Lower levels of the glial cell marker TSPO in drug-naive first-episode psychosis patients as measured using PET and [11C]PBR28.

Several lines of evidence are indicative of a role for immune activation in the pathophysiology of schizophrenia. Nevertheless, studies using positron emission tomography (PET) and radioligands for the translocator protein (TSPO), a marker for glial activation, have yielded inconsistent results. Whereas early studies using a radioligand with low signal-to-noise in small samples showed increases in patients, more recent studies with improved methodology have shown no differences or trend-level decreases. Importantly, all patients investigated thus far have been on antipsychotic medication, and as these compounds may dampen immune cell activity, this factor limits the conclusions that can be drawn. Here, we examined 16 drug-naive, first-episode psychosis patients and 16 healthy controls using PET and the TSPO radioligand [11C]PBR28. Gray matter (GM) volume of distribution (VT) derived from a two-tissue compartmental analysis with arterial input function was the main outcome measure. Statistical analyses were performed controlling for both TSPO genotype, which is known to affect [11C]PBR28 binding, and gender. There was a significant reduction of [11C]PBR28 VT in patients compared with healthy controls in GM as well as in secondary regions of interest. No correlation was observed between GM VT and clinical or cognitive measures after correction for multiple comparisons. The observed decrease in TSPO binding suggests reduced numbers or altered function of immune cells in brain in early-stage schizophrenia.

Mapping the distribution of serotonin transporter in the human brainstem with high-resolution PET: Validation using postmortem autoradiography data.

The human brainstem is a complex structure with several small nuclei and neural pathways of interest in the pathophysiology of central nervous system (CNS) disorders. In common with other monoaminergic systems, serotoninergic neurons originate from a group of nuclei located in the brainstem. The present study was designed to validate a user-independent approach for a detailed in vivo quantification of serotonin transporter (5-HTT) availability in the human brainstem using a template-based approach that consisted of three steps. First, 3T-MR images and parametric binding potential (BPND) [(11)C]MADAM images of ten healthy subjects were used to generate a PET template of 5-HTT availability. In the second step, volumes of interest (VOIs) for different brainstem nuclei were obtained using a method in which VOIs are initially delineated on MRI images using anatomical landmarks and then are finally tailored on the distribution of 5-HTT binding using a thresholding approach applied to the 5-HTT template. In the final step, the VOIs were transformed and applied individually to BPND images of 16 healthy subjects (14M/2F, 20-64years). The in vivo distribution of BPND values obtained with the template-based method were in good agreement with an individual-based approach taken as gold standard. Results were also in agreement with 5-HTT quantification using in vitro binding data obtained with autoradiography (ARG) studies using [(3)H]MADAM. The proposed template-based method can be applied to PET data acquired in several CNS disorders in which serotonin neurons in the brainstem might be affected.

Genetic and phenotypic heterogeneity in pattern dystrophy.

BACKGROUND: The pattern dystrophies (PD) represent a clinically heterogeneous family of inherited macular diseases frequently caused by mutations in the peripherin/RDS gene. Most previous studies have detailed the clinical findings in single families, making it difficult to derive data from which progression and visual outcome can be generalised. METHODS: Families were ascertained and clinically evaluated including angiography and electrophysiology where appropriate. RESULTS: In each of the six families with autosomal dominant PD, a mutation in the peripherin/RDS gene was identified, including a novel Cys250Phe variant. These data suggest that the condition is characterised by the accumulation of yellow to grey subretinal flecks, followed by pigmentary change accompanied by patches of chorioretinal atrophy. Subsequently, 50% (16/32) of individuals with PD developed poor central vision because of chorioretinal geographic atrophy or subretinal neovascularisation. The risk of these complications appears to increase with age. CONCLUSION: PD should not necessarily be considered a benign condition. Instead, patients should be counselled that there is a significant chance of losing central vision in their later years. Some elderly patients with probands showing PD may be misdiagnosed with age related macular degeneration owing to the phenotypic similarities between these conditions in the advanced state.

Three-month neoadjuvant hormonal therapy before radical prostatectomy: a 7-year follow-up of a randomized controlled trial.

OBJECTIVE: To describe the outcome, assessed as the level of prostate specific antigen (PSA), of a mature (more than half the events recorded) prospective randomized study with a median follow-up of 82 months of neoadjuvant hormonal therapy before radical prostatectomy, as this has been suggested to decrease the rate of positive surgical margins (i.e. provide greater potential to completely excise the tumour). PATIENTS AND METHODS: From December 1991 to March 1994, 126 patients with clinically localized prostate cancer were randomized between direct radical prostatectomy or a 3-month course of a gonadotrophin-releasing hormone analogue before surgery. The patients were followed by PSA determinations and a value of > 0.5 ng/mL used to define progression. RESULTS: The incidence of positive surgical margins decreased from 45.5% to 23.6% (P = 0.016) with hormone treatment. Despite this there was no difference in PSA progression-free survival at the last follow-up; it was 51.5% for those undergoing radical prostatectomy only and 49.8% for those who received hormonal pretreatment (P = 0.588). CONCLUSIONS: Three months of neoadjuvant hormonal therapy before radical prostatectomy offers no benefit to the patient and cannot be recommended for routine clinical use.

Hormonal treatment before radical prostatectomy: a 3-year followup.

PURPOSE: Hormonal treatment administered before radical prostatectomy has been shown to decrease the rate of positive surgical margins. We determine whether preoperative hormonal treatment has any impact on the subsequent failure rate. MATERIALS AND METHODS: We prospectively evaluated 122 patients with stages T1bNxM0 to T3aNxM0, grades 1 to 3 prostate cancer, including 64 randomly assigned to immediate radical retropubic prostatectomy and 58 randomly assigned to radical retropubic prostatectomy preceded by 3 months of pretreatment with a gonadotropin-releasing hormone agonist. We performed intention to treat analysis on the data with failure defined as lymph node involvement, serum prostate specific antigen greater than 0.5 ng./ml., or the need for postoperative hormonal or radiation adjuvant treatment. RESULTS: The positive margin rate was 23.6 versus 45.5% in the pretreatment plus prostatectomy versus prostatectomy only groups (p = 0.016). There were 20 failures (34.5%) in the pretreatment plus prostatectomy subgroup and 26 (40.6%) in the prostatectomy only group (p = 0.48). A negative surgical margin was associated with a significantly lower risk of progression than a positive surgical margin (20.8 versus 50.0%, p = 0.0016), and progression was delayed by approximately 1 year after hormonal pretreatment. However, at a median followup of 38 months there was no difference in progression-free survival (p = 0.57). CONCLUSIONS: Although hormonal pretreatment significantly decreased the positive margin rate, it did not result in any difference in progression-free survival when followup exceeded 3 years. Thus, our current results do not support the routine administration of hormonal treatment before radical prostatectomy.

The risk of malignancy in the surgical margin at radical prostatectomy reduced almost three-fold in patients given neo-adjuvant hormone treatment.

OBJECTIVES: To investigate the outcome of neo-adjuvant hormone treatment before radical prostatectomy regarding local tumour extension, peri-operative blood loss and operation time. PATIENTS: Of 111 surgically treated patients with prostate cancer (T1b-T3a, N0, M0, G1-3), 55 were randomised to immediate radical prostatectomy and 56 to 3 months of neo-adjuvant treatment with triptorelin (3.75 mg i.m. every 28 days) and cyproterone acetate (50 mg b.i.d. for 3 weeks to prevent flare). RESULTS: No differences were found in blood loss or operation time but patients who had neo-adjuvant treatment had a significantly lower frequency of positive margins (41 vs. 23%, p = 0.013). CONCLUSION: Neo-adjuvant treatment does not facilitate radical prostatectomy but may improve the chance of local cure. This must, however, be documented with long-term follow-up in randomised patients.