105 research outputs found
The role of macrophages and polymorphs in the levan-induced inhibition of Lewis lung carcinoma in C57BL mice.
High-mol.-wt levan injected locally inhibits the growth of Lewis lung carcinoma in C57BL mice. The inhibition is dependent on the number of tumour cells injected and on the dose of levan. The inhibition decreases tumour incidence and size as well as prolonging survival. The polysaccharide is most effective when injected daily beginning on the day of tumour-cell inoculation. Treatment begun on later dates is less effective. Treatment begun one day before tumour-cell inoculation enhances tumour growth. Histological studies showed that levan induces an intense polymorphonuclear (PMN) reaction followed by accumulation of vacuolated, levan-laden macrophages. Both PMN and activated macrophages seemed to have an inhibitory effect upon the growth of the tumour. The effector role of PMN was not explained by the histological study. Tumour cells in close contact with levan-laden macrophages appeared mostly necrotic. Administration of levan begun one day before tumour-cell inoculation produced a similar reaction, but the infiltrating cells did not appear to approach and damage the tumour cells
Efficient Photonic Integration of Diamond Color Centers and Thin-Film Lithium Niobate
On-chip photonic quantum circuits with integrated quantum memories have the
potential to radically progress hardware for quantum information processing. In
particular, negatively charged group-IV color centers in diamond are promising
candidates for quantum memories, as they combine long storage times with
excellent optical emission properties and an optically-addressable spin state.
However, as a material, diamond lacks many functionalities needed to realize
scalable quantum systems. Thin-film lithium niobate (TFLN), in contrast, offers
a number of useful photonic nonlinearities, including the electro-optic effect,
piezoelectricity, and capabilities for periodically-poled quasi-phase matching.
Here, we present highly efficient heterogeneous integration of diamond
nanobeams containing negatively charged silicon-vacancy (SiV) centers with TFLN
waveguides. We observe greater than 90\% transmission efficiency between the
diamond nanobeam and TFLN waveguide on average across multiple measurements. By
comparing saturation signal levels between confocal and integrated collection,
we determine a -fold increase in photon counts channeled into TFLN
waveguides versus that into out-of-plane collection channels. Our results
constitute a key step for creating scalable integrated quantum photonic
circuits that leverage the advantages of both diamond and TFLN materials
Neuropathological Findings In Chronic Relapsing Experimental Allergic Neuritis Induced In The Lewis Rat By Inoculation With Intradural Root Myelin And Treatment With Low Dose Cyclosporin A
Experimental allergic neuritis (EAN) was induced in Lewis rats by inoculation with bovine intradural root myelin and adjuvants. Rats treated with subcutaneous cyclosporin A (CsA) (4mg/kg on 3 days per week from the day of inoculation until day 29) developed a chronic relapsing course. Tissues from the spinal cord, nerve roots, dorsal root ganglia and sciatic nerve of CsA-treated rats sampled during relapses and remissions were studied during or after episodes of acute EAN. Both control and CsA-treated animals studied in the first episode of EAN had evidence of inflammation and primary demyelination of the nerve roots and dorsal root ganglia. In control and CsA-treated animals in the second episode there was severe inflammation and demyelination and remyelination in the spinal nerves and sciatic nerves and dorsal columns of the spinal cord, particularly in later stages of the disease. In later episodes there was less inflammation, but there was continuing demyelination and onion bulbs were present. In animals sampled after recovery from chronic relapsing EAN onion bulbs were present. Occasional small onion bulbs were also observed in control animals that were inoculated with higher doses of myelin. Plasma cells were present in the inflammatory lesions of later episodes. Mast cells were also observed at different stages of the disease. We conclude that the CsA form of chronic relapsing EAN has clinical and pathological similarities with the human disease, chronic inflammatory demyelinating polyradiculoneuropathy
Factors influencing overall survival rates for patients with pineocytoma
Given its rarity, appropriate treatment for pineocytoma remains variable. As the literature primarily contains case reports or studies involving a small series of patients, prognostic factors following treatment of pineocytoma remain unclear. We therefore compiled a systematic review of the literature concerning post-treatment outcomes for pineocytoma to better determine factors associated with overall survival among patients with pineocytoma. We performed a comprehensive search of the published English language literature to identify studies containing outcome data for patients undergoing treatment for pineocytoma. Kaplan–Meier analysis was utilized to determine overall survival rates. Our systematic review identified 168 total patients reported in 64 articles. Among these patients, 21% underwent biopsy, 38% underwent subtotal resection, 42% underwent gross total resection, and 29% underwent radiation therapy, either as mono- or adjuvant therapy. The 1 and 5 year overall survival rates for patients receiving gross total resection versus subtotal resection plus radiotherapy were 91 versus 88%, and 84 versus 17%, respectively. When compared to subtotal resection alone, subtotal resection plus radiation therapy did not offer a significant improvement in overall survival. Gross total resection is the most appropriate treatment for pineocytoma. The potential benefit of conventional radiotherapy for the treatment of these lesions is unproven, and little evidence supports its use at present
Genetics of human hydrocephalus
Human hydrocephalus is a common medical condition that is characterized by abnormalities in the flow or resorption of cerebrospinal fluid (CSF), resulting in ventricular dilatation. Human hydrocephalus can be classified into two clinical forms, congenital and acquired. Hydrocephalus is one of the complex and multifactorial neurological disorders. A growing body of evidence indicates that genetic factors play a major role in the pathogenesis of hydrocephalus. An understanding of the genetic components and mechanism of this complex disorder may offer us significant insights into the molecular etiology of impaired brain development and an accumulation of the cerebrospinal fluid in cerebral compartments during the pathogenesis of hydrocephalus. Genetic studies in animal models have started to open the way for understanding the underlying pathology of hydrocephalus. At least 43 mutants/loci linked to hereditary hydrocephalus have been identified in animal models and humans. Up to date, 9 genes associated with hydrocephalus have been identified in animal models. In contrast, only one such gene has been identified in humans. Most of known hydrocephalus gene products are the important cytokines, growth factors or related molecules in the cellular signal pathways during early brain development. The current molecular genetic evidence from animal models indicate that in the early development stage, impaired and abnormal brain development caused by abnormal cellular signaling and functioning, all these cellular and developmental events would eventually lead to the congenital hydrocephalus. Owing to our very primitive knowledge of the genetics and molecular pathogenesis of human hydrocephalus, it is difficult to evaluate whether data gained from animal models can be extrapolated to humans. Initiation of a large population genetics study in humans will certainly provide invaluable information about the molecular and cellular etiology and the developmental mechanisms of human hydrocephalus. This review summarizes the recent findings on this issue among human and animal models, especially with reference to the molecular genetics, pathological, physiological and cellular studies, and identifies future research directions
The Site and Cell of Origin of Optic Gliomas
N/A38 glial neoplasms of the optic pathways (16 nerve and 22 chiasm) seen at Massachusetts Eye and Ear Infirmary and Massachusetts General hospital from 1931 to 1972. In addition to the usually recorded signs of such tumors, there were 14 nerve and 15 chiasmatic tumor patients with pupillary disturbances.All were operated/necropsied at MEEI or MGH. Histopathologically all 16 optic nerve tumors were astrocytomas of the juvenile type, while in the optic chiasm group there were 1 glioblastoma multiforme, 1 oligodendroglioma, 1 meningeal glioma-tosis and 19 juvenile astrocytomas.Astrocytic cells containing microfilaments and Rosenthal fibers.SurgeryAttache
The role of macrophages and polymorphs in the levan-induced inhibition of Lewis lung carcinoma in C57BL mice
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