Unique cause for 60-cycle interference.
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Biomedical subjects
Publications and source records attributed to G R Haynes.
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Postoperative nausea and vomiting (PNV) is a common disorder at the forefront of ambulatory care issues. New antiemetic drugs and improved anesthetic techniques have decreased the incidence of anesthesia-induced PNV. Patient characteristics and surgical factors are now largely responsible for postoperative emesis. Clinicians need to understand these factors to deal effectively with PNV as the use of ambulatory surgery increases. Physicians should consider both prophylactic drug intervention and direct treatment.
When a profound fever occurs in a surgical patient, clinicians usually start thinking about the malignant hyperthermia syndrome. Simple consideration of the clinical situation, the patient's medical history, and a few rapid laboratory assessments are enough to direct appropriate treatment.
Postoperative pain is commonly treated with significant doses of narcotics, occasionally resulting in side effects including nausea, pruritus, and respiratory depression. One potential advantage of regional anesthesia is profound postoperative analgesia that reduces exposure to potent narcotics. To evaluate the efficacy of two long-acting local anesthetics, bupivacaine and etidocaine, in providing pain relief after major shoulder surgery, we randomized 20 patients to receive either bupivacaine or etidocaine for brachial plexus block as the primary anesthetic for shoulder surgery. Surgeons, patients, and the acute pain service were blinded as to drug selection. After the patient was sedated, an interscalene block was placed with the use of a nerve stimulator to facilitate proper needle placement. Forty milliliters of either 0.5% bupivacaine or 0.75% etidocaine containing 5 micrograms/mL epinephrine was injected into the brachial plexus sheath. An additional 8 mL of local anesthetic was administered for superficial cervical plexus blockade. Intraoperative sedation was accomplished with an intravenous infusion of methohexital as needed. After surgery, patients received a standard patient-controlled analgesia protocol providing incremental doses of morphine. The degree of postoperative analgesia resulting from residual local anesthetic effect was expressed as the time until first morphine requirement and the total dose of morphine required during the first 24 hours postoperatively. We found no statistically significant intergroup differences either in time of initial use of morphine or in the total dose of morphine required in the first 24 hours. Both etidocaine and bupivacaine provide prolonged analgesia after major shoulder surgery when injected into the brachial plexus. Bupivacaine, however, possesses significant cardiotoxicity and has a relatively delayed onset in peripheral neural blockade. Etidocaine is less cardiotoxic and also has a more rapid onset of effect. Thus etidocaine may be a preferable agent for interscalene block for major shoulder surgery.
BACKGROUND: CARCS (computer-assisted resident candidate selection) is a database application developed in 1983 at the Department of Anesthesiology of the Medical University of South Carolina to deal with the greatly increased quantity of applicant information. This article relates a representative sample of CARCS data to the process of selecting residents in general. METHOD AND RESULTS: CARCS files were analyzed for 1985-86, 1986-87, 1990-91, and 1991-92, and data for each year were derived as simple averages and percentages for two groups: (1) the entire pool of residency applicants (approximately 200 per year) and (2) the eight residency candidates per year who actually matched with the program through the National Resident Matching Program, Analyses showed that the standardized test scores, grades, and class ranks of the matched candidates were not significantly higher than those of the applicants; however, the matched candidates' scores for letters of reference and for interviews were consistently higher than those for the applicant pool. CONCLUSIONS: The results support the view of medical educators that the traditional academic criteria are not sufficiently predictive of clinical performance or interpersonal skills. Research relating residents' performances to personality, learning style, and other neuropsychological factors may provide needed alternatives to knowledge testing by developing combined cognitive-noncognitive profiles. The anesthesiology clerkship experience is now almost universal among applicants and could be structured to provide pertinent information about potential residents through direct observation as well as behavioral testing.
One useful but underused parameter of fluid replacement is colloid oncotic pressure. Colloid oncotic pressure (COP) is one of the Starling forces that maintain a balance between intravascular and extravascular fluid. Systemic and pulmonary circulations exhibit differences that limit the usefulness of COP manipulation in the treatment of pulmonary edema, especially that associated with hypoxic damage or pulmonary contusion. Systemic transcapillary fluid transport, however, is governed significantly by COP, and serial measurements of COP can serve as useful guides for colloid replacement. In this paper we present instances in which COP determinations were found to be clinically helpful, and discuss colloid replacement during surgery.
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1. The activity of thymidine kinase in rat liver supernatant decreased with development to a value in the adult that was 1% of that in the 17-day foetus. 2. The foetal enzyme was more stable than the adult to gel filtration on Sephadex G-25 at 0 degrees . 3. The greater stability of the foetal enzyme to incubation at 45 degrees was attributable to the presence of higher concentrations of nucleotides in foetal liver supernatant. 4. The K(m) values for foetal and adult enzymes were approx. 2.5mum- and 2.1mum-thymidine respectively. 5. The foetal enzyme was more sensitive to inhibition by thymidine triphosphate. 6. The decline in enzyme activity during the neonatal period was correlated with a shift in the enzyme properties from the foetal to the adult type, and may reflect the decrease in the proportion of haemopoietic tissue in the liver.
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1. An enzyme preparation from rat-liver microsomes incorporated all four ribonucleotides from the corresponding triphosphates into ribosomal RNA. The reaction was Mn(2+)-dependent, but UMP incorporation also occurred in the presence of Mg(2+). 2. The incorporation of any one ribonucleotide was inhibited by the presence of the other three ribonucleoside triphosphates and by denatured DNA. 3. The product of the reaction consisted of short chains of homopolymer attached to the primer ribosomal RNA. 4. ;Soluble' RNA, synthetic polyribonucleotides, and oligoribonucleotides were also effective primers for CMP incorporation. 5. When phosphodiesterase-treated ;soluble' RNA was the primer, CMP was incorporated into positions usually occupied by the normal terminal trinucleotide sequence of intact ;soluble' RNA, but the enzyme did not synthesize a specific terminal sequence consisting of a defined number of CMP residues.
1. s-RNA nucleotidyltransferase incorporated CMP into phosphodiesterase-treated s-RNA more rapidly in the presence of Mg(2+) (10mm) than in the presence of Mn(2+) (2mm). UMP was incorporated more rapidly in the presence of Mn(2+), and at high ionic strength the incorporation of CMP was also more rapid in the presence of Mn(2+). 2. The capacity of phosphodiesterase-treated s-RNA for CMP, UMP and AMP was increased in the presence of Mn(2+). Terminal sequences of more than one UMP or AMP residue were synthesized, but these atypical reactions were inhibited when CTP was added. CMP was incorporated rapidly to form -pCpC terminal sequences and then more slowly as longer chains were formed, but very little CMP was incorporated into s-RNA-pCpCpA. 3. CMP was incorporated into phosphodiesterase-treated 5s RNA and ribosomal RNA to form short chains of polyC attached to the primer RNA. This reaction was inhibited by the presence of s-RNA. 4. A small Mn(2+)-dependent incorporation of CMP was also primed by poly(A).(U) and poly(C).(I).