Interpretation of anatomic variations of computed tomography scans of the sinuses: a surgeon's perspective.

Four hundred computed tomography (CT) scans of patients undergoing endoscopic sinus surgery were studied with particular attention to anatomic variations. Six specific variations were identified that may predispose the surgeon to inadvertent penetration of the orbit or anterior cranial cavity. These anatomic variants are: 1. lamina papyracea lies medial to the maxillary sinus ostium; 2. maxillary sinus hypoplasia; 3. fovea ethmoidalis abnormalities, such as low or sloping fovea and encephaloceles; 4. lamina papyracea dehiscence resulting in herniation of orbital content into the ethmoids; 5. sphenoid sinus wall variations such as septa attached to the carotid covering, and penetration of the sphenoid by the internal carotid artery or optic nerve; 6. sphenoethmoid cells (Onodi cells), the most posterior ethmoid cells pneumatizing lateral and superior to the sphenoid and intimately associated with the optic nerve.

The Ojibwa Health Study: fish residue comparisons for Lakes Superior, Michigan, and Huron.

The Ojibwa Health Study is a descriptive epidemiology study of six Ojibwa reservations in the Upper Great Lakes. Fish consumption habits, contaminant (mercury [Hg], polychlorinated biphenyls [PCBs], and other organochlorines [OCs]) residues in dietary fish and humans, and chronic disease outcomes currently are being documented. Four hundred and fifty questionnaires and approximately 200 biological samples had been collected as of December 1994. Fish collections from reservations included lake trout, walleye, lake whitefish, and lake herring from Lakes Superior (three sites), Michigan, and Huron. Hg and OC residue analyses have been completed for the fish composite samples. A preliminary examination of the data has revealed regional differences in the contaminant burdens of the fish. Lake Michigan and Lake Huron whitefish composite samples had approximately twice the OC concentrations of Lake Superior whitefish samples. In general, the whitefish composite samples were far below the U.S. Food and Drug Administration or any state advisory limits for OC or Hg residues. Lake trout samples contained higher amounts of all residues than did the whitefish samples.

Incidence of perforation with Goode T-tube.

Two groups of patients from the same era were retrospectively studied in Cincinnati and Chicago. In Cincinnati two subgroups were studied. The first group received myringotomy with insertion of a 'T'-shaped ventilating tube (75 patients, 140 ears, 147 insertions). Fifty-eight ears still had the tube in place, 31 had healed after spontaneous extrusion, 17 had healed after removal of the tube, 20 had persistent perforation after the tube was gone, 2 had a cholesteatoma, and 4 patients (7 ears) were lost to follow-up. The second set received myringotomy and insertion of a small grommet (Donaldson tube, 71 patients, 140 ears, 164 insertions) tympanostomy tube. None could be documented to still have the tube in place, 156 ears healed after spontaneous extrusion, none required removal, 3 ears had a persistent perforation after the tube was gone, none had cholesteatoma, and 5 patients (5 ears) were lost to follow-up. The perforation rate for the T-tube is 13.6% and for the grommet is 1.8% (P = 0.0005). In Chicago, 93 patients who received the Goode T style tube (175 ears, 175 insertions) prior to March, 1986 were evaluated. The degree of retraction of the tympanic membrane preoperatively was recorded. No ears still had the tube in place, 145 had healed after spontaneous extrusion or removal of the tube, 30 had persistent perforation 12 months after the tube was gone, 4 had a cholesteatoma, and 8 patients (15 ears) were lost to follow-up. The rate of perforation is 18.8% which is not statistically different from the Cincinnati rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Do-not-resuscitate orders in an extended-care study group.

We examined the charts of 911 nursing home patients in Hennepin County, Minnesota, to determine the prevalence of written do-not-resuscitate (DNR) orders. Information regarding demographic characteristics, and whether a surrogate decisionmaker was available and participated in the decision, was also collected. Twenty-seven percent of patients had DNR orders. Ninety percent of all patients had potentially available surrogate decisionmakers. However, for 31% of patients with DNR orders, there was no documentation of patient or surrogate participation in the DNR decision. Univariate analysis identified female sex; increased age, level of care (skilled versus intermediate), presence of a potential surrogate decisionmaker, and increasing length of time since nursing home admission as factors associated with presence of DNR orders. When a logistic regression model was used, increased age, increased length of time since nursing home admission, skilled versus intermediate level of care, and presence of a surrogate decisionmaker were independently associated with presence of DNR status. Several variables are independently associated with written DNR orders; their relationship to the factors physicians use in decision making requires further study.

Interaction of AD2+D2 protein and simian virus 40 large T antigen with the large tumor antigen binding site I.

In a lytic infection of a permissive host by SV40, the large tumor antigen (T antigen), which is a product of early transcription of the SV40 A gene, has been previously shown to autoregulate its own transcription by binding to SV40 DNA. The DNA region to which T antigen binds most tightly was synthesized and subsequently introduced into the bacterial plasmid pUC8. The interaction of SV40 T antigen with the DNA duplexes, derived from both chemical synthesis and the recombinant plasmid, were examined by using nitrocellulose filter binding assays. An SV40-adenovirus hybrid protein, AD2+D2 protein, was also tested. The SV40 T antigen was found to bind more tightly than the hybrid protein. Kinetic assays demonstrated that the association rates for the two proteins with the DNA binding site were equivalent; however, once formed, the T antigen-DNA complex dissociated more slowly than the AD2+D2 protein-DNA complex.