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Biomedical subjects

A Montgomery

Publications and source records attributed to A Montgomery.

At least 37 records · Page 2Linked to original sources
PubMed2000

Computed tomography image-guided surgery in complex acetabular fractures.

Eleven complex acetabular fractures in 10 patients were treated by open reduction with internal fixation incorporating computed tomography image guided software intraoperatively. Each of the implants placed under image guidance was found to be accurate and without penetration of the pelvis or joint space. The setup time for the system was minimal. Accuracy in the range of 1 mm was found when registration was precise (eight cases) and was in the range of 3.5 mm when registration was only approximate (three cases). Added benefits included reduced intraoperative fluoroscopic time, less need for more extensive dissection, and obviation of additional surgical approaches in some cases. Compared with a series of similar fractures treated before this image guided series, the reduction in operative time was significant. For patients with complex anterior and posterior combined fractures, the average operation times with and without application of three-dimensional imaging technique were, respectively, 5 hours 15 minutes and 6 hours 14 minutes, revealing 16% less operative time for those who had surgery using image guidance. In the single column fracture group, the operation time for those with three-dimensional imaging application, was 2 hours 58 minutes and for those with traditional surgery, 3 hours 42 minutes, indicating 20% less operative time for those with imaging modality. Intraoperative computed tomography guided imagery was found to be an accurate and suitable method for use in the operative treatment of complex acetabular fractures with substantial displacement.

Acetabulum↗
PubMed2000

Measurement of dose in panoramic dental radiology.

The National Radiological Protection Board (NRPB) has recommended the introduction of dose-width product (DWP) for the measurement of patient dose in panoramic dental radiology and has proposed a reference level of 65 mGy mm for adult exposures. This paper describes a method for measuring DWP and dose-area product (DAP) using thermoluminescent dosemeters (TLDs). The technique was used on 16 sets with a range of exposure settings. The mean value of DWP was 14% higher than the mean value reported from a survey by the NRPB. This difference is most likely to be caused by systematic variations due to measurement method. The average DAP for a standard adult examination was shown to be 11.3 cGy cm2. Data are presented so that the DAP can be derived from the exposure factors (tube current and operating potential) and beam area. Based on published data for effective dose, it is estimated that the DAP to effective dose conversion factor is approximately 0.06 mSv(Gy cm2)-1. The average DAP value (11.3 cGy cm2) can be compared with the average value for intraoral radiography (9.3 cGy cm2) based on the NRPB survey of entrance surface doses assuming 6 cm circular collimation.

Humans↗
PubMed2000

A study of the application of paediatric reference levels.

Radiation exposure of paediatrics is of particular concern because of the greater health detriment. In this study, the application of patient dose reference levels to paediatric radiographic examinations has been investigated. The relationships between entrance surface dose and patient age and size parameters have been studied in three hospitals. The data have been used to derive conversion factors to describe relationships between doses for children of different ages. The usefulness of equivalent patient diameter, weight and age as variables relating to doses has been examined. Simple conversion factors in look-up tables have been derived that link doses for patients of a variety of ages and sizes for particular examinations. It is proposed that factors of this type could be applied to data for individual patients to allow a wider range of ages to be included in any group. This would enable sufficient dose data to be collected from non-specialist hospitals for comparison with reference levels. It would facilitate identification of hospitals where doses are higher so that changes could be made to radiographic practice.

Adolescent↗
PubMed1999

[Laparoscopy in acute abdomen as diagnostic and surgical aid].

In cases of acute abdomen, the preoperative diagnostic options are limited. Diagnostic laparoscopy offers a superior overview of the abdominal cavity with minimal trauma to the patient. If further surgery is needed, it may take the form of either laparoscopic procedures or conversion to open surgery, the incision being guided by laparoscopy findings. Complications associated to laparoscopy are few and can be minimized further by using minilaparotomy techniques. Intensive educational programmes for all categories of staff are required to make a 24-hours-a-day laparoscopy service available.

Abdomen, Acute↗
PubMed1999

Women's occupations, energy expenditure, and cardiovascular risk factors.

The purpose of this study was to examine the cardiovascular risk factors and energy expenditure of women from occupations that differ by physical activity level and socioeconomic level. Participants included 171 women randomly selected from employee lists at 10 employment sites. Measures included blood pressure, body mass index, levels of total and high-density lipoprotein (HDL) cholesterol, a submaximal aerobic fitness test on a bicycle ergometer, and a 12-month retrospective self-report of occupational, leisure time, and household energy expenditure. Women in active occupations had lower total cholesterol and higher HDL cholesterol than women in sedentary occupations. Women with higher occupational energy expenditure scores had higher HDL cholesterol and lower total cholesterol than women with lower occupational energy scores. Findings suggest that cardiovascular benefits, particularly for lipid profiles, may be derived from even small increases in occupational physical activity. The workplace may offer an environment for initiating policies to facilitate increased physical activity among women.

Activities of Daily Living↗
PubMed1999

Routine laparoscopy for nonpalpable testes?

There are still no accepted criteria for the selection of patients with nonpalpable testes for laparoscopy versus a primary surgical exploration. We here report our experience using routine laparoscopy in such patients. The aim was to determine whether laparoscopy should be the first operative intervention or follow an inguinal exploration. Included in the study were 61 boys with 69 nonpalpable testes. Thirty-three testes were found in the abdomen, and 36 testes were extra-abdominal or nonexistent. If an exploration of the inguinal region had been the initial surgical intervention, six testes would have been found, making laparoscopy unnecessary. On the other hand, in the search for 63 missing testes, laparoscopy saved the patients from laparotomy or an extensive inguinal exploration. We conclude that an accurate knowledge of testis, vas, and vessel location gained by laparoscopy facilitates the selection of an appropriate surgical strategy, saving at least 51% of patients from laparotomy or an extensive inguinal exploration.

Adolescent↗
PubMed1999

Reductions in finger doses for radiopharmaceutical dispensing afforded by a syringe shield and an automatic dose dispenser.

A gamma extremity monitoring system (GEMS) has been used to measure finger doses during radio-nuclide dispensing procedures. GEMS uses a small semi-conductor probe that can be attached to a finger from which a continuous read-out can be obtained that is related to dose rate. The pattern of dose accumulation can be analysed to allow doses received from individual operations within a procedure to be evaluated. GEMS has been used to compare the radiation dose reduction afforded by a syringe shield and an automatic dose dispenser. Dispensing procedures were simulated using 10% of the activity normally administered in order to avoid problems with detector saturation. Results show that the syringe shield and the automatic dose dispenser reduced finger doses by more than a factor of 10 for the procedures tested. The disadvantages of the automatic dispenser tested were a failure to transfer activity in 10% of cases and a longer time taken for the dispensing process. GEMS has the potential to facilitate greater optimization of finger doses through analysis of finger dose patterns.

Dispensatories as Topic↗
PubMed1998

Role of oxygen-derived free radicals in protease activation after pancreas transplantation in the pig.

The role of oxygen-derived free radicals in pancreatitis after pancreas transplantation was examined in a porcine pancreatic transplantation model. Trypsin activation, protease inhibitor consumption, kininogen consumption, and postoperative graft function were investigated in 24 pigs subjected to whole organ pancreaticoduodenal transplantation. The animals were divided into one control group and two groups treated with free radical scavengers. One group was given allopurinol, and one group was treated with superoxide dismutase in combination with catalase. In the early phase (within 1 hr) after reperfusion, no differences were seen between the groups as to protease activation. Neither trypsin-protease inhibitor imbalance nor any signs of kininogen consumption were seen. In a later phase (1-3 days after the transplantation), the trypsin activation, measured as high molecular weight immunoreactive cationic trypsin in plasma, was significantly less pronounced in allopurinol-treated animals. This finding indicates a less severe form of reperfusion pancreatitis in this group compared with the other groups. A tendency toward better function in the allopurinol-treated group was also seen. We conclude that oxygen-derived free radicals seem to be of importance in the development of reperfusion pancreatitis after pancreas transplantation in the pig. We also conclude that allopurinol, but not superoxide dismutase/catalase, possibly due to the administration regimens used in this series, is able to attenuate the trypsin activation and the development of pancreatitis in the later phase in this model.

Allopurinol↗
PubMed1998

Postoperative fever, bowel ischaemia and cytokine response to abdominal aortic aneurysm repair--a comparison between endovascular and open surgery.

OBJECTIVES: To study bowel ischaemia in transfemorally placed endoluminal grafting (TPEG) for abdominal aortic aneurysms, and any relation to cytokine response or postoperative fever. DESIGN: Prospective not randomised. University hospital setting. MATERIAL: Fourteen cases of conventional surgery and 23 cases of endovascular technique for infrarenal abdominal aortic aneurysm repair. METHODS: Tonometry was used for sigmoid colon pH, and ELISAs for serum IL-6. RESULTS: Mucosal pH in the sigmoid colon fell significantly during clamping and reperfusion in both groups. Lowest measured sigmoid colon pH was 7.10 in the open group, compared to 7.22 in the TPEG group (p < 0.05). The IL-6 levels in serum peaked after 4 h of reperfusion; 249 pg/ml in the open group, compared to 89 pg/ml in the TPEG group (p < 0.05). High levels of IL-6 in the postoperative period and persisting low sigmoidal pH were associated with serious complications. Postoperative temperature did not differ significantly between the groups, and no significant correlation could be found with sigmoid colon pH or IL-6 levels. CONCLUSIONS: The less pronounced perioperative bowel ischaemia in TPEG patients indicates an advantage of the TPEG technique. Splanchnic ischaemia was not related to postoperative fever, nor the IL-6 or TNF response.

Aged↗
PubMed1998

Diagnostic laparoscopy in 1043 patients with suspected acute appendicitis.

OBJECTIVE: To evaluate the efficacy of diagnostic laparoscopy in patients with suspected acute appendicitis, the number of complications associated with the laparoscopic technique, and the effect of leaving a macroscopically normal-looking appendix in place. DESIGN: Three prospective protocols. SETTING: Three departments of surgery, one in Norway and two in Sweden. SUBJECTS: 1043 patients aged 15 years or over. INTERVENTIONS: Diagnostic laparoscopy in patients with signs and symptoms of acute appendicitis who were to be operated on. MAIN OUTCOME MEASURES: Morbidity, mortality, and histological appearance of removed appendices, and outcome whether or not the patient was operated on. RESULTS: 819 patients had appendectomies (61% laparoscopically and 39% by conversion to open operation) with a total complication rate of 10%. In 211 patients a diagnostic laparoscopy was done as a single procedure. There were 181 women in this group and 86 of them had gynaecological disorders. The complication rate was 2% among these 211 patients and after a follow up of two years no patients had been readmitted for appendicectomy. 13 patients were subjected to other open procedures. The overall mortality was 0.4%. CONCLUSION: Diagnostic laparoscopy is safe and can be recommended in patients with suspected acute appendicitis, particularly in women. A macroscopically normal-looking appendix can be left in place.

Acute Disease↗
PubMed1998

Sociodemographic characteristics, biological factors, and symptom reporting in midlife women.

OBJECTIVE: The purpose of this study is to examine the influence of sociodemographic characteristics, reproductive hormones, and body composition on symptoms reported by generally well midlife women. DESIGN: The design was a 24-cell, randomly selected quota sample, stratified by four occupations that varied in professional status, two races, and three age groups. One hundred fifty-three women, aged 35 to 69, who worked 20 or more hours a week, who were not on hormone replacement therapy, who were not pregnant, and who did not have a hysterectomy prior to the age of 53 participated in the study. Data were collected at 10 employment sites. Symptoms were assessed by a 22-item symptom index. Serum hormone levels of estradiol and follicle stimulating hormone (FSH) were drawn for each woman, and body composition was assessed by body mass index (BMI). RESULTS: Chi-square tests showed that significantly more White women than Black women experienced nervous tension, loss of urine, and vaginal dryness. Analyses of variance showed that women experiencing hot flashes had significantly higher FSH levels, lower estradiol levels, and higher BMI than women not experiencing this symptom. Estradiol (odds ratio 0.988) and BMI (odds ratio 1.094) were significant predictors of experiencing hot flashes when entered into a stepwise logistic regression with age and FSH level as covariates. CONCLUSIONS: Findings suggest that symptoms experienced by midlife women are consistent across races, and that interventions targeting weight reduction may improve hot flashes experienced by midlife women.

Adult↗
PubMed1997

Application of a gamma extremity monitoring system in a radiopharmaceutical dispensary.

A new gamma extremity monitoring system (GEMS) was used to assess finger doses of staff working in a hospital radionuclide dispensary. The system is designed to give a continuous readout of dose rate from a small probe which may be attached to a finger. It allows the contributions to radiation dose to the fingers from different parts of a procedure to be measured for the first time and the detailed pattern of radiation exposure to be determined. The dose reduction benefits of small changes in procedure and the use of syringe shields were easily demonstrated after monitoring staff for a few sessions using GEMS, which would not have been possible using thermoluminescent or other integrating dosemeters. GEMS was calibrated against 99Tc(m), 241Am, 137Cs and 131I. The main disadvantage of the system is that the response of the detector increases significantly at lower radiation energies, with that at 60 keV being approximately 70 times the response at 662 keV. In addition, the response of the current detector is nonlinear and saturates around 7000 counts s(-1), which corresponds to a dose rate of 2200 microGy h(-1) for 99Tc(m). Despite these drawbacks, GEMS can play a significant part in the analysis of finger dose patterns and assist in dose reduction.

Americium↗
PubMed1997

Rate of decline of cortisol concentrations in ovarian follicles following ACTH treatment in the sow.

The rates of decline in cortisol concentrations in blood and ovarian follicular fluid were assessed in cyclic sows (n = 30) after treatment with saline or a depot form of adrenocorticotrophic hormone (ACTH). After a single injection of ACTH (0.5 iu/kg, BW, i.m.), peak cortisol values were achieved in blood within 3 to 4 h followed by a half-life net clearance rate (t1/2 of 2.40 +/- 0.29 (SE) h. The same dose of ACTH was then given at 12 h intervals from days 9 to 13 of the estrous cycle. On day 14 the concentrations of cortisol in follicular fluid were higher (P < 0.05) in ACTH-injected sows than in saline-injected controls. A t1/2 value of 37.81 h was determined for cortisol based on the decline in concentrations in follicular fluid collected on days 14, 16 and 18. This relatively slow rate of removal from developing ovarian follicles may have implications for the previously observed detrimental effects of increased cortisol concentrations on follicular development.

Adrenocorticotropic Hormone↗
PubMed1997

Appendicitis: laparoscopic versus conventional operation: a study and review of the literature.

A retrospective study was performed after introduction of the laparoscopic technique in patients with suspected appendicitis to validate it in comparison with conventional open appendectomy. A series of 103 patients with suspected acute appendicitis were included. In 51 consecutive patients, a diagnostic laparoscopy was performed, and, if needed, an appendectomy was carried out. Fifty-two consecutive patients underwent conventional appendectomy. The primary intention of the laparoscopy was diagnostic, but if the patient was found to suffer from appendicitis, a laparoscopic appendectomy was performed. Eight (16%) patients in the laparoscopic group had a healthy appendix that was left in place. Eleven (22%) patients in this group were converted to open appendectomy. There was no significant difference between the groups concerning age, sex, or diagnosis at the time of the operation, and there was also no significant difference in the postoperative hospital stay or complication rate between the groups. The postoperative need for analgesia was lower (p < 0.01) and the operation time was longer (p < 0.0001) in the laparoscopic group than the group that underwent open surgery. It can be concluded that the greatest benefits of the laparoscopic technique are that it causes less trauma, the diagnostic accuracy is better, and the cosmetic result is superior to that after a conventional operation. This is all at the price of a longer operation time.

Adolescent↗
PubMed1996

NADPH diaphorase activity in peptidergic neurones of the parasitic nematode, Ascaris suum.

The histochemical marker for nitric oxide synthase, NADPH diaphorase, is known to co-localize in mammalian neurones with various classical neurotransmitters and neuropeptides. The nervous system of the parasitic nematode Ascaris suum has previously been shown to contain both NADPH diaphorase activity and neuropeptide immunoreactivity. This study examined the possibility that NADPH diaphorase and neuropeptide immunoreactivity may co-exist in the same neurones. Two antisera were used, one raised to KYSALMFamide, a C-terminal synthetic analogue of SALMFamide 1 (GFNSALMFamide), and another that recognizes calcitonin-gene-related peptide (CGRP). We provide evidence that in a distinct subset of neurones in the ventral, dorsal and lateral ganglia NADPH diaphorase staining and SALMFamide-like immunoreactivity are co-localized, suggesting a possible role for nitric oxide in modulating neuropeptide activity in these regions. CGRP-like immunoreactivity was less widely distributed, and was not consistently co-localized with NADPH diaphorase.

Animals↗