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F Balk

Publications and source records attributed to F Balk.

9 recordsLinked to original sources
PubMed2005

Pharmacological treatment for psychotic depression.

BACKGROUND: Regarding the pharmacological treatment of psychotic depression there is uncertainty about the effectiveness of an antidepressant alone compared to the combination of an antidepressant and an antipsychotic. OBJECTIVES: To compare the clinical effectiveness of pharmacological treatments for patients with a psychotic depression: antidepressant monotherapy, antipsychotic monotherapy, and the combination of an antidepressant and an antipsychotic, compared with each other and/or with placebo. SEARCH STRATEGY: (1) The Cochrane Central Register of Controlled Trials (CENTRAL) was screened with the terms depressive disorder and drug treatment (April 2004). (2) MEDLINE (1966 to April 2004) and EMBASE (1980 to April 2004) were searched using terms with regard to treatment of unipolar psychotic depression.(3) Reference lists of related reviews and reference lists of all identified studies were searched.(4) Personal communications. SELECTION CRITERIA: All randomised controlled trials (RCTs) with patients with major depression with psychotic features as well as RCTs with patients with major depression with or without psychotic features which reported on the subgroup of patients with psychotic features separately. DATA COLLECTION AND ANALYSIS: Two reviewers assessed the methodological quality of the included studies, according to the Cochrane Handbook criteria. Data were entered into RevMan 4.2.5. We used intention-to-treat data. For dichotomous efficacy outcomes, the relative risk with 95% confidence intervals (CI) was calculated. For continuously distributed outcomes, it was not possible to extract data from the RCTs. Regarding the primary harm outcome, only overall drop-out rates were available for all studies. MAIN RESULTS: The search identified 3333 abstracts, but only 10 RCTs with a total of 548 patients could be included in the review. Due to clinical heterogeneity, few meta-analyses were possible. We found no conclusive evidence that the combination of an antidepressant and an antipsychotic is more effective than an antidepressant alone (two RCTs; RR 1.44, 95% CI 0.86 to 2.41), but a combination is more effective than an antipsychotic alone (three RCTs; RR 1.92, 95% CI 1.32 to 2.80). There were no statistically significant differences in the overall drop-out rates between any of the treatments, neither in individual studies nor after pooling of studies. AUTHORS' CONCLUSIONS: Treatment with an antipsychotic alone is not a good option. Starting with an antidepressant alone and adding an antipsychotic if the patient does not respond or starting with the combination of an antidepressant and an antipsychotic both appear appropriate options for patients with psychotic depression. In clinical practice the balance between risks and benefits suggests that initial antidepressive monotherapy and adding an antipsychotic if there is inadequate response should be the preferred treatment strategy for many patients. The general lack of available data limits confidence in the conclusions drawn.

Antidepressive Agents↗
PubMed2002

Selecting chemical substances for the UN-ECE POP protocol.

In 1998 the UN-ECE POP Protocol was signed. Sixteen substances are included in the protocol. They can be characterised as persistent, bioaccumulating and toxic organic substances prone to long-range atmospheric transport. The Dutch Ministry of Housing, Physical Planning and the Environment started a project to select possible candidates for the protocol. In the first phase of the project possible candidates were selected using the so-called 'PTB-database' applying the criteria from the protocol. From the 12 substances that met the criteria four substances were selected for which preliminary risk profiles were drafted: polychlorinated naphthalenes, dicofol, hexachlorobutadiene and pentachlorobenzene. These profiles are presented. Revised profiles have to be prepared for the UN-ECE LRTAP Ad hoc Expert Group on persistent organic pollutants (POPs). Ultimately, the process should lead to a proposal to include additional POPs to the UN-ECE POP Protocol.

Biological Availability↗
PubMed2000

Strain-dependent induction of cytokine profiles in the gut by orally administered Lactobacillus strains.

Different Lactobacillus strains are frequently used in consumer food products. In addition, recombinant lactobacilli which contain novel expression vectors can now be used in immunotherapeutic applications such as oral vaccination strategies and in T cell tolerance induction approaches for autoimmune disease. Both for food and clinical applications of lactobacilli, proper selection of wild type strains is crucial. For that purpose, eight different common Lactobacillus strains were analysed with respect to mucosal induction of pro- and anti-inflammatory cytokines, IgA-producing plasma cells in the gut, as well as systemic antibody responses against a parenterally administered antigen. Immunohistochemical analysis of cytokine-producing cells in the gut villi showed no significant induction of the cytokines IL-1alpha, IFN-gamma, IL-4 or IL-10 after oral administration of wild type Lactobacillus strains. In contrast, oral administration of L. reuteri and L. brevis induced expression of the proinflammatory/Th1 cytokines TNF-alpha, IL-2 and/or IL-1beta. Oral administration of these two strains and L. fermentum also significantly enhanced the IgG response against parenterally administered haptenated chicken gamma globulin (TNP-CGG). The five other strains did not show this adjuvanticity. L. reuteri induced relatively high levels of IgG2a compared to L. murines, a nonadjuving Lactobacillus strain. These findings imply that different Lactobacillus strains induce distinct mucosal cytokine profiles and possess differential intrinsic adjuvanticity. This suggests that rational Lactobacillus strain selection provides a strategy to influence cytokine expression and thereby influence immune responses.

Adjuvants, Immunologic↗
PubMed1999

Environmental risk assessment for the polycyclic musks AHTN and HHCB in the EU. I. Fate and exposure assessment.

For the environmental exposure assessment of the fragrance ingredients 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN) and 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-gamma-2-ben zopyran (HHCB) the following properties were determined: vapour pressure 0.0682 and 0.0727 Pa; water solubility 1.25 and 1.75 mg/l; log K(ow) 5.7 and 5.9; log K(oc) 4.80 and 4.86; bioconcentration factor in fish: 597 and 1584 (fresh weight) for AHTN and HHCB, respectively. Both substances are degraded to more polar metabolites in fish, in soil and during sewage treatment. A review is made of concentrations measured in sludge, in freshwater and marine systems including suspended matter, sediment and fish. The 90th-percentile in more than 200 surface water samples is 0.3 microg/l for AHTN and 0.5 microg/l for HHCB. The 90th-percentile of the concentrations in fish is 0.12 mg/kg fresh weight for both substances (n = 27). These concentrations are lower by a factor of 5-15 than predicted on the basis of the yearly use volumes in Europe, 585 tonnes for AHTN and 1482 tonnes for HHCB. Concentrations in sludge-amended soils and in earthworms are predicted based on concentrations measured in sludge. For AHTN, the predicted values are: PECsoil, 0.029 mg/kg and PECworm, 0.065 mg/kg while for HHCB the corresponding figures are 0.032 and 0.099 mg/kg. These concentrations assume a biodegradation half-life in the soil of 180 days based on preliminary soil biodegradation data.

Animals↗
PubMed1999

Environmental risk assessment for the polycyclic musks, AHTN and HHCB. II. Effect assessment and risk characterisation.

Reports of the polycyclic musks AHTN and HHCB in surface water and fish, primarily in Europe, have prompted studies of their environmental effects. These effects then are used, along with the predicted environmental concentrations in a risk assessment according to the approach developed under European Union Regulation 793/93, in line with the Technical Guidance Document for risk assessment of new and existing chemicals. In 72-h studies with algae (Pseudokirchneriella subcapitata), NOECs were 0.374 mg/l (AHTN) and 0.201 mg/l (HHCB). In 21-day reproductive tests with daphnia (Daphnia magna) NOECs were 0.196 (AHTN) and 0.111 mg/l (HHCB). In 21-day growth tests with bluegill sunfish (Lepomis macrochirus), NOECs were 0.067 (AHTN) and 0.068 mg/l (HHCB). And, finally 35-day early life stage tests with fathead minnows (Pimephales promelas) resulted in NOECs of 0.035 (AHTN) and 0.068 mg/l (HHCB). These results lead to Predicted No Effect Concentrations (PNEC) of 3.5 microg/l (AHTN) and 6.8 microg/l (HHCB) for aquatic organisms. For the soil compartment, 8-week studies with earthworms (Eisenia fetida) resulted in NOECs of 105 (AHTN) and 45 mg/kg (HHCB) and 4-week studies with springtails (Folsomia candida) resulted in a NOECs of 45 mg/kg for both substances. These values lead to a PNEC of 0.32 mg/kg dw for both materials. Using mammalian studies, PNECs for fish or worm eating predators of 10 mg/kg fw (AHTN) and 100 mg/kg fw (HHCB) can be derived. For sediment dwelling organisms, PNECs were derived by equilibrium partitioning using the aquatic PNECs. Comparing PNECs with the measured or predicted environmental exposures leads to risk characterisation ratios as follows: aquatic species: AHTN 0.086, HHCB 0.074; sediment organisms: AHTN 0.44, HHCB 0.064; soil organisms: AHTN 0.091, HHCB 0.10; fish eating predators: AHTN 0.012, HHCB 0.001; worm eating predators: AHTN 0.007, HHCB 0.001.

Animals↗
PubMed1998

Orally administered Lactobacillus strains differentially affect the direction and efficacy of the immune response.

In mice, strain dependent cytokine production profiles are induced after oral administration of Lactobacillus. Such a cytokine profile seems to determine the direction and efficacy of the humoral response. In SJL mice lactobacilli are able to enhance or inhibit the development of disease after induction of experimental autoimmune encephalomyelitis (EAE). Immuno-histochemical analysis of cytokine profiles showed that differential modulation is obtained dependent on the Lactobacillus strain applied. Serum antibody responses to i.p. immunisation with chicken gamma globulin in BALB/c mice are also modulated by oral application of Lactobacillus. Lactobacilli are now being developed as safe live antigen carriers for application in vaccine technology, but also for the excretion of autoantigens in order to induce tolerance. The findings of this study imply that by proper strain selection the direction of the response can be influenced by the induction of a specific cytokine profile.

Adjuvants, Immunologic↗
PubMed1997

Environmental risk assessment of musk ketone and musk xylene in The Netherlands in accordance with the EU-TGD.

An environmental risk assessment has been carried out for musk ketone and musk xylene according to the EU Technical Guidance Document for Environmental Risk Assessment for New and Existing Substances [1]. Musk ketone and musk xylene are used in fragrances for cosmetics and household products. For the fragrance industry these are important fragrance ingredients because of their excellent substantivity as well as for their unique smell, which determines largely the odor of a product. The initial environmental risk assessment is based on information provided by the fragrance industry as represented in the Netherlands by its association NEA, by the Research Institute for Fragrance Materials (RIFM) and data reported in the international open literature. The risk assessment includes and evaluation of the risks for aquatic organisms in surface water and sediment and for soil organisms in soil after application of sewage sludge. Secondary poisoning of fish-eating birds and mammals is considered as well. For each compartment the Predicted Environmental Concentration (PEC) is compared to the Predicted No Effect Concentration (PNEC) to obtain PEC/PNEC ratios. Since monitoring data are available in water, sediment and fish, similar ratios are obtained with measured concentrations instead of the predicted ones. For both substances, PEC/PNEC ratios are at or below 0.1 for organisms in the aquatic environment, including sediment organisms. PEC/PNEC ratios for fish-eating predators are 0.01. Ratios based on monitoring data are below 0.01 for all of these organisms. For soil organisms the PEC/PNEC ratio is 0.5 for musk ketone and 1.3 for musk xylene. Although in the Netherlands (as well as in some other European countries), sewage sludge presently finds no application as fertilizer on agricultural soil, the aim of environmental policy is to upgrade the sludge quality to enable future applications on agricultural and grassland. The reliability of the predicted soil concentrations can be greatly improved by obtaining experimental data on fate and behaviour of musk ketone and musk xylene in digested sludge and soil. The risk assessment provides reassurance for the aquatic compartment while pointing the way for obtaining additional data for the soil compartment.

Animals↗