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Biomedical subjects

J S Simpson

Publications and source records attributed to J S Simpson.

At least 37 records · Page 2Linked to original sources

Undergraduate education about cancer: a survey in Australian medical schools.

The goals of undergraduate medical education are to provide a core of basic knowledge, and a framework to permit further development of that knowledge. The structure of teaching and experience in cancer medicine should reflect the increasing importance of cancer in the community. Undergraduate teaching of oncology and its scientific bases is currently fragmented, and in some cases may be deficient. Until now, there have few analyses of what is being taught about cancer at different medical schools. We have undertaken a survey of final year medical students or recently qualified doctors in Australia enquiring about their cancer education. The results indicated that substantial differences existed between the medical schools, and we therefore surveyed the teaching faculty in the schools to determine their view of the validity of the questions we used. Together these surveys showed that significant disparities existed between what the faculty felt should be taught and what students had actually experienced.

Australia↗

A simple surgical audit.

A simple microcomputer based surgical audit system, written by one of the authors and implemented on a Tandy model IV microcomputer, is described. The system allows data from 2000 patients to be stored on a single disc. Data stored can be easily analysed and used to audit clinical activity.

Computers↗

Breast self-examination in an urban population: estimates of prevalence and quality of performance.

Interview data from 434 women (aged greater than or equal to 20 years) in two Wellington suburban areas were used to estimate the prevalence and quality of performance of breast self-examination. Although 98% of women were familiar with breast self-examination, and 73% had performed it at least once, only 39% did so at least monthly. Its practice was significantly more common in the middle years (30-59), among Europeans, and in women with tertiary education. Thoroughness or quality of performance was assessed by comparison with Cancer Society recommendations. Scores for examination technique were generally high (mean = 73%) compared with those assessing timing (mean = 47.5%) and conditions under which breast self-examination was performed (mean = 43.3%). Results from this study were compared with 1975-76 New Zealand survey data which produced lower estimates of the prevalence of monthly breast self-examination. Both studies found that more than a quarter of women have never practiced it. Future research and intervention efforts should be directed toward this group of women.

Adult↗

Comparison of histochemical and biochemical assays for oestrogen receptor in breast tumour tissue.

Oestrogen receptors were measured by a histochemical technique in tumour tissue from 45 patients with breast cancer, and the results compared with receptor levels measured by a standard biochemical dextran-charcoal assay. Histochemical measurements were made by incubating frozen sections of tumour tissue with 17-fluoresceinated oestrone, using dithiothreitol to inhibit uptake by low affinity binding sites, and estimating receptor content by the extent of fluorescence seen microscopically. Results from the two assays gave varying estimates of receptor concentration, with 66% of patients classed as receptor-positive by the biochemical assay, and 44% of patients classed as receptor-positive using the histochemical technique. Because of these discrepancies the histochemical assay cannot be considered a direct substitute for biochemical receptor measurements. Progesterone receptor was detected by biochemical measurement in 80% of the subgroup of patients who were positive for oestrogen receptor in both assays. The histochemical assay may thus identify a subset of those patients considered oestrogen receptor-positive by conventional receptor assays, and this group may be more likely to respond to hormonal therapy. However, whether the histochemical method provides a predictive measurement for endocrine responsiveness which is superior to standard progesterone receptor assay remains to be determined.

Adult↗

Frozen section evaluation of cervical conization specimens.

Frozen section evaluation was done on 96 conization specimens. One patient had invasive carcinoma, which was correctly diagnosed on frozen section. No patient received inappropriate therapy on the basis of an erroneous diagnosis made from the evaluation of frozen sections. The mean time from initiation of surgery to the surgeon's receipt of the frozen section diagnosis was 0.9 hours. There was no significant increase in the blood loss or intraoperative complication rate when frozen conization was added to either abdominal or vaginal hysterectomy.

Biopsy↗

Analysis of growth hormone and lactogenic binding sites cross-linked to iodinated human growth hormone.

GH (GHR) and lactogenic receptors were analyzed after use of the cross-linking reagent ethylene glycol bis-(succinimidyl succinate) to attach covalently iodinated human GH (hGH) to binding proteins 1) on intact IM-9 lymphocytes, 2) in a partially purified GHR preparation from rabbit liver, and 3) in crude microsomal fractions from rabbit liver, rabbit mammary gland, and rat liver. The latter two microsomal preparations contain primarily lactogenic receptors, whereas in IM-9 lymphocytes and the rabbit liver preparations, GHR predominate. Cross-linked [125I]hGH-receptor complexes were solubilized, reduced, and separated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Analysis of proteins cross-linked to [125I]hGH in the microsomal fraction from rabbit liver showed a specifically labeled complex with an estimated molecular weight (mol wt) of 75K. A slightly lower mol wt (71K) was determined for the complex labeled in the purified GHR preparation. In contrast to the relatively low mol wt complexes in rabbit liver, a complex that migrated with an apparent mol wt of 130K was identified in IM-9 lymphocytes. Labeled complexes were identified at 66K from rat liver and 61K from rabbit mammary gland. If it is assumed that hGH contributes 21K to the mol wt of the radiolabeled complexes, then the approximate mol wts of hGH-binding sites are 50-54K from rabbit liver, 109K from IM-9 lymphocytes, 45K from rat liver, and 40K from rabbit mammary gland.

Animals↗

A monoclonal antibody to the growth hormone receptor of rabbit liver membranes.

A monoclonal antibody which recognizes the [125I]human GH ([125I]hGH)-binding proteins of rabbit liver has been produced using hybridoma technology. A CB6F1/J mouse was immunized over a period of 82 days with a partially purified GH receptor (GHr) preparation. On the 83rd day, spleen cells from the mouse were fused with P3x20 mouse myeloma cells using polyethylene glycol 1540. Hydridomas were produced by selection in hypoxanthine, aminopterin, and thymidine in RPMI/1640 medium and screened for antibody production using a binding inhibition assay. Four antibody-secreting clones were isolated from the same primary well, and one of these was injected ip into mice to generate ascitic fluid. At a concentration of 1:10,000, the ascitic fluid inhibited 50% of the specific binding of [125I]hGH to rabbit liver GHr, and at higher concentrations, the ascitic fluid was capable of inhibiting 95% of the specific binding. The ascitic fluid does not bind [125I]hGH nor does it inhibit [125I]hGH binding to rat liver membranes, rabbit mammary gland, or IM9 lymphocytes. More than 90% of the antibody activity was abolished by goat antimouse immunoglobulin G antiserum. An immunoglobulin fraction from the ascitic fluid, precipitated by ammonium sulfate and coupled to activated CH Sepharose, specifically adsorbed an [125I]hGH binding moiety from Triton X-100-solubilized rabbit liver membranes. After dissociation by brief exposure to 0.1 M glycine (pH 2.0), the moiety retained hGH-binding activity. Preliminary experiments indicate that the antibody will be helpful in purification of the rabbit liver GH receptor.

Animals↗

20K is bound with high affinity by one rat and one of two rabbit growth hormone receptors.

A naturally occurring variant of human (h)GH, designated 20K, is equipotent with hGH(22K) in stimulating growth in hypophysectomized rats. However, despite high growth-promoting activity in vivo, 20K is a poor inhibitor of 125I-hGH(22K) binding to GH receptors in radioreceptor assays. In order to resolve the differences between bioassay and radioreceptor assay data, we have examined the binding of 20K to rat and rabbit liver GH receptors. Our data indicate that the GH receptor in rat liver binds 20K with an affinity only slightly lower than that for hGH(22K), in accordance with bioassay data. In the rabbit, however, 20K is bound with high affinity by only a small subset of the GH receptors which bind hGH(22K) with high affinity. The GH receptors which bind 20K appear to belong to the same of subset of receptors which bind rat and rabbit GH with high affinity.

Animals↗

Comparison of behaviour between 2 subspecies of owl monkey (Aotus trivirgatus) in a laboratory environment.

To evaluate potential factors affecting reproductive performance, 6 monkeys of Colombian and 6 of Bolivian origin, housed as mated pairs, were observed via closed circuit television and a remote-controlled camera. Behavioural differences in feeding and drinking, locomotor activity, environmental interaction, positive social interaction, autogrooming, nestbox occupancy, and playing were observed. The differences noted indicate that the subspecies may have different social structures.

Animals↗

Hybrid production in owl monkeys (Aotus trivirgatus).

A colony of owl monkeys was established with 63 breeding pairs, paired according to matching karyotypes. 3 pairs were formed as a result of limited space, even though karyotypes were considered incompatible. 2 of these pairs produced offspring.

Animals↗

Informed consent: a medical viewpoint.

Clinical trials now have an established place in the evaluation of new cancer treatments. It is vital that there should be no conflict between the scientific aspects of clinical trials and the interests of patients with cancer. This conflict can be avoided if trial designs meet accepted standards, and if patients are able to make "informed" decisions abut participation. This process of obtaining informed consent is the subject of much debate. How the debate can be resolved by an individual clinician depends on his perception of a number of fundamental ethical principles. There is growing agreement, however, that regardless of the details of the process of obtaining informed consent, certain basic requirements must be met. The patient must be told that he is participating in a research procedure, that entry is optional, that withdrawal at any time is his right, and he must understand the nature of the trial and the likely effects of treatment, both good and bad.

Attitude of Health Personnel↗

An assessment of the surgical treatment of adhesive small bowel obstruction in infants and children.

At The Hospital for Sick Children, Toronto, Canada, adhesive small bowel obstruction (SBO) ranks seventh as a cause of pediatric bowel obstruction. Between January 1968 and December 1979, 131 infants and children had adhesive SBO proven at laparotomy or autopsy: 123 had 1; 7 had 16 adhesiotomies; 1 died without surgery; 100 had 1 prior operation; and 31 had multiple operations. Over 80% of the SBOs developed within 2 yr of the prior operations. Appendectomy and subtotal colectomy were the most common prior operation. Postoperative morbidity occurred in 29 children; 20 were observed longer than 24 hr before laparotomy. The rate of wound infection ranged from 4% to 50%; it was lowest for those children who had lysis of adhesions only, and highest for those who had lysis and decompressive enterotomy or perforation repair. Results indicate that delaying adhesiotomy and entering the GI tract during adhesiotomy are associated with increased morbidity (p less than 0.01), and therefore should be avoided. Prophylactic antibiotics may have a protective role during anterolysis.

Adolescent↗

Ruptured spleen--when to operate?

Sixty-three patients with splenic injuries were treated during a 5-yr period from 1974-1979. The decision to operate was based on the patient's clinical course, not on the presence of splenic injury alone. Those who were stable on admission or after initial resuscitation were treated nonoperatively. This consisted of strict bed rest, nasogastric suction, and i.v. fluids--including blood--as required. Those who bled massively were operated on promptly. At operation, the spleen was repaired if possible or excised if damaged beyond repair. Forty patients were treated nonoperatively. Sixteen of these required blood transfusions (mean 31.2 +/- 5.3 ml/kg). One patient in this group developed a large defect on spleen scan at 3 wk post injury. There was no other morbidity and no mortality following nonoperative treatment. Nineteen required operation all within 16 hr of admission. Fifteen underwent splenectomy, 2 partial splenectomy, and 1 splenorrhaphy. In 1 the bleeding had stopped. All required blood before operation (mean 80.4 +/- 10.1 ml/kg). Seven in this group died (6 from head injuries and 1 from bleeding). Thus surgery was avoided in 2 out of 3 and the spleen saved in 3 out of 4 patients with documented splenic injuries. We believe that where adequate facilities exist nonoperative treatment of splenic injuries is both safe and effective. When bleeding is massive from the beginning or replacement requirements exceed 40 ml/kg, operation is indicated.

Adolescent↗