A fast radio burst source at a complex magnetized site in a barred galaxy.

Fast radio bursts (FRBs) are highly dispersed, millisecond-duration radio bursts1-3. Recent observations of a Galactic FRB4-8 suggest that at least some FRBs originate from magnetars, but the origin of cosmological FRBs is still not settled. Here we report the detection of 1,863 bursts in 82 h over 54 days from the repeating source FRB 20201124A (ref. 9). These observations show irregular short-time variation of the Faraday rotation measure (RM), which scrutinizes the density-weighted line-of-sight magnetic field strength, of individual bursts during the first 36 days, followed by a constant RM. We detected circular polarization in more than half of the burst sample, including one burst reaching a high fractional circular polarization of 75%. Oscillations in fractional linear and circular polarizations, as well as polarization angle as a function of wavelength, were detected. All of these features provide evidence for a complicated, dynamically evolving, magnetized immediate environment within about an astronomical unit (AU; Earth-Sun distance) of the source. Our optical observations of its Milky-Way-sized, metal-rich host galaxy10-12 show a barred spiral, with the FRB source residing in a low-stellar-density interarm region at an intermediate galactocentric distance. This environment is inconsistent with a young magnetar engine formed during an extreme explosion of a massive star that resulted in a long gamma-ray burst or superluminous supernova.

Preventing fragility hip fracture in high risk groups: an opportunity missed.

OBJECTIVE: The national guideline recommends selective case finding as the main strategy by identification of high risk people. This study assessed whether high risk patients were identified before their presentation with fragility fracture. METHODS: A prospective study for 3.5 consecutive months on patients with low energy hip fractures to Brighton and Sussex University Hospital NHS Trusts, which serves a population of 460,000. Data were collected by interview using standardised form, medical record review, and communication with family physicians. Definition of high risk: (1) untreated hypogonadism (2) corticosteroid users (3) disorders with increased bone loss (4) previous fragility fractures. RESULTS: 98 patients were admitted with hip fracture. Thirty nine (40%) had at least one high risk factor. High risk patients (7 of 39, 18%) were no more likely to receive prophylaxis compared with patients without high risk factor (5 of 59, 8%) (p = 0.21). Previous fragility fracture (23) was the commonest risk factor followed by disorders with increased bone loss (10), premature menopause (10), and corticosteroid users (5). Fifteen patients (15%) had susceptibility to frequent falls and two had maternal history of osteoporosis. The proportion of treated patients were 20% (2 of 10) in premature menopause, 10% (1 of 10) in diseases with secondary osteoporosis, 13% (3 of 23) in previous fragility fracture, and 80% (4 of 5) in corticosteroid users (p = 0.01) CONCLUSION: Prevention of hip fracture is still inadequate in high risk patients. Discrepancy seemed to exist in treatment frequency among different high risk groups suggesting that emphasis on prevention of osteoporosis has not been reinforced in all people at risk.

MitroFast® annuloplasty ring for complete posterior mitral leaflet destruction: a novel approach in active endocarditis.

We report the successful use of MitroFast® annuloplasty ring in the setting of active endocarditis to preserve the native valve mechanism despite complete posterior leaflet destruction. This patient remained well at 20 month follow-up after her surgery.

Tectal plate cyst in adults.

Tectal plate cysts are very rare. We report two adult patients with benign tectal plate cyst and secondary hydrocephalus. The first patient had an unusual eye movement disorder with bilateral upper eyelid retraction (Collier's sign), limited upgaze, severe upgaze evoked nystagmus and retraction nystagmus. The second patient presented with ataxia and failure of upward gaze. Endoscopic fenestration of the tectal plate cyst and endoscopic third ventriculostomy in both cases result in neurological improvement. To the best of our knowledge, similar lesions at this site have not been reported in adults. The differential diagnosis with arachnoid cysts of the quadrigeminal CSF cistern is discussed.

An unusual progression of benign thoracic spinal cord teratoma in pregnancy: a hormonally-mediated pathway?

Intradural spinal cord teratoma is a very rare tumour that can be associated with dysraphism. The relationship of this lesion to pregnancy is unknown and its occurrence during pregnancy in the thoracic spine has not been previously reported. We report a 19-year-old pregnant woman with spinal dysraphism, who presented with a new onset thoracic myelopathy. The MRI scan showed an intradural, extramedullary lesion with solid and cystic component in the thoracic spine at the level of T5-T6. A thoracic laminectomy and excision of this lesion was followed by significant improvement of her lower limb function. Histopathology confirmed a benign mature teratoma. The rapid progression of this lesion during pregnancy suggests a hormonal mediated pathway for the tumour growth. Further analysis from the resected specimen confirmed that the tumour was oestrogen and progesterone receptors positive.