Anaplastic thyroid carcinoma, thyroid lymphoma, and metastasis to thyroid

Anaplastic thyroid carcinoma, thyroid lymphoma, and secondary metastasis to the thyroid gland are uncommon thyroid malignancies. They represent significant challenges for the surgeon owing to difficulties in diagnosis, aggressive biology, and the infrequency of their presentation. An awareness and appreciation of multimodality treatment strategies is essential for their management.     

The Trojan Chicken study, Minnesota

We conducted a study in the summer of 2004 at county fairs in the Midwest to investigate the role poultry exhibits have in spreading avian pathogens to humans. A nearly invisible powder (pathogen surrogate) that fluoresces under UV light was surreptitiously sprinkled each day on 1 show bird at each of 2 fairs. A UV light box was used to daily examine the hands of 94 poultry-exhibit participants (blinded regarding UV box results) for up to 4 days during the poultry shows. Enrollment and end-of-study questionnaires collected data on pathogen risk factors. Eight (8.5%) of 94 participants had evidence of fluorescent powder contamination (95% confidence interval 2.76%-14.26%). This contamination and infrequent handwashing practices suggest that county fairs are a possible venue for animal-to-human pathogen transmission.     

Effect of incisional friction and ophthalmic viscosurgical devices on the heat generation of ultrasound during cataract surgery

PURPOSE: To determine the thermal features of the Legacy (Alcon) and Sovereign (Advanced Medical Optics) phacoemulsification machines in a cadaver eye and with 7 ophthalmic viscosurgical devices (OVDs). SETTING: In situ and in vitro study. METHODS: Temperature without occlusion was recorded at the sleeve placed in the wound of a cadaver eye, and temperature over baseline was determined after 60 seconds. The result was then compared with the results in a previous study that used balanced salt solution (BSS) in artificial chambers. In the second portion of the experiment, with irrigation and aspiration lines occluded, temperature was recorded at the sleeve placed in an artificial chamber filled with sodium hyaluronate 2.3% (Healon5), sodium hyaluronate 1.4% (Healon GV), sodium hyaluronate 1.0% (Healon), sodium hyaluronate 1.6% (Amvisc Plus), sodium hyaluronate 1.0% (Provisc), sodium hyaluronate 3.0%-chondroitin sulfate 4.0% (Viscoat), or hyaluronate 3.0% (Vitrax). Temperature over baseline was also determined after 60 seconds. These results were compared with each set of OVD data and with the results in the prior BSS study. RESULTS: In the eye-bank model, the Legacy machine had a 62% temperature increase from incisional friction and the Sovereign machine had a decrease of 8.6% over results in an artificial anterior chamber. The OVD temperature increases were greater for the Sovereign (P<.001) and followed the same general trend for the Legacy. The least temperature increase was with Amvisc Plus, Healon, and Healon GV; the intermediate increases were with Provisc and Vitrax; and the greatest increases were with Viscoat and Healon5. The OVD findings did not correlate with viscosity or pseudoplasticity. CONCLUSIONS: Incisional friction alone increased heat generation in the Legacy, a stroke-length driven instrument, more than in the Sovereign, a power-driven instrument. Ophthalmic viscosurgical devices are not only a concern due to outflow occlusion but can also add up to 6 times the heat in comparison with BSS. The need to aspirate the OVD before using ultrasound is thus verified.     

Substantia nigra transplants into denervated striatum of the rat: ultrastructure of graft and host interconnections

A number of recent experiments suggest that grafted dopaminergic neurons provide functional input to a host caudoputamen which previously had been deprived of its dopaminergic input. The purpose of the present study was to determine whether tyrosine hydroxylase immunoreactive processes which originate in the graft participate in morphologically identifiable synapses in the host neuropil. Prior to transplantation, adult Sprague-Dawley rats received unilateral injections of 6-hydroxydopamine into the medial forebrain bundle. Animals were screened for the success of striatal denervation by a test of apomorphine-induced rotation. Transplants of fetal substantia nigra then were placed into cavities in the caudoputamen. After a 6-8 month survival period, animals were perfused and prepared for tyrosine hydroxylase immunocytochemistry. No evidence of sprouting of the host catecholoaminergic system was observed, even after long survival times. Both pre- and postsynaptic immunoreactive elements were clearly present in the host caudoputamen. Immunoreactive axons made synaptic contact with unlabeled dendrites; immunoreactive dendrites were postsynaptic to unlabeled axon terminals. The present results suggest that both host-to-graft and graft-to-host synapses are present in the host caudoputamen.