Cerebral metabolic responses to 5-HT2A/C receptor activation in mice with genetically modified serotonin transporter (SERT) expression

Variation in the human serotonin transporter gene (hSERT; 5-HTT) resulting in a life-long alteration in SERT function influences anxiety and the risk of developing affective disorders. The mechanisms underlying the influence of the hSERT gene on these phenotypes remain unclear but may involve altered 5-HT receptor function. Here we characterise the cerebral metabolic response to 5-HT_2A/C receptor activation in two transgenic mouse models of altered SERT function, SERT knock-out (SERT KO) and hSERT over-expressing (hSERT OE) mice, to test the hypothesis that genetically mediated variability in SERT expression alters 5-HT_2A/C function. We found that a constitutive increase in SERT expression (hSERT OE) enhanced, whereas a constitutive decrease in SERT expression (SERT KO) attenuated, 5-HT_2A/C function. Therefore, altered 5-HT_2A/C receptor functioning in response to hSERT gene variation may contribute to its influence on affective phenotypes.     

Lipopolysaccharide produces dose-dependent reductions of the acoustic startle response without impairing prepulse inhibition in male rats

This study examined the dose-dependent effects of Lipopolysaccharide (LPS) on the acoustic startle response and prepulse inhibition (PPI) in male Long-Evans rats. LPS is known to stimulate the innate immune system and result in behavior modifications referred to as "sickness behaviors". The purpose of this study was to assess the ability of LPS to modulate sensorimotor reflexes (Startle-Only trials) and/or sensory processing (PPI trials). Rats were injected intraperitoneally with LPS (50, 100 or 200 microg/kg LPS, n=9/group) or saline vehicle (n=14) on 2 test days 72 h apart. Subjects were placed in a familiar startle box apparatus where startle response magnitudes were recorded following 115 dB Startle-Only trials and PPI trials (with prepulses at +3, +6 and +12 dB above background noise). Analysis of Startle-Only trials indicated a significant dose-dependent effect of LPS on Test Day 1. The 200 microg/kg LPS group exhibited significantly reduced startle response magnitude relative to all other treatments. On the PPI trials no LPS groups displayed significantly different performance from vehicle controls. Also, DayxDrug interactions for both Startle-Only and PPI trial types indicated behavioral tolerance to LPS. LPS reduced the acoustic startle response in a dose-dependent manner on Test Day 1. From the PPI data, it is evident that all treatment groups elicited near-normal inhibition levels indicating adequate sensory function. In combination, the results suggest that the range of sickness behaviors following LPS-administration to adult rats includes decreased non-voluntary motor activity as reflected by reduced startle magnitude.     

Study rationale and protocol: prospective randomized comparison of metal ion concentrations in the patient's plasma after implantation of coated and uncoated total knee prostheses

Background  

Any metal placed in a biological environment undergoes corrosion. Thus, with their large metallic surfaces, TKA implants are particularly prone to corrosion with subsequent release of metal ions into the human body which may cause local and systemic toxic effects and hypersensitivity reactions, and increase cancer risk. To address this problem, a new 7-layer zirconium coating developed especially for cobalt-chrome orthopaedic implants was tested biomechanically and found to lower metal ion release.     

Cannabis induces different cognitive changes in schizophrenic patients and in healthy controls

It is known that 60 to 80% of schizophrenic patients show deficits in cognition. There may be an increase in these deficits as a result of additional regular use of cannabis. The aim of the study was to evaluate the effect of chronic cannabis consumption on the cognitive functions of schizophrenic patients and healthy control subjects after a minimum abstinence time of 28 days. The study sample consisted of 39 schizophrenics (19 cannabis-abusers and 20 non-abusers) and 39 healthy controls (18 cannabis-abusers, 21 non-abusers). In a 2x2-factorial design (Diagnostic Groups [healthy controls, schizophrenic patients]xCannabis abuse [without, with]) with diagnostic group and cannabis consumption considered between-subject factors) we tested the hypothesis that dually diagnosed patients (i.e. suffering both from schizophrenia and cannabis abuse) perform worse in neuropsychological tests than schizophrenic patients without cannabis abuse. On the whole, schizophrenic patients performed worse than healthy control subjects. Surprisingly, rather than deteriorating neuropsychological performance, regular cannabis abuse prior to the first psychotic episode improved cognition in some tests. This was even more pronounced when regular consumption started before the age of 17. On the other hand, cannabis use deteriorated test performance in healthy controls, especially in cases when regular consumption started before the age of 17. To sum up, regular cannabis abuse has a different effect on cognitive function in schizophrenic patients and healthy controls.     

Neurogenesis and schizophrenia: dividing neurons in a divided mind?

Forty years after the initial discovery of neurogenesis in the postnatal brain of the rat, convincing evidence has been accrued that functional neurons are generated throughout the entire lifespan, particularly in the dentate gyrus (DG) and the subventricular zone (SVZ). This phenomenon has been termed adult neurogenesis (AN) and while it was detected in all examined mammalian species including humans, the physiological role of this process remains unknown. Although a plethora of animal studies indicate an involvement of AN in the pathophysiology of depression, this view has recently kindled considerable controversy. Pertinent studies in humans failed to confirm a role of reduced hippocampal neural stem cell proliferation (NSP) in depression but suggest a contribution to the pathophysiology of schizophrenia. The functional relevance of disturbed AN may encompass erroneous temporal encoding of new memory traces, thereby contributing to cognitive deficits observed in schizophrenia. This AN-hypothesis of schizophrenia is supported by neuroimaging, as well as by several genetically modified rodent models, e.g. reelin and NPAS3 knockout mice. Furthermore, several genes impacting on AN, including NPAS3, were also found to be associated with schizophrenia by case-control studies. In conclusion, several lines of evidence suggest that reduced AN may contribute to the etiopathogenesis of schizophrenic disorders, whereas it does not seem to be a critical risk factor for affective disorders. The work of the authors is supported by the Deutsche Forschungsgemeinschaft (Grant RE1632/1–1 and 1–3 to A.R., KFO 125/1–1 D to A.R. and K.P.L., and SFB 581 to K.P.L.), BMBF (IZKF 01 KS 9603) and the European Commission (NEWMOOD LSHM-CT-2003-503474).     

Femoral head injuries: Which treatment strategy can be recommended?

Despite different operative and non-operative treatment regimens, the outcome after femoral head fractures has changed little over the past decades. The initial trauma itself as well as secondary changes such as posttraumatic osteoarthritis, avascular necrosis or heterotopic ossification is often responsible for severe loss of function of the afflicted hip joint. Anatomic reduction of all fracture fragments seems to be a major influencing factor in determining the outcome quality. Eight years ago we inaugurated a new surgical approach for better access and visualisation for the treatment of femoral head fractures, using the "trochanteric flip" (digastric) osteotomy. Thus inspection of the entire hip joint and accurate fragment reduction under direct visual control are possible. After good initial experiences with this operative procedure we changed our standard treatment regimen to this approach in an attempt to achieve the most accurate anatomic reduction of the femoral head in every affected patient. Between 1998 and 2006 we operated on 12 patients with femoral head fractures associated with posterior hip dislocation, using the new surgical approach. Patients were followed for 2-96 months and outcome was documented with the Merle d'Aubigne and Postel score as well as the Thompson and Epstein score. The posttraumatic formation of heterotopic bone was documented with the Brooker score. Retrospective analysis of these 12 patients showed good or excellent results in 10 patients (83.3%). The two patients with poor outcome developed an avascular necrosis of the femoral head and underwent total hip arthroplasty. Periarticular heterotopic ossification was seen in five patients. In four patients this caused a significantly reduced range of motion and was therefore considered as a posttraumatic complication. The two patients with the most severe heterotopic bone formation (Brooker III and IV) had initially sustained multiple injuries including brain injury. Comparing our results with earlier published series including our own before changing the treatment protocol, the data suggest a favorable outcome in patients with trochanteric flip (digastric) osteotomy for the treatment of femoral head fractures.     

Comparison of fesoterodine and tolterodine in patients with overactive bladder

OBJECTIVE

To compare, in a post hoc analysis of a phase III trial, the maximum recommended doses of fesoterodine (8 mg) and tolterodine (4 mg) for improving overactive bladder (OAB) symptoms and health‐related quality of life (HRQoL), as fesoterodine effectively reduces OAB symptoms vs placebo.

PATIENTS AND METHODS

Eligible patients with frequency (≥eight voids/24 h) and either urgency (≥six episodes over 3 days) or urgency urinary incontinence (UUI; ≥three episodes over 3 days) were randomized to placebo, fesoterodine 4 or 8 mg, or tolterodine extended‐release (ER) 4 mg for 12 weeks; fesoterodine 4 mg data were published elsewhere. Patients completed a 3‐day bladder diary in which they recorded the time of each void, voided volume (VV), and the severity of urgency. A post hoc inferential analysis was conducted on the primary endpoint (voids/24 h), the two co‐primary endpoints (UUI episodes/24 h and treatment response), several secondary endpoints (severe urgency plus UUI per 24 h, mean VV (MVV)/void, and continent days/week), HRQoL, using the King’s Health Questionnaire (KHQ) and the International Consultation on Incontinence Questionnaire‐Short Form (ICIQ‐SF), and self‐reported bladder‐related problems. A subanalysis also assessed all endpoints for patients who were incontinent at baseline. Tolerability and safety were assessed by evaluating adverse events, residual urine volume, laboratory variables and treatment withdrawals.

RESULTS

By week 12, patients with OAB in both active‐treatment groups showed significant improvements in most bladder diary variables and treatment response rates compared with placebo. Fesoterodine 8 mg was statistically significantly better than tolterodine ER 4 mg for improving UUI episodes, severe urgency plus UUI, mean VV, and number of continent days/week. In addition, the fesoterodine and tolterodine ER groups showed significantly greater improvements in HRQoL than the placebo group, with positive changes in most domains of the KHQ and an improvement in ICIQ‐SF score. The fesoterodine 8‐mg group had statistically significant improvements over placebo in eight of nine KHQ domains. A major improvement in the severity of bladder‐related problems was reported by 39% of the fesoterodine 8 mg and 34% of the tolterodine ER groups vs 25% of those on placebo (P ≤ 0.01). Results for the subgroup of incontinent patients at baseline were similar to the overall results. Adverse events reported most commonly with active treatment included dry mouth, constipation, dry eye, dry throat, and nausea.

CONCLUSIONS

Both fesoterodine and tolterodine ER significantly improved OAB symptoms and HRQoL, with statistically significant advantages for fesoterodine 8 mg compared with tolterodine ER on several important endpoints.     

Spermatogenesis in the contralateral testis of patients with testicular germ cell cancer: histological evaluation of testicular biopsies and a comparison with healthy males

OBJECTIVE: To assess histologically signs of testicular dysgenesis (TD) in the contralateral testes of patients with testicular germ cell tumours (GCTs) and to compare these findings with the spermatogenetic quality in healthy men, as the contralateral testis is considered to be involved with dysgenetic features such as poor sperm production, and accordingly, GCTs are hypothesized to be part of the 'TD syndrome' (TDS). One testicular biopsy is thought to represent spermatogenesis in the entire testis. We evaluated this view by using testicular two-site biopsies. PATIENTS AND METHODS: 2318 patients with testicular GCT had a contralateral testicular two-site biopsy. Testicular biopsies taken on forensic autopsy from 1388 presumably healthy men served as controls. Spermatogenesis was rated histologically according to a modified Johnsen score. Clinical factors were recorded to explore associations with reduced spermatogenesis. Differences in spermatogenesis scoring results among two-site biopsies were noted. Statistical analysis involved Wilcoxon-Mann-Whitney and Jonckheere-Terpstra tests for comparing patients and controls, and for studying associations with clinical factors. Classification and regression-tree analysis was used to explore multivariate associations. RESULTS: Histologically, patients had significantly poorer spermatogenesis than healthy men. Clinically, hypospermatogenesis was significantly associated with testicular atrophy, undescended testes, male infertility, and advanced clinical stage; 5.4% of cases (95% confidence interval 4.43-6.27) had discordant findings of >2 points on double biopsy and 9.8% had differences of 1 point. Discordance was significantly associated with poor spermatogenesis and testicular atrophy. CONCLUSIONS: We confirmed histologically that there is markedly reduced spermatogenesis in the contralateral testes of patients with GCT. This result lends credence to the view that GCT is part of the so-called TDS. But as hypospermatogenesis is associated with advanced clinical stage, impairment of sperm production might at least partly be acquired secondary to the endocrine activity of GCT. There were clinically relevant discordant results on double biopsy in 5.4%, predominantly in infertile patients and in atrophic testes. Thus the histological evaluation of male infertility is best done by multiple biopsies.     

Neo-capsule tissue reactions in metal-on-metal hip arthroplasty

Background Modern-generation metal-on-metal articulations have a high wear resistance and may therefore be able to improve the long-term performance of artificial joints. However, the biological effects are still under debate. This study was undertaken to review the histopathological changes in neo-capsule tissues of different metal-on-metal hip arthroplasties.

Methods Neo-capsule tissue samples from 46 hips with modern second-generation metal-on-metal articulations (39 hip resurfacings and 7 non-cemented total hip replacements) with a variety of failure mechanisms were examined histopathologically and immunohistochemically.

Results A distinct lymphocytic infiltration was found in all cases with in situ times of more than 7 months, consisting of CD20-positive B-lymphocytes and CD3positive T-lymphocytes and sometimes thinly distributed CD138-positive plasma cells without dominant T-cell or plasma cell infiltrates.

Interpretation This distinct lymphocytic infiltration has not been reported in tissue analyses of metal- or ceramic-on-polyethylene hip replacements, and may therefore be considered to be a characteristic histological pattern of tissue reactions on metal particles and/or ions around metal-on-metal bearings.