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Biomedical subjects

B Thompson

Publications and source records attributed to B Thompson.

At least 55 records · Page 3Linked to original sources

Use of a tunneling device to aid in positioning of a graft.

A tunneling device can be used to ensure easy placement of a prosthetic or autogenous graft. This can be done without the danger of the graft twisting, kinking or having the clips and ties pulled off. The often frustrating problem of ensuring that the arterial graft lies properly in position can be greatly simplified with the use of this technique.

Anastomosis, Surgical

The epidemiology of infertility in Aberdeen.

OBJECTIVE: To study the prevalence of infertility, both primary and secondary, outcome of pregnancy, occupation, and uptake of medical services in a total population of women from a geographically defined area. DESIGN: A postal questionnaire survey of an age cohort of women who had completed their fertility, and who were randomly selected from the Grampian Health Board's primary care register. SETTING: Aberdeen city district. SUBJECTS: 1024 Women in the age group 46-50, of whom 130 had to be excluded. Of the remaining 894 women, 766 (86%) responded to the questionnaire. MAIN OUTCOME MEASURES: Response to questionnaire on pregnancy history, the length of time taken to become pregnant each time, and whether medical advice had been sought. RESULTS: Among the 766 women contacted, 602 (79%) reported no difficulties in having children, 56 (7%) had chosen not to have children, and the remaining 108 (14%) had experienced infertility, defined as having difficulty in becoming pregnant for more than two years. In total 68 (9%) women had primary infertility, of whom 41 (5%) eventually conceived. Of the 40 (5%) with secondary infertility, 23 (3%) conceived. Overall, 52 (7%) of the population were left with an unresolved problem of infertility. Only 67 (62%) infertile women had made use of hospital services, and a further 8 (7%) had consulted their general practitioners. Among those who conceived there was no difference in the proportion who sought advice compared with those who did not. CONCLUSION: The overall prevalence of infertility was 14%, although half of these women eventually conceived. Primary infertility was more common than secondary infertility. Only 62% of infertile women attended a hospital clinic for treatment of their infertility.

Ambulatory Care Facilities

An update on American College of Radiology-National Electrical Manufacturers Association standards activity.

The American College of Radiology-National Electrical Manufacturer's Association (ACR-NEMA) Standard was published 5 years ago. Implementations are just now becoming available in a form other than a prototype. Though this seems like a long interval between the initial work and results, the organization responsible for the standard, the ACR-NEMA Digital Imaging and Communications Standards Committee, has not been idle. Much of the progress which has been made is the result of cooperative work involving industry, the Committee and its Working Groups (WG), and the medical imaging user community. This paper will briefly review the history of the development of what is now a family of ACR-NEMA standards, describe the current activity of the WGs, and indicate in what directions the WGs are headed for both new and updated standards.

Electronics, Medical

High linoleic acid diets ameliorate diabetic nephropathy in rats.

The value of high polyunsaturated fatty acid (PUFA) diets in preventing diabetic nephropathy in rats was studied. Diabetes was induced by intravenous injection of streptozotocin (SZ), 65 mg/kg. Rats were divided in four groups fed diets containing 11% fat for 38 weeks. Dietary fat derived from four sources: beef tallow (BT; rich in saturated fatty acids), evening primrose oil (EPO; rich in gamma linolenic [GLA] and linoleic acids [LA]), safflower oil (SO; rich in LA), and fish oil (FO; rich in eicosapentaenoic [EPA] and docosahexaenoic [DHA] acids). Ultralente insulin was administered every other day to maintain the blood glucose levels between 11.1 and 22.2 mmol/L (200 and 400 mg/dL). The diets prepared with EPO and SO had a clear beneficial effect on proteinuria, glomerular sclerosis, and tubular abnormalities, as compared with BT. Both diets also increased the ratio of renal cortical production of 6-keto-PGF1 alpha to thromboxane B2 (TXB2), the stable metabolites of PGI2 and TXA2, respectively. They did not induce significant changes in plasma lipid composition. The FO diet did not have an effect on renal disease, but decreased plasma lipids and inhibited eicosanoid synthesis by platelets and kidney cortex. FO feeding was associated with a lowered 6-keto-PGF1 alpha/TXB2 ratio. It is concluded that high LA diets are protective in this model of diabetic nephropathy. The effect may be secondary to modifications of the eicosanoid balance. Diets containing FO have a beneficial effect on plasma lipids in this model.

Animals

Clinician interpersonal communication skills and contact lens wearers' motivation, satisfaction, and compliance.

The relation between the practitioner and patient may have important effects upon the safety and success of contact lens wear. In this study we investigated the interrelations among clinicians' interpersonal communication skills and patients' motivation, satisfaction, and compliance with care and maintenance instructions. These variables were measured through questionnaires and interviews. Significant associations were found among many aspects of the clinicians' interpersonal skills and aspects of the patients' motivation and satisfaction. These findings are consistent with those from other health care settings and indicate that the quality of the contact lens practitioner's interpersonal skills can substantially influence patient outcomes and perceptions.

Adult

Treatment compliance and hostility levels of head-injured psychiatric outpatients.

Twenty-eight head-injured psychiatrically ill patients were compared in terms of compliance with psychiatric treatment and hostility levels to a matched control group of 28 non-head-injured psychiatrically ill patients attending a community mental health clinic. Results indicated that the two groups did not differ in treatment compliance. However, the head-injured group had significantly less rapport with their therapists. Hostility measures revealed that male head-injured patients scored significantly higher on the assaultive scale; and the severity of the head injury correlated positively with levels of hostility and with reported problems at school.

Adult

The use of tissue-type plasminogen activator for acute myocardial infarction in the elderly: results from thrombolysis in myocardial infarction Phase I, open label studies and the Thrombolysis in Myocardial Infarction Phase II pilot study. The TIMI Investigators.

The impact of age on hospital mortality, incidence of major hemorrhagic events and transfusion requirements was examined in 756 patients with acute myocardial infarction enrolled in the Thrombolysis in Myocardial Infarction (TIMI) Phase I, open label studies and the TIMI Phase II pilot study. The mortality rate significantly increased with age and was 3.5%, 11.5% and 12% in patients less than 65, 65 to 69 and 70 to 76 years of age, respectively (p less than 0.001). Logistic regression analyses selected female gender, diabetes mellitus, extensive coronary artery disease, history of congestive heart failure, continuing chest pain immediately after recombinant tissue-type plasminogen activator (rt-PA) administration, low systolic blood pressure at the time of admission and advanced age as variables predictive of in-hospital death. The incidence of major hemorrhagic events among patients not undergoing cardiac surgery during hospitalization was 8.7%, 14.5% and 24.7% in patients aged less than 65, 65 to 69 and greater than or equal to 70 years, respectively (p less than 0.001). The majority of hemorrhages were secondary to cardiac catheterization or puncture wounds. Variables related to a major hemorrhagic event included protocol, age, rt-PA dose/kg body weight and elevated diastolic blood pressure on admission. Of five intracranial bleeding events, three occurred in patients greater than 65 years. Transfusion requirements significantly increased with age (p less than 0.001). Reperfusion status at 90 min in the TIMI Phase I and open label studies A to C was similar in the three age groups studied and ranged from 60% to 71%.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors

The reliability of self-reports of smoking and alcohol consumption by pregnant women.

The reliability of self-reports of prepregnancy smoking and drinking habits was assessed in over 700 pregnant smokers who participated in a randomized clinical trial of smoking cessation intervention. The participants provided self-reports of their prepregnancy smoking and drinking habits prior to the 18th week (test) and again in the eighth month of gestation (retest). About half the subjects gave identical reports of prepregnancy smoking habits at test and retest. Among those who changed their estimates, the changes were usually small. The reliability of reports of prepregnancy alcohol intake was also high. The reliability of reports by the treatment group - which experienced an anti-smoking intervention and extensive contact with study personnel - was very similar to that of the control group.

Adult

Randomized study of epinephrine versus methoxamine in prehospital ventricular fibrillation.

Experimental data suggest that a pure alpha-agonist, such as methoxamine, may improve the outcome of patients in ventricular fibrillation. A double-blind, randomized, prospective study was conducted in a paramedic system comparing the use of methoxamine with epinephrine in enhancing conversion of ventricular fibrillation while otherwise following American Heart Association protocols. One hundred two patients in ventricular fibrillation not responding to initial defibrillations with a pulsatile rhythm were randomized into one of two groups, each containing 51 patients. Equipressor doses of epinephrine (0.5 mg) and methoxamine (5 mg) were given intravenously and repeated according to American Heart Association guidelines. The mean age, sex ratio, and mean paramedic response times were comparable for the two groups. The mean time at scene until conversion was 22 +/- 10 minutes for methoxamine and 17 +/- 7 minutes for epinephrine (P = NS). The methoxamine group received 3.1 +/- 1.4 doses as compared with 2.8 +/- 1.3 doses for the epinephrine group (P = NS). Conversion rate, defined as the percentage of patients who developed a pulse during resuscitation, was 27.5% for the methoxamine group and 49.0% for the epinephrine group (P less than or equal to .03). Successful resuscitation, defined as the conveyance of a patient to an emergency department with a pulse and rhythm, was 17.7% for the methoxamine group and 39.2% for the epinephrine group (P less than or equal to .02). Save rate, defined as the percentage of patients discharged alive after hospitalization, was 7.8% for the methoxamine group and 19.6% for the epinephrine group (P less than or equal to .07).(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical Trials as Topic

A multivariate model for assessing eating patterns and their relationship to cardiovascular risk factors: the Bogalusa Heart Study.

Eating patterns were studied in 1275 adolescents and young adults (aged 12-24 y). Factor analysis of 64 foods consumed weekly revealed 17 eating-pattern factors, accounting for 57% of the item variance. Factor I (12 food items from either the seafood or meat group) accounted for 8% of the variance, factor II (snacks), 5%, and factors III (fats and pasta) and IV (beef and chicken), 4% each. Remaining factors accounted for from 1.9% to 3.9%. The factors were effective in discriminating eating patterns across race and gender. Significant age effects were also noted for 10 of the 17 factors. Eating patterns for persons in the upper or lower quartiles differed consistently for specific cardiovascular (CV) risk factors. Use of this statistical model to identify differences in eating patterns by race, gender, and CV risk factors during maturation can assist health professionals in targeting food sources for changing eating behavior.

Adolescent

Chronic stressors and maternal depression: implications for prevention.

We report on the use of an instrument to measure exposure to stressors among 149 women presenting with their children for pediatric care at an urban primary care center. Overall, 38.3 percent of the women had significant levels of depressive symptoms; 71.4 percent of those in the "high stress" group had an adjusted prevalence odds ratio of 5.00 [95% CI = 2.12, 11.82]. We conclude that screening in the pediatric office is feasible for identifying women at high risk of becoming depressed.

Depression

Selection of patients with acute pulmonary embolism for thrombolytic therapy. Thrombolysis in pulmonary embolism (TIPE) patient survey. The TIPE Investigators.

During a recent one-year period, 44 clinical centers in the United States saw 2,539 patients with diagnoses of pulmonary embolism as supported by high probability lung scans and/or positive pulmonary angiograms. In developing proposals for a clinical trial of Thrombolysis in Pulmonary Embolism (TIPE), investigators in the 44 clinical centers reviewed the 2,539 patients' medical charts for contraindications to thrombolytic therapy. Overall, 1,345 (53.5%) patients surveyed in the TIPE clinical centers would have been acceptable for treatment with thrombolytic therapy, a proportion higher than generally anticipated. Risks of major blood loss were the most frequent contraindications to thrombolytic therapy and were found in 838 (33.3%) patients. Risks to the CNS were found to contraindicate thrombolytic therapy in 453 (17.9%) patients. Risks of bleeding into special compartments were found to contraindicate thrombolytic therapy in 76 (3.0%) patients. Pulmonary embolism is underdiagnosed in most clinical settings, and even more patients than found in the TIPE survey could benefit from appropriate diagnosis and treatment. The question remains as to whether pulmonary embolism patients will benefit from thrombolytic therapy. Only a randomized clinical trial will provide a satisfactory answer.

Data Collection

Measurement characteristics of a short form of the questionnaire on resources and stress.

The psychometric integrity of a short form of a measure of ecological stress was evaluated based on data provided by both fathers and mothers representing intact families, half of which included children with handicaps and half of which did not. Alpha reliability, factor structure, and construct validity analyses generally supported the conclusion that the short form of the Questionnaire on Resources and Stress is reasonably reliable and valid.

Adult

Divergence in primary structure between the molecular forms of acetylcholinesterase.

We have isolated a COOH-terminal tryptic peptide from the hydrophobic globular (5.6 S) form of Torpedo californica acetylcholinesterase that exhibits divergence in amino acid sequence from the catalytic subunit of the dimensionally asymmetric (17 S + 13 S) enzyme. The divergent peptide could be recovered from the glycophospholipid-modified 5.6 S enzyme only after treatment with phosphatidylinositol-specific phospholipase C. Upon reduction, carboxymethylation with [14C]iodoacetate, and trypsin digestion the resultant peptides were purified by gel filtration followed by high performance liquid chromatography. The high performance liquid chromatography profiles of 14C-labeled cysteine peptides from lipase-treated 5.6 S enzyme revealed unique radioactive peaks which had not been present in digests of the asymmetric form. These peaks all yielded identical amino acid sequences. The difference in chromatographic behavior of the individual peptides most likely reflects heterogeneity in post-translational processing. Gas-phase sequencing and composition analysis are consistent with the sequence: Leu-Leu-Asn-Ala-Thr-Ala-Cys. Composition includes 2-3 mol each of glucosamine and ethanolamine which is indicative of modification by glycophospholipid. Glucosamine is also present in an asparagine-linked oligosaccharide. The two forms of acetylcholinesterase diverge after the threonine residue within this peptide sequence; the hydrophobic form terminates with cysteine whereas the asymmetric form extends for 40 residues beyond the divergence. The locus of divergence and absence of any other amino acid sequence difference suggest that the molecular forms of acetylcholinesterase arise from a single gene by alternative mRNA processing.

Acetylcholinesterase

A diet containing n-3 and n-6 fatty acids favorably alters the renal phospholipids, eicosanoid synthesis and plasma lipids in nephrotic rats.

The nephrotic syndrome was induced in rats by intravenous adriamycin (3 mg/kg). The rats were then divided into four groups which, for six weeks, were pair-fed diets containing beef tallow (BT), fish oil (FO), a source of n-3 fatty acids, evening primrose oil (EPO), a source of n-6 fatty acids, or a combination of evening primrose oil and fish oil, 75:25 (EPO:FO). The fat content of the diets was 15%. Significant incorporation of the fatty acids into kidney phospholipids was demonstrated. Diets containing FO, EPO and EPO:FO lowered plasma triglycerides and total cholesterol levels as compared with diets containing BT. Only EPO:FO raised high density lipoprotein (HDL) cholesterol levels, as compared with BT. The combination EPO:FO prevented the tenfold suppression of aortic 6-keto-PGF1 alpha caused by FO. These changes in plasma lipids and eicosanoid production are potentially antiatherogenic and may prevent glomerular sclerosis. The combination of EPO and FO, containing n-6 and n-3 fatty acids may offer advantages over either family of fatty acids in this model of nephrotic syndrome.

Animals

MR imaging of head trauma: review of the distribution and radiopathologic features of traumatic lesions.

The distribution and extent of traumatic lesions were prospectively evaluated with MR imaging in 40 patients with closed head injuries. Primary intraaxial lesions were classified according to their distinctive topographical distribution within the brain and were of four main types: (1) diffuse axonal injury (48.2%), (2) cortical contusion (43.7%), (3) subcortical gray-matter injury (4.5%), and (4) primary brainstem injury (3.6%). Diffuse axonal injury most commonly involved the white matter of the frontal and temporal lobes, the body and splenium of the corpus callosum, and the corona radiata. Cortical contusions most frequently involved the inferior, lateral, and anterior aspects of the frontal and temporal lobes. Primary brainstem lesions were most commonly seen in the dorsolateral aspects of the rostral brainstem. The pattern and distribution of primary lesions seen by MR were compared with those expected from previous pathologic studies and found to be quite similar. Our data and review of the literature would also indicate that MR detects a more complete spectrum of traumatic lesions than does CT. Secondary forms of injury (territorial arterial infarction, pressure necrosis from increased intracranial pressure, cerebral herniation, secondary brainstem injury) were also visible by MR in some cases. The level of consciousness was most impaired in patients with primary brainstem injury, followed by those with widespread diffuse axonal injury and subcortical gray-matter injury. The best MR imaging planes, pulse sequences, and imaging strategies for evaluating and classifying traumatic lesions were evaluated, and the mechanisms by which traumatic stresses result in injury were reviewed. MR was found to be superior to CT and to be very effective in the detection of traumatic head lesions and some secondary forms of injury. While T2-weighted images were most useful for lesion detection, T1-weighted images proved to be most useful for anatomic localization and classification.

Adolescent