Faculty Bibliography

PURPOSE: Cervical spondylotic myelopathy (CSM) is a condition resulting from cervical stenosis. Manifestations of CSM include paresthesia in the extremities, loss of fine motor skills, balance problems, and bowel and bladder dysfunction in advanced disease. Laminoplasty is one surgical treatment option. The goal of laminoplasty is to reposition the laminae to expand the spinal canal, allowing the spinal cord to migrate posteriorly. There are various laminoplasty techniques; the main ones being open-door laminoplasty and double-door laminoplasty. This manuscript demonstrates a double-door laminoplasty otherwise known as a "French-door" laminoplasty discusses the indications and outcomes of this procedure. METHODS: The double-door laminoplasty creates an opening in the midline of the spinous processes and a symmetrical expansion with hinges on both laminae. Bilateral troughs are drilled on each laminae using a bur, and opened liked a French-door, allowing the spinal cord to move posteriorly in the enlarged spinal canal. The space between the gapped laminae are then stabilized by allograft. RESULTS: This manuscript presents the case of a 56-year-old man with CSM caused by multilevel cervical stenosis. The patient had classic signs and symptoms of CSM including problems with fine motor skills and walking difficulty. The video demonstrates the spinal cord decompression achieved with the French-door technique from C4 to C6 with a dome laminectomy at C3. CONCLUSIONS: There are many surgical treatments for cervical stenosis including anterior cervical discectomy and fusions and posterior procedures such as laminoplasty or laminectomy and fusion. The indications and technical pearls for French-door laminoplasty are presented as an effective option for the treatment of multilevel cervical stenosis.

OBJECTIVES/HYPOTHESIS/OBJECTIVE:To determine if training with a chicken wing model improves performance of endoscopic endonasal surgery (EES) with microvascular dissection. STUDY DESIGN/METHODS:Randomized experimental study. METHODS:A single-blinded randomized clinical trial of trainees with various levels of endoscopic experience was conducted to determine if prior training on a nonhuman model augments endoscopic skill and efficiency in a surrogate model for live surgery. Medical students, residents, and fellows were randomized to two groups: a control group that performed an endoscopic transantral internal maxillary artery dissection on a silicone-injected anatomical specimen, and an interventional group that underwent microvascular dissection training on a chicken wing model prior to performing the anatomic dissection on the cadaver specimen. Time to completion and quality of dissection were measured. RESULTS:A Mann-Whitney test demonstrated a significant improvement in time and quality outcomes respectively across all interventional groups, with the greatest improvements seen in participants with less endoscopic experience: medical students (P = .032, P = .008), residents and fellows (P = .016, P = .032). CONCLUSIONS:Prior training on the chicken wing model improves surgical performance in a surrogate model for live EES.

One of the key risk drivers at radioactive waste disposal facilities is radioiodine, especially 129I. As iodine mobility varies greatly with iodine speciation, experiments with 129I-contaminated aquifer sediments from the Savannah River Site located in Aiken, SC, were carried out to test iodine interactions with soils and aquifer sediments. Using tracer 125I- and stable 127I- additions, it was shown that such interactions were highly dependent on I- concentrations added to sediment suspensions, contact time with the sediment, and organic carbon (OC) content, resulting in an empirical particle-water partition coefficient (Kd) that was an inverse power function of the added I- concentration. However, Kd values of organically bound 127I were 3 orders of magnitude higher than those determined after 1-2 weeks of tracer equilibration, approaching those of OC. Under ambient conditions, organo-iodine (OI) was a major fraction (67%) of the total iodine in the dissolved phase and by implication of the particulate phase. As the total concentration of amended I- increased, the fraction of detectable dissolved OI decreased. This trend, attributed to OC becoming the limiting factor in the aquifer sediment explains why at elevated I-concentrations OI is often not detected.

We report nine new families of human medium reiteration frequency interspersed repetitive elements (MER elements). They were identified by computer-assisted analyses. Six of them were independently confirmed as repetitive families by DNA-DNA hybridization, and the number of elements for each of these families was estimated by plaque hybridization assay. The involvement of some of the reported MER elements in genetic rearrangements is demonstrated.

Fourteen novel medium reiteration frequency (MER) families were found, in the human genome, by using two different methods. Repetition frequencies per haploid human genome were estimated for each of these families as well as for six previously described MER DNA families. By these measurements, the families were found to contain variable numbers of elements, ranging from 200 to 10,000 copies per haploid human genome.

The pilot study for a sentinel health events surveillance system for deaths among persons under age 45 with diabetes was conducted in six states in 1984 and 1985. Two hundred and thirty-three events were identified. Information from death certificates, physicians, and families revealed that 22% died from acute complications of diabetes and 53% from chronic complications. Blood pressure measurement and urinalysis testing had been performed in the last year for almost all of the decedents, but other preventive practices were reported less frequently. Hypertension was present in 57% and of those, was not controlled in 73%. Forty-four percent were cigarette smokers at the time of death. Agreement between physicians and families was generally higher for clinical conditions than for care practices. This surveillance system appears to yield information about the health care of persons with diabetes not readily available from other sources, although modifications may be necessary before implementation.

The nucleotide sequence of the human adenosine deaminase gene was determined. The gene was isolated in a series of overlapping lambda phage clones containing human germ line DNA. A total of 36,741 base pairs were sequenced, including 32,040 base pairs from the transcription initiation site to the polyadenylation site, 3935 base pairs of 5'-flanking DNA, and 766 base pairs of 3'-flanking DNA. The gene contains 12 exons separated by 11 introns. The exons range in size from 62 to 325 base pairs while the introns are 76-15 166 base pairs in size. The area sequenced contains 23 copies of Alu repetitive DNA and a single copy of an "O" family repeat. All but one of these repeat sequences are located in the first three introns or the 5'-flanking region. The apparent promoter region of the gene lacks the "TATA" and "CAAT" sequences often found in eucaryotic promoters and is extremely G/C rich. Contained within this region are areas homologous to other G/C-rich promoters, including six decanucleotide sequences that are highly homologous to sequences identified as functional binding sites for transcription factor Sp1.

CC-1065 is a unique antitumor antibiotic produced by Streptomyces zelensis. The potent cytotoxic effects of this drug are thought to be due to its ability to form a covalent adduct with DNA through N3 of adenine. Thermal treatment of CC-1065-DNA adducts leads to DNA strand breakage. We have shown that the CC-1065 structural modification of DNA that leads to DNA strand breakage is related to the primary alkylation site on DNA. The thermally induced DNA strand breakage occurs between the deoxyribose at the adenine covalent binding site and the phosphate on the 3' side. No residual modification of DNA is detected on the opposite strand around the CC-1065 lesion. Using the early promoter element of SV40 DNA as a target, we have examined the DNA sequence specificity of CC-1065. A consensus sequence analysis of CC-1065 binding sites on DNA reveals two distinct classes of sequences for which CC-1065 is highly specific, i.e., 5'PuNTTA and 5'AAAAA. The orientation of the DNA sequence specificity relative to the covalent binding site provides a basis for predicting the polarity of drug binding in the minor groove. Stereo drawings of the CC-1065-DNA adduct are proposed that are predictive of features of the CC-1065-DNA adduct elucidated in this investigation.