Re-use of equipment between patients receiving total intravenous anaesthesia.
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Anesthesia, Intravenous↗
Biomedical subjects
R L Marshall
Publications and source records attributed to R L Marshall.
Are surgery training programs ready for virtual reality? A survey of program directors in general surgery.
BACKGROUND: The use of advanced technology, such as virtual environments and computer-based simulators (VR/CBS), in training has been well established by both industry and the military. In contrast the medical profession, including surgery, has been slow to incorporate such technology in its training. In an attempt to identify factors limiting the regular incorporation of this technology into surgical training programs, a survey was developed and distributed to all general surgery program directors in the United States. STUDY DESIGN: A 22-question survey was sent to 254 general surgery program directors. The survey was designed to reflect attitudes of the program directors regarding the use of computer-based simulation in surgical training. Questions were scaled from 1 to 5 with 1 = strongly disagree and 5 = strongly agree. RESULTS: A total of 139 responses (55%) were returned. The majority of respondents (58%) had seen VR/CBS, but only 19% had "hands-on" experience with these systems. Respondents strongly agreed that there is a need for learning opportunities outside of the operating room and a role for VR/CBS in surgical training. Respondents believed both staff and residents would support this type of training. Concerns included VR/CBS' lack of validation and potential requirements for frequent system upgrades. CONCLUSIONS: Virtual environments and computer-based simulators, although well established training tools in other fields, have not been widely incorporated into surgical education. Our results suggest that program directors believe this type of technology would be beneficial in surgical education, but they lack adequate information regarding VR/CBS. Developers of this technology may need to focus on educating potential users and addressing their concerns.
Clinical Competence↗
Use of a human patient simulator in the development of resident trauma management skills.
BACKGROUND: Computerized human patient simulators (HPSs) have been used to improve diagnostic and therapeutic decision making. The goal of this study was to investigate the impact of HPSs and Advanced Trauma Life Support (ATLS) on the development of trauma management skills and self-confidence in surgical interns. METHODS: Three teams of interns completed two ATLS-like trauma scenarios on the HPS (pre-ATLS). They then took the ATLS provider course. After ATLS, the interns were evaluated on two different HPS trauma scenarios (post-ATLS). Two teams of senior residents, experienced in trauma care, completed the same HPS scenarios and were used as controls. Trauma management skills were scored in three areas--critical treatment decisions, potential for adverse outcomes, and team behavior--by staff trauma surgeons. After participating in the HPS trauma scenarios, the interns completed self-confidence questionnaires and a course evaluation survey. RESULTS: Trauma management skill scores increased 23% in critical treatment decisions, 25% in potential for adverse outcomes, and 47% in team behavior after ATLS/HPS (p < 0.002). Senior residents' performance on HPS trauma scenarios was better than the interns (p < 0.05) in all three areas evaluated. The interns' self-confidence scores rose significantly after the course. (p < 0.01) The HPS course evaluation survey averaged 8.3 out of a maximum 10. CONCLUSION: Use of HPSs in conjunction with ATLS appears to enhance the development of trauma management skills. The surgical interns participating in the study deemed the HPS to be a worthwhile experience and a confidence-building tool. In particular, trauma team behavior improved significantly after ATLS/HPS.
Clinical Competence↗
Solution-phase combinatorial synthesis and evaluation of piperazine-2,5-dione derivatives.
An efficient one-pot synthesis of a 61-membered combinatorial chemistry library of piperazine-2,5-diones was accomplished. Results of combinatorial synthesis, purification, analysis, and biological evaluation are described.
Animals↗
Practical training for postgraduate year 1 surgery residents.
BACKGROUND: Surgical interns accept significant patient care responsibilities with minimal orientation. We have developed a multifaceted training program for incoming surgical interns in which learning in a simulated environment plays a key role. The purpose of this study was to evaluate resident perceptions of simulated clinical calls as an educational modality and to measure the effect on self-ratings of confidence. METHODS: A multidisciplinary team compiled 15 clinical scenarios. Simulated nurse-to-resident clinical call sessions were held on 3 separate days. Daily course evaluation surveys and identical precourse and postcourse confidence surveys were completed. RESULTS: The resident confidence measure increased significantly postcourse (6.73 versus 8.35, P <0.03). The evaluation survey score averaged 4.35 out of 5. CONCLUSIONS: Simulated clinical call sessions were well received and resulted in a significant increase in resident confidence levels. Based on this modality's apparent efficacy and ease of implementation, we offer it as a useful educational tool for incoming postgraduate year-1 surgical residents.
Attitude of Health Personnel↗
End user analysis of a force feedback virtual reality based surgical simulator.
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Biomechanical Phenomena↗
Detection of GB virus C by the RT-PCR LCx system.
The recent publication of representative genomic sequences of GBV-C has permitted the selection of PCR primers for detection of GBV-C in clinical samples by PCR techniques. Traditional amplification methodologies which couple reverse transcription polymerase chain reaction (RT-PCR) and Southern blot detection are slow, cumbersome, and can be technique dependent. This has hampered studies to determine the clinical significance of GBV-C. We report the selection of highly conserved PCR primers and a probe useful for semi-automated RT-PCR using the Abbott LCx system. This adaptation of the LCx system expands its capabilities to include the detection of RNA by RT-PCR, in addition to DNA detection by ligase chain reaction (LCR).
Automation↗
Comparison of the effect of two dose schedules of oral omeprazole with oral ranitidine on gastric aspirate pH and volume in patients undergoing elective surgery.
We have compared gastric aspirate pH and volume at induction of anaesthesia in 222 patients who had received either omeprazole or ranitidine before elective operations. Omeprazole was given orally either as 40 mg on the evening before and 40 mg on the morning of surgery or as 80 mg on the morning of surgery. Ranitidine 150 mg was given orally on the evening before surgery and 2 h before anaesthesia. Treatment success was defined as aspirate pH > or = 2.5 and volume < 25 ml at induction of anaesthesia. Treatment was successful in 84% (95% confidence interval (CI) 73-91%) of patients in the omeprazole 40 + 40 mg group, 84% (95% CI 73-91%) in the ranitidine group and 73% (95% CI 61-83%) in the omeprazole 80 mg group. There were no statistically significant differences between the groups. Twelve patients in the omeprazole 80 mg group had gastric pH < 2.5 and four had volume > 25 ml. Only three patients had a gastric pH < 2.5 in the omeprazole 40 + 40 mg group and none had volume > 25 ml, which compared well with the ranitidine group. Omeprazole, given as 40 mg in the evening and 40 mg on the morning of operation, has a potential role for use in patients at risk for aspiration during general anaesthesia.
Adolescent↗
Effect of use of vasopressors in organ donors on immediate function of renal allografts.
The purpose of this study was to determine whether use of vasopressors in cadaveric donors of renal transplants was associated with an increased prevalence of acute tubular necrosis after kidney transplantation. We compared immediate allograft function in 26 consecutive renal allograft recipients whose donors had been given vasopressors with that in 26 recipients whose donors had nor. The donors treated with vasopressors had been given more than 10 micrograms/kg per minute of dopamine, norepinephrine, or epinephrine, alone or in combination. The groups were matched with respect to donors' age, recipients' disease, and cold ischemic time. The prevalence of immediate allograft function was significantly lower in recipients whose donors had required use of vasopressors (38.5%) than in recipients whose donors had not required vasopressors (65.4%). We conclude that use of vasopressors in kidney donors leads to an increased prevalence of acute tubular necrosis.
Adolescent↗
In situ expression of platelet-derived growth factor (PDGF-beta) during chronic rejection is abolished by retransplantation.
We have shown that Fischer 344-->Lewis renal allografts (ALLO) develop chronic rejection which is not detected in Lewis-->Lewis isografts (ISO). The progression of chronic rejection in ALLO can be reversed by retransplantation (RE-TX) of kidneys from ALLO back into syngeneic Fischer 344 recipients. The purpose of this study was to assess the in situ expression of PDGF-beta, a cytokine associated with wound injury, in ISO, ALLO, and RE-TX. In situ PDGF-beta mRNA expression in kidney sections was assessed early (8 weeks) and late (16 weeks) during the development of chronic rejection. Kidneys from ALLO were transplanted back into syngeneic Fischer recipients at 12 weeks and evaluated for PDGF-beta expression 12 weeks later. Differences in glomerular staining were graded quantitatively on a minimum of 25 glomeruli per section with grade 0, no positive cells in the glomerulus; grade 1, 1 or 2 positive cells; grade 2, 3 or more positive cells in a segmental distribution; and grade 3, > 4 positive cells of moderate intensity in a diffuse distribution. According to this grading system, glomerular PDGF-beta mRNA expression in isografts (N = 6) at 8 and 16 weeks after transplantation was 0.09 +/- 0.03 and 0.2 +/- 0.04, respectively. In allografts (N = 6), PDGF-beta mRNA was significantly higher (P < .001) for the same time periods, 1.28 +/- 0.6 and 1.89 +/- 0.08, respectively. In situ expression of PDGF in retransplants (N = 6) at 24 weeks, 0.07 +/- 0.02, was significantly diminished (P < .001) at 24 weeks compared to allografts at 8 or 16 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Detection of HCV RNA by the asymmetric gap ligase chain reaction.
The ligase chain reaction (LCR) and the gap ligase chain reaction (gLCR) are exponential amplification techniques for the detection of DNA sequences in a sample. Both techniques depend on the enzyme, DNA ligase, to join adjacent probes annealed to a DNA molecule. However, DNA ligase joins DNA inefficiency on an RNA target. Consequently, LCR and gLCR cannot amplify RNA efficiency. RNA detection methods using LCR or gLCR require a cDNA synthesis step. The carryover of four dNTPs from the cDNA reaction inhibits gLCR. Although LCR can use cDNA reaction products directly, background generated by blunt-end ligation does not allow the high sensitivity typically needed for HIV or HCV detection. The asymmetric gap ligase chain reaction (AGLCR) is a modification of gLCR that allows for the detection of RNA by using < or = 3 of the 4 nucleotides in the cDNA step and the gLCR step. Fewer than 50 copies of synthetic RNA transcript can be reproducibly detected. HCV, an RNA virus with no DNA intermediate, was chosen as the initial RNA model system. HCV antibody-positive and normal samples were analyzed, and the results were found to correlate with the results obtained using nested RNA-PCR. AGLCR provides a new nucleic acid amplification technique that can aid in the diagnosis of disease when the detection of RNA is critical.
Base Sequence↗
The ligase chain reaction in DNA-based diagnosis.
Clinical specimens containing a suspected pathogen often have too little of the pathogen's DNA to be detected directly. It is generally necessary to first amplify the DNA and then to detect the amplification products. An amplification technique called the ligase chain reaction (LCR) is described, which in conjunction with an automated, nonradioactive readout format allows less than 10 molecules of target DNA to be detected. A prototype HIV assay and two prototype Chlamydia assays have sensitivities and specificities equivalent to PCR.
Chlamydia trachomatis↗
Venous gas embolism during gynaecological laparoscopy.
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Adult↗
Effects of formalin inactivation on bovine herpes virus-1 glycoproteins and antibody response elicited by formalin-inactivated vaccines in rabbits.
The possibility of using a radioimmune assay (RIA) to measure the retention of antigenic determinants on gI, gIII, and gIV, the three major bovine herpes virus 1 (BHV-1) glycoproteins, during the formalin inactivation and aluminium hydroxide adsorption commonly used in the manufacture of killed virus vaccines was investigated. Monoclonal antibodies were used to measure thirteen previously identified glycoprotein epitopes in experimental vaccines containing live BHV-1 or formalin-killed BHV-1 and a commercial formalin-inactivated BHV-1 vaccine. All four epitopes on gI lost 80-97% of their ability to bind monoclonal antibodies. Two of five epitopes on gIII were preserved but the other three epitopes on gIII and five on gIV were reduced as much as 88%. To show that the measured loss of epitopes was biologically relevant, the vaccines were administered to rabbits and the resulting antibody responses against the same epitopes were evaluated by competition RIA. Little correlation was found between the measured antigenic site destruction and the rabbit response against those antigenic sites, suggesting that monoclonal antibody reactivity of a formalin-inactivated vaccine could not provide a meaningful measure of antigenic activity.
Aluminum Hydroxide↗
Monoclonal antibody analysis of bovine herpesvirus-1 glycoprotein antigenic areas relevant to natural infection.
Neutralizing antigenic areas on the glycoproteins of bovine herpesvirus-1 (BHV-1) were identified by reciprocal competition radioimmunoassays using monoclonal antibodies. Three interrelated and two independent antigenic areas were identified on the 77-kDa (K) gIV envelope glycoprotein. Antigenic analysis of this protein has not been previously described. Four interrelated and one independent antigenic areas were found on the 97K gIII envelope glycoprotein. A third group of monoclonal antibodies reacting in Western blot with the 74K subunit of gI, a 130K disulfide-linked 74K/55K heterodimer, revealed four interrelated antigenic areas. All of the antigenic areas on all three glycoproteins were reactive with neutralizing monoclonal antibodies and all were targets for antibody-complement lysis. However, antibodies against gIV were the most efficient at neutralizing the virus and rendering infected cells susceptible to antibody-complement lysis. Convalescent sera from experimentally infected calves were used in a competitive radioimmunoassay to confirm that each antigenic area on the gI, gIII, or gIV glycoproteins was a target for bovine antibodies during primary infection with BHV-1.
Animals↗
Passively administered neutralizing monoclonal antibodies do not protect calves against bovine herpesvirus 1 infection.
Monoclonal antibodies specific for defined epitopes on the gI, gIII and gIV envelope glycoproteins of BHV-1 were used individually or in glycoprotein-monospecific pools for passive immunization of young calves. Although serum antibody titres comparable to those found in naturally infected and recovered calves were achieved, passive immunization failed to prevent the growth of BHV-1 in nasal and ocular mucosa and did not decrease the duration of viral shedding.
Animals↗
Epitope specificity and protective efficacy of the bovine immune response to bovine herpesvirus-1 glycoprotein vaccines.
Bovine herpesvirus-1 (BHV-1) envelope glycoproteins gI, gIII and gIV were individually purified on monoclonal antibody affinity columns and injected intradermally into BHV-1 seronegative calves. The calves developed serum neutralizing antibodies that monospecifically precipitated the immunizing glycoprotein from a preparation of 125I-labelled BHV-1 envelope proteins. A competitive radioimmunoassay using the bovine antisera demonstrated that known functional epitopes had been retained in the glycoprotein vaccines. Calves immunized with the gI, gIII or gIV glycoproteins were not protected from intranasal challenge with BHV-1 and had levels and duration of viral shedding in their nasal secretions similar to those of non-immunized control calves.
Animals↗
Characterization of envelope proteins of infectious bovine rhinotracheitis virus (bovine herpesvirus 1) by biochemical and immunological methods.
Ten glycoproteins of molecular weights of 180,000, 150,000, 130,000, 115,000, 97,000, 77,000, 74,000, 64,000, 55,000, and 45,000 (designated as 180K, 150K, etc.) and a single nonglycosylated 107,000-molecular-weight (107K) protein were quantitatively removed from purified bovine herpesvirus 1 (BHV-1) virions by detergent treatment. Immunoprecipitations with monospecific and monoclonal antibodies showed that three sets of coprecipitating glycoproteins, 180K/97K, 150K/77K, and 130K/74K/55K, were the major components of the BHV-1 envelope. These glycoproteins were present in the envelope of the virion and on the surface of BHV-1-infected cells and reacted with neutralizing monoclonal and monospecific antibodies. Antibodies to 150K/77K protein had the largest proportion of virus-neutralizing antibodies, followed by antibodies to 180K/97K protein. Monoclonal antibodies to 130K/74K/55K protein were neutralizing but only in the presence of complement; however, monospecific antisera produced with 55K protein did not have neutralizing activity. Analysis under nonreducing conditions showed that the 74K and 55K proteins interact through disulfide bonds to form the 130K molecule. Partial proteolysis studies showed that the 180K protein was a dimeric form of the 97K protein and that the 150K protein was a dimer of the 77K protein, but these dimers were not linked by disulfide bonds. The 107K protein was not glycosylated and induced antibodies that did not neutralize BHV-1. The 64K protein was not precipitated by anti-BHV-1 convalescent antisera, and monospecific antisera to this protein precipitated several polypeptides from uninfected cell lysates, suggesting that 64K is a protein of cellular origin associated with the BHV-1 virion envelope.
Animals↗