Time Course Of Lesions Research Articles

The time course of acute Percheron artery ischemic coma on imaging: A retrospective cohort study

We were to investigate the time course of lesions for awakening in acute Percheron artery ischemic coma (PAIC), which was previously unknown. Patients who had newly identified acute PAIC events in 2012–2015 and had not received thrombolytic therapy were enrolled retrospectively. The time course of lesions in PAIC was investigated by diffusion-weighted imaging (DWI). Ninety-three patients met the inclusion criteria, of whom 63 and 30 had transient PAIC and persistent PAIC, respectively. The time course of awakening events in persistent PAIC decreased over time, with large lesions in the bilateral paramedian thalamus/ rostral midbrain on DWI almost in all patients who was either plus or minus a “top of basilar artery” strokes. Whereas awakening events in transient PAIC increased over time, with small or lacunar lesions in the unilateral or bilateral thalamus/rostral midbrain about in 30.2 % cases, and the rest in naturally recanalization of infarcts or TIA. Lesion volumes were larger for persistent PAIC than for transient PAIC (median, 2.4 cm3 vs. 0.03 cm3, P < 0.0001). In Cox hazards ratio (HR) analysis, a lower GCS score was associated with mortality (HR, 5.5; 95 % confidence interval [CI],1.427–21.45). Multivaliate analysis shown that the predictors of higher risk of persistent PAIC were only increased NIHSS scores (HR,1.3; 95 % CI,1.109–1.640) and large lesions in bilateral thalamus/rostral midbrain (HR,15.0; 95 % CI,1.440–58.13). The time course of acute PAIC included transient and persistent. Most persistent PAIC was associated with large lesions in bilateral paramedian thalamus/ rostral midbrain, and with high mortality.

Oculopathologic Findings in Flavivirus-Infected Gallinaceous Birds

Using eye samples of nine 9-week-old experimentally West Nile virus (WNV)-infected red-legged partridges (Alectoris rufa), time course of lesions and WNV antigen appearance in ocular structures were examined. In addition, eye samples of 6 red-legged partridges and 3 common pheasants (Phasianus colchicus) naturally infected with Bagaza virus (BAGV) were used to study lesions and flavivirus antigen distribution in relation to apparent blindness in the former. The rapid onset of microscopic lesions and early presence of viral antigen in the eye of experimentally WNV-infected partridges, prior to the central nervous system involvement, suggested hematogenous spread of the virus into the eye. BAGV-infected partridges had a more pronunced inflammatory reaction and more widespread flavivirus antigen distribution in the retina compared with pheasants and experimentally fatally WNV-infected partridges. Our results suggest that flavivirus replication and development of lesions in ocular structures of gallinaceous game birds vary with the specific virus and host species involved.

Non-Langerhans Cell Histiocytoses

Based on our series of 111 cases of non-Langerhans cell histiocytoses, we present a new unifying concept for this rare group of disorders. The common denominator is the monocyte/ macrophage, which presents with various histologic features probably due to the influence of cytokines. Non-Langerhans cell histiocytoses are classified according to the predominant mononuclear (vacuolated, spindle-shaped, xanthomatized, scalloped, and oncocytic) and/or multinucleate (Touton, ground-glass appearance, Langhans, and foreign body) histiocytic cell types. Variable mixtures of these cell types produce common polymorphous patterns with prominence of vacuolated, spindle-shaped, and xanthomatized histiocytes in juvenile xanthogranulomas and of scalloped and oncocytic histiocytes in adult xanthogranulomas. Rarely, unusual monomorphous reaction patterns are observed: mostly vacuolated histiocytes are seen in the mononuclear variant of xanthogranulomas, (early benign cephalic histiocytosis, and generalized eruptive histiocytoma. Xanthomatized histiocytes predominate papular xanthoma and rarely xanthoma disseminatum, whereas spindle-shaped histiocytes are evident in spindle cell xanthogranuloma and progressive nodular histiocytosis, scalloped histiocytes are evident in most cases of xanthoma disseminatum, and finally oncocytic histiocytes are evident in reticulohistiocytoma and multicentric histiocytosis. Immunohistochemical, ultrastructural, and clinical findings can rationally be adjusted to this unifying concept of non-Langerhans cell histiocytoses. The time course of lesions, the age of the patients, and the presence or absence of underlying internal diseases are, or may, at least partially, be related to and thus explain variations on the theme of the non-Langerhans cell histiocytic reaction.

608 The time course of lesions in aging and Alzheimer disease

608 The time course of lesions in aging and Alzheimer disease

MRI and MRS studies on the time course of rat brain lesions and the effect of drug treatment: volume quantification and characterization of tissue heterogeneity by parameter selection.

Magnetic resonance imaging has been used to follow the time course of lesions induced in the rat brain as an animal model for characterization of the volume of the lesion. The dispersion in spin-spin relaxation has been used to characterize the nature of the brain lesion. Parameter selective estimation of T2, quantitative determination of the lesion size and volume selective in vivo proton spectroscopy have been employed for the purpose. The work has been carried out on rats which were subject to lesioning by ibotenic acid as a model for excitotoxicity and also on rats which received doses of ibotenic acid and subsequent doses of the NMDA antagonist drug MK 801 (dizocilpine). The time course of the progress of the lesions in untreated animals and the effect of neuroprotection by MK 801 was continuously monitored in all test animals. Further, a relatively new inhalation anesthetic agent, isoflurane, has been employed. A more logical and semiquantitative T2 bandwidth demarkation useful in distinguishing different degrees of lesioning from the onset and up to the 'edema' stage through penumbra (mild lesion), medium degree lesion and severe lesion has been proposed.