Early visual information processing in schizophrenia compared to recurrent depression

Patients with schizophrenia have repeatedly shown deficits in early visual processing using backward masking (VBM) tasks. Whether this represents a specific dysfunction in schizophrenia is an unsolved question. Patients with recurrent unipolar depression represent an interesting comparison group to examine the question of specificity, but have never previously been assessed on VBM. In addition to comparing VBM performance in patients with schizophrenia and patients with depression, we wanted to examine the relations between VBM and clinical symptoms. Fifty-one patients with schizophrenia were compared to 49 patients with recurrent unipolar depression and 47 healthy controls. All subjects were administered a two-digit identification task in a no-masking and four masking conditions. Patients with schizophrenia performed significantly worse than normal controls on four of the five conditions. No significant difference was found between depression patients and normal controls. The effect of masking stimuli had no differential effects on the three groups. VBM correlated strongly with positive symptoms in the schizophrenia group.     

Dependency issues in survival analyses of 55,782 primary hip replacements from 47,355 patients

Artificial hip joints are used in only one hip for about 85 per cent of the patients and in both hips (bilateral) for about 15 per cent of the patients. The occurrence of bilateral prostheses and the influence they have in survival analyses of joint arthroplasties are seldom considered. In this study we therefore focus on issues related to bilateral primary hip prostheses, time to revision surgery, and some commonly used statistical methods. We used information from 47,355 patients with 55,782 primary hip prostheses reported to the Norwegian Arthroplasty Register between 1987 and 2000. Due to the large number of diagnoses, fixation techniques for the prostheses, and combination of prostheses brands, we furthermore considered a 'homogeneous' subset of 8703 prostheses from 7930 patients with primary osteoarthritis, and Charnley prosthesis fixed with antibiotic-containing Palacos cement. Kaplan-Meier curves for all prostheses, ignoring that some patients have bilateral prostheses, were compared with Kaplan-Meier curves using only the first inserted prostheses, and with survival curves modified for patients with bilateral prostheses. Cox regression analyses were used to assess explanatory variables and to adjust for confounding factors. The results from the ordinary Cox regression analyses were compared with results from a marginal model, a shared gamma frailty model, and a model using a time dependent covariate to condition on failures in the opposite hip. We found no practical difference between the three calculated survival curves for the hip replacement data. The ordinary Cox-model and the marginal model gave equivalent results. In the shared gamma frailty model estimates for the risk factors were comparable with the former two approaches. The estimated frailty variance was higher when all data were used, even after adjustment for confounding factors. For the 'homogeneous' data the estimated frailty variance was negligible. Using a time dependent covariate to condition on previous revisions in the opposite hip, we found a higher risk of revision for the remaining primary hip prosthesis if the opposite hip had been revised (RR = 3.49, p < 0.0001). There was no difference in risk for revision between right and left hip prostheses. If the time interval between the two primary operations was more than two years, for the full data, the first hip prosthesis had an increased risk of revision compared to prostheses in patients with only one prosthesis (RR = 1.25, p = 0.01). For the 'homogeneous' data no statistically significant difference was found between unilateral and bilateral prostheses. A revision in one hip, for patients with bilateral prostheses, is a risk factor for revision of the other hip. Thus, in analyses of prostheses survival, dependencies between two hip prostheses from one patient should be considered. However, ignoring possible dependencies does not necessarily have an impact on the results on standard risk factors.     

Spinal substance P release in vivo during the induction of long-term potentiation in dorsal horn neurons

Long-term potentiation (LTP) in wide dynamic range (WDR) neurons in the dorsal horn has been suggested to contribute to central sensitization and the development of chronic pain. Indirect experimental evidence indicates an involvement of substance P (SP), in this respect. The aim of the present study was to monitor the extracellular level of substance P-like immunoreactivity (SP-LI) in the dorsal horn of the rat during and after induction of LTP in WDR neurons in vivo. Electrophysiological recordings of single (WDR) neurons were performed in parallel with microdialysis in the dorsal horn under urethane-anaesthesia. The amount of SP-LI in the microdialysate was determined by radioimmunoassay. As previously shown, high frequency conditioning stimulation of the sciatic nerve induced an increased firing response of WDR neurons. An increased response to C-fibre stimulation, but not A-fibre stimulation, could be determined. A significant increase of the extracellular level of SP-LI in the dorsal horn was detected during, but not after, induction of LTP. These data suggest that SP may be involved in the induction of LTP by high frequency stimulation. However, the maintenance of spinal LTP following high frequency peripheral nerve stimulation does not seem to depend on an increased release of SP.     

Rational Prescribing in Primary Care (RaPP-trial). A randomised trial of a tailored intervention to improve prescribing of antihypertensive and cholesterol-lowering drugs in general practice [ISRCTN48751230]

Background  

The underlying reasons for differences between clinical practice and systematically developed guidelines vary from one clinical problem to another. It is therefore logical to tailor strategies to support the implementation of guidelines to address identified barriers to change. The objective of this trial is to evaluate the effects of a tailored intervention to support the implementation of systematically developed guidelines for the use of antihypertensive and cholesterol-lowering drugs for the primary prevention of cardiovascular disease.     

Antibiotic prophylaxis in total hip arthroplasty: effects of antibiotic prophylaxis systemically and in bone cement on the revision rate of 22,170 primary hip replacements followed 0-14 years in the Norwegian Arthroplasty Register

We studied the effects of antibiotic prophylaxis, systemically and in bone cement, on the revision rate of cemented total hip arthroplasties (THAs) in data from the Norwegian Arthroplasty Register during the period 1987-2001. To have comparable groups, only THAs performed because of primary osteoarthritis, using cemented implants with documented good results, and high-viscosity cement were included. If systemic antibiotic prophylaxis had been given, only operations with cephalosporin or penicillin were selected. Cox-estimated survival relative revision risks (RR) are presented with adjustment for differences among groups in gender, age, cement brand, type of systemic antibiotic prophylaxis, type of prosthesis, type of operating room, and duration of the operation. Of 22,170 THAs studied, 696 THAs (3.1%) were revised, 440 (2.0%) for aseptic loosening and 102 (0.5%) for deep infection. We found the lowest risk of revision when the antibiotic prophylaxis was given both systemically and in the cement (15,676 THAs). Compared to this combined regime, patients who received antibiotic prophylaxis only systemically (5,960 THAs) had a 1.4 times higher revision rate with all reasons for revision as endpoint (p = 0.001), 1.3 times higher with aseptic loosening (p = 0.02) and 1.8 times higher with infection as the endpoint (p = 0.01). With the combined antibiotic regime, the results were better if antibiotics were given 4 times on the day of surgery (2,194 THAs), as compared to once (1,424 THAs) (p < 0.001), twice (2,680 THAs) (p < 0.001), or 3 times (5,522 THAs) (p = 0.02). Those who received systemic prophylaxis a single day 1, 2 or 3 times, as compared to 4 times, had a revision rate 1.8-3.5 times higher with all reasons for revision as endpoint, 1.5-3.1 times higher with aseptic loosening, and 2.7-6.8 times higher with infection. When we compared systemic prophylaxis 4 times in 1 day, no further improvement resulted in those given systemic prophylaxis for 2 days (1,928 THAs) or 3 days (717 THAs). In a subset of data including only the Charnley prosthesis, we obtained similar results. This observational study shows that the best results were recorded when antibiotic prophylaxis was given both systemically and in the bone cement, and if the systemic antibiotic was given 4 times on the day of surgery.     

A maritime disaster: reactions and follow-up

In 1999, 69 people survived a maritime disaster on the Norwegian coast, during which 16 others died. Besides immediate psychosocial assistance, post-disaster intervention included psychological debriefings after one week, follow-up debriefing a month later, screening of those in need of individual help, and help for those returning to the scene of the disaster. The results of the psychometric tests showed that a considerable number of survivors scored above clinical cut-off points for extreme stress reactions. These results were compared with results from other studies of maritime disasters. Although the life threat and exposure in this disaster were extreme, the scores were lower than for the other studies, with one exception. The authors concluded the lower distress scores compared to other maritime disasters were probably impacted by the structured and caring system that was implemented to care for survivors. Almost all (93%) considered the debriefing meetings as helpful, and they were able to discriminate between different functions served by the meetings.     

Macromolecular contrast medium (feruglose) versus small molecular contrast medium (gadopentetate) enhanced magnetic resonance imaging: differentiation of benign and malignant breast lesions

RATIONALE AND OBJECTIVES: To compare the diagnostic performance of the blood pool agent feruglose and the standard extracellular contrast agent gadopentetate in their abilities to differentiate benign and malignant breast tumors. PATIENTS AND METHODS: Fourteen women, aged 35-77 years (mean, 55 years), with 19 breast lesions underwent dynamic fast field echo 14/1/30 degrees (TR/TE/alpha) magnetic resonance imaging of the breast after bolus injection of feruglose (Clariscan; Amersham Health, Amersham, UK: dose, 2 mg Fe/kg) and an additional, comparative gadopentetate (dose, 0.2 mmol gadolinium/kg)-enhanced fast field echo 10/4/30 degrees (TR/TE/alpha) magnetic resonance study within 1-11 days (mean, 4.8 days) before or after the feruglose study. All breast tumors were surgically excised within 1-6 days (mean, 2.5 days) after completion of the magnetic resonance studies. Data were analyzed by measuring quantitative enhancement data and qualitatively by categorizations of the shape of the tumor enhancement curves. Group differences between quantitative data of the two contrast agents and between benign and malignant tumors were evaluated using a two-tailed paired-sample t test. Differences in curve type distribution between benign and malignant tumors were tested with the chi2 test. RESULTS: Histopathology showed a spectrum of 10 benign and nine malignant breast lesions: five mastopathies, two fibroadenomas, two chronic inflammations, and one papillomatosis, as well as five invasive ductal carcinomas and four invasive lobular carcinomas. Substantial differences were observed between feruglose- and gadopentetate-enhanced images: the mean tumor deltaSI(%) peak enhancement and wash-in rate were significantly higher for gadopentetate- as compared with feruglose-enhanced images (P < .05). Using either contrast agent, morphologic enhancement characteristics showed a considerable overlap between benign and malignant breast lesions. However, the kinetic enhancement profiles of benign and malignant lesions were significantly different based on feruglose-enhanced data (chi2 = 9.017; P = .0027) but not gadopentetate-enhanced data (chi2 = 2.239; P = .3264). CONCLUSION: Compared with gadopentetate, the new blood pool agent feruglose provided an improved characterization of the evaluated breast lesions; however, at the cost of weaker overall tumor enhancement.     

SUPPORT Tools for evidence-informed health Policymaking (STP) 8: Deciding how much confidence to place in a systematic review

This article is part of a series written for people responsible for making decisions about health policies and programmes and for those who support these decision makers.The reliability of systematic reviews of the effects of health interventions is variable. Consequently, policymakers and others need to assess how much confidence can be placed in such evidence. The use of systematic and transparent processes to determine such decisions can help to prevent the introduction of errors and bias in these judgements. In this article, we suggest five questions that can be considered when deciding how much confidence to place in the findings of a systematic review of the effects of an intervention. These are: 1. Did the review explicitly address an appropriate policy or management question? 2. Were appropriate criteria used when considering studies for the review? 3. Was the search for relevant studies detailed and reasonably comprehensive? 4. Were assessments of the studies' relevance to the review topic and of their risk of bias reproducible? 5. Were the results similar from study to study?