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Biomedical subjects

J Thorburn

Publications and source records attributed to J Thorburn.

At least 55 records · Page 3Linked to original sources
PubMed1994

A comparison of 25 G and 27 G Whitacre needles for caesarean section.

Spinal needles with a pencil-point tip and those of a finer gauge are known to be associated with a lower incidence of postdural puncture headache. This study set out to determine if fine pencil-point needles were acceptably easy to use in routine clinical practice. Two hundred and twelve women undergoing elective Caesarean section were randomly allocated to receive a subarachnoid block using either a 25 G or 27 G Whitacre needle. Factors determining ease of needle use, adequacy of block, incidence of postdural puncture headache, backache and neurological sequelae were assessed. Successful intrathecal injection was achieved in all patients in the 25 G group. Using the 27 G needle, the anaesthetist failed to reach the subarachnoid space in eight patients of which seven subsequently had a successful intrathecal injection with a larger needle. These failures were attributed to excessive needle flexibility which was the only significant difference in ease of use between the 25 G and 27 G needles. In the 25 G group, there was one severe postdural puncture headache which required an epidural blood patch and three mild headaches which resolved spontaneously. There were no postdural puncture headaches in the 27 G group. We conclude that the final choice of needle is a compromise between the ease of use and lower failure rate of the 25 G needle and the, as yet unproven, possibility of a lower incidence of postdural puncture headache with the 27 G needle.

Anesthesia, Obstetrical↗
PubMed1994

Prediction of persistent ectopic pregnancy after laparoscopic salpingostomy.

OBJECTIVE: To evaluate whether preoperative measurements of progesterone and hCG in serum can predict the risk of needing a second therapeutic intervention after laparoscopic salpingostomy. METHODS: In 158 patients with unruptured tubal pregnancies smaller than 4 cm, serum progesterone and hCG levels were measured in two venous blood samples taken preoperatively. Fourteen complicated cases, in which a second therapeutic intervention was necessary, were compared with 144 uncomplicated cases. RESULTS: Eleven of the 14 complicated cases (79%) had preoperative progesterone values exceeding 35 nmol/L, whereas this was true for only 15 (10%) of the uncomplicated cases. Among the complicated cases, 12 (86%) had preoperative daily hCG changes above 100 IU/L, compared to 44 (31%) of the uncomplicated cases. Cases with a progesterone level above 35 nmol/L and a daily hCG change exceeding 100 IU/L had a 61% risk for a second therapeutic intervention, whereas with a progesterone value below 35 nmol/L and/or a daily hCG change of less than 100 IU/L, the risk was only 2%. CONCLUSION: The risk for a second therapeutic intervention after laparoscopic salpingostomy for ectopic pregnancy can be predicted by the combined use of two sequential serum hCG samples and one serum progesterone sample, the last of each taken within 24 hours preoperatively.

Chorionic Gonadotropin↗
PubMed1993

[Fertility after conservative surgical treatment of ectopic pregnancy, evaluated by a randomized trial].

In order to evaluate the fertility outcome after laparoscopic surgery for ectopic pregnancy, randomised trial of laparoscopy versus laparotomy was performed between May 1987 and June 1989. The study was conducted in a clinical university centre, Sahlgrens Hospital. A group a 105 patients with tubal pregnancy were stratified with regard to risk determinants and age randomized to laparoscopy or laparotomy. Eighty-seven patients who desired pregnancy were evaluated for subsequent fertility outcome. Linear salpingotomy was performed in both groups. The fertility outcome after laparoscopic salpingotomy was compared with that following laparotomy. There was no difference between the groups in the overall fertility outcome. A substantially higher proportion of patients in the laparotomy group were subjected to adhesiolysis performed at a second-look laparoscopic surgery. Adhesiolysis at a second-look laparoscopy, especially after laparotomy, might be beneficial in selected cases and may serve to improve subsequent fertility.

Adult↗
PubMed1993

HRas-dependent pathways can activate morphological and genetic markers of cardiac muscle cell hypertrophy.

We have investigated the role of the proto-oncogene HRas in cardiac cell growth and hypertrophy. By direct needle microinjection of activated Ras protein into primary neonatal rat ventricular cardiac myocytes, we find that, unlike many other cell types, Ras does not induce DNA synthesis in these cells. However, injection of activated Ras does induce expression of both the c-Fos and atrial natriuretic factor (ANF) genes. Expression of both these genes is associated with the hypertrophic response in ventricular myocytes suggesting that Ras is involved in the hypertrophic signalling pathway. Ras injection also causes morphological changes in the cells so that they increase in profile and show changes in the organization of the contractile apparatus. Further support for a role for Ras in the hypertrophic response was obtained from studies showing that activated Ras stimulates ANF promoter activity in transient transfection assays. We also show that a dominant interfering Ras mutant inhibits the hypertrophic stimulation of the ANF promoter by phenylephrine, indicating a role for Ras in the hypertrophic effect of an alpha-adrenergic agonist.

Animals↗
PubMed1993

Changes in pulmonary function tests during spinal anaesthesia for caesarean section.

We report the changes in forced vital capacity, forced expiratory volume in 1 s, and peak expiratory flow rate during caesarean section under spinal anaesthesia, as indirect indices of the ability to cough effectively. There were progressive falls in forced expiratory volume in 1 s (FEV(1)), forced vital capacity (FVC) and peak expiratory flow rate (PEFR) from the onset of anaesthesia till the abdomen was open, with these results failing to return to pre-incision levels by the time the patient reached the recovery room. Although none of our patients complained of dyspnoea or difficulty in coughing such falls in PEFR and FEV(1) may lead to an inability to cough effectively or clear inhaled vomit especially in patients with previously impaired respiratory function.

Journal Article↗
PubMed1993

Acute pharyngolaryngeal oedema in a pre-eclamptic parturient with systemic lupus erythematosus and a recent renal transplant.

The case of a 30-year-old parous patient with multi-organ involvement due to systemic lupus erythematosus and severe hypertension at 33 weeks gestation is described. Despite uneventful general anaesthesia for a classical caesarean section she developed acute airway obstruction postoperatively which was attributed to pre-eclampsia induced laryngeal oedema.

Journal Article↗
PubMed1992

Fertility outcome after conservative surgical treatment of ectopic pregnancy evaluated in a randomized trial.

OBJECTIVE: To evaluate the fertility outcome after laparoscopic surgery for ectopic pregnancy. DESIGN: A randomized trial versus laparotomy was performed between May 1987 and June 1989. SETTING: The study was conducted in a clinical university center, the Sahlgrens Hospital. PATIENTS: A group of 105 patients with tubal pregnancy were stratified with regard to risk determinants and age and randomized to laparoscopy or laparotomy. Eighty-seven patients who desired pregnancy were evaluated for subsequent fertility outcome. INTERVENTIONS: Linear salpingotomy was performed in both surgical groups. MAIN OUTCOME MEASURE: We evaluated the fertility outcome after laparoscopic salpingotomy for comparison with the outcome after laparotomy. RESULTS: There was no difference between the groups in the overall fertility outcome. A substantially higher proportion of patients in the laparotomy group were subjected to adhesiolysis performed at a second-look laparoscopy. CONCLUSIONS: The fertility prospects are not impaired by laparoscopic surgery. Adhesiolysis at a second-look laparoscopy, especially after laparotomy, might be beneficial in selected cases and may serve to improve subsequent fertility.

Female↗
PubMed1992

Continuous extradural analgesia: comparison of midwife top-ups, continuous infusions and patient controlled administration.

We have compared three techniques used to provide extradural analgesia during the first stage of labour: 0.25% plain bupivacaine 10 ml demand top-ups delivered by the midwife; continuous infusion of 0.125% plain bupivacaine 10 ml h-1; and patient-controlled extradural analgesia (PCEA) delivering 3-ml boluses of 0.25% bupivacaine. Each technique produced comparable analgesia achieving equivalent maternal satisfaction, with no difference in mode of delivery and no complications. This regimen for PCEA proved a viable alternative for continuous extradural analgesia and was popular with the mothers, midwives and anaesthetists.

Adolescent↗
PubMed1992

Distinction between early normal intrauterine pregnancies and pathological pregnancies by means of a logistic model.

The probability of an unclear very early pregnancy being a normal intrauterine pregnancy was estimated using a logistic model. Five diagnostic measures of prognostic value were identified in the model: (i) daily change in human chorionic gonadotrophin (HCG), (ii) results of transvaginal ultrasound, (iii) vaginal bleeding, (iv) serum progesterone level and (v) risk score for ectopic pregnancy. With the use of this model, the probability of a normal intrauterine pregnancy has been estimated as 96.7%.

Chorionic Gonadotropin↗
PubMed1992

Differential diagnosis of early human pregnancies: impact of different diagnostic measures.

A total of 261 women in early pregnancy, either with mild symptoms of ectopic pregnancy (EP) or being at an increased risk for this condition, were included in a longitudinal study. The effectiveness of different diagnostic measures in obtaining correct final diagnoses was analyzed. In addition to clinical findings and symptoms, the use of serum human chorionic gonadotropin, serum progesterone, endovaginal sonography and a risk score for EP were all proven to be valuable in distinguishing normal intrauterine pregnancies from pathological pregnancies.

Chorionic Gonadotropin↗
PubMed1992

Microinjection of antibodies and expression vectors into living myocardial cells. Development of a novel approach to identify candidate genes that regulate cardiac growth and hypertrophy.

BACKGROUND: Microinjection approaches in the cardiac cell context have allowed delivery of various calcium dyes and monitoring of short-term physiological responses. However, unlike other cell types, it has proved difficult to microinject myocardial cells without the concomitant loss of long-term cell viability. METHODS AND RESULTS: An analysis of experimental variables was conducted to adapt microinjection techniques to the neonatal rat ventricular cell context. Among the variables optimized were the selection of culture dishes, plating substrate, microinjection parameters, and a variety of maneuvers to inhibit myocyte hypercontracture, injury, and consequent death after micropuncture. With the modified technique, the percentage of injected cells that maintained long-term viability (48 hours) increased from less than 1% to 30%. Similarly, an increased efficiency of gene transfer and expression (measured as the percentage of injected cells that express the delivered gene) was obtained after either cytoplasmic or nuclear injection of a beta-galactosidase expression vector into cardiac myocytes. Microinjection of marker immunoglobulin G does not interfere with the induction of the hypertrophic response or the expression of a coinjected atrial natriuretic factor promoter-luciferase reporter fusion gene construct. CONCLUSIONS: To the best of our knowledge, this study provides the first description of the efficient microinjection of neonatal cardiac muscle cells with maintenance of long-term cell viability. The microinjection technique is now a viable approach to examine cause-and-effect relations between specific gene products and any defined feature or response of cardiac myocytes that can be assayed at a single-cell level.

Animals↗
PubMed1992

Electrocardiographic changes during cesarean section under regional anesthesia.

To determine electrocardiographic changes and whether myocardial ischemia occurs during cesarean section, electrocardiograms were recorded continuously using Holter monitoring in 25 patients undergoing elective cesarean section under either spinal or epidural anesthesia. In addition, in 13 of the patients, two-dimensional precordial echocardiography was carried out before and during cesarean section. ST segment depression suggestive of myocardial ischemia occurred in 16 patients including 8 of the 13 with echocardiograms. Wall motion remained entirely normal during episodes of ST segment depression. Patients in whom ST depression developed had significantly more rapid heart rates at delivery than those who did not experience ST depression. We conclude that ST segment depression is a common feature of the electrocardiogram during cesarean section under regional anesthesia and is not the result of myocardial ischemia.

Anesthesia, Conduction↗
PubMed1992

Advancing conservative treatment of ectopic pregnancy--laparoscopic and "non-surgical" management.

Improvements in diagnostic measures have contributed to the earlier diagnosis of ectopic pregnancy which in turn has led to the development of new and alternative methods of managing tubal pregnancies. Laparoscopic salpingotomy offers advantages such as a reduction in operating time and shorter hospital stays and convalescence as compared with conventional abdominal surgery. Furthermore, neither the frequency of persistent trophoblasts nor of second operations is increased, and the subsequent fertility rate is at least equal to that after laparotomy. "Non-surgical" treatment of ectopic pregnancy, such as systemic administration of methotrexate and laparoscopic/transvaginal ultrasonic--guided local injection of methotrexate, prostaglandins or hyperosmolar glucose, are attractive alternative methods in selected cases. These methods are safe and effective and have a high success rate and promising results for fertility. Laparoscopy is preferred to conventional abdominal surgery for the treatment of ectopic pregnancy. In selected cases, "non-surgical" treatment can be an attractive alternative therapy.

Dinoprost↗
PubMed1992

Low-dose oral methotrexate as second-line therapy for persistent trophoblast after conservative treatment of ectopic pregnancy.

The aim of this study was to evaluate the efficacy of methotrexate as second-line treatment for ectopic pregnancy. Oral methotrexate was used in 15 patients with evidence of persistent trophoblast after conservative laparoscopic surgery for tubal pregnancy. The treatment was successful in 14 of 15 cases, and the mean time for decline of serum hCG to nonpregnant levels was 24 days. In the remaining case, hCG continued to rise. Side effects were noticed, even at a low dosage, but only in those subjects not receiving citrovorum rescue. As an alternative to a second operation, oral methotrexate appears to be an effective and well-tolerated therapy for persistent trophoblast.

Chorionic Gonadotropin↗
PubMed1991

Diagnosis and treatment of tubal pregnancy as related to risk determinants.

To evaluate whether identification of 'high risk' patients for ectopic pregnancy (EP) is beneficial for early recognition and treatment, 178 cases of tubal pregnancy were analysed. Patients with 'high risk' and 'low risk' for EP were compared for diagnostic procedures, clinical features and surgical management. The 'high risk' patients presented a shorter gestational length, lower blood loss volume, a smaller size of the tubal gestation, a lower rate of tubal rupture and underwent more conservative treatment. We conclude that identification of risk determinants may be of great importance for early recognition and hence, application of the new modalities for treatment of ectopic pregnancy.

Adult↗