An unusual manifestation of Paget's disease of bone: spinal epidural hematoma presenting as acute cauda equina syndrome

Neurologic sequelae of Paget's disease of bone include involvement of the spinal cord or cauda equina due to mechanical compression by enlarged vertebrae, ischemia caused by a spinal artery, steal syndrome or neoplasm. We describe a patient with Paget's disease of bone who presented with acute cauda equina syndrome due to a spinal epidural hematoma. Clinicians need to recognize this entity since surgical intervention may result in a favorable outcome.     

In-situ photopolymerization of oriented liquid-crystalline acrylates, 3. Oriented polymer networks from a mesogenic diacrylate

Synthesis, mesomorphism, orientation and photo-initiated chain crosslinking of the liquid-crystalline diacrylate 1,4-phenylene bis{4-[6-(acryloyloxy)hexyloxy]benzoate} ( 1 ) are studied. Monomer 1 exhibits a broad nematic phase between 108 and 155°C and a monotropic smectic phase below 88°C. The monomer is uniaxially oriented in its nematic phase at a substrate which has been coated with polyimide and unidirectionally rubbed with tissue. At the transition temperature to the smectic phase the order parameter is measured to be 0,7. During polymerization, the ordering of the mesogens is frozen-in, yielding a uniaxially crosslinked network. The clear films of oriented poly( 1 ) exhibit a birefringence Δn between 0,12 and 0,15, depending on the polymerization temperature. In the highest oriented state of 1 a small reduction of the degree of order is observed during the crosslinking reaction, whereas at higher temperatures and lower ordering of 1 , the uniaxially orientation increases upon reaction. A special feature of the oriented networks is that the ordering is maintained while heating at high temperatures. The polymerization of the acrylate groups in the mesomorphic phases proceeds fast and to high conversion. Below 90°C the polymerization behaviour is similar to that of conventional isotropic diacrylates. Above 90°C the polymerization reaction of the liquid-crystalline diacrylate proceeds faster than that of an isotropic diacrylate.     

Management of zygomatic complex fracture in armed forces

Introduction: The Armed Forces personnel are exposed to various kinds of injuries due to the nature of their duties. Increase in motorized population without taking protective measures and rise in violence has contributed towards maxillofacial injuries. The aim of this study was to determine the incidence, aetiology and management of injuries resulting in fracture of the Zygomatic complex in Armed Forces personnel and their families.     

Giant cell tumors of synovium (Pigmented villonodular synovitis) involving the vertebral column

Giant cell tumors of synovium (pigmented villonodular synovitis) involving the vertebral column recently have been seen in two women: the third and fourth cases to be reported in the English-language literature. Unlike the previously reported cases, both these tumors grew outside the dura and produced symptoms of spinal cord compression. The first case involved lumbar vertebrae 5 and 6; the second, lumbar vertebrae 2 and 3. Even though initial resection of both tumors was incomplete, the patients improved postoperatively. One tumor was known to be unresectable at the time of surgery. In the other patient, a recurrence of symptoms required second and third resections 4 and 8 months after the first, respectively. Although synovial giant cell tumors rarely metastasize, the rate of local recurrence is high, especially if excision is incomplete. For this reason, close follow-up of patients with lesions in the spinal column is indicated. Increased physician awareness that synovial giant cell tumors can occur in the spine will help to ensure that these tumors are not misdiagnosed in this location.     

Angiotropic intravascular large-cell lymphoma (malignant angioendotheliomatosis): report of a case and review of the literature

We present a case of angiotropic large-cell lymphoma and review the literature in order to define the neurologic features of this rare disorder. This is the first report of gadolinium-DTPA imaging in angiotropic large-cell lymphoma that demonstrates infarcts of multiple ages, as well as striking meningeal enhancement. Angiotropic large-cell lymphoma should be suspected in patients with clinical evidence of small and large cerebral vessel disease and diagnosis requires skin, liver, renal, meningeal, or brain biopsy. Single modality treatment, using either radiation therapy or steroids, has been ineffective, and new findings of a lymphomatous origin of this neoplasm suggest that combination chemotherapy may be indicated.     

钩藤碱对血小板聚集和血栓形成的影响

钩藤碱(Rhy)明显抑制AA,胶原及ADP诱导的大鼠血小板聚集。Rhy不影响血小利用外源性AA合成TXA_2,但抑制胶原诱导的TXA_2生成;在抗血小板聚集有效剂量时,对PGI_2的生成无影响。Rhy有显著降低血栓形成诱导剂ADP及胶原加肾上腺素静脉注射所致小鼠死亡率。     

In-situ photopolymerization of oriented liquid-crystalline acrylates, 4. Influence of a lateral methyl substituent on monomer and oriented polymer network properties of a mesogenic diacrylate

Mesomorphism and the molecular orientation of 1,4-phenylene bis{4-(6-(acryloyloxy)hexyloxy)benzoate} ( 1 ) and its derivative with a methyl-substituent in the central phenylene group ( 2 ) are studied. The methyl group affects the transition temperatures and the thermodynamic parameters, but not the order parameter of the monomers. The photoinitiated polymerization of the diacrylate monomers in their uniaxially oriented state leads to highly oriented and densely crosslinked polymer networks. The order parameter of these networks depends on the polymerization temperature, but becomes nearly temperature-independent after polymerization. The presence of the methyl group leads to a significant lower degree of order in the polymeric state. In addition, data are presented on the monomeric viscosity of 2 and on the tensile moduli, glass transitions and refractive indices of the oriented polymer networks. In order to extend the mesomorphous temperature range, mixtures of 1 and 2 are also investigated.     

L‐ and M‐cone input to 12Hz and 30Hz flicker ERGs across the human retina

We recorded L‐ and M‐cone isolating ERGs from human subjects using a silent substitution technique at temporal rates of 12 and 30 Hz. These frequencies isolate the activity of cone‐opponent and non‐opponent post‐receptoral mechanisms, respectively. ERGs were obtained using a sequence of stimuli with different spatial configurations comprising; (1) circular stimuli of different sizes which increased in 10° steps up to 70°diameter, or (2) annular stimuli with a 70° outer diameter but with different sized central ablations from 10° up to 60°. L‐ and M‐cone isolating ERGs were obtained from five colour normal subjects using a DTL fibre electrode. Fourier analysis of the ERGs was performed and we measured the amplitude of the first harmonic of the response. For 12 Hz ERGs the L:M cone response amplitude ratio (L:M_ERG) was close to unity and remained stable irrespective of the spatial configuration of the stimulus. The maintenance of this balanced ratio points to the existence of cone selective input across the human retina for the L‐M cone opponent mechanism. For 30 Hz the L:M_ERG ratio was greater than unity but varied depending upon which region of the retina was being stimulated. This variation we consider to be a consequence of the global response properties of M‐cone ERGs rather than representing a real variation in L:M cone ratios across the retina.