Sex differences in physiological response to increased neuronal excitability in a knockin mouse model of pediatric epilepsy

BACKGROUND

Epilepsy is a common neurological disease; however, few if any of the currently marketed antiseizure medications prevent or cure epilepsy. Discovery of pathological processes in the early stages of epileptogenesis has been challenging given the common use of preclinical models that induce seizures in physiologically normal animals. Moreover, despite known sex dimorphism in neurological diseases, females are rarely included in preclinical epilepsy models.

METHODS

We characterized sex differences in mice carrying a pathogenic knockin variant (p.N1768D) in the Scn8a gene that causes spontaneous tonic-clonic seizures (TCs) at ∼3 months of age and found that heterozygous females are more resilient than males in mortality and morbidity. To investigate the cellular mechanisms that underlie female resilience, we utilized blood-brain barrier (BBB) and hippocampal transcriptomic analyses in heterozygous mice before seizure onset (pre-TC) and in mice that experienced ∼20 TCs (post-TC).

RESULTS

In the pre-TC latent phase, both sexes exhibited leaky BBB; however, patterns of gene expression were sexually dimorphic. Females exhibited enhanced oxidative phosphorylation and protein biogenesis, while males activated gliosis and CREB signaling. After seizure onset (chronic phase), females exhibited a metabolic switch to lipid metabolism, while males exhibited increased gliosis and BBB dysfunction and a strong activation of neuroinflammatory pathways.

CONCLUSION

The results underscore the central role of oxidative stress and BBB permeability in the early stages of epileptogenesis, as well as sex dimorphism in response to increasing neuronal hyperexcitability. Our results also highlight the need to include both sexes in preclinical studies to effectively translate results of drug efficacy studies.

Platinum-Based Chemotherapy 'Rechallenge' in Advanced Non-ovarian Solid Malignancies

Platinum-based chemotherapy forms the backbone of treatment for many solid cancers. However, resistance inevitably develops in those with advanced disease. Platinum rechallenge is a well-established concept in the management of ovarian cancer, small cell lung cancer and germ cell tumours. In other solid malignancies there is a lack of quality evidence to support platinum rechallenge, yet it is a widely adopted strategy. Often, patients are within the last year of life, making questions of efficacy, treatment-related toxicity and quality of life critical factors for treatment recommendations. In this overview we appraise the available evidence for platinum rechallenge and strategies being developed to attempt resensitisation of tumours to platinum-based chemotherapy.

A novel fuel cell design foroperandoenergy-dispersive x-ray absorption measurements

A polymer electrolyte fuel cell has been designed to allowoperandox-ray absorption spectroscopy (XAS) measurements of catalysts. The cell has been developed to operate under standard fuel cell conditions, with elevated temperatures and humidification of the gas-phase reactants, both of which greatly impact the catalyst utilisation. X-ray windows in the endplates of the cell facilitate collection of XAS spectra during fuel cell operation while maintaining good compression in the area of measurement. Results of polarisation curves and cyclic voltammograms showed that theoperandocell performs well as a fuel cell, while also providing XAS data of suitable quality for robust XANES analysis. The cell has produced comparable XAS results when performing a cyclic voltammogram to an establishedin situcell when measuring the Pt LIII edge. Similar trends of Pt oxidation, and reduction of the formed Pt oxide, have been presented with a time resolution of 5 s for each spectrum, paving the way for time-resolved spectral measurements of fuel cell catalysts in a fully-operating fuel cell.

Stability of internal versus external fixation in osteoporotic pelvic fractures - a biomechanical analysis

INTRODUCTION

Osteoporosis-related fragility fractures of the pelvic ring (FFP) differ fundamentally from pelvic fractures in younger patients. However, very little is known about biomechanical stability of different osteosynthesis procedures addressing the anterior pelvic ring in these fractures. The aim of this study was to compare standard external fixation with internal fixation using a novel screw-and-rod system in osteoporotic fractures of the pelvic ring in terms of stiffness, plastic deformation and maximum load under cyclic loading in a human cadaveric model.

MATERIALS AND METHODS

A total of 18 embalmed osteoporotic cadaver pelvis specimens were randomized based on the T-score into a group for external fixation and a group for internal fixation. FFP type-IIB fractures were created. In addition to the external or internal fixator, a cement-augmented sacroiliac screw was implanted. Afterwards, axial cyclic loading was performed in a testing setup simulating one-leg stand.

RESULTS

Mean plastic deformation and stiffness both were significantly better in the internal fixation group than in the external fixation group (plastic deformation: 0.37 mm (SD: 0.23) versus 0.71 mm (SD: 0.26), p = 0.011; stiffness: 43.69 N/mm (SD: 18.39) versus 26.52 N/mm (SD: 9.76), p = 0.029). Maximum load did not differ significantly between internal fixator (506.3 N; SD: 129.4) and external fixator (461.1 N; SD: 147.4) (p = 0.515).

CONCLUSIONS

Submuscular internal fixation might be an interesting alternative to external fixation in clinical practice because of better biomechanical properties as well as several advantages in clinical use.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Cement-augmented sacroiliac screw fixation with cannulated versus perforated screws - A biomechanical study in an osteoporotic hemipelvis model

INTRODUCTION

Cement-augmentation is a well-established way to improve the stability of sacroiliac screw fixation in osteoporosis-associated fragility fractures of the posterior pelvic ring. However, to date little is known about the influence of different techniques of cement augmentation on construct stability. The aim of this study was to evaluate the primary stability of cement-augmented sacroiliac screw fixation with cannulated versus perforated screws under cyclic loading.

MATERIALS AND METHODS

A total of eight fresh-frozen human cadaveric hemipelvis specimens with osteoporosis were used. After generating ventral osteotomies on both sides of the sacrum, each specimen was treated using a cement-augmented cannulated screw on one side and a cement-augmented perforated screw on the other side. Afterwards, axial cyclic loading was performed.

RESULTS

No statistically significant difference was found between cannulated and perforated screws concerning maximum load (356.25 N versus 368.75 N, p = 0.749), plastic deformation (1.95 mm versus 1.43 mm, p = 0.798) and stiffness (27.04 N/mm versus 40.40 N/mm, p = 0.645).

CONCLUSIONS

Considering the at least equivalent results for perforated screws, cement augmentation via perforated screws might be an interesting option in clinical practice because of potential advantages, e.g. radiological control before cement application, reduced risk of cement displacement and time saving.

Patient factors associated with increased acute care costs of hip fractures: a detailed analysis of 402 patients

The aim of the present study was to identify patient factors associated with higher costs in hip fracture patients. The mean costs of a prospectively observed sample of 402 patients were 8853 €. The ASA score, Charlson comorbidity index, and fracture location were associated with increased costs.

PURPOSE

Fractures of the proximal end of the femur (hip fractures) are of increasing incidence due to demographic changes. Relevant co-morbidities often present in these patients cause high complication rates and prolonged hospital stays, thus leading to high costs of acute care. The aim of this study was to perform a precise cost analysis of the actual hospital costs of hip fractures and to identify patient factors associated with increased costs.

METHODS

The basis of this analysis was a prospectively observed single-center trial, which included 402 patients with fractures of the proximal end of the femur. All potential cost factors were recorded as accurately as possible for each of the 402 patients individually, and statistical analysis was performed to identify associations between pre-existing patient factors and acute care costs.

RESULTS

The mean total acute care costs per patient were 8853 ± 5676 € with ward costs (5828 ± 4294 €) and costs for surgical treatment (1972 ± 956 €) representing the major cost factors. The ASA score, Charlson comorbidity index, and fracture location were identified as influencing the costs of acute care for hip fracture treatment.

CONCLUSION

Hip fractures are associated with high acute care costs. This study underlines the necessity of sophisticated risk-adjusted payment models based on specific patient factors. Economic aspects should be an integral part of future hip fracture research due to limited health care resources.

[Living will, durable power of attorney and legal guardianship in the trauma surgery routine : Data from a geriatric trauma center]

BACKGROUND

Due to the increasing number of elderly patients, trauma surgeons are often confronted with end-of-life treatment decisions. Advance directives can help reduce the lack of clarity in those situations.

OBJECTIVES

The aim of this study was to identify the presence of living wills, durable power of attorney, legal guardianship and appointment of guardianship in the geriatric trauma center of a university hospital.

MATERIALS AND METHODS

The data of all patients treated in our geriatric trauma center from 01/01/2013 to 03/31/2014 were analyzed regarding the presence of a living will, durable power of attorney, legal guardianship and appointment of guardianship as well as the procedure of documenting those items.

RESULTS

Out of 181 patients, 63 % (n = 114) had one or more of these documents. Most frequently used was the durable power of attorney in 33 % (n = 59), followed by a living will in 27 % (n = 48), legal guardianship in 20 % (n = 37) and appointment of guardianship in 7 % (n = 12). The existence of those documents was recorded in 88 % (n = 100) of patients within 24 h after admission; documentation in the medical records was found in 58 % (n = 66).

CONCLUSION

A large proportion of patients had one or more of the documents named above. In this respect, standardized documentation of advance directives in the medical record is an important issue for all persons involved.

An international surgical collaboration: humanitarian surgery in Brazil

PURPOSE

Brazil is the fifth most populous country in the world with widespread regional and social inequalities. Regional disparities in healthcare are unacceptably large, with the remote and poor regions of the north and northeast having reduced life expectancy compared to the south region, where life expectancy approaches that of rich countries. We report our experience of a humanitarian surgery mission to the Amazonas state, in the northwest part of Brazil.

METHODS

In August 2014, a team of seven consultant surgeons, and two trainees with the charity 'International Hernia', visited three hospitals in the Amazonas state to provide hernia surgery and training.

RESULTS

Eighty-nine hernias were repaired in 74 patients (female = 22, male = 52) with a median age of 44 years (range 2-83 years). Nine patients underwent more than one type of hernia repair, and there were 9 laparoscopic inguinal and ventral incisional hernia repairs. Local doctors were trained in hernia repair techniques, and an International Hernia Symposium was held at the University of the State of Amazonas, Manaus.

CONCLUSION

The humanitarian mission provided hernia surgery to an underserved population in Brazil and training to local doctors, building local sustainability. Continued cooperation between host and international surgeons for future missions to Brazil will ensure continuing surgical training and technical assistance.

[10-Year Follow-Up of the NexGen CR Total Knee Prosthesis]

BACKGROUND

The purpose of this study was to evaluate long-term clinical and radiological results as well as survival rates of the NexGen® CR posterior cruciate retaining prosthesis.

PATIENTS AND METHODS

We evaluated a consecutive series of 761 total knee replacements performed on 716 patients from 1999 to 2001 at our institution. All patients had been recorded prospectively in our in-house arthroplasty register. Follow-up data were available for 379 patients at 10 years postoperatively. Functional outcome was evaluated using the Knee Society score. An additional radiographic evaluation was performed on 224 patients at 10 years. The mean age of the patients at the time of surgery was 71 years. 75 % of the patients were female, 25 % were male. Mean BMI of the patients was 29.2 kg/m(2). The preoperative diagnosis was osteoarthritis in 91 %, rheumatoid arthritis in 5,5 % and posttraumatic osteoarthritis in 2 %. Patella resurfacing was performed in 4 %. All components were cemented.

RESULTS AND DISCUSSION

Mean Knee Society clinical score improved from 26.7 points preoperatively to 88.5 points at the time of the latest follow-up, and mean Knee Society function score improved from 48.3 to 55.2 points. Flexion improved from a mean of 106.7° preoperatively to 111.4° at 10 years. Patellofemoral pain was indicated by 66 % of the patients before surgery and 4 % at the latest follow-up. 96 % were satisfied with the result of the surgery at 10 years. Radiographic evaluation was performed on 224 patients at the time of the latest follow-up. 203 patients (91 %) had normal radiographic findings, 21 patients (9 %) showed pathological findings. Radiolucencies were seen in 18 patients on the AP view of the tibia, 1 patient had an additional femoral radiolucency. There was an osteolysis located in the lateral tibia seen in 1 patient and an occurrence of heterotopic ossification in another patient. One knee showed a patella subluxation. No patient had radiographic evidence of loosening. 17 knees had required revision surgery with exchange of at least one of the components up to 10 years after the index procedure. 5 of the patients had revision for a deep infection, 2 for periprosthetic fractures of the distal femur with loosening of the prosthesis, 1 for fracture of the proximal tibia due to osteoporosis, 4 for aseptic loosening, 3 for instability and 2 for severe pain. Kaplan-Meier survival of all components using revision for any reason as the end point was 97.8 % at 10 years.

CONCLUSION

The good clinical and radiological long-term results as well as the satisfactory survival rate after total knee replacement with the NexGen CR® prosthesis are comparable with the results of other long-term studies using the NexGen CR® and assimilable prosthesis. Our results demonstrate that quality of life was improved by the implantation of the NexGen CR® prosthesis even a long time after the index procedure despite old age and comorbidity of the patients.

A Microfluidic Method for the Selection of Undifferentiated Human Embryonic Stem Cells and in Situ Analysis

Conventional cell-sorting methods such as fluorescence-activated cell sorting (FACS) or magnetic-activated cell sorting (MACS) can suffer from certain shortcomings such as lengthy sample preparation time, cell modification through antibody labeling, and cell damage due to exposure to high shear forces or to attachment of superparamagnetic Microbeads. In light of these drawbacks, we have recently developed a label-free, microfluidic platform that can not only select cells with minimal sample preparation but also enable analysis of cells in situ. We demonstrate the utility of our platform by successfully isolating undifferentiated human embryonic stem cells (hESCs) from a heterogeneous population based on the undifferentiated stem-cell marker SSEA-4. Importantly, we show that, in contrast to MACS or FACS, cells isolated by our method have very high viability (~90%). Overall, our platform technology could likely be applied to other cell types beyond hESCs and to a variety of heterogeneous cell populations in order to select and analyze cells of interest.

A of the breast present at screening mammography

A previously well 54-year-old woman presented for screening mammography with a 3-day history of an inflamed lump in her right breast. She was subsequently admitted to hospital with acute melioidosis where right breast abscesses were drained. Following recovery and discharge, she was reviewed at the mammographic screening unit where her previous abnormal mammogram was found to be due to melioidosis. To our knowledge this is the first reported case of melioidosis of the breast and its appearance on mammography and ultrasound are described.

A distinctive aphthous ileitis linked to Ancylostoma caninum

Ileal ulceration is diagnosed commonly at colonoscopy in northeastern Australia. This observation has occurred contemporaneously with the description of a painful enteritis caused through supposedly rare infections by Ancylostoma caninum, the cosmopolitan dog hookworm. In this study, we describe the morphology and prevalence of ileal ulcers and investigate their cause. There were 182 patients with a distinctive aphthous ileitis highlighted by haemorrhage into the tips of surrounding villi. The annual rate reached 4.7% of ileal examinations. Eosinophilic enteritis was the characteristic, but inconsistent, histological appearance. Ulceration was linked to infection by A. caninum through serological testing and, in three patients, by the retrieval of single hookworms. Affected patients were also more likely to own a dog (53%) than the total colonoscopic population (43%; P < 0.02). The monthly rates of diagnosis were related to climate with fewest recordings during winter. Pain was the chief indication for colonoscopy (49%), proportionally higher than in controls (28%; P < 0.0001). Patients with ulcers had increased blood eosinophil, immunoglobulin E and serological values. These results were higher still in the subset with pain compared with the rest. Most patients, however, had colonoscopy performed for unrelated reasons, such as bowel cancer surveillance, and were identified as having subclinical ulceration (rate 3.2%). The findings establish a distinctive aphthous ileitis characterized by tissue eosinophilia. The cause has been tentatively linked to canine hookworms. It is proposed that infection in this geographic region is common and only rarely does a painful enteritis develop as a consequence of hypersensitization.

Chemical peeling

This article explores the wide range of chemical facial peels, which include phenol, trichloroacetic acid, and alpha-hydroxy acids. The application of these substances will be described in addition to the contraindications to this type of treatment.

[Fetal hydrothorax]

Three cases of bilateral congenital hydrothorax concomitant with hydrops fetalis are presented and compared with similar cases in literature. The hydrops fetalis to our opinion is caused by peripheral hypoxia. The hypoxia has its origin in the restricted cardiac output caused by the bilateral hydrothorax.