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Biomedical subjects

E Morgan

Publications and source records attributed to E Morgan.

At least 55 records · Page 3Linked to original sources

An investigation of natural genetic variation in the circadian system of Drosophila melanogaster: rhythm characteristics and methods of quantification.

Variation in four characteristics of the circadian locomotor activity rhythm was investigated in 24 true-breeding strains of Drosophila melanogaster with a view to establishing methods of phenotypic measurement sufficiently robust to allow subsequent biometric analysis. Between them, these strains formed a representative sample of the genetic variability of a natural population. Period, phase, definition (the degree to which a rhythmic signal was obscured by noise), and rhythm waveform were all found to vary continuously among the strains, although within each strain the rhythm phenotype was remarkably consistent. Each characteristic was found to be sufficiently robust to permit objective measurement using several different methods of quantification, which were then compared.

Animals↗

Diversity among seniors. A Toledo, OH, hospital assesses the healthcare needs of elderly African Americans and Hispanics.

In 1992, leaders at Mercy Hospital, Toledo, OH, realized the facility's outreach programs were not reaching as many elderly African-American and Hispanic residents from the surrounding neighborhood as they would have liked. Mercy's leaders therefore decided that the hospital could offer cultural-specific programs that better meet the healthcare needs of these populations. To secure residents' perspective, an assessment process was launched. The data gathered from participants in face-to-face interviews revealed that some had problems with access to healthcare. A lack of money and other resources seemed to be the major barriers to care. The key concern of the elderly persons interviewed is securing personalized care or services that help them maintain their independence. A number of participants wanted free transportation (other than to and from the hospital). They need help getting to their physician's office, the pharmacy, the grocery store, and the bank. Public agencies may offer such transportation services. In addition, the Hispanic elderly interviewed would like to see Spanish-speaking personnel in admissions and the emergency department.

Black or African American↗

Catamenial haemoptysis: a rare cause.

Since the first report of pulmonary endometriosis as a cause of catamenial haemoptysis all cases have been assumed to be due to pulmonary endometriosis, even in the absence of histopathological proof. A case is presented where the histological findings were of a pulmonary arteriovenous malformation.

Adult↗

Ultrastructural identification of exocytosis of granules from human gut eosinophils in vivo.

Twenty-two percent of 117 biopsies of human intestinal tissues had ultrastructural images of classical regulated secretion from eosinophils in vivo i.e. eosinophil granule extrusion (EGE). Replicate intestinal biopsies that were positive for bacteria had EGE more often than not (p < 0.05); 77% of the isolates were Staphylococci. Some of the intestinal biopsies also had damaged nerves; all that had EGE and damaged enteric nerves also had positive bacterial cultures. The EGE that we observed could not account for all enteric nerve damage, suggesting multifactorial mechanisms for nerve damage in gut tissues. Among the possibilities are release of neurotoxic eosinophil granule proteins by an alternate secretory route, i.e., piecemeal degranulation, direct toxicity of tissue invasive bacteria and/or damaged nerves of unknown etiology such as those that are regularly present in uninvolved tissues of patients with Crohn's disease.

Axons↗

Bipedalism.

Reasons why mammalian bipedalism is so rare. Problems encountered by the larger arboreal mammals when they descend to ground level. Reasons for believing that hominid ancestors were never knuckle-walkers. Primate models which combine arboreal life with incipient bipedalism. Disadvantages of mammalian bipedalism. Critique of some of the savannah-based theories on the origins of human bipedalism.

Animals↗

Is type II diabetes mellitus (NIDDM) a surgical disease?

Since February 1, 1980, 515 morbidly obese patients have undergone the Greenville gastric bypass (GGB) operation. Of these, 212 (41.2%) were euglycemic, 288 (55.9%) were either diabetic or had glucose intolerance, and 15 (2.9%) were unable to complete the evaluation. After the operation, only 30 (5.8%) patients remained diabetic (and 20 of these improved), 457 (88.7%) became and have remained euglycemic, and inadequate data prevented classification of the other 28 (5.4%). The patients who failed to return to normal glucose values were older and their diabetes was of longer duration than those who did. The effect of the GGB was not only limited to the correction of abnormal glucose levels. The GGB also corrected the abnormal levels of fasting insulin and glycosylated hemoglobin in a cohort of 52 consecutive severely obese patients with non-insulin-dependent diabetes. The GGB effectively controls weight. If morbid obesity is defined as 100 pounds over ideal body weight, 89% of the patients are no longer "morbidly" obese within 2 years. In most patients, the control of the weight has been well maintained during the 11 years of follow-up; most of the upward creep in weight of 20.8% between 24 and 132 months was from the 49 (9.5%) patients who had staple line breakdowns between the large and small gastric pouches. Non-insulin-dependent diabetes, previously considered a chronic unrelenting disease, can be controlled in the severely obese by the gastric bypass. Whether the correction of glucose metabolism affects the complications of diabetes is unknown. Whether the gastric bypass should be considered for patients with advanced non-insulin-dependent diabetes but who are not severely obese deserves consideration. The GGB has an unacceptably high rate of staple line failure. Accordingly, the authors have recently changed their procedure to one that divides the stomach rather than partitions it with staples.

Adolescent↗

Human gut mucosal mast cells: ultrastructural observations and anatomic variation in mast cell-nerve associations in vivo.

One hundred and seventeen coded intestinal biopsy specimens were examined by electron microscopy. All surgical biopsies were obtained from uninvolved sites of patients with two inflammatory bowel diseases (ulcerative colitis or Crohn's disease) and from patients with preneoplastic and neoplastic diseases (adenocarcinoma, rectal polyp, familial polyposis). Biopsy sites included normal ileum, colon, and rectum as well as conventional ileostomies and continent pouches constructed from the ileum. The data reported here describe the ultrastructural anatomy of human gastrointestinal tract mucosal mast cells in vivo and their anatomic associations with enteric nerves.

Adenocarcinoma↗

Ultrastructural evidence for piecemeal and anaphylactic degranulation of human gut mucosal mast cells in vivo.

One hundred and seventeen coded intestinal biopsies were examined by electron microscopy and evaluated for morphological evidence of mast cell and basophil secretion in situ. Sixty percent of the biopsies had evidence of secretion. Mast cell secretion was evident in control biopsies, many of which were obtained from uninvolved tissues of patients with inflammatory bowel disease. Biopsies of inflamed continent pouches from ulcerative colitis (UC) patients showed more mast cell secretion than noninflamed UC pouch biopsies. This evidence of mast cell secretion supports recent work that documents high constitutive levels of histamine in jejunal fluids of Crohn's disease patients and suggests a proinflammatory role for mast cells in inflammation associated with pouchitis.

Basophils↗

Ultrastructural immunogold localization of prostaglandin endoperoxide synthase (cyclooxygenase) to non-membrane-bound cytoplasmic lipid bodies in human lung mast cells, alveolar macrophages, type II pneumocytes, and neutrophils.

Lipid bodies are non-membrane-bound, lipid-rich cytoplasmic inclusions that occur in many mammalian cell types. Because lipid bodies are more prominent in cells associated with inflammation and are repositories of arachidonyl-phospholipids, a role for lipid bodies in the oxidative metabolism of arachidonic acid to form eicosanoids has been suggested. To evaluate further whether lipid bodies, in addition to serving as non-membranous sources of substrate arachidonate, are involved in eicosanoid formation, we used cells isolated from human lung to investigate the intracellular localization of prostaglandin endoperoxide (PGH) synthase (cyclooxygenase), the key initial, rate-limiting enzyme in the formation of prostaglandins and thromboxanes. Isolated lung cells containing a mixture of mast cells, alveolar macrophages, Type II alveolar pneumocytes, and neutrophils from short-term cultures were fixed in suspension in a dilute aldehyde mixture, post-fixed in osmium tetroxide, stained en bloc with uranyl acetate, dehydrated in a graded series of alcohols, and embedded in Epon. A post-embedding immunogold procedure was used with a primary PGH synthase monoclonal antibody and 20-nm gold-conjugated secondary antibody to demonstrate enzyme locations. Specificity controls were also done. We found PGH synthase in lipid bodies of human lung mast cells, alveolar macrophages, Type II alveolar pneumocytes, and neutrophils. Specific secretory and lysosomal granules and plasma membranes did not express PGH synthase. Specificity controls, including omission of the primary antibody or substitution with an irrelevant antibody, were negative. Absorption of the specific PGH synthase antibody with purified solid-phase PGH synthase resulted in a marked reduction of label in lipid bodies of all four cell types. These findings establish the presence of PGH synthase in lipid bodies of human lung mast cells, alveolar macrophages, Type II alveolar pneumocytes, and neutrophils and, in concert with previous studies, suggest that these cytoplasmic lipid-rich organelles may be non-membrane sites of eicosanoid formation.

Cells, Cultured↗

Evaluation of LY203647 on cardiovascular leukotriene D4 receptors and myocardial reperfusion injury.

In vitro studies have shown LY203647 to be a selective antagonist of contractile responses to leukotriene (LT) D4 and LTE4 in guinea pig ileum, trachea and lung parenchyma. In pithed rat, i.v. injection of LTD4 produced pressor responses that were selectively antagonized by LY203647 in a dose-dependent manner [ED50 7.5 (6.0-9.5) mg/kg, i.v.]. In normal anesthetized rats and dogs, LTD4 reduced aortic blood flow and stroke volume in association with systemic vasoconstriction, variable blood pressure responses and no change in cardiac rate. LTD4 did not alter myocardial contractility corrected for alterations in afterload. Pretreatment of rats and dogs with LY203647 (1-10 mg/kg, i.v.) produced dose-related inhibition of the myocardial and systemic hemodynamic effects of LTD4, whereas coadministration of LY203647 reversed established myocardial depression and systemic and pulmonary vasoconstriction during continuous infusion of LTD4 in dogs. LY203647 (10 mg/kg over 90 min, i.v.) infusion in normal dogs abolished or greatly antagonized hemodynamic responses to LTD4 for 6 hr. In subsequent experiments, myocardial infarct size was measured after 1 hr of occlusion of the circumflex coronary artery and 5 hr of reperfusion. LY203647 (10 mg/kg over 90 min, i.v.) treatment did not alter cardiovascular parameters when compared to time-related alterations observed in control dogs. ST segment deviation and the intensity and duration of cardiac arrhythmias associated with coronary artery occlusion and reperfusion also were similar between groups. Resultant infarct sizes were 46 +/- 1 and 45 +/- 1% of the left ventricular mass placed at risk in control and LY203647-treated dogs, respectively. Present data illustrate the prominent cardiac and systemic hemodynamic effects of LTD4 and indicate that LY203647 produces selective and sustained antagonism of cardiovascular LTD4 receptors. Lack of containment of infarction by LY203647 suggests that endogenous cysteinyl-LT do not contribute to reperfusion injury of ischemic myocardium.

Acetophenones↗

Plasma concentration of furosemide versus specific gravity of urine in predicting dose of administration in race horses.

This study was undertaken to determine the applicability of plasma concentration of furosemide and specific gravity (SG) of urine in regulating the use of furosemide administered 4 hours prior to race time in Exercise-Induced Pulmonary Hemorrhage (EIPH) race horses. Nonbleeders (CTL) and certified bleeders (FUR) actively racing in Illinois (IL) and Pennsylvania (PA) were used in the study. Various doses (less than 250, 250, 300, 350, 400 and 500 mg) were administered either as a single intravenous (IV) dose or as a combination (IV-IM) of IV and intramuscular (IM) administrations 4 hours before race time. Plasma and urine samples were obtained post race for determination of furosemide concentration in plasma and measurement of SG of the urine in both CTL and FUR groups. Plasma samples were analyzed for furosemide using High Performance Liquid Chromatography with Fluorescence Detection. SG was measured using a digital refractometer. The results indicate a significant difference (p less than 0.0001) in the SG of the urine samples between the CTL and FUR groups irrespective of the route of administration (IV versus IV-IM). However, SG values of the urine in some CTL samples were lower than those in some FUR samples and vice versa. Thus, the use of SG alone is not reliable for predicting either the dose or the administration of furosemide to race horses. The plasma concentrations of furosemide following the administration (IV) of 250 mg or 500 mg 4 hours prior to race time were indistinguishable (25.91 +/- 4.45 versus 28.12 +/- 6.99 ng/ml, respectively); the majority of the horses in the groups had a plasma concentration of less than 40 ng/ml. When taken in total, plasma concentration of furosemide can only be used as a guide in regulating the administration of furosemide to race horses.

Animals↗

An ultrastructural analysis of tumor-promoting phorbol diester-induced degranulation of human basophils.

Release reactions stimulated in human basophils by a variety of secretagogues show biochemical and morphologic differences as well as similarities. Biochemical differences include those of rate, amount, and order of mediator release, as well as mediator type released or generated. Morphologic diversity of release reactions includes prototypic anaphylactic degranulation (AND), or piecemeal degranulation (PMD), and a continuum of anatomic release comprised of PMD followed by AND that is seen when human basophils are stimulated by the bacterial peptide, formyl methionyl leucyl phenylalanine (FMLP). AND is characterized by extrusion of membrane-free granules through multiple plasma membrane pores; PMD is characterized by partially to completely empty, nonfused granule containers in the cytoplasm of basophils. AND is further characterized by diminished-to-absent granules and reduced cytoplasmic vesicles at peak histamine release intervals; PMD does not show decreases in numbers of granules, and cytoplasmic vesicles are plentiful. Smooth membrane-bound vesicles with granule particles and vesicles that appear empty comprise this organelle population. PMD is the single most evident activation change present in basophils that traffic into tissues in multiple diseases in vivo. In this study, we examined the ultrastructural kinetic morphology associated with stimulation of human basophils with tetradecanoyl phorbol acetate (TPA)--a tumor-promoting phorbol diester known to elicit histamine (but not LTC4) release. Partially purified human basophils were prepared for electron microscopy and examined either after control incubations in buffer alone or at 0 time, 1, 2, 5, 10, 30, and 45 minutes after TPA stimulation. Standard morphology and ultrastructural quantitation of vesicles and granules and contents of vesicles or alteration of granules was done and compared with previous ultrastructural kinetic analyses of human basophil release reactions stimulated by different triggers. Like biochemical studies that have determined that TPA is a unique secretogogue for human basophils, the morphology stimulated by TPA and associated with histamine release was also unique. For example, very minor images of AND were evident. Far greater amounts of PMD were imaged. PMD was associated with approximately 50% alteration of cytoplasmic granules by 45 minutes after TPA stimulation. This evidence of empty granules was associated with, and preceded by, a rapid, extensive, and sustained increase in particle-containing cytoplasmic vesicles, as compared with buffer controls (P < 0.001 for each TPA stimulation time compared with unstimulated basophils). In addition, previously undescribed interactions of releasing granules and their overlying plasma membranes characterized TPA-stimulated cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Basophils↗

Effects of short-term isolation on the locomotor activity of the angelfish (Pterophyllum scalare).

Two experiments were conducted to test in angelfish (Pterophyllum scalare) some implications of Gallup and Suarez's (1980) ethological model of open-field behavior and to differentiate between the initial locomotor effects of a novel environment and those of isolation per se. Juveniles placed alone in a novel environment initially showed increased locomotion compared with their previous level when kept as a group and with that of fish placed in the novel environment in groups of three and five. When placed alone in a novel tank, individuals that had already been isolated for 10 days moved about less than those that had been isolated for 4 days. During isolation, angelfish significantly reduced activity to a minimum after 3 to 4 days, and after 10 days the level was still lower than in the group situation. The results suggest that, in addition to birds and rodents, Gallup and Suarez's model is applicable to fish and may account for the effects of longer exposure to a novel environment.

Animals↗

Impact of chromosomal translocations on prognosis in childhood acute lymphoblastic leukemia.

The presence of a chromosomal translocation in the leukemic cells at diagnosis of acute lymphoblastic leukemia (ALL) in children is associated with a high risk for treatment failure. We have reexamined the relationship between translocations and prognosis in 146 children with ALL who received risk-based therapy such that high-risk patients were treated with intensive drug schedules. In univariate analysis, multiple factors were associated with a relatively poor event-free survival (EFS) including age less than 2 years or greater than 10 years (combined group), WBC count greater than 10 x 10(9)/L, French-American-British (FAB) morphologic classification L2, absence of common ALL antigen (CALLA, CD10) expression, absence of hyperdiploidy with a chromosome number of 50 to 60, and presence of the specific translocations t(4; 11)(q21;q23) or t(9;22)(q34;q11) (combined group). However, there was no disadvantage with respect to EFS in patients with translocations compared with those who lacked translocations (73% at 4 years in both groups). Furthermore, when patients with specific cytogenetic abnormalities for which the prognostic significance has been well established (hyperdiploid 50 to 60, t(4;11), and t(9;22] were removed from the analysis, the remaining group with other translocations had a better EFS than the remaining group lacking translocations, although this was not statistically significant (81% v 65% at 4 years, P = .24). In a multivariate analysis, a model including WBC count and FAB classification was the strongest predictor of EFS. The presence or absence of translocations was not an independent predictor of EFS and did not contribute to the ability of any model to predict EFS. In conclusion, when effective intensive therapy is used to treat childhood ALL with high-risk clinical features, categorization of patients on the basis of chromosomal translocations without attention to the specific abnormality is not useful as a prognostic factor.

Adolescent↗

An appraisal of tidal activity rhythms.

Organisms of the marine littoral zone experience a much wider range of periodicities in their environment than do their terrestrial counterparts. Tidal cycles of semidiurnal, diurnal, lunar, and semilunar frequencies may all recur at the same locality, in addition to the diel cycle of light and darkness. The relationship of endogenous activity patterns to the prevailing geophysical variables thus poses problems for the temporal organization of the organism. The way in which intertidal animals synchronize their behaviour and physiology to such a diversely fluctuating environment, and the efficacy of different environmental factors as entraining agents is considered. Evidence pertaining to the endogenous control mechanisms, both physiological and behavioural, is reviewed, and the organization of the endogenous time-keeping system discussed in terms of identifiable oscillators of different frequencies.

Animals↗