Neoadjuvant temozolomide followed by complete resection of a 1p- and 19q-deleted anaplastic oligoastrocytoma: case study

A 38-year-old woman presented with an infiltrative tumor of the right frontal lobe and genu of the corpus callosum that was deemed only partially resectable. A stereotactic biopsy was performed, which revealed a right frontal oligoastrocytoma that had some anaplastic features as well as allelic loss of chromosome arms 1p and 19q. The patient was treated with temozolomide for 24 months. The partial response of the tumor to chemotherapy rendered the lesion amenable to gross total resection, which was performed subsequently. The patient remains alive and well without evidence of recurrence 7 months after resection and 48 months after initial diagnosis. Thus, preoperative chemotherapy decreased tumor mass to a degree that subsequently enabled a gross total resection. This treatment strategy, although common in the treatment of other solid tumors, is rarely utilized in adult neuro-oncology and raises another potential role for chromosome testing in oligodendroglial tumor management.     

Application of the lattice Boltzmann model to simulated stenosis growth in a two-dimensional carotid artery

The lattice Boltzmann model is used to observe changes in the velocity flow and shear stress in a carotid artery model during a simulated stenosis growth. Near wall shear stress in the unstenosed artery is found to agree with literature values. The model also shows regions of low velocity, rotational flow and low near wall shear stress along parts of the walls of the carotid artery that have been identified as being prone to atherosclerosis. These regions persist during the simulated stenosis growth, suggesting that atherosclerotic plaque build-up creates regions of flow with properties that favour atherosclerotic progression.     

Infantile hyperinsulinism associated with enteropathy, deafness and renal tubulopathy: clinical manifestations of a syndrome caused by a contiguous gene deletion located on chromosome 11p

We describe the clinical features of a new syndrome causing hyperinsulinism in infancy (HI), severe enteropathy, profound sensorineural deafness, and renal tubulopathy in three children born to two pairs of consanguineous parents. This combination of clinical features is explained by a 122-kb contiguous gene deletion on the short arm of chromosome 11. It deletes 22 of the 39 exons of the gene coding for the SUR1 component of the KATP channel on the pancreatic beta-cell thereby causing severe HI. It also deletes all but two of the 28 exons of the USH1C gene, which causes Usher syndrome and is important for the normal development and function of the ear and the eye, the gastrointestinal tract, and the kidney, thereby accounting for the symptoms of deafness, vestibular dysfunction and retinal dystrophy seen in type 1 Usher syndrome, diarrhoea, malabsorption, and tubulopathy. This contiguous gene deletion provides important insights into the normal development of several body organ systems.     

Cannulation of the axillary artery with a side graft reduces morbidity

BACKGROUND: The axillary artery is our preferred arterial cannulation site when the ascending aorta cannot be cannulated. Previously, we cannulated the artery directly; now we use a side graft. The purposes of this study were to (1) investigate cannulation-related morbidity and (2) determine whether use of a side graft reduces it. METHODS: From January 1993 to January 2001, 392 patients underwent 399 axillary artery cannulations. Indications included calcified ascending aorta (129, 32%), ascending aortic aneurysm (115, 29%), type I aortic dissection (85, 21%), cardiac reoperation (70, 18%), and calcified femoral artery (26, 6%). The axillary artery was cannulated directly in 212 (53%) and with a side graft in 187 (47%). Comparisons of cannulation-related morbidity between the direct cannulation and side graft groups were made overall and after both adjusting and matching for propensity score. RESULTS: Cannulation-related morbidity was infrequent, with brachial plexus injury in 7 (1.8%), axillary artery damage in 7 (1.8%), aortic dissection in 3 (0.8%), and arm ischemia in 3 (0.8%). Only 4 of 187 (2.1%) occurred in the side graft group, versus 16 of 212 (7.0%) with direct cannulation (p = 0.03). After propensity adjustment, the odds ratio for reduction of risk of cannulation-related morbidity with use of a side graft was 0.15 (p = 0.002). CONCLUSIONS: Use of the axillary artery as inflow for cardiopulmonary bypass is associated with low morbidity. However, cannulation with a side graft was associated with less cannulation-related morbidity than direct cannulation. Routine use of a side graft is recommended whenever axillary artery cannulation is indicated.     

MRI changes in the rat hippocampus following proton radiosurgery

PURPOSE: To define radiographic dose-response relationships for proton radiosurgery using a rat brain model. METHODS AND MATERIALS: A group of 23 rats was treated with Bragg peak proton beam irradiation involving the right hippocampus. Single doses of 5, 12, 20, 30, 60, 90 and 130 cobalt gray equivalents (CGE) were delivered to groups of 3 animals using single fraction technique. One extra animal was included at the 130- and 30-CGE doses. Animals were imaged using a standard 1.5-tesla GE Signa MRI. A 3-inch surface coil was employed to obtain T1-weighted sagittal images (TR 600 and TE 30) and dual echo T2-weighted coronal images (TR 3,000 and TE 30/90). Animals were imaged at 1.5, 3, 4.5, 6 and 9 months. Volumetric analysis with custom software was done to evaluate areas of increased signal on T2-weighted images, and signal change versus time curves were generated. Gadolinium-enhanced T1-weighted imaging was also done at the 9-month time point to further evaluate tissue injury. The development of hydrocephalus was also examined. RESULTS: Peak tissue injury was greater and occurred earlier with higher versus lower doses of radiation. Statistically significant differences were seen between the 130- and 90-CGE animals and between the 90- and 60-CGE animals (p < 0.0016) using ANOVA. Signal changes can be seen in at least 1 of the animals at 20 CGE. The largest volume of tissue enhancement at 9 months was seen in animals at 60 CGE, which may represent an intermediate zone of tissue injury and gliosis compared with greater tissue loss at higher doses and less injury at lower doses. Hydrocephalus developed first in the untreated hemisphere in 130- and 90-CGE animals as a result of mass effect while it occurred at a later time in the treated hemisphere in lower-dose animals. CONCLUSIONS: Following single-dose proton radiosurgery of rat hippocampus, serial MRIs show T2 signal changes in animals ranging from 130 down to 20 CGE as well as the development of hydrocephalus. Dose-effect relationships using proton radiosurgery in rats will be a helpful step in guiding further studies on radiation injury to brain tissue.