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Biomedical subjects

N Johnson

Publications and source records attributed to N Johnson.

At least 181 records · Page 10Linked to original sources
PubMed1994

Which is more painful? A randomized trial comparing loop with laser excision of the cervical transformation zone.

We compared the pain of excisional cervical surgery by the laser or loop diathermy (LLETZ) in a randomised controlled clinical trial. Eighty women with CIN III were recruited from a laser colposcopy clinic specifically adapted to run randomized trials. They were scheduled for excision of their cervical transformation zone and both groups were matched for age, parity, and size of lesion. We measured linear analogue pain scores, subjective pain scores, and operative time. The laser and loop diathermy inflicts similar discomfort and there is no detectable difference between the median pain scores of women in either group (P = 0.99). However, in the hands of an experienced surgeon it takes 4 min extra to excise the cervical transformation zone with a laser compared to loop diathermy. The average time from sitting in the chair to the end of the procedure was 13.02 min (SD 3.65) for the group allocated diathermy surgery compared to 17.30 min (SD 5.33) for a laser excision log transformed t(log transformed data) = 3.7 (P < 0.001).

Adult↗
PubMed1994

Pain after laparoscopy: an observational study and a randomized trial of local anesthetic.

Our objective was to determine if local anesthesia reduces pain after a laparoscopy. Eighty women were assigned randomly 10 ml of 0.5% bupivacaine or 0.9% saline flushed over the peritoneal folds and into the abdominal wall after laparoscopy under general anesthesia. Pain scores from the deep abdomen, skin, shoulder, and back were collected 30 min, 2 h, 4 h, and the day following laparoscopy. Pain scores also were correlated with patients' height, weight, operative findings, surgical technique and procedure, and volume of gas insufflated into the abdomen. Bupivacaine has a small effect on abdominal and skin pain 2 h after surgery (p = 0.01) but has no effect on shoulder or back discomfort. Women who have been sterilized, have not had previous abdominal surgery, or have evidence of old pelvic inflammation report more postoperative backache and deep abdominal pain but no greater skin or shoulder discomfort. Weight, height, whether the abdominal wall was picked up, and the volume of gas used to insufflate the abdomen are independent of all postoperative pain scores. Local anaesthetic instilled down the laparoscopy trocar reduces skin discomfort 2 h after surgery, but this beneficial effect is small compared with other factors influencing pain after laparoscopy.

Anesthesia, General↗
PubMed1994

Fetal pulse oximetry: a new method of monitoring the fetus.

Experimental pulse oximetry devices, similar to the existing systems used in adult and neonatal monitoring, can be used on the fetus to provide safe, and rapid information about oxygenation. They have been calibrated using fetal lambs and validated in human cross-sectional studies. Experiments have shown that fetal oxygen saturation decreases during normal labour, and drops after a uterine contraction especially with oxytocin-induced tachysystole. When the mother is given oxygen the fetal oxygen saturation increases. Readings are effected by caput and movement, and trends seem to be more meaningful than absolute values. Pulse oximetry can predict fetal outcome and a normal oxygen saturation result is specific for a good outcome perhaps even if the CTG is abnormal. However the technique is still experimental and there is insufficient data to support its use as a replacement for fetal blood sampling or a discriminator for an abnormal fetal heart trace.

Animals↗
PubMed1994

Clinical value of antenatal fetal pulse oximetry.

The aim of this prospective observational study was to see if high quality fetal pulse oximetry signals can be obtained from the fetus before labour. It was carried out in Labour Ward, Clarendon Wing, Leeds General Infirmary and St. James Hospital, Leeds. We studied Caucasian term fetuses antenatally and 20 fetuses during labour. Antenatal fetal oxygen saturation was measured using a sensor passed through the cervix onto the membranes covering the fetus before the onset of labour. The quality of these signals was compared to data obtained from 20 fetuses monitored during active labour after amniotomy. High quality pulse oximetry signals were obtained for less than 1% of the monitoring time before the onset of labour (95% CI 0-2.5%). High quality data was seen 38.6% of the time once the membranes were ruptured and the head descendend into the pelvis. With present technology fetal pulse oximetry will not contribute to antenatal fetal assessment.

Evaluation Studies as Topic↗
PubMed1994

E-selectin and interleukin-2 receptor alpha-chain expression in alopecia universalis.

A study of the histopathological abnormalities in a case of alopecia universalis was accompanied by immunohistochemical analysis of the expression of intercellular adhesion molecule-1 (ICAM-1) and E-selectin (formerly known as endothelial leukocyte adhesion molecule-1) within the skin. ICAM-1 expression on follicular epithelium co-localized with intraepithelial mononuclear cells (MNC) positive for the interleukin-2 receptor alpha-chain (IL-2R) or HLA-DR. Aberrant expression of E-selectin was observed on dermal endothelium. Although restricted to one case, these new observations concerning the expression of E-selectin and IL-2R in alopecia universalis are consistent with the view that extravascular trafficking of MNC into follicular epithelium may play a key role in the pathogenesis of alopecia universalis and that use of agents that interfere with this process may be an effective therapeutic strategy.

Adult↗
PubMed1994

Influence of FK 506 (tacrolimus) on circulating CD4+ T cells expressing CD25 and CD45RA antigens in 19 patients with chronic progressive multiple sclerosis participating in an open label drug safety trial.

We have taken the opportunity of a clinical trial of the potential efficacy and safety of FK 506 (tacrolimus) in chronic progressive multiple sclerosis (MS) to examine the influence of this potent new immunosuppressant on circulating T-lymphocytes in an otherwise healthy non-transplant population. Peripheral blood levels of subsets of CD4+ T lymphocytes expressing the activation molecule interleukin-2 receptor (p55 alpha chain; CD25) or the CD45RA isoform were determined sequentially in 19 patients that were treated continuously with oral FK 506 (starting dose 0.15 mg/kg/day) for 12 months. No significant change in the proportion of circulating CD25+ CD4+ cells was observed over the study period in which the mean trough plasma FK 506 level rose from 0.3 +/- 0.2 to 0.5 +/- 0.4 ng/ml. There was also no significant effect of FK 506 on the percentage of CD45R+ CD4+ cells in the peripheral blood at 12 months compared with pretreatment values. Analysis of a subgroup of 7 patients, who showed a sustained reduction in CD25+ CD4+ cells and a reciprocal increase in CD45RA+ CD4+ cells for at least 6 months after start of treatment, did not reveal any difference in disability at one year compared with the treatment group as a whole. The side effects of FK 506 were mild and the overall degree of disability estimated by the mean Kurtzke expanded disability status scale (EDSS) score or the ambulation index did not deteriorate significantly in the 19 patients studied over the 12 months of FK 506 administration.

Administration, Oral↗
PubMed1994

Role of primary care in the prevention of malignant melanoma.

One of the targets for health in the United Kingdom is the reduction in the year-on-year increase in the incidence of skin cancer. Most of the mortality associated with skin cancer is attributable to malignant melanoma. One possible way to reduce the incidence of malignant melanoma is to develop a strategy for prevention based in primary care. This paper considers the arguments for and against three possible strategies: giving general advice; identifying patients at high risk; and undertaking early diagnosis. It is concluded that elements of all three strategies are likely to prove useful, but that major studies need to be undertaken before any strategy is adopted on a national basis.

Adult↗
PubMed1993

Decision analysis for best management of mildly dyskaryotic smear.

Should a woman with a mildly dyskaryotic cervical smear be referred for colposcopy or should the smear be repeated? One way to answer this question is to use decision analysis and compare the expected mortality and cost of each policy. Data for each component of the question were obtained from published work worldwide and were supplemented with an audit of mildly dyskaryotic smears in West Yorkshire, UK. 2 out of 1000 women with an initial mildly dyskaryotic smear will develop cancer if a conservative repeat smear policy is adopted in association with five-yearly cervical screening. This number can be reduced to 1.6 per 1000 if cervical screening is offered every three years. A policy of immediate referral for colposcopy is also associated with a subsequent cancer rate of 1.6 per 1000. Therefore, repeating the smear is almost as effective as an immediate referral to a colposcopy unit. Even if a five-yearly cervical screening programme is adopted, 2500 women with a mildly dyskaryotic smear will need to be referred for immediate colposcopy to save 1 additional cancer. A conservative policy is not financially cheaper: an average of six additional smears is required to save each colposcopy referral. Sensitivity analysis shows that the excess cost of the conservative policy increases exponentially as the risk of a subsequent cytological abnormality exceeds 60%. Local cytopathology laboratories should audit their recurrent dyskaryosis rate associated with borderline, mild, and moderate dyskaryosis before accepting the U-turn in the national recommendations.

Colposcopy↗
PubMed1993

Worrying about waste: living close to solid waste disposal facilities in southern Ontario.

As a complement to an epidemiological survey, depth interviews were used to discover the individual level impacts of living close to waste disposal facilities in southern Ontario. The paper begins by describing the nature of the sites and reporting some of the survey findings, which the depth interviews explored. Sample selection and data analysis methods are described. A by-code analysis of the material is presented, emphasizing both within- and between-site differences in type and concern (or impact). Concern varied according to type of exposure and site context. The paper ends with a discussion which relates the study's findings on non-toxic facilities to other research on psychosocial effects, lay reasoning and risk perceptions and assessments.

Adaptation, Psychological↗
PubMed1993

Pacemaker function during irradiation: in vivo and in vitro effect.

With an ageing population in Australia, one would expect the probability of treating cancer patients who have a cardiac pacemaker to increase. In this paper the effect of ionizing radiation and electromagnetic interference on pacemaker function is discussed. A case of a cancer patient, with pacemaker, treated with radiotherapy without ill effect, is described. Concurrently, four pacemakers were tested in vitro with gamma radiation from a 60 Cobalt machine and no adverse effect was found. A list of precautions is recommended.

Aged↗