Biomedical subjects
Publications and source records attributed to R Robertson.
Multi-Link coronary stents, both 15 and 25 mm, can be used from the radial artery approach with a high degree of efficacy. The complexity of coronary artery stenting is greatly diminished by using the Multi-Link stent delivery system, which eliminates the need for "bare stenting."
Dome growth at the Soufriere Hills volcano (1996 to 1998) was frequently accompanied by repetitive cycles of earthquakes, ground deformation, degassing, and explosive eruptions. The cycles reflected unsteady conduit flow of volatile-charged magma resulting from gas exsolution, rheological stiffening, and pressurization. The cycles, over hours to days, initiated when degassed stiff magma retarded flow in the upper conduit. Conduit pressure built with gas exsolution, causing shallow seismicity and edifice inflation. Magma and gas were then expelled and the edifice deflated. The repeat time-scale is controlled by magma ascent rates, degassing, and microlite crystallization kinetics. Cyclic behavior allows short-term forecasting of timing, and of eruption style related to explosivity potential.
We have cloned a human cDNA, SEMP1 (senescence-associated epithelial membrane protein 1), using differential display (DD) of mRNA. We compared mRNA expression profiles between cultured normal senescent human mammary epithelial cells (HMECs) and proliferating, early passage HMECs. From the amino acid sequence of the open reading frame (ORF) of the cDNA, we infer that the protein belongs to a family of membrane-associated, epithelial cell-specific proteins. The translation product has 91% identity to a mouse protein, claudin-1, a tight junction (TJ)-associated protein. SEMP1 mRNA is expressed in human tissues, including adult and fetal liver, pancreas, placenta, adrenals, prostate and ovary but at low or undetectable levels in a number of human breast cancer cell lines. SEMP1 is a member of a superfamily of epithelial membrane proteins (EMPs), which may have multiple potential functions, including maintenance and regulation of cell polarity and permeability, perhaps through mechanisms involving tight junctions.
We examined 15 published continuous family history measures (scores) as well as two new formulations in terms of several desirable properties. We applied the scores to sample pedigrees and found that some systematically increase with family size. In contrast to aggregate scores, non-aggregate scores are sensitive to the age, sex, and covariate status of individual relatives but are unstable when the families are small. We also applied these scores to our own population case-control data, characterised by a high proportion of missing and false-negative responses. In these small families, all scores provided significant discrimination between CHD cases and controls beyond the usual categorical definition of positive family history, but appeared no better than detailed categorical definitions or even simple counts. Our new formulations offer no solution to the problems of few data; most scores apply asymptotic approximations to differences between observed and expected number of affected relatives and are not suited to small families. All scores would be improved by ruling out families with only one affected relative, as is being done in the NHLBI Family Heart Study. We recommend that researchers, when using a family history measure, consider the number of informative families and other characteristics of their data prior to choosing any particular formulation.
We report the case of a 27-week premature infant in whom magnetic resonance imaging (MRI) at 4 postnatal weeks (postconceptional age, 31 weeks), term, and 6 months of age documented the postnatal postmigrational evolution of bilateral perisylvian polymicrogyria. The polymicrogyria was readily detected by ultrafine 1.5-mm coronal slices on three-dimensional, Fourier-transformed, spoiled gradient-recalled and T2-weighted MRI sequences. These MRI sequences provide the first in vivo documentation of the postmigrational evolution of polymicrogyria. The likelihood that the polymicrogyria was related to an ischemic encephaloclastic mechanism is supported by the simultaneous occurrence of periventricular leukomalacia.
Periventricular leukomalacia (PVL), the principal form of brain injury in the premature infant, is characterized by overt focal necrotic lesions in periventricular white matter and less prominent, more diffuse cerebral white matter injury. The early detection of the latter, diffuse component of PVL is not consistently possible with conventional brain imaging techniques. We demonstrate the early detection of the diffuse component of PVL by diffusion-weighted magnetic resonance imaging (DWI). In a premature infant with no definite cerebral abnormality detectable by cranial ultrasonography or conventional magnetic resonance imaging, DWI showed a striking bilateral decrease in water diffusion in cerebral white matter. The DWI abnormality (ie, decreased apparent diffusion coefficient) was similar to that observed with acute cerebral ischemic lesions in adults. At 10 weeks of age, conventional magnetic resonance imaging and ultrasonography showed striking changes consistent with PVL, including the presence of small cysts. The observations indicate the importance of DWI in the early identification of the diffuse component of PVL and also perhaps the role of ischemia in the pathogenesis of the lesion.
OBJECTIVE: African-Americans are at increased risk for type 2 diabetes. We have previously demonstrated that African-American children are hyperinsulinemic and insulin resistant compared with their white American peers. The aim of the present investigation was to assess the impact of family history of type 2 diabetes on insulin sensitivity in African-American children. RESEARCH DESIGN AND METHODS: A total of 13 prepubertal healthy children with negative family history (FH-) and 9 with positive family history (FH+) of type 2 diabetes underwent a 3-h hyperinsulinemic (40 mU x m(-2) x min(-1))-euglycemic clamp study to assess insulin sensitivity. The groups were comparable for age, pubertal status, total body adiposity determined by dual-energy X-ray absorptiometry, abdominal adiposity assessed by computed tomography scan at the level of L4-5 lumbar vertebra, and physical fitness measured by maximal oxygen consumption (VO2max). RESULTS: The FH+, compared with the FH-, group had lower insulin-stimulated glucose disposal (10.9+/-1.2 vs. 14.2+/-0.9 mg x kg(-1) x min(-1), P = 0.035) and lower nonoxidative glucose disposal (5.7+/-0.8 vs. 8.3+/-0.6 mg x kg(-1) x min(-1), P = 0.015), with no differences in rates of glucose oxidation, fat oxidation, or insulin-mediated free fatty acid suppression. Fasting hepatic glucose production assessed with [6,6-2H2]glucose and basal rates of glucose and fat oxidation were not different between the two groups. CONCLUSIONS: These data suggest that in African-American children, family history of type 2 diabetes is a risk factor for insulin resistance. These children manifest important metabolic alterations, including impaired insulin-stimulated total and nonoxidative glucose disposal early in the first decade of life. We propose that this familial tendency, combined with environmental influences, could lead to type 2 diabetes decades later.
BACKGROUND AND PURPOSE: The Emory Functional Ambulation Profile (E-FAP) measures time to walk in different environments and accounts for use of assistive devices. This study assessed the reliability and validity of walking time measurements using these components. SUBJECTS: Twenty-eight subjects who had strokes and 28 subjects without impairment were recruited. METHODS: The E-FAP, Berg Balance Test, Functional Reach Test, and Timed 10-Meter Walk Test were administered in random order during a single data collection session. RESULTS: Interrater reliability for the total E-FAP was > or = .997. Subjects without impairment performed better on all 4 tests than did subjects who had strokes. Increased times on the E-FAP correlated with poor performance on the Berg Balance Test and slow gait speeds on the Timed 10-Meter Walk Test in the subjects who had strokes. The E-FAP scores and the Functional Reach Test scores were not correlated. CONCLUSION AND DISCUSSION: The E-FAP can be administered easily and inexpensively. Because the E-FAP scores differentiated subject groups and correlated with known measures of function, the E-FAP may be a clinically useful measure of ambulation.
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The authors carried out a population-based case-control study to estimate the risk of an acute coronary disease event associated with various definitions of a family history of coronary heart disease (CHD). A detailed family history questionnaire was completed by 403 cases and 236 controls in Newcastle, New South Wales, Australia from 1992 to 1994. Odds ratios of an acute coronary disease event adjusted for proband age and sex ranged from 2.7 (95% confidence interval (CI) 1.8-4.1) for the simplest definition (one or more first-degree relatives with CHD at any age) to 5.4 (95% CI 1.7-16.8) for the most stringent definition (two or more first-degree relatives with CHD before age 55 years). In a series of nested models, the authors examined the improvement in model fit as each component of the detailed family history was added. Additional information was provided by accounting for "don't know" responses, the number of affected relatives, the age of the affected relative, and whether the first-degree relative was a sibling rather than a parent. The results were similar when the data were analyzed as a cohort design with proband disease status as the exposure variable. The authors suggest that, to facilitate preventive efforts in a population, more detailed family history definitions should be used to better target high risk subjects.
AIMS: To use serology to investigate an outbreak of verocytotoxin (VT) producing Escherichia coli O157 in a hospital nursery, following the detection of faecal E coli O157 (phage type 49) producing VT type 2. METHODS: ELISA and immunoblotting techniques, based on lipopolysaccharide (LPS) purified from E coli O157; diagnostic bacteriology; serotyping and phage typing; DNA probes for VT. RESULTS: 29 of 126 sera contained antibodies to the LPS of E coli O157: 10 were from children, three were from staff, and 11 were from hospital kitchen staff. Five parents of children attending the nursery were antibody positive. Sixty four sera from other hospital staff and controls did not contain antibodies to the LPS of E coli O157. CONCLUSIONS: Serology detected evidence of infection with E coli O157 in 23% of sera examined. By bacteriology alone, only a single case of infection with E coli O157 would have been detected. Serology is valuable in providing evidence of infection with E coli O157.
Familial intracranial arteriovenous malformations (AVMs) are rare. We describe a father and son both presenting in childhood with cerebral AVMs. Both patients underwent successful surgical extirpation of the AVM. Familial AVMs present at a young age and tend to be multiple, as was the case in one of our patients. Imaging of asymptomatic family members may detect previously undiagnosed AVMs, and we recommend screening of the relatives of patients with a strong family history of such lesions.
We conducted a retrospective cohort study to assess the risk of amniocentesis in twin pregnancy for adverse outcomes. The study base consisted of women who had an amniocentesis performed during twin pregnancy and a comparison representative sample of women who carried a twin pregnancy, but did not have invasive prenatal diagnosis. The 227 women in each of the exposed and non-exposed groups were residents of the state of New South Wales, Australia, over the period 1980-92, and were matched on maternal age and period of the infant's birth. Nearly 10% of twin pregnancies among the women having an amniocentesis were affected by a stillbirth, and the stillbirth rate among exposed fetuses (5.3%) was nearly twice as high as among non-exposed fetuses (3.1%). After adjustment for confounding and excluding abnormalities, there was a non-significant elevated relative risk of stillbirth after exposure to amniocentesis. The analysis by type of amniocentesis (with and without methylene blue dye) was limited by small numbers, but the burden of risk was primarily among women who had dye exposure during amniocentesis (relative risk = 3.64, 95% confidence interval = 1.15, 11.48). This increase remained after adjusting for confounding, although the confidence interval was wide. In conclusion, we were unable to establish with certainty whether an increased risk of stillbirth could be ruled out among women who had any type of amniocentesis in twin pregnancy.
BACKGROUND: Asthma clinics have become widespread in general practice with nurses now playing an important role in asthma review. However, little is known about training of nurses carrying out reviews and how this affects the nurse role in patient management. OBJECTIVES: We aimed to discover the level of asthma training of practice nurses carrying out review of adult asthma patients in one Health Authority and to see if this has any effect on their perception of their role. METHOD: All 187 practice nurses in Grampian were sent a postal questionnaire investigating how asthma review is organized in general practice, their role in review and the asthma training they had received. Personal interviews were carried out with 17 nurses, exploring in more depth the topics covered in the questionnaire. RESULTS: A total of 167 nurses from 92% of the practices in Grampian responded, of whom 61% carried out asthma reviews. Among nurses carrying out reviews 71% did so on their own. 49% of nurses had or were training for advanced asthma qualification. Nurses without an asthma qualification were significantly more likely to feel that their training was not sufficient for their asthma related tasks (54% versus 11%, P = 0.0002). Nurses without advanced asthma qualifications were less likely to provide or review a self-management plan (29% versus 49%, P = 0.01), to review patient PEF recording (38% versus 65%, P < 0.01), to discuss patient worries (75% versus 94%, P < 0.05) or to make the initial diagnosis of asthma (24% versus 76%, P < 0.005). Nurses were unlikely to view their role as fully responsible unless they had an asthma qualification (13% versus 49%, P < 0.001). CONCLUSION: Nurses without advanced asthma qualifications do not feel fully confident in responsibility for patient management. Nurses without training are more likely to only carry out routine monitoring at reviews while nurses with asthma training are more likely to actively develop patient self-management skills. This suggests that nurses should be supported to obtain asthma qualifications if they are to give the best possible care to asthma patients.
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We attempted to ascertain renal, hematologic, and neurologic tolerance to ifosfamide (IFX) in pediatric patients previously treated with large single and cumulative doses of cis-Diamminedichloroplatinum-II (CDP) for osteosarcoma (OS). Twenty OS patients were treated with CDP: initially 150 mg/m2 was administered every 2 weeks for a maximum of seven courses. Later, other agents, including additional CDP, were also administered. Twelve patients were treated with intra-arterial CDP, one with intra-arterial, and later intravenous CDP, and seven with intravenous CDP. Patients who relapsed were treated with IFX. Renal function was monitored by measuring creatinine clearance, serum electrolytes, total protein, albumin and CO2 content, and urine analysis during IFX therapy. Prior to initiation of IFX, creatinine clearance was above 60 ml/min/m2 in all except one patient who had developed a hemolytic uremic syndrome (HUS). Cumulative CDP doses ranged from 300 to 22,500 mg/m2, and cumulative IFX doses 12 to 128 gm/m2. Myelosuppression was monitored by obtaining routine hemograms midway between each course of treatment. Neurologic tolerance was assessed by reviewing the medical records for any abnormality. The interval between CDP and IFX ranged from 1 to 64 months. All patients experienced a progressive reduction in creatinine clearance with CDP. The reduction in creatinine clearance, measured from base-line after three to four courses varied from 10 to 53.7%, after four to seven courses from 19 to 78%, and after seven courses from 12 to 80.5%. In all patients except five, including the HUS patient, creatinine clearance remained above 60 ml/min/m2 during IFX therapy. Twelve patients developed hypo-magnesemia in the vicinity of 1.4 to 1.6 mg/dl during CDP treatment and required magnesium supplementation. They were asymptomatic and the abnormality did not affect IFX tolerance. Fourteen patients intermittently displayed variable degrees of glycosuria, phosphaturia, and/or proteinuria during IFX therapy. This was considered to be a forma frustre type of Fanconi's syndrome. Approximately 80% of courses of IFX were associated with reversible myelosuppression. No neurologic abnormalities were detected. The abnormalities detected during IFX treatment were not major, did not give rise to symptomatology, and did not require discontinuation of therapy. Renal abnormalities were considered a forma frustre type of Fanconi's syndrome. Provided a creatinine clearance of 60 ml/min/m2 is accepted as a prerequisite for treatment, and no major preexisting renal disease is present, IFX is well tolerated by most patients previously exposed to very high cumulative doses of CDP.
Methylene blue dye use during mid-trimester amniocentesis in twin pregnancy is associated with a high risk of small intestinal atresia. It is plausible that the effects of methylene blue as a fetotoxic agent may also lead to fetal death. We conducted a retrospective cohort study of all women who had an amniocentesis during twin pregnancy from 1980 through 1991 in New South Wales, Australia. Women who were exposed to methylene blue dye during the procedure were compared with women who had amniocentesis without dye exposure. Fetal death occurred in 31.8 per cent of pregnancies that had exposure to a high concentration of methylene blue, compared with 14.5 per cent of pregnancies exposed to a low concentration and 4.3 per cent of pregnancies with no exposure to dye. The unadjusted and adjusted risks and 95 per cent confidence intervals (CIs) for fetal death after any exposure to dye were 5.03 (2.12-11.91) and 8.52 (2.28-31.80), respectively. The adjusted odds ratio and 95 per cent CIs for the low and high concentration dye solutions were 4.63 (0.93-23.13) and 14.98 (3.40-66.08), respectively (chi-squared test for trend P < 0.001). Fetus papyraceous was significantly more likely among pregnancies exposed to a high concentration of methylene blue (P < 0.001) than among unexposed pregnancies. These results support the hypothesis that methylene blue dye use during mid-trimester amniocentesis in twin pregnancy increases the risk of fetal death.
BACKGROUND: Missed injuries can lead to delays. In the rural environment, where patients are frequently seen in multiple hospitals prior to reaching the trauma center, different problems arise. METHODS: Level-1 trauma center admissions from January 1993 through June 1995 were reviewed. Missed injuries were those not identified within 24 hours of injury. Data extracted included demographics, mechanism, severity and outcome. Comparisons were made between missed injury patients and typical trauma patients. RESULTS: Of 3,996 patients, 70 missed injuries were identified in 56 patients. Compared with typical trauma patients, missed injury patients suffered more blunt trauma, were more severely injured, had longer intensive care unit and hospital stays, and a lower mortality rate. Transferred patients accounted for 60% of missed injuries. CONCLUSIONS: Transferred patients with blunt injury have the highest risk for missed injury. Delayed transports and prior examination may contribute to complacency. All trauma patients must be repeatedly evaluated thoroughly, and all diagnostic studies reviewed for adequacy.