Introducing a gatekeeping system for amyloid status assessment in mild cognitive impairment.

BACKGROUND: In patients with mild cognitive impairment (MCI), enhanced cerebral amyloid-ß plaque burden is a high-risk factor to develop dementia with Alzheimer's disease (AD). Not all patients have immediate access to the assessment of amyloid status (A-status) via gold standard methods. It may therefore be of interest to find suitable biomarkers to preselect patients benefitting most from additional workup of the A-status. In this study, we propose a machine learning-based gatekeeping system for the prediction of A-status on the grounds of pre-existing information on APOE-genotype 18F-FDG PET, age, and sex. METHODS: Three hundred and forty-two MCI patients were used to train different machine learning classifiers to predict A-status majority classes among APOE-ε4 non-carriers (APOE4-nc; majority class: amyloid negative (Aß-)) and carriers (APOE4-c; majority class: amyloid positive (Aß +)) from 18F-FDG-PET, age, and sex. Classifiers were tested on two different datasets. Finally, frequencies of progression to dementia were compared between gold standard and predicted A-status. RESULTS: Aß- in APOE4-nc and Aß + in APOE4-c were predicted with a precision of 87% and a recall of 79% and 51%, respectively. Predicted A-status and gold standard A-status were at least equally indicative of risk of progression to dementia. CONCLUSION: We developed an algorithm allowing approximation of A-status in MCI with good reliability using APOE-genotype, 18F-FDG PET, age, and sex information. The algorithm could enable better estimation of individual risk for developing AD based on existing biomarker information, and support efficient selection of patients who would benefit most from further etiological clarification. Further potential utility in clinical routine and clinical trials is discussed.

Use of a gamma-2 herpesvirus as a vector to deliver antibodies to rhesus monkeys.

The gamma-2 herpesvirus of rhesus monkeys, rhesus monkey rhadinovirus (RRV), persists principally in B cells of its host. We constructed recombinant strains of RRV expressing the rhesus monkey-derived anti-SIV monoclonal antibodies 4L6 and 5L7 and compared the RRV-mediated in vivo delivery of these antibodies in rhesus monkeys with previous studies that utilized intramuscular delivery with an adeno-associated virus (AAV) vector. Recombinant RRV-4L6 and RRV-5L7 were both shown to stably produce the antibodies in persistently infected B-cell lines in culture. Two RRV-negative rhesus monkeys were experimentally infected with recombinant RRV-4L6 and two with recombinant RRV-5L7. Following infection, the appearance of the delivered antibody was readily detected in all four animals. However, the levels of the delivered antibody were considerably lower than what has been typically observed following intramuscular AAV delivery. Furthermore, three of the four monkeys had an antibody response to the delivered antibody as had been observed previously with intramuscular AAV delivery of these same antibodies. We conclude that this recombinant herpesvirus has no inherent advantage over AAV for delivery of potentially therapeutic monoclonal antibodies in a rhesus monkey model.

Long-term outcomes after endothoracic sympathetic block at the T4 ganglion for upper limb hyperhidrosis.

BACKGROUND: The aim of this study was to evaluate long-term results, quality of life, satisfaction and compensatory sweating after endothoracic sympathetic block at T4 (ESB4). METHODS: Patients who underwent an ESB4 procedure for palmar or palmoaxillary hyperhidrosis between 2001 and 2008 were included in a prospective study at a university hospital. Questionnaires devised by Keller and Milanez de Campos were applied to evaluate disease-specific quality of life. RESULTS: A total of 189 patients underwent 374 ESB4 procedures. Of 174 evaluated patients, 54 (31·0 per cent) had palmar and 120 (69·0 per cent) had palmoaxillary hyperhidrosis. Median follow-up was 92 months. In both groups, treatment successfully reduced hyperhidrosis (P < 0·001) and quality of life increased significantly after ESB4 (P < 0·001), remaining stable after 5 years. Overall satisfaction rates decreased owing to the development of compensatory sweating and recurrence during follow-up. Compensatory sweating affected 41 patients (23·6 per cent), and was severe in 11 (6·7 per cent) of 163 patients at 5-year follow-up; eight of these 11 patients had been treated for palmoaxillary sweating. The severity of compensatory sweating did not deteriorate with time. The severe recurrence rate increased to 11·0 per cent during follow-up, and was twice as common in patients treated for palmoaxillary sweating as in those treated for palmar sweating (13·2 versus 6·1 per cent respectively). Nine reoperations (5·2 per cent) were performed for persistent sweating, recurrence or compensatory sweating. CONCLUSION: T4 endothoracic sympathetic clip application is safe and effective in patients with upper limb hyperhidrosis, with stable long-term improvements in quality of life.

E-Health intervention for subthreshold depression: Reach and two-year effects of a randomized controlled trial.

BACKGROUND: There is evidence for e-Health interventions for full-blown depression. Little is known regarding commonly untreated subthreshold depression in primary care. This randomized controlled multi-centre trial assessed reach and two-year-effects of a proactive e-Health intervention (ActiLife) for patients with subthreshold depression. METHODS: Primary care and hospital patients were screened for subthreshold depression. Over 6 months, ActiLife participants received three individualized feedback letters and weekly messages promoting self-help strategies against depression, e.g., dealing with unhelpful thoughts or behavioural activation. The primary outcome depressive symptom severity (Patient Health Questionnaire;PHQ-8) and secondary outcomes were assessed 6, 12 and 24 months. RESULTS: Of those invited, n = 618(49.2 %) agreed to participate. Of them, 456 completed the baseline interview and were randomized to ActiLife (n = 227) or assessment only (n = 226). Generalised estimation equation analyses adjusting for site, setting and baseline depression revealed that depressive symptom severity declined over time, with no significant group differences at 6 (mean difference = 0.47 points; d = 0.12) and 24 months (mean difference = -0.05 points; d = -0.01). Potential adverse effects were observed at 12 months, with higher depressive symptom severity for ActiLife than control participants (mean difference = 1.33 points; d = 0.35). No significant differences in rates of reliable deterioration or reliable improvement of depressive symptoms were observed. ActiLife increased applied self-help strategies at 6 (mean difference = 0.32; d = 0.27) and 24 months (mean difference = 0.22; d = 0.19), but not at 12 months (mean difference = 0.18; d = 0.15). LIMITATIONS: Self-report measures and lack of information on patients' mental health treatment. DISCUSSION: ActiLife yielded satisfactory reach and increased the use of self-help strategies. Data were inconclusive in terms of depressive symptom changes.

Is there a role for dynamic swallowing MRI in the assessment of gastroesophageal reflux disease and oesophageal motility disorders?

OBJECTIVES: To evaluate the diagnostic value of dynamic MRI swallowing in patients with symptoms of Gastroesophageal Reflux Disease (GERD). METHODS: Thirty-seven patients (17 m/20f) with typical signs of GERD underwent MR swallowing in the supine position at 1.5 T with a phased-array body coil. Using dynamic, gradient echo sequences (B-FFE) in the coronal, sagittal and axial planes, the bolus passages of buttermilk spiked with gadolinium chelate were tracked. MRI, pH-metry and manometry were performed within 31 days and results were compared. RESULTS: MRI results were concordant with pH-metry in 82% (23/28) of patients diagnosed with abnormal oesophageal acid exposure by pH-metry. Five patients demonstrated typical symptoms of GERD and had positive findings with pH monitoring, but false negative results with MRI. In four of six patients (67%), there was a correct diagnosis of oesophageal motility disorder, according to manometric criteria, on dynamic MRI. The overall accuracy of MRI diagnoses was 79% (27/34). A statistically significant difference was found between the size of hiatal hernia, grade of reflux in MRI, and abnormal acid exposure on pH-monitoring. CONCLUSIONS: MR fluoroscopy may be a promising radiation-free tool in assessing the functionality and morphology of the GE junction. KEY POINTS: • Swallowing MRI can assess anatomy and function of the gastroesophageal-junction • Swallowing MRI can help identifying reflux and motility disorders • Definition of the size of hiatal hernias is possible in all three planes in MR. • Short duration of swallowing MRI enables its application in routine clinical practice.

The association of cognitive distortions and the type of gambling in problematic and disordered gambling.

BACKGROUND: Previous studies have shown that particular types of gambling are related to the development of gambling-related problems. Further, gambling-related cognitive distortions contribute to the development of disordered gambling. The aim of the present study is to compare different gambling types with respect to cognitive distortions and the development of disordered gambling. METHODS: Based on a proactively screened sample of vocational school students (N = 6718), 309 students were selected to undergo an in-depth interview. We assessed the Gamblers-Belief-Questionnaire (GBQ) to measure gambling-related cognitive distortions and the Stinchfield questionnaire for assessing gambling-related problems. Associations between cognitive distortions, gambling-related symptoms, and types of gambling were analysed using logistic regression analyses. RESULTS: Higher scores on the GBQ subscale "belief in luck/perseverance" led to a significantly higher chance to be classified as a person with Gambling Disorder (Conditional Odds Ratio (COR) = 1.05, Confidence Interval (CI) = 1.02-1.08) as well as problematic gambling (COR = 1.04, CI = 1.01-1.06). Higher scores on the subscale "illusion of control" were also associated with problematic gambling (COR = 1.04, CI = 1.00-1.08). The multivariate analyses of the gambling types identified only sports betting as a predictor for problematic gambling (COR = 1.91, CI = 1.05-3.49). When controlling for cognitive distortions, sports betting was not significant anymore. With respect to disordered gambling, gambling on electronic gambling machines (EGMs) turned out to be a risk factor besides cognitive distortions (COR = 2.59, CI = 1.04-6.49). DISCUSSION: The present study confirmed the high relevance of cognitive distortions for problematic and disordered gambling especially for sports betting and gambling on EGMs. Preventive measures and psychotherapy should take these relationships into account.

New epidemiological aspects of patients with severe hyperhidrosis presenting for sympathetic surgery.

BACKGROUND: Epidemiological data on individuals suffering from severe primary hyperhidrosis are scarce. OBJECTIVE: This study aims to prospectively assess disease-specific characteristics of patients with severe, mostly therapy-resistant hyperhidrosis presenting for sympathetic surgery. METHODS: We evaluated a total of 227 patients (69.6% women) with a mean age of 30 years (standard deviation, 9.5 years) using a standardized questionnaire. Severity of disease was rated on a visual analogue scale (VAS) graded between 0 (no symptoms) and 10 (worst symptom). Age, sex, previous therapies, hormonal therapies and body mass index were analysed for their possible influence on severity of the disease and on hyperhidrosis sites. In addition, allergies were investigated for the first time in this patient population. RESULTS: There was a positive correlation between age of onset and sites of hyperhidrosis. The most commonly affected areas were palmar-axillary-plantar (51.1%) and palmar-plantar (15.0%), with sex-specific differences. Two hundred and twelve patients (93.4%) had previous conservative therapies; 219 patients (96.5%) reported VAS scores between 8 and 10. Female patients stated higher VAS scores for palmar (P = 0.009) and axillary (P = 0.012) sites. Type IV allergies were found to be much higher than in the general Austrian female population. Hormonal therapies and the body mass index had no influence on severity of hyperhidrosis after analysis of VAS scores. CONCLUSION: Sex-dependent aspects can be found in patients strongly affected by primary upper limb hyperhidrosis.

Clostridium difficile toxin B is more potent than toxin A in damaging human colonic epithelium in vitro.

Toxin A but not toxin B, appears to mediate intestinal damage in animal models of Clostridium difficile enteritis. The purpose of this study was to investigate the electrophysiologic and morphologic effects of purified C. difficile toxins A and B on human colonic mucosa in Ussing chambers. Luminal exposure of tissues to 16-65 nM of toxin A and 0.2-29 nM of toxin B for 5 h caused dose-dependent epithelial damage. Potential difference, short-circuit current and resistance decreased by 76, 58, and 46%, respectively, with 32 nM of toxin A and by 76, 55, and 47%, respectively, with 3 nM of toxin B, when compared with baseline (P < 0.05). 3 nM of toxin A did not cause electrophysiologic changes. Permeability to [3H]mannitol increased 16-fold after exposure to 32 nM of toxin A and to 3 nM of toxin B when compared with controls (P < 0.05). Light and scanning electron microscopy after exposure to either toxin revealed patchy damage and exfoliation of superficial epithelial cells, while crypt epithelium remained intact. Fluorescent microscopy of phalloidin-stained sections showed that both toxins caused disruption and condensation of cellular F-actin. Our results demonstrate that the human colon is approximately 10 times more sensitive to the damaging effects of toxin B than toxin A, suggesting that toxin B may be more important than toxin A in the pathogenesis of C. difficile colitis in man.