Spinal extradural arachnoid cysts are rare lesions which typically involve the thoracic spine and are an asymptomatic condition of unknown origin. They may also produce symptoms by compressing the spinal cord or nerve roots. Surgery is the treatment of choice in such lesions, but asymptomatic patients can be managed conservatively. We present a case of symptomatic, probable traumatic origin, spinal arachnoid cyst at our center in Hospital Kuala Lumpur, Malaysia. Magnetic resonance imaging spine showed well-defined, nonenhancing extradural cystic lesion from T5 to T6 vertebrae level compressing spinal cord anteriorly. The patient underwent T5, T6 laminoplasty, T4 partial laminectomy and excision of the cyst. Histologically, the cyst wall comprised of collagen and meningothelial cells. This surgical intervention achieved neurological improvement in terms of motor power in our follow-up of this patient.
Multilocus microsatellite genotyping of Plasmodium knowlesi isolates previously indicated 2 divergent parasite subpopulations in humans on the island of Borneo, each associated with a different macaque reservoir host species. Geographic divergence was also apparent, and independent sequence data have indicated particularly deep divergence between parasites from mainland Southeast Asia and Borneo. To resolve the overall population structure, multilocus microsatellite genotyping was conducted on a new sample of 182 P. knowlesi infections (obtained from 134 humans and 48 wild macaques) from diverse areas of Malaysia, first analyzed separately and then in combination with previous data. All analyses confirmed 2 divergent clusters of human cases in Malaysian Borneo, associated with long-tailed macaques and pig-tailed macaques, and a third cluster in humans and most macaques in peninsular Malaysia. High levels of pairwise divergence between each of these sympatric and allopatric subpopulations have implications for the epidemiology and control of this zoonotic species.
The nearby radio galaxy M87 is a prime target for studying black hole accretion and jet formation1,2. Event Horizon Telescope observations of M87 in 2017, at a wavelength of 1.3 mm, revealed a ring-like structure, which was interpreted as gravitationally lensed emission around a central black hole3. Here we report images of M87 obtained in 2018, at a wavelength of 3.5 mm, showing that the compact radio core is spatially resolved. High-resolution imaging shows a ring-like structure of [Formula: see text] Schwarzschild radii in diameter, approximately 50% larger than that seen at 1.3 mm. The outer edge at 3.5 mm is also larger than that at 1.3 mm. This larger and thicker ring indicates a substantial contribution from the accretion flow with absorption effects, in addition to the gravitationally lensed ring-like emission. The images show that the edge-brightened jet connects to the accretion flow of the black hole. Close to the black hole, the emission profile of the jet-launching region is wider than the expected profile of a black-hole-driven jet, suggesting the possible presence of a wind associated with the accretion flow.