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Biomedical subjects

M E Burke

Publications and source records attributed to M E Burke.

18 recordsLinked to original sources
PubMed1998

Comparison of articulate brachiopod nuclear and mitochondrial gene trees leads to a clade-based redefinition of protostomes (Protostomozoa) and deuterostomes (Deuterostomozoa)

Nuclear and mtDNA sequences from selected short-looped terebratuloid (terebratulacean) articulate brachiopods yield congruent and genetically independent phylogenetic reconstructions by parsimony, neighbour-joining and maximum likelihood methods, suggesting that both sources of data are reliable guides to brachiopod species phylogeny. The present-day genealogical relationships and geographical distributions of the tested terebratuloid brachiopods are consistent with a tethyan dispersal and subsequent radiation. Concordance of nuclear and mitochondrial gene phylogenies reinforces previous indications that articulate brachiopods, inarticulate brachiopods, phoronids and ectoprocts cluster with other organisms generally regarded as protostomes. Since ontogeny and morphology in brachiopods, ectoprocts and phoronids depart in important respects from those features supposedly diagnostic of protostomes, this demonstrates that the operational definition of protostomy by the usual ontological characters must be misleading or unreliable. New, molecular, operational definitions are proposed to replace the traditional criteria for the recognition of protostomes and deuterostomes, and the clade-based terms 'Protostomoza' and 'Deuterostomozoa' are proposed to replace the existing term 'Protostomia' and 'Deuterostomia'.

Animals↗
PubMed1998

Transbronchial lung biopsy: can specimen quality be predicted at the time of biopsy?

STUDY OBJECTIVES: To determine the bronchoscopist's ability to predict specimen quality at the time of transbronchial biopsy and to determine the influence of biopsy specimen size and alveolar content on diagnostic value. DESIGN: Prospective, blinded, observational analysis. SETTING: Tertiary care academic hospital-based pulmonary practice. PATIENTS: Forty-three adult patients who underwent transbronchial lung biopsy. INTERVENTIONS: Each of 170 biopsy specimens was rated as to likelihood of containing diagnostic tissue, size and ability to float, tissue types present, number of alveoli, and pathologic diagnosis. RESULTS: Fifteen percent of biopsy specimens were small and 40% were large. Seventy-six percent of specimens floated; 61.8% of the 170 biopsy specimens contained abnormal lung tissue; and 14.7% of individual specimens were diagnostic. Fifty-two percent of specimens contained >20 alveoli. Larger biopsy specimens were more likely to contain diagnostic tissue (r=0.29, p=0.001). Cup forceps retrieved smaller pieces of tissue (p=0.007) and were less likely to obtain diagnostic tissue (p=0.06). Physician ratings of specimen quality (mean+/-SD) did not differ between specimens containing normal and abnormal tissue (5.98+/-2.3 vs 5.46+/-5.5; p=0.24) or between specimens containing diagnostic vs nondiagnostic tissue (5.56+/-2.5 vs 6.25+/-2.1; p=0.14). Specimens that floated were no more likely to be diagnostic or abnormal than specimens that sank (p<0.05). Diagnosis when established was made by the first biopsy specimen in 53.3% and the second in 33.3% CONCLUSIONS: Physician estimate of biopsy specimen quality and the float sign are not helpful in predicting that the biopsy specimen contains abnormal or diagnostic tissue. Diagnostic biopsy specimen will likely be obtained if the size of the specimen fills the forceps, 2 to 4 biopsies are performed, and toothed forceps are used.

Adult↗
PubMed1996

Fetal hyperinsulinism at 14-20 weeks and subsequent gestational diabetes.

OBJECTIVE: To examine the predictive value of amniotic fluid (AF) insulin at 14-20 weeks' gestation for subsequent gestational diabetes and macrosomia in unselected gravidas 35 years or older at time of genetic amniocentesis. METHODS: We identified 296 pregnancies through stored AF samples from genetic amniocenteses (collected March 1987 through August 1992) in women meeting the following criteria: age 35 years or older, amniocentesis at 14-20 weeks, performance of a 50-g glucose challenge test, and adequate delivery data. RESULTS: A modified double-antibody radioimmunoassay reliably measured AF insulin with a detection limit of 0.35 microU/mL. Pregnant women in whom gestational diabetes was later diagnosed had higher median AF insulin levels than women who did not (0.60 versus 0.42 microU/mL, respectively; P = .026). A stepwise logistic regression analysis of gestational age at amniocentesis, maternal second-trimester weight, maternal age, and log AF insulin value on gestational diabetes showed only AF insulin to have a significant association with gestational diabetes (P = .004). Seven of 21 cases of gestational diabetes had AF insulin values exceeding the 95th percentile (1.33 microU/mL) compared with only 14 of 275 women with normal glucose tolerance (P < .001). Amniotic fluid insulin did not predict macrosomia in either nondiabetic or gestational diabetic pregnancies. CONCLUSION: Gestational diabetes is associated with increased AF insulin at 14-20 weeks, suggesting augmentation of fetal insulin production in the early fetal period in at least some cases of gestational diabetes.

Adult↗
PubMed1994

Peptidase activity of Escherichia coli aminopeptidase A is not required for its role in Xer site-specific recombination.

Xer site-specific recombination is required for the stable inheritance of multicopy plasmids and the normal segregation of the bacterial chromosome in Escherichia coli. Two related recombinases and two accessory proteins are essential for Xer-mediated recombination at cer, a recombination site in the plasmid ColE1. The accessory proteins, ArgR and PepA, function in ensuring that the Xer recombination reaction acts exclusively intramolecularly, converting plasmid dimers into monomers and not vice versa. PepA is an amino-exopeptidase, but its molecular role in the Xer recombination mechanism is unclear. Here we show that a mutation directed at the presumptive active site of PepA creates a protein with no detectable peptidase activity in vitro or in vivo, but which still functions normally in Xer site-specific recombination at cer.

Amino Acid Sequence↗
PubMed1994

Critical care obstetrics: experts' round table discussion.

A panel of leading experts in critical care obstetric (CCOB) nursing met to discuss the specialty and its future, the impact of changes in the health care system, educational opportunities to learn and update CCOB nursing, formation and use of standards for the specialty, patient placement (dedicated obstetric intensive care units [OB ICU], labor and delivery intensive care units [L & D ICU], regular intensive care units [ICU]), patient populations, and interactions and working relationships with the physicians who care for CCOB patients (perinatologists, obstetricians, internists, obstetric medicine specialists, anesthesiologists, other subspecialists). The topics for discussion were chosen by Carol J. Harvey, RNC, MS, who acted as moderator and Mary Ellen Burke, RN, MS, coordinated the publication of the discussion.

Critical Care↗
PubMed1993

Myasthenia gravis and pregnancy.

Pregnancy is certainly an option open to patients with myasthenia gravis. Preconceptional counseling is the ideal, with the goal of discontinuing or reducing corticosteroid medications in patients requiring those agents. Alterations in physiology will require ongoing and careful assessment of the pregnant myasthenic or cholinergic crises. Antenatal testing for fetal well-being may be difficult to interpret. A small number of fetuses with fetal myasthenia gravis will be diagnosed by ultrasound. Attempts may be made to decrease the amount of circulating antibody crossing to the fetus. Interventions may include starting or increasing corticosteroid therapy, therapy with azathioprine, or plasmapheresis. Thymectomy is usually not performed during pregnancy. The intrapartum period will increase fatigue in the mother and may precipitate a myasthenic crisis. Epidural anesthesia is currently the agent of choice for decreasing pain and fatigue. An outlet forceps or vacuum delivery will shorten the second stage of labor in those patients who are unable to push repetitively. Cesarean delivery is preferably avoided in those patients at risk for pulmonary and thrombo-embolic complications. Narcotic and sedative medications may be used in the presence of careful and continuous assessment; they may increase respiratory and muscular symptoms. The postpartum period may be associated with an increase in exacerbations. Support services may help to eliminate or to reduce potent stressors during this time. Medication dosages may need to be adjusted as the mother's body returns to her prepregnant state. Transient, neonatal myasthenia is seen in up to 21% of maternal myasthenic cases, even in those patients with no detectable circulating antibody.

Adrenal Cortex Hormones↗
PubMed1991

ECG interpretation for obstetric nurses.

Obstetric nurses are not routinely called on to perform continuous cardiac monitoring or ECGs. However, obstetric nurses will be caring for most pregnant women with cardiac complications. Basic and advanced ECG courses and Advanced Cardiac Life Support (ACLS) courses are offered at most hospitals. Obstetric nurses are encouraged to take advantage of these courses, as even nurses in Level I institutions are caring for patients on continuous ECG monitors. A basic understanding of the ECG is expected of all nurses. Obstetric nurses are encouraged to participate in an ACLS program. Full reviews of the anatomy, physiology, and electrical pathways are available in numerous texts.

Electrocardiography↗
PubMed1990

Chronic renal disease and pregnancy.

Women who have chronic renal disease are at increased risk for maternal and fetal morbidity and mortality during pregnancy. The severity of the renal disease is correlated with the degree of morbidity and mortality. Chronic renal disease ranges from asymptomatic bacteriuria (ASB) to end stage renal disease requiring hemodialysis and/or renal transplantation. Pregnant women with chronic renal disease require specialized nursing care. Communication between obstetrical nurses and renal nurses is extremely important to ensure holistic care of these patients.

Counseling↗
PubMed1990

Anorexia nervosa and bulimia nervosa: chronic conditions affecting pregnancy.

Anorexia nervosa and bulimia nervosa primarily affect women who are in the childbearing years. While many anorectic patients are unable to ovulate second to the disruptions of normal body function associated with anorexia, there are still women who will ovulate and become pregnant. Bulimia nervosa may also disrupt the normal menstrual cycle if the disease is very severe. However, many bulimic patients will become pregnant. Both of these disease states cause a decrease in circulating plasma volume, fluid and electrolyte shifts, and other alterations that may increase the risk to a pregnancy and developing fetus. Severe disease states are associated with intrauterine fetal growth retardation (IUGR). The nursing care of the anorectic or bulimic patient who becomes pregnant is specialized and requires coordination between nursing, perinatology, and the psychiatric team, as well as support services including nutritionists. The nursing care of anorectic patients is difficult and requires an understanding of the complex psychological and physical pathophysiology of the disease. Bulimia nervosa also requires a complete understanding of the psychological and pathophysiology of the disease process. This article provides a review of the syndromes, risk factors, definitions of the disease states, and the nursing management of those patients experiencing a pregnancy complicated by the predisposing factors of anorexia nervosa, and/or bulimia nervosa.

Adult↗
PubMed1974

Distribution of purple photosynthetic bacteria in wetland and woodland habitats of central and northern Minnesota.

Enrichment cultures for purple nonsulfur and sulfur photosynthetic bacteria were prepared from soil samples collected in central and northern Minnesota. The purple nonsulfur bacteria were found in most wetland soils sampled but were uncommon in woodland and grassland soils. The pH range of the soils in which these bacteria occurred was 3.8 to 7.8, and the oxidation-reduction potential (E(h)) range was +510 to -65 mV. Soils with a pH below 5.0 or an E(h) above +370 mV had few purple nonsulfur bacteria (<10/g of soil). Rhodopseudomonas viridis, a photosynthetic bacterium containing bacteriochlorophyll b, and the purple sulfur bacteria were common only in low-acidity wetland soils that were usually being reduced.

Bacteria↗
PubMed1967

Purification and characterization of a staphylolytic enzyme from Pseudomonas aeruginosa.

A strain of Pseudomonas aeruginosa has been shown to produce an enzyme that lyses viable cells of Staphylococcus aureus. The maximal yield of the enzyme was obtained from shake flask cultures of P. aeruginosa which were grown for 18 to 22 hr at 37 C in Trypticase Soy Broth. A 333-fold purification of the enzyme was obtained by acetone precipitation of the culture liquor, followed by column chromatography on phosphonic acid cellulose and Bio-Gel P2. The staphylolytic enzyme exhibited maximal activity at 37 C in 0.01 m sodium phosphate (pH 8.5) and was stable at 37 C in the pH range of 7.5 to 9.5. The inhibition and stabilization of the enzyme by various organic and inorganic materials was investigated. Spheroplasts of S. aureus were formed by treating viable cells with the staphylolytic enzyme in 1 m sucrose or human serum.

Bacteriolysis↗