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Biomedical subjects

H Ellis

Publications and source records attributed to H Ellis.

At least 19 recordsLinked to original sources

Incidence of cardiovascular disease in the dissecting room: a valuable teaching asset.

The purpose of this study was to determine the incidence of cardiovascular pathology in 50 cadavers in the dissecting room of the Department of Anatomy at Guy's Campus, King's College, London, and to demonstrate the importance of dissection in teaching the anatomy of normal and pathological hearts. After external evaluation of each heart the four chambers were dissected and studied. The features noted included evidence of coronary atherosclerosis, myocardial infarction, variations in coronary artery anatomy, valvular disease, variations in left ventricular wall thickness and atrial dimensions, and atrial anomalies. All the hearts studied had at least one pathology. The majority had severe coronary atherosclerosis (44) and aortic valve pathology (23). A large number had left ventricular hypertrophy (13) and left atrial enlargement (9). A small number showed evidence of myocardial infarction (4). Anatomical anomalies were also found, and included persistent foramen ovale (1), three coronary arterial ostia (3), and anatomical variations of the orientation of the main stem of the left coronary artery (2). This study demonstrates that dissection is not only an excellent way of studying normal cardiac anatomy, but also a valuable method for introducing common cardiac pathologies to the medical student.

Anatomy↗

Medical student participation in surface anatomy classes.

Surface anatomy is an integral part of medical education and enables medical students to learn skills for future medical practice. In the past decade, there has been a decline in the teaching of anatomy in the medical curriculum, and this study seeks to assess the attitudes of medical students to participation in surface anatomy classes. Consequently, all first year medical students at the Guy's, King's and St Thomas's Medical School, London, were asked to fill in an anonymous questionnaire at the end of their last surface anatomy session of the year. A total of 290 medical students completed the questionnaires, resulting in an 81.6% response rate. The students had a mean age of 19.6 years (range 18-32) and 104 (35.9%) of them were male. Seventy-six students (26.2%) were subjects in surface anatomy tutorials (60.5% male). Students generally volunteered because no one else did. Of the volunteers, 38.2% would rather not have been subjects, because of embarrassment, inability to make notes, or to see clearly the material being taught. Female medical students from ethnic minority groups were especially reluctant to volunteer to be subjects. Single-sex classes improved the volunteer rate to some extent, but not dramatically. Students appreciate the importance of surface anatomy to cadaveric study and to future clinical practice. Computer models, lectures, and videos are complementary but cannot be a substitute for peer group models, artists' models being the only alternative.

Adolescent↗

Variations in the surface anatomy of the spinal accessory nerve in the posterior triangle.

Iatrogenic injury to the spinal accessory nerve has been widely documented and can have medico-legal implications. The resulting syndrome of pain, paralysis and winging of the scapula are often the source of considerable morbidity. This paper researches the degree of accuracy achievable in mapping the surface anatomy of the spinal accessory nerve in the region of the posterior triangle with a view to creating a cartographical aid to surgical procedures. The necks of 25 adult cadavers were dissected bilaterally to expose the spinal accessory nerve. Variations in the course and distribution of the spinal accessory nerve in the posterior triangle were recorded along with its relationship to the borders of sternocleidomastoid and trapezius. Considerable variation was seen in the surface and regional anatomy of the nerve and in the contribution of the cervical plexus to the spinal accessory nerve in the posterior triangle. Measurements of the running course and exit point of the nerve into and from the posterior triangle differed significantly from those previously recorded. Delineation of an accurate surface anatomy was not possible. Creating a map to define the surface anatomy of the spinal accessory nerve in the posterior triangle is an unrealistic goal given its wide variations in man. Avoidance of damage to the spinal accessory nerve cannot be achieved by slavishly adhering to surface markings given in textbooks, but only by cautious dissection during operations on the posterior triangle.

Accessory Nerve↗

Distribution of fluid within the peritoneal cavity: a cadaveric study.

This study assesses the distribution of varying volumes of fluid within the peritoneal cavity of cadavers of different sizes (small < or =60 kg; medium = 60-100 kg; large > or =100 kg). The results help to predict the volumes of therapeutic solutions (e.g., adhesiolysis solutions used in the prevention of post-operative adhesion formation) that would be required to reach all the relevant spaces within the greater sac of the peritoneal cavity. Twenty-one cadavers (9 male, 12 female) were selected randomly. Midline laparotomy and bilateral subcostal incisions were made to visualize the distribution of 500 ml of water into the pelvic cavity, paracolic gutters, right subhepatic, and subphrenic spaces. A further 500 ml of water was then added and the distribution was again recorded. The results showed that 500 ml of water was found to distribute to all areas in 47.8% of cadavers, and 1,000 ml distributed to all areas in 81.0% of cadavers. One hundred percent of small cadavers achieved maximum distribution with 500 ml irrespective of gender. Seventy percent of medium cadavers achieved maximum distribution with 1,000 ml, and 75% of large cadavers achieved maximum distribution with 1,000 ml. Anatomical variation in the size of the phrenicocolic ligament was found to be an important limiting factor in the distribution of fluid to the space inferior to the left lobe of the liver and the left subphrenic space. Pre-existing intra-abdominal pathology and previous abdominal surgery also influenced the distribution of fluid within the peritoneal cavity.

Aged↗

Stability of premixed syringes of diamorphine and hyperbaric bupivacaine.

BACKGROUND: It is common clinical practice to add diamorphine to heavy bupivacaine when performing spinal anaesthesia for either obstetric or general surgical procedures. If pre-filled syringes were available potential problems arising due to the wrong mixture being administered could be reduced, whilst also providing greater assurances of sterility and accuracy of dosage. It is therefore necessary to establish whether diamorphine 100 microg/mL is stable in solution with 0.5% hyperbaric bupivacaine, to allow production of pre-filled syringes for use in spinal anaesthesia. METHOD: Diamorphine hydrochloride was dissolved in water for injection, and added to hyperbaric bupivacaine then stored in 5-mL plastic syringes. Eleven syringes were stored at 40 degrees C/75% relative humidity, 25 degrees C/60% relative humidity and 7 degrees C for 90 days. Samples were taken at five time points for measurement of diamorphine and bupivacaine concentrations using high performance liquid chromatography. RESULTS: Diamorphine concentrations fell over the study period. No significant changes were observed the bupivacaine content of the samples. There was 10% degradation of diamorphine after 4 days at 40 degrees C, after 7 days at 25 degrees C, and after 26 days at 7 degrees C. CONCLUSION: Diamorphine is stable in hyperbaric bupivacaine at 7 degrees C for long enough to allow preparation of pre-filled syringes in advance (by hospital pharmacy aseptic units) for use in spinal anaesthesia.

Analgesics, Opioid↗

Retrograde migration of glove powder in the human female genital tract.

BACKGROUND: This study in humans was undertaken to evaluate earlier results from animal research showing a retrograde migration of glove powder from the vagina into the intra-abdominal cavity. METHODS: One study group was gynaecologically examined with powdered gloves the day before an abdominal hysterectomy and another group 4 days pre-operatively. There were two control groups similarly examined with powder-free gloves. Cell smears were taken from the peritoneal fluid and during the operation further smears were taken from the Fallopian tubes, uterine cavity and cervical canal. RESULTS: Statistically significant differences were found for large starch particles at all locations between the study and control groups examined 1 day pre-operatively. Considering small starch particles, there were significant differences in cervix (P < 0.001), uterus (P < 0.01) and the Fallopian tubes (P < 0.01). The combined results also show significant differences between both large and small starch particles in cervix, uterus and the Fallopian tubes. There were also differences between the study and control groups examined 4 days pre-operatively, but these were not statistically significant except for small and large starch particles in uterus (P < 0.01, P < 0.05) and cervix (P < 0.05, P < 0.05). CONCLUSIONS: This study has pointed out a retrograde migration of starch also in humans after a gynaecological examination with powdered gloves. Consequently, powder or any other potentially harmful substance that can migrate from the vagina should be avoided.

Biological Transport↗

Surface anatomy of the inferior epigastric artery in relation to laparoscopic injury.

The inferior epigastric artery (IEA) is at risk of injury in laparoscopic surgery. Current descriptions of the course of the IEA do not provide surface landmarks useful to the surgeon. This study aimed to define surface relations and propose guidelines for safer trocar placement. The posterior surfaces of the anterior abdominal walls of 30 preserved cadavers were dissected. The surface anatomy of 60 IEAs and their branches were defined. At the level of the anterior superior iliac spine (ASIS), the IEA is 38% +/- 18% (95% confidence interval [CI]) from the midline to the ASIS. At the mid-inguinal point the relation is 40% +/- 17% and at the umbilicus 40% +/- 22%. The pattern of branches is highly variable. Although giving guidelines for trocar insertion can be treacherous, we found the following to be of value: 1) the midline is avascular; 2) the main stem of the IEA will be avoided if trocars are inserted more than two-thirds of the distance along a horizontal line between the midline and the ASIS; and 3) IEA branches are least frequently found in the lowest part of the abdomen lateral to the artery.

Aged↗

Attitudes of medical and dental students to dissection.

Guy's, King's, and St. Thomas's School of Medicine encourages students to learn anatomy from human dissection. Today, there is a worldwide move of anatomy-based teaching away from dissection to prosection. This study investigates how attitudes toward dissection vary with gender and ethnicity. We assessed students' reactions and concerns regarding the dissecting room, any coping strategies they use to combat them, and analyzed effective methods of teaching anatomy to medical and dental students. Three questionnaires were distributed amongst 474 first-year medical and dental students before dissection and 1 week and 12 weeks after exposure to the dissecting room. Over the 3 months we found significant changes in the concerns of students about dissection. There were also significant differences (P < 0.05) between medical and dental students, males and females, and students of differing ethnic backgrounds, which persisted over 12 weeks. Both medical and dental students found tutorials and textbooks of most value in learning anatomy. Dental students found prosection more useful than medical students (P < 0.001) though neither group demonstrated a significant preference for prosection over dissection. Of concern, 7% reported recurring images of cadavers and 2% insomnia after commencing dissection. Interest in the subject matter and discussion were the commonest methods used to combat stress. This study contributes to the ongoing debate about the value of the dissecting room in the medical school curriculum.

Adaptation, Psychological↗

Joseph Towne (1806-1879), master modeller of wax.

Joseph Towne (1806-1879) was a pioneer in the art of wax modelling of anatomical and dermatological material. He began his career at the age of 17, at Guy's Hospital, London, where he spent the whole of his professional life. He was a secretive, self-taught individual, and the finer points of his technique died with him. His brilliant works are on view at the Gordon Museum at Guy's, and are still used for teaching.

Anatomy↗

Postoperative adhesions: ten-year follow-up of 12,584 patients undergoing lower abdominal surgery.

PURPOSE: Postoperative adhesions are a significant problem after colorectal surgery. However, the basic epidemiology and clinical burden are unknown. The Surgical and Clinical Adhesions Research Study has investigated the scale of the problem in a population of 5 million. METHODS: Validated data from the Scottish National Health Service Medical Record Linkage Database were used to define a cohort of 12,584 patients undergoing open lower abdominal surgery in 1986. Readmissions for potential adhesion-related disease in the subsequent ten years were analyzed. The methodology was conservative in interpreting adhesion-related disease. RESULTS: In the study cohort 32.6 percent of patients were readmitted a mean of 2.2 times in the subsequent ten years for a potential adhesion-related problem. Although 25.4 percent of readmissions were in the first postoperative year, they continued steadily throughout the study period. After open lower abdominal surgery 7.3 percent (643) of readmissions (8,861) were directly related to adhesions. This varied according to operation site: colon (7.1 percent), rectum (8.8 percent), and small intestine (7.6 percent). The readmission rate was assessed to provide an indicator of relative risk of adhesion-related problems after initial surgery. The overall average rate of readmissions was 70.4 per 100 initial operations, with 5.1 directly related to adhesions. This rose to 116.4 and 116.5, respectively, after colonic or rectal surgery-with 8.2 and 10.3 directly related to adhesions. CONCLUSIONS: There is a high relative risk of adhesion-related problems after open lower abdominal surgery and a correspondingly high workload associated with these readmissions. This is influenced by the initial site of surgery, colon and rectum having both the greatest impact on workload and highest relative risk of directly adhesion-related problems. The study provides sound justification for improved adhesion prevention strategies.

Abdomen↗

Medicolegal consequences of postoperative intra-abdominal adhesions.

Postoperative adhesions are an almost invariable consequence of abdominal and pelvic surgery. Their most important morbidity is small-bowel obstruction, but other sequelae include female infertility and dyspareunia and increased risk of visceral injury at subsequent laparotomy or laparoscopy. Whether chronic abdominal pain is truly a consequence of adhesions is debatable, although it is likely to be accepted as an entity by both patients and their legal advisors. Of 14 successful claims dealt with by a British medical defence organization, 5 were for perforations after laparoscopic division of adhesions, 2 for adhesions after laparoscopic surgery, 1 for infertility as a result of adhesions and 6 for delayed diagnosis of obstruction. General practitioners, surgeons and gynaecologists need to be aware of the increasing burden of medicolegal claims arising from these complications.

Abdominal Pain↗

Medial exposure for dissection of the cranial nerves in situ by medical students.

In this article, we illustrate and briefly describe a medial approach, in the sagittally sectioned preserved human head, to display all of the cranial nerves, in situ and in continuity. The method has been successfully used by more than six cohorts of our second-year medical students, and can be completed within a 90-min dissecting session.

Cadaver↗

Embryologic and anatomic basis of esophageal surgery.

The embryogenesis, congenital anomalies, and surgical anatomy and applications of the esophagus for benign and malignant processes are detailed in this article. Emphasis is placed on the role of embryology and the anatomy involved in surgical decisions.

Esophageal Diseases↗

A fast and simple method for the determination of clavulanic acid in human plasma using derivatisation reaction kinetics.

A stopped-flow mixing technique is used to determine clavulanic acid in human plasma after plasma deproteinisation with acetonitrile and removal of the organic solvent by extraction with dichloromethane. The reaction kinetic profiles for the reaction between clavulanic acid and imidazole are determined by measuring the absorbance at 312 nm of the imidazole derivative. The reaction rates are proportional to the concentration of the clavulanic acid and by plotting reaction rates against clavulanic acid concentrations linear calibration curves could be constructed over the range 0.30-10.0 microg/ml.

Anti-Bacterial Agents↗