding domain at its N-terminus. Here we report that direct binding experiments between the proposed Ras-binding domain of myr 5 and Ras failed to demonstrate any interaction. Molecular modelling suggests that this domain in myr 5 adopts a similar folding topology as the Ras-binding domain of Raf kinase. However, unlike the Ras-binding domain of Raf kinase, the myr 5 domain lacks the positive surface charges necessary for binding the negatively charged Ras contact site. This result exemplifies the functional diversity of similar structures and suggests that the identified Ras-binding motif does not reliably predict Ras-binding domains.