Biomedical subjects

G J Sheplock

Publications and source records attributed to G J Sheplock.

4 recordsLinked to original sources

PubMed1994

Probable cervical midline epidural septum complicating the treatment of a patient with upper extremity sympathetically maintained pain.

We present a woman who developed left arm sympathetically maintained pain (SMP, or "shoulder-hand syndrome") as a result of brachial plexus injury. After confirmatory diagnosis with both stellate local anesthetic block and intravenous phentolamine infusion, the patient had a cervical epidural catheter placed and a local anesthetic infusion started. After numerous unilateral blocks were obtained, a cervical epidurogram demonstrated a probable cervical midline epidural septum. Catheter placement was adjusted, and a successful chemical sympathectomy was performed for 6 days. This resulted in significant relief of the patient's shoulder pain as well as almost complete resolution of the patient's left arm SMP symptoms. This case represents, to our knowledge, the first documentation of the use of phentolamine for the diagnosis of SMP secondary to pathology at a site proximal to that of symptomatology, as well as the first documentation of presumptive cervical midline epidural septum.

Adult↗

PubMed1984

Transient kinetic studies of fatty acid synthetase. A kinetic self-editing mechanism for the loading of acetyl and malonyl residues and the role of coenzyme A.

A kinetic self-editing mechanism for correcting errors in the loading of thioester substrates is described for the animal fatty acid synthetase reaction. In the catalyzed reaction, these substrates load competitively on a common phosphopantetheine site, and during each of the eight loading steps the enzyme sites are partitioned between competent and incompetent substrate molecules. The incompetently bound substrate is removed by CoA through reversal of the loading reaction and partitioning again occurs. The loading-unloading cycle is repeated until competent enzyme complex is formed and the reaction proceeds. Furthermore, at each step the loading of a malonyl residue is competitively favored as is the unloading of enzyme-bound acetyl groups. This mechanism is entirely consistent with the recently postulated role (Stern, A., Sedgwick, B., and Smith, S. J. Biol. Chem. (1982) 257, 799-803) of CoA as a co-substrate. Supporting evidence is obtained by monitoring the progress curves of NADPH oxidation by chicken liver fatty acid synthetase in the stopped flow apparatus. At noninhibiting acetyl-CoA, the reaction shows an initial lag period as the result of preferential formation of malonyl-enzyme and time-dependent recycling of the loading step to obtain competent acetyl-enzyme. At a malonyl-CoA/acetyl-CoA ratio of 2:1, the induction time of the reaction is 1.02 +/- 0.05 s at 6 degrees C. It decreases with increasing acetyl-CoA concentration or preincubation of the enzyme with acetyl-CoA which promotes acetyl-enzyme formation but is slightly increased upon preincubation with malonyl-CoA. Increasing acetyl-CoA causes a parallel decrease in steady state cycle time (i.e. the average time required to complete a single malonyl-CoA condensation cycle), suggesting that the latter is limited by the lag period. At inhibitory acetyl-CoA, the steady state cycle time is lengthened due to acetyl-enzyme formation at malonyl-CoA loading steps and to the recycling necessary to obtain competent malonyl-enzyme. A requirement of CoA for the first condensation cycle is unequivocally demonstrated in conventional spectrophometric assays and stopped flow experiments by using phosphotransacetylase and acetyl phosphate as a CoA trap. This requirement at each loading step is normally met by CoA generated through initial loading. At noninhibitory acetyl-CoA, added CoA inhibits the reaction and slightly increases the lag.(ABSTRACT TRUNCATED AT 400 WORDS)

Acetyl Coenzyme A↗

PubMedDate not supplied

The anesthesiologist's guide to Palm Computing.

Handheld personal computers (HPCs) are permeating the clinical and personal lives of anesthesia care providers. Common characteristics include low cost, portability, easy PC data sharing, and applications such as a calendar, phone directory, memo pad, and a task list. Additional software includes databases for case logs, medication lists, task organizers, and document readers. This article discusses the Palm brand HPC (Palm Computing, A 3Com Company, Santa Clara, CA) including purchasing tips, common uses, backing up information, security concerns, and information resources on the Internet including websites providing free trial software.

Anesthesiology↗

PubMedDate not supplied

An introduction to the World Wide Web.

BACKGROUND AND OBJECTIVES: Anesthesiologists are increasingly utilizing the Internet for personal and professional purposes. Without guidance, the task of searching the Internet for information may be time-consuming and frustrating. This article includes a basic introduction to the Internet with suggestions and guidelines for accessing information resources. Future articles will address locating articles about human anatomy, regional anesthesia and pain medicine. EDITORS NOTE: This is the first in an informal series of articles demonstrating and describing information technology. The articles will include nontechnical information and will detail the experiences and wisdom obtained from experienced anesthesiologists. The series is geared toward the computer novice with interest in regional anesthesia and pain medicine. These articles are also available in full text on the American Society of Regional Anesthesia website (www.asra.com) with links to the websites in the article.

Anesthesia, Conduction↗