Conidial germination patterns in powdery mildews.

Four conidial germination types namely, polygoni (syn. Pseudoidium), cichoracearum (syn. Reticuloidium), pannosa (syn. Fibroidium) and fuliginea (syn. Magnicellulatae) are commonly used as an aid in the identification of the Oidium anamorphs of powdery mildews. However, results of germination tests and a survey of the literature showed that these types did not adequately distinguish all taxa and did not reflect the range of species covered. Hence two new main types, Striatoidium and Blumeria, are proposed for the newly created genus Neoerysiphe and for the unique pattern of B. graminis. Two new names, orthotubus and brevitubus subtypes of Fibroidium, are proposed for the pannosa and fuliginea types respectively. Also proposed is a special longitubus pattern for the long, undifferentiated, negatively hydrotropic germ tubes prevalent in Erysiphe trifolii and species in Golovinomyces sect. Depressi. The recognition of the Striatoidium type of N. galeopsidis as distinct from the Pseudoidium type of E. elevata facilitated the detection of a simultaneous infection of Catalpa by these two powdery mildews. A key is provided for the identification of Oidium genera based on germination types. A review of germination patterns in the tribe Phyllactinieae found no consistent differences amongst the genera. Golovinomyces sect. Depressi is re-described to accommodate Golovinomyces spp. often having a longitubus pattern of germination. It includes G. cichoracearum var. latisporus, now considered a separate species based on its germination type, other anamorphic morphology and previous molecular sequence analyses. A new combination, Golovinomyces ambrosiae, is proposed for this species. Other anomalies within G. cichoracearum s. lat. were addressed by proposing another new combination, G. fischeri for the former G. cichoracearum var. fischeri that differs from G. cichoracearum s. str. in having larger chasmothecia and a well distinguished anamorph, and by proposing a new species, G. sonchicola, that is biologically, phylogenetically and morphologically distinct from G. cichoracearum s. str.

The tolerance of the field slug Deroceras reticulatum to freezing temperatures.

Cold hardiness of ectotherms has been widely studied in arthropods, but there is a more limited literature on the survival of molluscs at low temperatures. A number of intertidal species have been examined in detail, but terrestrial molluscs have largely been overlooked until recently. This paper reports results of laboratory experiments to evaluate the cold hardiness of the terrestrial slug, Deroceras reticulatum. The mean supercooling point (SCP) rose from -4.2 degree C in summer to -3.6 degree C in winter. The SCP that caused 50 percent mortality (LSCP50) remained constant at -4.7 to -4.8 degree C in both seasons, but slugs were able to survive the frozen state for longer in winter (LD50 of 31.8 minutes compared with 17.0 minutes in summer). Slug survival at freezing temperatures was prolonged to at least five hours when placed on a moist, absorbent substrate. D. reticulatum exhibits partial freeze tolerance, with an increased survival in winter. The results are discussed in relation to the natural environment of slugs.

An integrated pharmacodynamic analysis of erythropoietin, reticulocyte, and hemoglobin responses in acute anemia.

PURPOSE: To determine by pharmacodynamic (PD) analysis physiologically relevant parameters of the cellular kinetics of erythropoiesis in acute anemia. METHODS: The PD relationships among erythropoietin (EPO), reticulocyte, and RBC (Hb) responses were investigated in young adult sheep in acute anemia induced twice by two controlled phlebotomies separated by a 4-week recovery period. RESULTS: The phlebotomies resulted in rapid increases in plasma EPO, with maximal levels occurring at 3 to 8 days, followed by a reticulocyte response with a delay of 0.5 to 1.5 days. The Hb returned to prephlebotomy base line at the end of the 4-week recovery period. The EPO, reticulocyte count, and Hb responses were well described by a PK/PD model (r = 0.975) with the following cellular kinetics parameters: the lag time between EPO activation of erythroid progenitor cells and reticulocyte formation; the reticulocyte-to-RBC maturation time; the reticulocyte and Hb formation efficacy coefficients, quantifying EPO's efficacy in stimulating the formation of reticulocytes and Hb, respectively; the C50 PK/PD transduction parameter defined as the EPO level resulting in half the maximum rate of erythropoiesis. CONCLUSION: Physiologically relevant cellular kinetics parameters can be obtained by an endogenous PK/PD analysis of phlebotomy data and are useful for elucidating the pathophysiologic etiology of various anemias.

TH1 cytokine response of CD57+ T-cell subsets in healthy controls and patients with alcoholic liver disease.

Patients with chronic inflammatory diseases, including Crohn's disease and rheumatoid arthritis, as well as those with certain viral infections, and patients who are transplant recipients or who have certain hematologic malignancies have been observed to have CD57+ T cell expansion in both CD4+ and CD8+ subsets. We have reported previously that alcoholic patients also have CD57+ T cell expansion. Because many alcoholics become seriously deficient in cell-mediated immunity, it is of interest to determine whether the expanded CD57+ subsets can respond to stimulation with normal T helper cell subtype 1 (TH1) cytokine production. We report evaluation of the CD57 T-cell subsets of patients with alcoholic liver disease (ALD) with the use of cytoplasmic staining after stimulation through the T-cell receptor (TCR). The CD57+ subsets of the T cells of both healthy individuals and patients with ALD express significantly higher amounts of cytoplasmic tumor necrosis factor-alpha (TNF-) and interferon-gamma (IFN-) after 6 h of stimulation than do the CD57- subsets. This increased production can persist up to 46 h of continuous stimulation. Under these assay conditions, very little cytoplasmic interleukin (IL)-4 is observed in the T cells of either healthy control subjects or patients with ALD. Measurement of cytokine secretion by sort-purified CD57 T-cell subsets with the use of enzyme-linked immunosorbent assay (ELISA) shows that the CD57+ T-cell subset produces 18- to 30-fold more TNF- and IFN-, respectively, than does the CD57- subset in the first 12 h of stimulation. This response requires only stimulation through the TCR for the CD57+ subset, whereas significant secretion by the CD57- subset requires added IL-2 or anti-CD28 antibody. These results are consistent with the concept of the CD57+ T-cell subset as a differentiated effector cell and demonstrate that patients with ALD who are not drinking at the time of evaluation have normal or increased immediate TH1 T-cell responses.

Ethanol induces cell death and cell cycle delay in cultures of pheochromocytoma PC12 cells.

Animal models have clearly established that ethanol exposure can deplete neurons in the developing nervous system. However, the mechanism by which ethanol reduces cell number is unclear. In our study, cultures of pheochromocytoma cells, a neuronal-like cell line, were maintained in media, which supported cell proliferation. Although cell numbers continued to increase in the presence of ethanol, this increase was partially inhibited by ethanol exposure. This inhibitory effect was concentration and duration dependent. Cell proliferation was still partially inhibited after removal of ethanol, but this inhibition was temporary and disappeared after a 24-hr recovery period in ethanol-free conditions. Further study indicated that ethanol partially inhibited the increase in cell numbers by two mechanisms: (1) studies with vital stains indicated that ethanol induced cell death; (2) experiments using synchronized pheochromocytoma cell cultures showed that ethanol can induce cell cycle delay, thereby lengthening the doubling time of the cells. Analysis by flow cytometry indicated that with ethanol exposure, the cells accumulated in the G1 phase of the cell cycle. Our results suggest that in the developing nervous system, ethanol may limit the numbers of proliferating, neuronal precursor cells by two simultaneous mechanisms, cell death and cell cycle delay.

Alcohol abuse, alcoholism, and damage to the immune system--a review.

Chronic alcohol abuse exacts a major social and medical toll in the United States and other Western countries. One of the least appreciated medical complications of alcohol abuse is altered immune regulation leading to immunodeficiency and autoimmunity. The consequences of the immunodeficiency include increased susceptibility to bacterial pneumonia, tuberculosis, and other infectious diseases. In addition, the chronic alcoholic often has circulating autoantibodies, and recent investigations indicate that the most destructive complications of alcoholism, such as liver disease and liver failure, may have a component of autoimmunity. Current research on altered cytokine balance produced by alcohol is leading to new insights on the regulation of the immune system in the chronic alcoholic. There is also recent development of exciting new techniques designed to improve or restore immune function by manipulation of cytokine balance. Although much remains to be learned, both in the abnormalities produced by alcohol and in the techniques to reverse those abnormalities, current progress reflects a rapidly improving understanding of the basic immune disorders of the alcoholic.

Ethanol and natural killer cells. I. Activity and immunophenotype in alcoholic humans.

The human lymphocyte fraction with the greatest fresh killing activity against K562 targets is phenotypically the CD3-CD19-CD56+ subset. There have been reports of reduced natural killer (NK) activity in human alcoholics, but overall consistency is lacking and phenotypic monitoring has been inadequate to allow reliable estimates of changes in the active cell fractions. We have evaluated a range of cell surface markers and fresh NK activity in controls and alcoholics, and now report abnormalities in both phenotype and function in some alcoholics, but a normal profile in others. Patients without evidence of active liver disease (AWLDs) tend to have normal fresh basal activities and phenotypic profiles. Patients with alcoholic liver disease (ALDs) have fewer Lin- lymphocytes that are CD56+. Three of 14 ALDs assayed in the present work had absent NK activity, whereas others were activated. In normal controls and in AWLDs, the presence of monocytes in the lytic assay consistently inhibits lysis; but, in some patients with ALD, the presence of monocytes is stimulatory to NK activity. In alcoholics as one group, there is a statistically significant relative increase in a novel Lin- subset of unknown function; this subset has a phenotype of Lin-CD56-CD45RO+.

Ethanol and natural killer cells. II. Stimulation of human natural killer activity by ethanol in vitro.

A single ethanol ingestion of 1 g/kg by healthy individuals under controlled conditions does not inhibit and may stimulate fresh natural killer (NK) activity measured 16 hr later. However, ethanol inhibits fresh human NK activity when added to the lytic assay medium, as reported previously by other investigators. In contrast, using the same target (K562 erythroleukemia cells), peripheral blood mononuclear cells cultured 3 days with 50 units/ml of interleukin-2 are no longer inhibited significantly by the same concentration of ethanol that inhibited the fresh cells by 80%. When freshly isolated peripheral blood mononuclear cells, monocyte-depleted lymphocytes, or partially purified NK cells are pre-exposed to ethanol in vitro for 1 to 7 days, washed, and assayed for lytic activity against K562, the lytic activity is increased compared with nonethanol-exposed cells incubated concurrently. This increase is not dependent on accessory cells, added cytokines, or cell growth, and seems to be an intrinsic response of the NK subset to ethanol exposure. The finding of NK stimulation by ethanol, considered together with the observation of NK cell loss in some chronic alcoholics, suggests that loss of NK activity in the chronic alcoholic may result from cell loss rather than direct ethanol inhibition of NK activity.

Effect of a single ethanol exposure on HIV replication in human lymphocytes.

BACKGROUND: Alcoholism is known to cause perturbations in cellular and humoral immunity, and some data suggest that acute alcohol ingestion enhances HIV replication in the lymphocytes of drinkers. METHODS: To study the acute effects of alcohol ingestion on HIV replication, oral ethanol (1 g/kg) was administered to 12 healthy volunteers in a controlled clinical setting. In vitro replication of HIV in the subjects' cultured lymphocytes and changes in lymphocyte phenotypes were evaluated. RESULTS: Statistically significant increases in peripheral lymphocytes and natural killer cell numbers were identified after the initial ethanol trial. HIV replication also increased in the isolated lymphocytes of some subjects after ethanol ingestion, but most subjects in the second trial showed essentially no changes in any of these parameters. CONCLUSIONS: Our results are consistent with either a subtle, study-induced stress-related enhancement in HIV replication or significant individual variation in response to ethanol. The results do not provide evidence for a general increase in HIV replication in the lymphocytes of subjects following a single in vivo ethanol dose of 1 g/kg.

The use of the Beck Airway Airflow Monitor for verifying intratracheal endotracheal tube placement in patients in the pediatric emergency department and intensive care unit.

Traditional methods of confirming that the endotracheal tube is in the trachea are often unavailable or difficult to perform in some clinical situations, such as interfacility transport or other times outside the neonatal intensive care unit. We evaluated the Beck Airway Airflow Monitor (BAAM), through which airflow makes a whistling sound, for its safety and efficacy in neonates. We studied 46 neonates ranging in weight from 0.6 to 3.7 kg. We found that the BAAM consistently produced the desired whistling sound signaling intratracheal placement of the endotracheal tube in all infants weighing above 1.5 kg. No adverse effects or complications were noted. The results support the safety and efficacy of the BAAM in confirming intratracheal endotracheal tube position in neonates.

Noncompliance with scheduled revisits to a pediatric emergency department.

OBJECTIVES: To determine the incidence of, the risk factors associated with, and the consequences of noncompliance (NC) with a scheduled revisit to a pediatric emergency department (ED). DESIGN: A prospective, inceptive cohort study. SETTING: An urban pediatric ED. PATIENTS: A sample of 179 children. INTERVENTIONS: Interviews of parents and physicians. RESULTS: Overall, 91 (51%) of the parents were noncompliant, and just 21% were noncompliant because "the child was better." Of the 124 patients who ED physicians believed were "certain to return," 57 (46%) were noncompliant. Six factors were associated with NC: (1) the parent believed that the child was not severely ill (relative risk [RR], 2.92; 95% confidence interval [CI], 1.31-6.49); (2) the parent was judged to be unable to recognize a clinical deterioration of the child (RR, 1.95; 95% CI, 1.55-2.45); (3) the parent did not own a car (RR, 1.77; 95% CI, 1.23-2.54); (4) the parent was younger than 21 years (RR, 1.48; 95% CI, 1.12-1.95); (5) no laboratory testing was performed during the initial ED visit (RR, 1.36; 95% CI, 1.03-1.80); and (6) the parent was judged "not certain" to return (RR, 1.34; 95% CI, 1.01-1.78). CONCLUSIONS: The high rate and the lack of predictability of NC with a scheduled revisit to an ED should influence patient disposition decisions. The factors associated with NC in this study may serve as a model for identifying parents who are at a high risk of NC and as a foundation for interventions designed to improve compliance.

The Beck Airway Air Flow Monitor as an aid for evaluation of endotracheal tube placement in neonatal patients.

We evaluated the Beck Airway Air Flow Monitor (BAAM), through which airflow makes a whistling sound, for its safety and efficacy in confirming that an endotracheal tube is in the trachea. We studied 46 neonates ranging in weight from 0.6 to 3.7 kg. We found that the BAAM consistently produced the desired whistling sound signaling intratracheal placement of the tube in all infants weighing more than 1.5 kg. No adverse effects or complications were noted.

Loss of the CD5+ and CD45RAhi B cell subsets in alcoholics.

Chronic alcoholics are frequently immunodeficient, have polyclonal hypergammaglobulinaemia, and often have autoantibodies. Recent work in other diseases has shown that functional distinctions of possible relevance to autoimmunity and immunodeficiency can be found among the B cell subsets defined by differential expression of the surface markers CD5 and CD45RA. Therefore, we have evaluated the CD5, CD45RA B cell subsets of both chronic alcoholics without evidence of active liver disease (AWLD), and alcoholics admitted for acute alcoholic liver disease (ALD). Mean B cell numbers were normal in AWLD, but significantly reduced in ALD. Analysis of B cells by three-colour flow cytometry in 20 patients and 29 controls revealed a sharp decrease in the percentage of alcoholics' B cells which were CD5+, 37.6% versus 16.3%, P < 0.000 01; absolute CD5+ B cell numbers were similarly reduced (58.9 cells/microliters versus 20.9; P = 0.0012). In addition to the loss of CD5+ B cells, there was a reduction in the percentage of B cells which are CD5- CD45RAhi, leaving many patients with a B cell profile which was predominantly CD19+ CD5- CD45RAlo. This subset appears phenotypically similar to the IgM-producing CD5- CD45RAlo subset described by others, and may be enriched for autoantibody-producing cells. One outlier patient was an ALD with 61% of B cells which were CD5+, which also is a profile consistent with increased autoantibody production.

Effect of chronic erythropoietin administration on plasma iron in newborn lambs.

Erythropoietin, the primary stimulator of erythropoiesis, represents an important potential therapy for the anemia of prematurity. Enhancement of the therapeutic benefit of recombinant human erythropoietin (rhEp) in very-low-birth-weight infants will require a better understanding of rhEp's pharmacodynamic effects including its interaction with iron in stimulating erythropoiesis. The purpose of this study was to determine the effects of chronic rhEp administration on plasma iron levels and hematopoiesis using a twin lamb model. Nine pairs of twin lambs in which one twin was randomized to receive rhEp, and the other saline, were studied during a 1-week baseline and a subsequent 4- to 5-week treatment period. The effects of therapy on plasma iron levels and erythropoiesis were measured by integrating the areas under the concentration-time curves (AUC) of the study variables. During the rhEp treatment period, significantly greater negative daily AUCs were observed in the rhEp-treated lambs for plasma iron concentration (p = 0.0008), while significantly greater positive daily AUCs were observed for hemoglobin concentration (p = 0.04) and reticulocyte count (p = 0.02). In the rhEp-treated group, pretreatment iron concentrations were directly associated with the magnitude of the iron response during treatment such that the greater the pretreatment iron, the greater the daily AUC below the plasma iron concentration-time plot (r = -0.66, p = 0.05). For the placebo-treated group, this association tended toward, but did not achieve, statistical significance (r = -0.52, p = n.s.). These observations suggest that treatment of rapidly growing newborn lambs with rhEp results in increased iron utilization due to increased erythropoiesis and depends on iron status at the initiation of rhEp treatment. Use of the term neonatal lamb model offers advantages over studies in human infants for more detailed or invasive examinations of the interaction of iron and rhEp treatment.

The Institute of Medicine report on emergency medical services for children: thoughts for emergency medical technicians, paramedics, and emergency physicians.

The emergency medical technician, the paramedic, and the emergency physician, as well as emergency physicians who have additional expertise in emergency medical service (EMS) prehospital care or pediatric emergency medicine (through experience or formal fellowship training), will all find the Institute of Medicine's report, Emergency Medical Services for Children (EMS-C), to be an invaluable background resource as well as a guide for EMS system and EMS-C-related planning. With both breadth and depth, it reviews many of the issues in EMS-C today from many perspectives and provides practical information to enable these care givers to understand better the "big picture" of EMS-C as well as to assist them in continuing to make a difference in the day-to-day emergency care for children. It is well referenced, engenders respect for all members of the team within the broad continuum of EMS-C, and provides encouragement to them to work together to identify and address issues and solve problems to improve the quality of care for our nation's children.

Modulation of T-cell adhesion markers, and the CD45R and CD57 antigens in human alcoholics.

Direct and indirect evidence indicates that T cells are altered in alcoholics. The most commonly reported changes under direct examination have been consistent with an increased level of activation as reflected by shifts in the ratio of common leukocyte antigen isoforms expressed at the cell surface, by increases in the expression of class II antigen, or by alterations in the expression of various adhesion molecules. Functional evidence for T-cell abnormality includes loss of delayed hypersensitivity and a number of findings attributed to dysregulation of B cells by alcoholic T cells; these include the widely reported distrubances of immunoglobulin production in vivo and a range of abnormal responses when T and B cells are combined in vitro. Detailed flow cytometric examination of T cells from alcoholics with or without active liver disease reveals a significant loss of L-selectin CD8+ T cells, but not usually of CD4+ T cells. There is an inverse increase in the expression of CD11b on the CD8+ cells that have decreased L-selectin+ percentages. Both CD8+ and CD4+ T cells in alcoholics display a significant loss of the CD45RA isoform and a gain of cells exhibiting the CD45RO isoform. Other surface alterations include increased expression of CD57, a marker most commonly associated on T cells with conditions of chronic increased antigenic exposure. It is argued that these and other T-cell alterations in alcoholics are cytokine-driven in part and result in T-cell differentiation states that are functionally inappropriate.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of a Beck Airway Airflow Monitor and controllable-tip endotracheal tube in two cases of nonlaryngoscopic oral intubation.

Alternative techniques and equipment for intubation may be particularly useful in settings such as air-medical transport, prehospital on-scene care, mass casualty incidents, or incidents in which there may be a lack of medications or equipment. Once traditional techniques of endotracheal intubation and tube verification have been mastered, emergency medicine residents and other intubators should be encouraged to learn alternative techniques, such as these, that may be of use in some special situations, even within the ED. Neither of these two techniques of BAAM-assisted blind oral intubation can be considered essential, nor should it be contended that these techniques supplant learning of more conventional methods of endotracheal intubation and tube placement verification. However, particularly in the setting of residency training, multiple methods of endotracheal intubation should be taught in order to allow the clinician alternative methods if unable to intubate by traditional means in a particular setting. Use of a BAAM to assist in blind oral intubation of a spontaneously breathing patient may allow for oral intubation of awake patients without the additional use of paralytic medications. Use of the BAAM with a digital technique during external cardiac massage may facilitate intubation by the digital technique and help to verify endotracheal tube position. These two additional uses for the BAAM should be noted and these two additional methods of airway control be recognized as backup methodologies in the armamentarium for situations in which they may be needed.