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Biomedical subjects

J A Goodrich

Publications and source records attributed to J A Goodrich.

36 records · Page 2Linked to original sources

Lumbar spine arthrodesis. A comparison of hospital costs between 1986 and 1993.

The purpose of this project was to evaluate the hospital costs of one- and two-level spinal arthrodesis and to determine areas where costs may be effectively reduced. The hospital bills of 40 patients (20 each in 1986 and 1993) who had undergone single-level and double-level lumbar arthrodesis were reviewed. Each patients's bill was examined and the specific charge items were assigned to one of seven "service centers." To effectively compare costs in the two different years, dollar values on 1986 bills were converted to inflation-adjusted 1993 amounts (the consumer price index over this interval was about 35%). The hospital cost (mean) for single- and double-level spinal arthrodesis increased from $7,457 (1986) to $19,712 (1993). In inflation-adjusted 1993 dollars the actual increase was 97%. All but two service centers demonstrated increased costs. The most dramatically increased in price was implant cost ($300 in 1986 vs $2,967 in 1993, a 638% increase with inflation adjustment). When adjusted for inflation, surgeons' fees actually decreased by 18% at our institution ($7,503 in 1986 vs $8,338 in 1993). The other service center that showed a decrease was the hospital room (-15%). The anesthesia charge, recovery-room fee, operating-room charge, and the "other" charges increased between 36% and 288%. As a percentage of the total hospital bill, implant cost accounted for approximately 4% of the 1986 charges, whereas in 1993 it accounted for more than 15% of the total bill. None of the other service centers showed such a drastic increase. Increasingly sophisticated technology has dramatically raised hospital charges. Strategies to reduce the overall cost of spinal surgery should concentrate on controlling the cost of spinal implants.

Cost Control↗

Transcription factors IIE and IIH and ATP hydrolysis direct promoter clearance by RNA polymerase II.

Using a defined RNA polymerase II (pol II) transcription system, we have investigated the roles of basal factors at discrete stages during the transcription cycle (e.g., initiation, promoter clearance, and transcript elongation). Abortive initiation assays revealed that TATA-binding protein, transcription factors TFIIB and TFIIF, and pol II were necessary and sufficient to form functional initiation complexes on both linear and supercoiled templates. By contrast, TFIIE, TFIIH, and ATP hydrolysis were additionally required during promoter clearance from linear templates, while negative supercoiling obviated the need for these auxiliary factors. Furthermore, TFIIE, TFIIH, and supercoiling were not required during elongation. Our results suggest a role for TFIIH-associated helicase activity or supercoiling during promoter clearance rather than open complex formation. These results establish abortive initiation as a useful assay for studying functional initiation complex formation in defined eukaryotic transcription systems and provide a framework for investigating regulation at different stages of the eukaryotic transcription cycle.

Adenosine Triphosphate↗

Transcription factor IIE binds preferentially to RNA polymerase IIa and recruits TFIIH: a model for promoter clearance.

The basal factor TFIIE is an important component of the RNA polymerase II transcription machinery. In our efforts to determine the role of TFIIE in the transcription process, we have begun to define the interactions between TFIIE and other basal transcription factors. Here we report that TFIIE binds selectively to the nonphosphorylated form of RNA polymerase II (IIa) and that this interaction is mediated by the 56-kD subunit of TFIIE. Additional binding studies reveal that TFII can interact with TBP as well as TFIID and that this interaction is mediated primarily via the 56-kD subunit. Our studies indicate that TFIIE also interacts with both subunits of TFIIF and with TFIIH, a multisubunit basal factor reported to catalyze RNA polymerase II CTD phosphorylation. Protein affinity assays demonstrate that TFIIE binds directly to ERCC-3, a DNA repair protein associated with TFIIH. More importantly, TFIIE affinity resin can selectively isolate transcriptionally competent TFIIH from a partially purified preparation and thereby may recruit TFIIH to the transcription complex in vivo. These multiple interactions between TFIIE, Pol II and TFIIH support a model in which TFIIE plays a role in promoter clearance as well as in the recruitment of proteins required for transcription-coupled DNA repair.

Binding Sites↗

TBP-TAF complexes: selectivity factors for eukaryotic transcription.

Recent evidence indicates that the TATA-binding protein (TBP) is central to transcription by all three eukaryotic RNA polymerases (I, II, and III). Interestingly, the majority of the TBP does not appear to be free protein in vivo. Instead, it is found associated with other factors (TAFs) in multisubunit complexes. The past year has brought significant advances in our understanding of the subunit compositions and biochemical functions of these complexes. In addition, the crystal structures of the TBP core domain and the TBP-TATA box DNA complex provide new insights into how this small protein might interact with many different partners.

Animals↗

Drosophila TAFII40 interacts with both a VP16 activation domain and the basal transcription factor TFIIB.

Enhancement of RNA polymerase II transcription by the viral transactivator VP16 requires the TFIID complex, which consists of the TATA-binding protein (TBP) and TBP-associated factors (TAFs). Here we report the molecular cloning, expression, and biochemical characterization of Drosophila TAFII40 (dTAFII40), a subunit of TFIID. In vitro protein-protein interaction assays revealed direct binding between dTAFII40 and a 39 amino acid VP16 activation domain. In addition, affinity chromatography indicated a direct binding of the basal factor TFIIB to immobilized dTAFII40. Since VP16 also binds TFIIB, our results suggest a ternary interaction among an activator, a coactivator, and a basal transcription factor. Antibodies directed against dTAFII40 inhibited activation by GAL4-VP16 without affecting basal transcription. These results, taken together with previous studies of Sp1 and dTAFII110, establish that different activators interact with distinct TAFs in the TFIID complex and that TAFs can contact both activators and basal factors.

Amino Acid Sequence↗

Effects of ridogrel on the prostacyclin-thromboxane ratio in nulliparous third trimester-pregnant rhesus monkeys.

The effects of ridogrel, a thromboxane synthetase inhibitor and endoperoxide receptor antagonist, were studied in twelve pregnant, nulliparous Rhesus monkeys (Macaca mulatta) during the last trimester of pregnancy. Ridogrel was administered intravenously in two groups of animals (n = 6), at either 0.1 mg/kg or 1.0 mg/kg. Ultrasonic assessment of the fetuses during and after the infusion period revealed no obvious changes in fetal condition. Both dosages reduced serum thromboxane levels 30 minutes after administration, 96.6% and 99.6% suppression, 0.1 mg/kg and 1.0 mg/kg, respectively (P < 0.0001), while the 1.0 mg/kg dose produced continued suppression for 24 hours (78% suppression, P < 0.0001) and was lower than the 0.1 mg/kg 24 hour value (P < 0.008). Prostacyclin levels increased to 340% and 472% of baseline values, 0.1 mg/kg and 1.0 mg/kg, respectively at 30 minutes and to 928% and 255% of baseline at 24 and 48 hours after treatment in the 1.0 mg/kg group (P < 0.0003). Ridogrel caused no changes in maternal or neonatal outcome. The potential for the use of this compound for the treatment of preeclampsia is discussed.

6-Ketoprostaglandin F1 alpha↗

Drosophila TFIIA-L is processed into two subunits that are associated with the TBP/TAF complex.

The basal factor TFIIA has been shown to act early during initiation in both the mammalian and yeast transcription systems, but a TFIIA-like activity has not been identified in Drosophila. While characterizing the Drosophila TFIID complex, we discovered that a 30-kD protein that cofractionated with dTFIID was homologous to the previously identified, large subunit of yeast TFIIA. Here, we report the cloning and biochemical characterization of Drosophila TFIIA-L. Coimmunoprecipitation studies with anti-dTBP, anti-dTFIIA-L, and anti-TAF antibodies indicated a tight association of the endogenous dTFIIA and dTFIID. However, dTFIIA could be dissociated from dTFIID under conditions that did not elute the TAFs, and the eluted material had mobility shift and transcriptional activities associated with TFIIA. Peptide sequence and Western analysis with antibodies raised against the amino- and carboxy-terminal portions of recombinant dTFIIA-L revealed that a precursor 48-kD species was cleaved in vivo, giving rise to the 30- and 20-kD subunits of dTFIIA that remain associated with each other and with dTFIID. Protein-protein interaction assays identified dTBP and dTAFII110 as targets for binding TFIIA in the TFIID complex. These results suggest that TFIIA may form a specific complex with both TAFs and other components of the transcriptional machinery during formation of the initiation complex.

Amino Acid Sequence↗

Regulation of open complex formation at the Escherichia coli galactose operon promoters. Simultaneous interaction of RNA polymerase, gal repressor and CAP/cAMP.

The regulation of open complex formation at the Escherichia coli galactose operon promoters by galactose repressor and catabolite activator protein/cyclic AMP (CAP/cAMP) was investigated in DNA-binding and kinetic experiments performed in vitro. We found that gal repressor and CAP/cAMP bind to the gal regulatory region independently, resulting in simultaneous occupancy of the two gal operators and the CAP/cAMP binding site. Both CAP/cAMP and gal repressor altered the partitioning of RNA polymerase between the two overlapping gal promoters. Open complexes formed in the absence of added regulatory proteins were partitioned between gal P1 and P2 with occupancies of 25% and 75%, respectively. CAP/cAMP caused open complexes to be formed nearly exclusively at P1 (98% occupancy). gal repressor caused a co-ordinated, but incomplete, switch in promoter partitioning from P1 to P2 in both the absence and presence of CAP/cAMP. We measured the kinetic constants governing open complex formation and decay at the gal promoters in the absence and presence of gal repressor and CAP/cAMP. CAP/cAMP had the largest effect on the kinetics of open complex formation, resulting in a 30-fold increase in the apparent binding constant. We conclude that the regulation of open complex formation at the gal promoters does not result from competition between gal repressor, CAP/cAMP and RNA polymerase for binding at the gal operon regulatory region, but instead results from the interactions of the three proteins during the formation of a nucleoprotein complex on the gal DNA fragment. Finally, we present a kinetic model for the regulation of open complex formation at the gal operon.

Base Sequence↗

Competing promoters in prokaryotic transcription.

Two (or more) bacterial promoters are often found in close proximity, and may compete for the binding of RNA polymerase. These competing promoters have interesting characteristics in vitro and analysis of the competition should be valuable to kinetic studies of more complex transcription systems.

Binding, Competitive↗

Searching for and predicting the activity of sites for DNA binding proteins: compilation and analysis of the binding sites for Escherichia coli integration host factor (IHF).

An analysis of the sequence information contained in a compilation of published binding sites for E. coli integration host factor (IHF) was performed. The sequences of twenty-seven IHF sites were aligned; the base occurrences at each position, the information content, and an extended consensus sequence were obtained for the IHF site. The base occurrences at each position of the IHF site were used with a program written for the Apple Macintosh computers in order to determine the similarity scores for published IHF sites. A linear correlation was found to exist between the logarithm of IHF binding and functional data (relative free energies) and similarity scores for two groups of IHF sites. The MacTargsearch program and its potential usefulness in searching for other sites and predicting their relative activities is discussed.

Bacterial Proteins↗

Acinetobacter calcoaceticus foot infection secondary to high-pressure injection injury: a case report.

Injection injuries are surgical emergencies occurring most often in the hand and frequently associated with widespread tissue necrosis and infection. This report presents a case of high-pressure injection injury of the foot associated with extensor hallucis longus laceration and infection with Acinetobacter calcoaceticus variant anitratus. This injury occurred with a high-pressure "water-blaster" tool used to remove paint from pavement. Similar injuries in the foot have not been reported. A. calcoaceticus is a widely distributed normal flora of low virulence, often waterborne, which is rarely found in orthopaedic infections in young healthy patients. Clinical features of high-pressure injection injuries, principles of treatment, and the characteristics of A. calcoaceticus are reviewed.

Accidents, Occupational↗

Drinking water and cancer mortality.

The problem of understanding the possible adverse health effects of organic chemical contaminants in drinking water is not new, but national concern has intensified in recent years. Despite this concern and regulatory efforts, no definitive relationship has been established between organic contamination and human health effects. This paper examines some of the sources of possible organic contamination, current knowledge concerning human health effects and the most current epidemiological data. Historic CCE and CAE data were extracted from STORET and used in regression analyses. Age-adjusted 20-year average cancer mortality rates were regressed against the sum of CAE and CCE for those counties with STORET monitoring data of their drinking water source. Results indicate statistically highly significant relationships particularly for GI-urinary tract cancers.

Carcinogens↗

Isolated proximal musculocutaneous nerve palsy: case report.

Isolated musculocutaneous nerve injury is extremely rare. The few reported cases were associated with heavy exercises and violent extension of the forearm. The lesions in those cases were below the coracobrachialis muscle, involving the biceps, brachialis, and cutaneous nerves of the forearm. This patient's lesion was unique, located proximal to the coracobrachialis. There was no antecedent trauma. At follow-up six weeks and four months after onset of symptoms, significant improvement was noted both clinically and electrophysiologically. Musculocutaneous nerve palsy is important to distinguish in certain differential diagnoses, particularly with C5 or C6 radiculopathy and brachial plexus injury.

Adult↗

Analysis of bone biopsies.

The orthopedic surgeon is frequently confronted with the decision of when to perform a bone biopsy and whether to do a needle biopsy or an open biopsy. Frequently consultations are received from other services requesting bone biopsies with questionable indications. The indications and contraindications for performing bone biopsies are discussed as well as advantages and disadvantages of either closed or open technique. Four selective cases are discussed with illustrations. The challenge of undiagnosed osseous lesions is best met by rational evaluation of each individual case and coordinated with the team effort of the primary care physician, surgeon, pathologist, and radiologist. The decision for either an open or closed biopsy technique must be based on the experience and skills of the surgeon and pathologist.

Abscess↗

Acromion fracture associated with posterior shoulder dislocation.

We report a case involving combined acromion fracture and posterior glenohumeral dislocation. To our knowledge, this combination of injuries has not been reported previously in the literature. In our case, the shoulder dislocation was initially missed. The utility of additional radiographic views to detect this type of injury is emphasized. The mechanism of injury, course of treatment, and clinical outcome are presented.

Acromion↗

Chronic cannulation and fistulization procedures in swine: a review and recommendations.

Swine are important animal models in biomedical research. Some experimental procedures may require chronic access to blood vessels, organs, and structures. Chronic access procedures may be utilized for collection of blood and body fluids as well as for the infusion of test substances. This manuscript reviews methodologies that have been reported to be effective for these procedures. It also makes recommendations on the maintenance of indwelling catheters, cannulas, and fistulas.

Animals↗