[Collaborative care for co-morbid major depressive disorder in chronically ill outpatients in a general hospital]. / Collaborative care voor de behandeling van comorbide depressieve stoornis bij chronisch lichamelijk zieke patiënten op een polikliniek van een algemeen ziekenhuis.

BACKGROUND: Depression is highly prevalent in patients with chronic physical illnesses. A promising intervention for this group of patients is the collaborative care treatment as developed in the us. AIM: To demonstrate the prevalence of depression and the risk factors of depression in diabetes patients, to describe how the screening for depression can be carried out and to assess whether the collaborative care treatment in the Netherlands is effective. METHOD: A questionnaire was completed every three months in order to determine whether there was an improvement in patients' depression and physical symptoms. The outcomes were analysed by means of the multilevel logistic regression analyses. RESULTS: On the basis of the Patient Health Questionnaire, about 26% of the diabetes patients were found to have a depression. This questionnaire was validated for the measurement of depression in diabetes patients, the best results being found at a cut-off point of 12. In cases of fairly severe depression, collaborative care had no effect on depressive symptoms but did reduce severe physical complications. In cases of more severe depression, collaborative care only had an effect on depressive symptoms, but was not found to have any effect on physical complications. CONCLUSION: There is evidence that collaborative care can reduce depression and physical complications in chronically ill patients. However, more research is needed to find out whether collaborative care can become more effective if it is supplemented with digital methods and group therapy.

More co-morbid depression in patients with Type 2 diabetes with multiple complications. An observational study at a specialized outpatient clinic.

AIMS: The impact of depression on patients with chronic medical illnesses such as diabetes is well documented. Depression is relatively common in diabetes patients with diabetes-related complications and they are more likely to be referred to specialized outpatient facilities. Only a few studies have addressed the association between depression and multiple diabetes-related complications at these specialized outpatient facilities. The aim of this study was to determine the association between diabetes with multiple complications and depression in patients with Type 2 diabetes at a specialized outpatient clinic. METHODS: After giving informed consent, 1194 patients were screened for depression using the Patient Health Questionnaire (PHQ-9). Additional data on the type of diabetes and complications were taken from the medical records. Logistic regression analysis was conducted, with complications as the predictor variable and the probability of depression as the dependent variable. RESULTS: A total of 596 (63%) patients with Type 2 diabetes participated in the study. The presence of two or more complications (OR 2.23, 95% CI 1.02­2.94) was significantly associated with depression. Neuropathy (OR 1.7, 95% CI 1.10­2.77) and nephropathy (OR 1.68, 95% CI 1.00­2.48) were especially related to depression. CONCLUSIONS: Patients with Type 2 diabetes with two or more complications, especially neuropathy or nephropathy, are at high risk of depression. Knowing this can help clinicians identify patients at risk for depression and facilitate timely and adequate treatment.

tRNAs and proteins are imported into mitochondria of Trypanosoma brucei by two distinct mechanisms.

Import of tRNA into the mitochondrial matrix of Trypanosoma brucei was reconstituted in vitro. Efficient import required the hydrolysis of externally added ATP and was shown to be a carrier-mediated process depending on proteinaceous receptors on the surface of mitochondria. A partly synthetic tRNA(Tyr) as well as a physiological tRNA(Lys) were imported along the same pathway. Contrary to import of all matrix-localized proteins, tRNA import does not require a membrane potential. Furthermore, addition of an excess of import-competent tRNA had no effect on import of a mitochondrial matrix protein. In summary, these results show that tRNAs and proteins in T. brucei are imported by fundamentally different mechanisms.

Isolation of tubulin polyglutamylase from Crithidia; binding to microtubules and tubulin, and glutamylation of mammalian brain alpha- and beta-tubulins.

Trypanosomatids have a striking cage-like arrangement of submembraneous microtubules. We previously showed that alpha- and beta- tubulins of these stable microtubules are extensively modified by polyglutamylation. Cytoskeletal microtubular preparations obtained by Triton extraction of Leishmania tarentolae and Crithidia fasciculata retain an enzymatic activity that incorporates radioactive glutamic acid in a Mg2+-ATP-dependent manner into alpha- and beta-tubulins. The tubulin polyglutamylase is extracted by 0.25 M salt. The Crithidia enzyme can be purified by ATP-affinity chromatography, glycerol-gradient centrifugation and ion-exchange chromatography. After extraction from the microtubular cytoskeleton the glutamylase forms a complex with alphabeta tubulin, but behaves after removal of tubulin as a globular protein with a molecular mass of 38x10(3). In highly enriched fractions a corresponding band is the major polypeptide visible in SDS-PAGE. The enzyme from Crithidia recognises mammalian brain tubulin, where it incorporates glutamic acid preferentially into the more acidic variants of both alpha- and beta-tubulins. Synthetic peptides with an oligoglutamyl side chain, corresponding to the carboxy-terminal end of brain alpha- and beta-tubulins, are accepted by the enzyme, albeit at low efficiency. The polyglutamylase elongates the side chain by up to 3 and 5 residues, respectively. Other properties of the tubulin polyglutamylase are also discussed.

In vitro import of proteins into mitochondria of Trypanosoma brucei and Leishmania tarentolae.

In eukaryotic evolution, the earliest branch of organisms to have mitochondria are the trypanosomatids. Their mitochondrial biogenesis not only includes import of most proteins, but also, unlike in other organisms, import of the whole set of tRNAs. In order to investigate these processes, we devised novel procedures for the isolation of mitochondria from two trypanosomatid species: Trypanosoma brucei and Leishmania tarentolae. Isotonic cell lysis followed by equilibrium density centrifugation in Nycodenz gradients yielded mitochondrial fractions exhibiting a membrane potential. Furthermore, we have used these fractions to reconstitute import of mitochondrial matrix proteins in vitro. Energy-dependent uptake of an artificial precursor protein, containing a trypanosomal presequence attached to mouse dihydrofolate reductase and of yeast mitochondrial alcohol dehydrogenase could be demonstrated. The presequences of both proteins were processed in T. brucei whereas only the trypanosomal one was cleaved in L. tarentolae. Trypsin pretreatment abolished the ability of the mitochondria to import proteins, indicating the involvement of proteinaceous components at the surface of mitochondria.