When is the vestibular aqueduct enlarged? A statistical analysis of the normative distribution of vestibular aqueduct size

BACKGROUND AND PURPOSE

The size of vestibular aqueducts (VAs) seen on CT studies varies. The current practice of calling a VA enlarged when it exceeds a certain threshold (eg, 1.5 mm at the midpoint) is arbitrary. Our hypothesis was that statistical analysis of the range of VA widths in a normal-hearing population would lead to a mathematic definition of the upper-limit-of-normal VA width.

MATERIALS AND METHODS

The VA midpoint and opercular widths were measured in 73 children with normal hearing. Statistical analysis yielded values of the 99 th, 97.5th, 95th, 90th, 75th, and 50th percentiles for this normal distribution.

RESULTS

The upper-limit-of-normal (95th percentile) values for the VA midpoint and opercular widths were 0.9 and 1.9 mm, respectively. The VAs with greater widths may reasonably be considered enlarged.

CONCLUSION

The VAs with midpoint or opercular widths of 1.0 and 2.0 mm or greater, respectively, are enlarged.

Focused antibody response in plasma cell-infiltrated non-medullary (NOS) breast cancers

Breast tumors with prominent plasma cell (PC) infiltrates often have a more favorable natural course that may plausibly be mediated by anti-tumor activity of the elicited antibodies. These breast tumor-associated PCs are typically IgG dominant in contrast to normal breast PCs, which are mainly IgA. It is our hypothesis that this PC infiltration represents a host immune response that is driven by one or more tumor antigens. Previously, we and others showed that medullary carcinoma (MC) had a focused repertoire and features suggestive of a protein antigen driven response. Infrequently, non-MC, not otherwise specified (NOS) breast tumors may exhibit heavy PC infiltrations, also of IgG isotype. In this first characterization of this favorable prognosis NOS subgroup, IgG heavy chain (Hc) and light chain (Lc) variable (V) regions from three PC-infiltrated NOS tumors were randomly cloned and sequenced. We found biased (V) gene usage by the infiltrating PCs and somatic hypermutation in the rearranged Ig Hc and Lc V regions that were compatible with antigenic selection of the progenitor B cells. The antibody response of NOS infiltrated breast cancer is repertoire-focused, with 13-68% of isolates being clonally reiterated in the samples. Each NOS patient used distinct Hc V-D-J and Lc V-J rearrangements, with her own immune response "footprint," but the overall pattern of gene usage followed that typical of exogenous antigen-induced immune responses. The data are consistent with the hypothesis that PC infiltrates infrequently arising in NOS tumors, as previously inferred for MC, are in response to one or more breast cancer-associated protein tumor antigens.

Effect of intra-arterial tissue plasminogen activator and urokinase on autologous arterial emboli in the cerebral circulation of rabbits [corrected]

We conducted a randomized, blinded controlled trial to test the efficacy of fibrinolytic therapy with tissue plasminogen activator and urokinase in the treatment of acute embolic stroke. Embolic stroke was simulated in rabbits by injecting three 0.5 x 0.5 mm fragments of autologous arterial thrombus harvested from a traumatized auricular artery. Thirty minutes after embolization the rabbits were blindly treated with tissue plasminogen activator (n = 21), urokinase (n = 20), or 0.9% saline (n = 20). At 6 hours the rabbits were sacrificed, and the cerebral vasculature was inspected for the location and number of emboli. The brain was then cut into 0.5-cm-thick coronal sections and stained with triphenyltetrazolium chloride to define areas of infarction. Treatment with either tissue plasminogen activator or urokinase significantly reduced the number of emboli present in the cerebral circulation (p less than 0.05). The area of ischemic injury was also significantly reduced (p less than 0.05) by acute fibrinolytic therapy with either tissue plasminogen activator or urokinase. However, only treatment with tissue plasminogen activator significantly reduced (p less than 0.05) the incidence of infarction. There was no evidence of intracerebral hemorrhage in any rabbit. Early fibrinolytic therapy improved outcome in this model of acute embolic stroke.