Biomedical subjects
Publications and source records attributed to C Sutton.
This study suggests that appendicectomy should be routinely performed at laparoscopy for suspected acute appendicitis and that this can be achieved with minimal morbidity.
Acquiring laparoscopic surgical skills involves initial learning of cognitive and motor skills followed by refinement of those skills. The successful use of a virtual reality simulator depends on the quality of the interface for the human-computer interaction and this can be determined by the initial learning rate. MIST VR, a part-task virtual reality laparoscopic simulator, provides objective assessment of psychomotor skills and can generate an overall score for performance, based upon errors made and time taken for six different tasks. This study analysed the rate of early task/instrument/computer familiarization on consecutive scores achieved by surgically experienced and naive individuals. Eleven surgeons, 18 medical students and seven non-medical personnel were tested on the simulator up to ten consecutive times, within a 2-week period. Performance data from every task and repetition were analysed to obtain individual scores of task performance. The calculation of overall score penalized errors far more heavily than total time taken, with high scores indicating poor performance. The surgeon-computer interface generated a rapid and significant early familiarization curve up to the third session on the simulator, with significant reductions in both time taken and total contact errors made. These results suggest that MIST VR represents a high quality interface. Surgeons scored consistently and significantly better than other subjects on all tasks. For surgically naive individuals, it was possible to predict the level of laparoscopic skills performance that would be attained after overcoming initial simulator learning curve, by studying their initial score. Overall scores reflected surgical experience and suggest that the simulator is measuring surgically relevant parameters. MIST VR provides a validated and much needed method for objective assessment of laparoscopic skills, for a variety of surgical disciplines.
The cerebellum has long been the subject of scientific investigation, but its role in nonmotor functions has only recently begun to receive serious consideration. Despite the growing literature linking the cerebellum to nonmotor/cognitive functions in humans, some controversy remains concerning the cerebellum's role in these processes. We present a patient who developed both specific language processing and verbal memory deficits and emotional changes in the context of normal intelligence following a bilateral cerebellar ischemic stroke. Despite having multiple localized cerebellar lesions, this patient had no significant motor problems, nor was there radiological evidence of focal forebrain lesions to which the cognitive and emotional effects might be attributed. The role of the cerebellum in cognition and the relevance of cerebellum-associated cognitive/emotional dysfunction to the practicing clinician are discussed.
An affinity chromatography strategy was used to search for proteins in A549 cells which interact with the N-terminus of lipocortin 1 (annexin 1). Using the biologically active fragment Lc13-25 as the affinity ligand, two proteins of molecular weight (m.w.) 52 and 48kDa were extracted. Affinity blots of these proteins bound iodinated Lc13-25. Partial tryptic digests of these proteins were analysed by matrix assisted laser desorption mass spectrometry and found to display fragmentation patterns with a strong similarity to those of cytokeratin 8 and 18 respectively. Subsequent blotting with a panel of specific cytokeratin antibodies strongly supported the idea that the two proteins were cytokeratin 8 and cytokeratin 18. Cytokeratin 8 was isolated from A549 cells in intermediate filament (IF) preparations which were also found to contain lipocortin 1 as a potential intermediate filament associated protein (IFAP). This association persisted throughout cycles of IF assembly and disassembly. Dual-labelling immuno-histochemistry in A549 cells showed strong co-localization of lipocortin 1 and cytokeratin 8. The implications of this finding are discussed in the light of the biological activity and possible function of lipocortin 1.
OBJECTIVE: To evaluate the benefits of a policy of performing screening blood tests in new patients with arterial disease referred to the vascular outpatients department. METHODS: Clinical audit over a 12-month period of all new referrals with arterial disease to the vascular outpatients department at the Leicester General Hospital. RESULTS: Two hundred and seventy-two patients had at least one blood test performed at their outpatient visit. All of these patients had a full blood count performed, of which 21 results (21%) were abnormal. Further investigation of patients with abnormal results revealed one case of bladder cancer, one case of leukaemia and one patient with polycythaemia. Urea and electrolytes were measured in 269 patients (99%). Of these, 26 (10%) were expectedly abnormal in patients with known renal impairment. A further 27 patients (10%) were identified to have some degree of unrecognised renal impairment. Serum non-fasting glucose was measured in 252 patients (93%). There were 11 unexpectedly raised results, but further investigation of these patients only diagnosed one of these patients as diabetic. Serum cholesterol was measured in 201 patients (74%). One hundred and thirty-two patients (66%) had an abnormally raised serum cholesterol level. Of these, only 12 patients (6%) were known to have hyperlipidaemia. CONCLUSIONS: Screening new patients with arterial disease in vascular outpatients does identify significant abnormalities, in particular renal impairment and hyperlipidaemia. Correction of these abnormalities may reduce the morbidity associated with contrast induced nephrotoxic acute renal failure, and also contribute to secondary prevention of vascular events associated with raised lipids.
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This review article has focussed on identifying the evidence from randomized controlled trials for the medical and surgical management of endometriosis. A critical summary of the medical management has shown that there is little difference in effectiveness of various medical treatments, but there are differences in the side-effect profiles. Few randomized controlled trials have been undertaken in surgery, but these have shown that surgical management is effective in the management of both painful symptoms and subfertility.
Objective assessment of surgical technique is currently impossible. A virtual reality simulator for laparoscopic surgery (MIST VR) models the movements needed to perform minimally invasive surgery and can generate a score for various aspects of psychomotor skill. Two studies were performed using the simulator: first to assess surgeons of different surgical experience to validate the scoring system; second to assess in a randomised controlled way, the effect of a standard laparoscopic surgery training course. Experienced surgeons (> 100 laparoscopic cholecystectomies) were significantly more efficient, made less correctional submovements and completed the virtual reality tasks faster than trainee surgeons or non-surgeons. The training course caused an improvement in efficiency and a reduction in errors, without a significant increase in speed when compared with the control group. The MIST VR simulator can objectively assess a number of desirable qualities in laparoscopic surgery, and can distinguish between experienced and novice surgeons. We have also quantified the beneficial effect of a structured training course on psychomotor skill acquisition.
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In the relatively long history of man, surgery has been a comparatively recent development; the abdomen was first deliberately opened to remove an ovarian cyst by Ephraim McDowell in Kentucky in 1809. The first abdominal hysterectomy was performed by Charles Clay in Manchester, England in 1843; unfortunately the diagnosis was wrong and the patient died in the immediate post-operative period. The following year, Charles Clay was almost the first to claim a surviving patient, however she died post-operatively and it was not until 1853 that Ellis Burnham from Lowell, Massachusetts achieved the first successful abdominal hysterectomy although again the diagnosis was wrong. Vaginal hysterectomy dates back to ancient times. The procedure was performed by Soranus of Ephesus 120 years after the birth of Christ, and the many reports of its use in the middle ages were nearly always for the extirpation of an inverted uterus and the patients rarely survived. The early hysterectomies were fraught with hazard and the patients usually died of haemorrhage, peritonitis, and exhaustion. Early procedures were performed without anaesthesia with a mortality of about 70%, mainly due to sepsis from leaving a long ligature to encourage the drainage of pus. Thomas Keith from Scotland realized the danger of this practice and merely cauterized the cervical stump and allowed it to fall internally, thereby bringing the mortality down to about 8%. Hysterectomy became safer with the introduction of anaesthesia, antibiotics and antisepsis, blood transfusions and intravenous therapy. During the 1930s, Richardson introduced the total abdominal hysterectomy to avoid serosanguineous discharge from the cervical remnant and the risk of cervical carcinoma developing in the stump. Apart from this innovation, and the transverse incision introduced by Johanns Pfannenstiel in the 1920s, there was little advance in hysterectomy techniques until the advent of endoscopic surgery and the performance of the first laparoscopic hysterectomy by Harry Reich in Kingston, Pennsylvania in 1988. The refinement and increasing safety of laparoscopic hysterectomy suggests that it will be used increasingly in the future, although developments in pharmacology and photodynamic therapy and interventional radiology may reduce the traditional indications for the operation.
OBJECTIVE: To assess the long-term outcome of patients who had an artificial urinary sphincter (AUS) implanted between 10 and 15 years ago. PATIENTS AND METHODS: Of 68 patients who had an AUS implanted more than 10 years ago, 61 were followed with sufficient detail for analysis. Thirty-four had a neuropathic bladder with sphincter dysfunction, 15 had post-prostatectomy sphincter weakness incontinence and 12 further patients had a variety of indications. RESULTS: The 61 patients experienced a total of 58 major complications and 49 have required at least one revision procedure. Currently eight (13%) patients are satisfactorily continent with their original AUS in situ and 29 others have a satisfactory revised AUS. Thus 37 of 61 (61%) are continent using an AUS at least 10 years after first implantation. Eleven patients died and of these two had a satisfactory original AUS in situ and seven had successful revisions. In two patients the AUS failed but they were considered unfit for revision. Four female patients were continent and used intermittent catheterization after the explantation of eroded AUS cuffs. In seven patients the AUS was abandoned; two of these patients reverted to condom drainage and five had continent or incontinent urinary diversions fashioned. Thus, if those who died with a functioning AUS are included, 46 of 61 (75%) achieved long-term continence with the AUS. CONCLUSIONS: Despite the high complication and revision rate, these results show that acceptable continence rates can be achieved in the long-term, particularly in the male neuropathic bladder and in those with post-prostatectomy sphincter weakness. Many of the complications encountered may be less common with the current re-designed models of the AUS. However, it is essential that both surgeon and patient recognize and accept the likelihood of complications and revisions before using the AUS. The continued use of the AUS where simpler methods of obtaining continence are inappropriate remains justified.
The key bimanual instrument tasks involved in laparoscopic surgery have been abstracted for use in a virtual reality surgical skills evaluator and trainer. The trainer uses two laparoscopic instruments mounted on a frame with position sensors which provide instrument movement data that is translated into interactive real time graphics on a PC (P133, 16 Mb RAM, graphics acceleration card). An accurately scaled operating volume of 10 cm3 is represented by a 3D cube on the computer screen. "Camera" position and size of target objects can be varied for different skill levels. Targets appear randomly within the operating volume according to the skill task and can be grasped and manipulated with the instruments. Accuracy and errors during the tasks and time to completion are logged. Mist VR has tutorial, training, examination, analysis and configuration modes. Six tasks have been selected and include combinations of instrument approach, target acquisition, target manipulation and placement, transfer between instruments, target contact with optional diathermy, and controlled instrument withdrawal/replacement. Tasks can be configured for varying degrees of difficulty and the configurations saved to a library for reuse. Specific task configurations can be assigned to individual students. In the examination mode the supervisor can select the tasks, repetitions and order and save to a specific file for that trainee. Progress can be assessed and there is the option for playback of the training session or examination. Data analyses permit overall, including task, and right or left hand performances to be quantified. Mist VR represents a significant advance over the subjective assessment of training performances with existing "plastic box" basic trainers.
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The VestaBlate system uses a multielectrode intrauterine balloon as a device to create effective and safe endometrial ablation (EA). The surface of the distensible balloon is impregnated with thermistors and thin, platelike electrodes. It is designed to deliver low-power electroenergy to the endometrium. Unlike the resectoscope techniques that require nonelectrolytic fluids for uterine distention, moving electrodes at high power outputs, and other variables that are operator dependent, the VestaBlate is computer controlled using a standard type electrosurgical generator. A respiratory enzyme stain, nitroblue tetrazoleum, was used to determine the extent and depth of tissue necrosis to a myometrial depth of 2 to 4 mm with uniform destruction of tissue with power setting at 45 W for a 4-minute application of energy. Sixty-nine patients have been treated, with 45 followed for at least 3 to 9 months. The amenorrhea rate is 40%; the oligomenorhea-hypomenorrhea rate is 49%.
Trp repressor (TrpR) can be converted into a site-specific nuclease by chemical modification of the cysteine mutants TrpR D46C or TrpR E49C with 5-iodoacetamido-1,10-phenanthroline (OP). In the presence of cupric ion and 3-mercaptopropionic acid, TrpR-regulated operators are cleaved. The properties of these semisynthetic scission reagents have been compared. The E49C construct cleaves efficiently at two sites within the operator and the D46C cleaves at multiple sites. Molecular modeling indicates that the reason for the focused reactivity of E49C is that the OP is rigidly oriented in the protein-DNA complexes whereas the OP can adopt several orientations in TrpR D46C. Mutations and reaction conditions that increase the affinity of the repressor enhance the scission efficiency which approaches 100% within the acrylamide matrix. TrpR E49C-OP smoothly cleaves the trpEDCBA operator in a plasmid in a reaction dependent on the corepressor L-tryptophan. In the absence of tryptophan, non-specific cleavage of the plasmid is observed under the same conditions. Therefore, tryptophan not only directs cleavage to a specific site but also blocks it at non-specific sites. The analysis of the cleavage pattern of the trpEDCBA operator provides strong evidence for the tandem binding model in which protein-protein interactions stabilize binding on the DNA. TrpR E49C-OP should serve as the basis for the engineering of a family of highly specific semisynthetic scission reagents.
We have assessed the specificity of antibodies from the leukemic B cells of five patients with both chronic lymphocytic leukemia and autoimmune hemolytic anemia (CLL-AHA). Leukemic cells from one patient displayed surface immunoglobulin with heavy and light chain isotypes identical to that of the patient's anti-red blood cell (RBC) antibodies, and the leukemic cells secreted antibodies in vitro with anti-RBC activity. However, in the remaining patients, the leukemic cells displayed surface immunoglobulin with light chain isotypes different from that of the patient's anti-RBC antibodies and secreted antibodies in vitro with no detectable anti-RBC activity. Thus, there are two distinct classes of CLL-AHA patients, differentiated by the presence or absence of an anti-RBC antibody-producing leukemic B cell clone. The apparent heterogeneity in the source of pathogenic anti-RBC antibodies may impact the treatment response of the two classes of CLL-AHA patients.
The power sources used in endoscopic surgery are varied and numerous, and will continue to improve as technology progresses. Early attempts at operative laparoscopy were crude, limited by the available instrumentation, and tended to be frustrating: scissors that had to be frequently sharpened and endocoagulators that took a seemingly interminable time to achieve their tissue effect. New developements in ultrasonic energy and different wavelengths of laser energy are used alongside increasingly sophisticated electrosurgical tools, employing both monopolar and bipolar systems, and innovative delivery systems such as the argon beam coagulator and the Helica Thermal Coagulator. All of these systems have their advocates and their detractors, but in the end the choice of power source is determined by the type of equipment that the operator feels most comfortable with. The surgeon must have a detailed knowledge of the physical concepts required to generate the power source, and be able to understand the complications that can be created by the energy, how to avoid them, how and to deal with them if they occur. Although there are subtle differences in the reaction of the different energy sources with human tissue, the clinical outcome appears to be much the same, and depends more on the skill of the individual surgeon than the power source employed.
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