Deconvolving molecular signatures of interactions between microbial colonies

Motivation: The interactions between microbial colonies through chemical signaling are not well understood. A microbial colony can use different molecules to inhibit or accelerate the growth of other colonies. A better understanding of the molecules involved in these interactions could lead to advancements in health and medicine. Imaging mass spectrometry (IMS) applied to co-cultured microbial communities aims to capture the spatial characteristics of the colonies’ molecular fingerprints. These data are high-dimensional and require computational analysis methods to interpret.

Results: Here, we present a dictionary learning method that deconvolves spectra of different molecules from IMS data. We call this method MOLecular Dictionary Learning (MOLDL). Unlike standard dictionary learning methods which assume Gaussian-distributed data, our method uses the Poisson distribution to capture the count nature of the mass spectrometry data. Also, our method incorporates universally applicable information on common ion types of molecules in MALDI mass spectrometry. This greatly reduces model parameterization and increases deconvolution accuracy by eliminating spurious solutions. Moreover, our method leverages the spatial nature of IMS data by assuming that nearby locations share similar abundances, thus avoiding overfitting to noise. Tests on simulated datasets show that this method has good performance in recovering molecule dictionaries. We also tested our method on real data measured on a microbial community composed of two species. We confirmed through follow-up validation experiments that our method recovered true and complete signatures of molecules. These results indicate that our method can discover molecules in IMS data reliably, and hence can help advance the study of interaction of microbial colonies.

Availability and implementation: The code used in this paper is available at: https://github.com/frizfealer/IMS_project.

Contact:vjojic@cs.unc.edu

Supplementary information:Supplementary data are available at Bioinformatics online.

Cell-substratum adhesion strength as a determinant of hepatocyte aggregate morphology

Cultured hepatocytes typically form multicellular aggregates which are either monolayered or spheroidal in morphology. We propose that the aggregate morphology resulting from a particular cell-substratum interaction has a biophysical basis: when cell contractile forces are greater than cell-substratum adhesion forces, spheroidal aggregates form; when cell contractile forces are weaker than cell-substratum adhesion forces, cells remain essentially spread and form monolayered aggregates. We tested this hypothesis by systematically varying the morphology of hepatocellular aggregates formed on substrata coated with a series of different concentrations of Matrigel, and correlating aggregate morphology with the cell-substratum adhesion strength measured in a shear flow detachment assay. Aggregate morphology was binary-spheroidal aggregates formed at low Matrigel concentrations and monolayered aggregates formed at high Matrigel concentrations. Cell-substratum adhesion strength was similarly binary, with low adhesion strengths correlated with spheroidal aggregates and high adhesion strengths correlated with formation of monolayered aggregates. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 53: 415-426, 1997.

Motility behavior of hepatocytes on extracellular matrix substrata during aggregation

Aggregation of hepatocytes in culture is an important phenomenon to control in tissue engineering applications. Aggregation generally enhances maintenance of differentiated functions but inhibits cell growth. At present there exists insufficient information for rational design of substrata that control aggregation. Indeed, the cellular mechanism(s) underlying the aggregation process is poorly understood, although cell motility is generally considered to be an essential phenomenon. In this article we provide the first study investigating the relationship between hepatocyte aggregation and motility behavior on various extracellular matrix substrata, including Matrigel, laminin, and fibronectin. We find that the extent of aggregation depends on the concentration of the extracellular matrix proteins, as well as on the type. Furthermore, we find that the extent of aggregation appears to be independent of classical single-cell locomotion. In fact, under conditions giving rise to substantial aggregation, the fraction of cells exhibiting classical locomotion is essentially negligible. Instead, aggregation appears to involve intracellular contacts accomplished via a different form of cell motility: active cell membrane extensions followed by adhesive cell-cell interactions. An implication of these findings is that aggregation may be largely governed by relative strengths of cell-cell versus cell-substratum interactions. These observations could be helpful for improved design of cell transplantation devices and cell culture substrata. (c) 1996 by John Wiley & Sons, Inc.

Regulation of parasympathetic neurons by mast cells and histamine in the guinea pig heart

The potential interaction between the immune system and the autonomic nervous system was examined in the cardiac ganglia of guinea pigs. Intracellular voltage recordings were used to determine the effects of mast cell degranulation on the membrane properties of parasympathetic neurons in animals actively sensitized to ovalbumin. Stimulation of mast cell degranulation by perfusion with ovalbumin (10 micrograms/ml) produced a depolarization and increase in the excitability of intracardiac neurons. These effects could be mimicked by histamine application, either by perfusion (10 microM) or by local pressure application (100 microM, 1-2 s application). In either case, histamine application resulted in a similar membrane depolarization and increase in excitability. Immunohistochemical experiments demonstrated that histamine-immunoreactive mast cells are located in close proximity to parasympathetic postganglionic neurons. The histamine response was not due to release of other neurotransmitters from adjacent nerve terminals and both the depolarization and increase in excitability were inhibited by the H1 antagonist, pyrilamine (300 nM), and were unaffected by the H2 antagonist cimetidine (5 microM). Incubation of cardiac ganglion preparations from sensitized animals with pyrilamine prior to ovalbumin perfusion resulted in the inhibition of both the depolarization and increase in excitability. These results demonstrate that mast cell degranulation, and the subsequent release of histamine, results in the stimulation of intracardiac neurons via the activation of H1 receptors. Thus, local inflammatory reactions in the cardiac tissue can lead to the rapid activation of parasympathetic neurons, thereby altering cardiac function.

Adhesion-guided in vitro morphogenesis in pure and mixed cell cultures

The ability to understand and control the morphogenesis of mammalian cells is a fundamental objective of cell and developmental biology and tissue engineering research. Numerous processes, both biochemical and biophysical in nature, have been studied in an attempt to elucidate the mechanisms underlying this behavior. We focus here on the contributions of biophysical phenomena to the morphogenetic behavior of pure and mixed cell populations on solid surfaces in vitro. These principles are illustrated using characteristic liver tissue cells as a model system. The studies discussed demonstrate that cell-substratum and cell-cell adhesive forces are critical determinants of the ultimate morphology, cytoarchitecture, and organization achieved by these cells in vitro.

In vitro organogenesis of liver tissue

The high metabolic rate of hepatocytes severely limits the mass of cells which can be transplanted without a vascular supply. We are developing an alternative approach in which vascularized tissue is grown ex vivo for anastamosis into the portal vein. Here, we discuss the key design issues for in vitro organogenesis of vascularized hepatic tissue, describe a fabrication approach for making complex degradable polymer scaffolds to organize cells in three dimensions on the scale of hundreds of microns, and demonstrate the feasibility of using these scaffolds for in vitro tissue organization in mixed-cell cultures.

Posterior occipitoatlantal hypermobility in Down syndrome: an analysis of 199 patients

We endeavored to determine the prevalence of occipitoatlantal hypermobility in individuals with Down syndrome, to establish objective radiographic criteria for this entity, and to correlate this with neurologic abnormality. In a retrospective analysis, upper cervical spine radiographs of 210 patients with Down syndrome were compared with those of 102 normal individuals. Radiographs were evaluated using the Powers ratio. Patients identified with radiographic evidence of posterior occipitoatlantal hypermobility were then examined clinically and compared with a matched group of patients with Down syndrome and normal Powers ratios. Of the patients with Down syndrome, 8.5% had a Powers ratio of < 0.55, which was indicative of posterior occipitoatlantal hypermobility (POAH). Furthermore, 66% of those with an abnormal Powers ratio had positive neurologic findings upon physical exam, a finding that was statistically significant when compared to a matched group of patients with Down syndrome and normal Powers ratio.

Quality of life of hemodialysis patients

The purpose of this study was to assess the quality of life of hemodialysis patients. The sample (n = 349) was selected randomly from the adult, inunit hemodialysis patient population of 90% of the counties of Illinois, with the exception of those dialyzed by the Veterans Administration. The findings indicate that the patients in this study were satisfied with their lives in general. Nevertheless, the results also indicated that continued efforts are needed to improve the health and financial independence of hemodialysis patients.

Needs of family members of intensive care unit patients

To identify important needs of families of critically ill patients, and the degree to which these needs were being met, 64 family members and 58 nurses were asked to complete a modified version of the Critical Care Family Needs Inventory (Molter & Leske, 1983). Family members and nurses identified many similar important needs, such as the need to have questions answered honestly, the need to be called at home about changes in the patient's condition, and the need to know why things were done for the patient. However, family members indicated that some needs were both more important and less satisfactorily met than the nurses perceived: the need to know the occupational identity of staff members, directions as to what to do at the patient's bedside, and having friends for support.

Psychometric assessment of the Quality of Life Index

The purpose of this study was to examine the psychometric properties of the Quality of Life Index (QLI) (Ferrans & Powers, 1985a). The sample consisted of 349 patients selected randomly from the adult, in-unit hemodialysis patient population of Illinois. Factor analysis was used to examine the underlying factor structure. A four-factors solution best fit the data, indicating that there were four dimensions underlying the QLI: health and functioning, socioeconomic, psychological/spiritual, and family. Factor analysis of the four primary factors revealed one higher order factor, representing quality of life. Construct validity also was supported by the contrasted groups approach. As predicted, it was found that those who had higher incomes had significantly higher quality of life scores on the social and economic subscale. Support for convergent validity was provided by a strong correlation (r = .77) between scores from the QLI and an assessment of life satisfaction. Findings supported the internal consistency reliability of the entire QLI (alpha = .93) and the four subscales (alphas = .87, .82, .90, .77).

Development of an instrument to measure hope

The purpose of this study was to develop an instrument to measure hope in adults and to evaluate its psychometric properties. A 40-item Miller Hope Scale (MHS) was developed based on critical elements of hope revealed in a comprehensive review of the literature and on an exploratory study of hope in persons who survived a critical illness. The instrument was critiqued by measurement and content experts, and content validity was established. The MHS was pretested on 75 subjects. The refined instrument was next evaluated using 522 healthy adults. The intent was to establish norms on the instrument before using it on ill subjects. The range of scores on the MHS is 40 to 200, with high scores indicating high hope. Mean hope score for this healthy sample was 164.46 (SD = 16.31). A leptokurtic curve, skewed to the left, was noted in these responses. As expected, the instrument detected high hope in individuals who were screened to have no physical or mental health problems. The internal consistency alpha coefficient was .93 with a 2-week test-retest reliability of .82. Criterion-related construct validity was established by correlating the MHS to the Psychological Well-Being Scale, r = .71, the Existential Well-Being Scale, r = .82, and a 1-item hope self-assessment, r = .69. Divergent validity with the Hopelessness Scale was established, r = -.54. Maximum likelihood factor analysis with oblimin rotation resulted in a three-factor solution: I, Satisfaction with Self, Others, and Life; II, Avoidance of Hope Threats; and III, Anticipation of a Future.

Satisfaction with health care of hemodialysis patients

The purpose of this study was to assess the satisfaction with care of hemodialysis patients, and to explore the relationships between satisfaction with care, quality of life, and background variables. The sample (n = 416) was randomly selected from the adult, in-unit hemodialysis patient population of a north central state. Overall, patients were satisfied with their care (M = 5.04, range = 1 to 6). An ANOVA demonstrated that patients were most satisfied with physician related aspects of care, followed by nursing/dialysis treatment aspects, and least satisfied with financial/transportation aspects (F(2,830) =28.44. p less than .0001). Overall satisfaction with care was most highly correlated with satisfaction with medical (r = .74) and nursing care (r = .74). Satisfaction with care was moderately correlated with quality of life (r = .42) and satisfaction with health and functioning (r = .42). Somewhat weaker relationships were found between satisfaction with care and socioeconomic aspects of life (r = .31), psychological/spiritual aspects (r = .32), and family (r = .27). Patients who had been on dialysis for a shorter length of time or who had less education were more satisfied with care.

Profile of the well-controlled, well-adjusted hypertensive patient

The study purpose was to identify discriminant predictors of blood pressure control and adjustment to chronic illness in 450 hypertensive patients. Hypertension control was determined by physician judgment, and adjustment was assessed by Derogatis' (1977) Psychosocial Adjustment to Illness Scale. Potential predictors of the outcome variables were measured by structured interview, formal instruments, and chart review. Well-controlled hypertensive patients had better health adjustment scores, reported more illness-related job problems and less illness-related sexual problems, were more satisfied with health care, knew what to do about medication side effects, were on medications longer, and had lower blood pressure readings on chart review. Well-adjusted hypertensive patients had fewer hypertension-related problems; had their blood pressure under control; were less likely to eat, smoke, or use drugs to handle tension; had no recent weight gain; knew what to do about medication side effects and that there is no cure for hypertension; were less pessimistic and less likely to worry; rated their stress level lower and their quality of life higher; felt that their health was under their own control; tried to problem solve when coping with stress; were on hypertensive medications a shorter time and on fewer medications overall; did not like to be alone when feeling stressed; and ate fewer high sodium foods.

Stressors associated with coronary bypass surgery

The purpose of this study was to: design and test an instrument to evaluate the incidence and severity of stressors associated with coronary bypass surgery and assess the concordance between patient and nurse perceptions of such stressors. The patient sample consisted of 30 patients recovering without complications from coronary bypass surgery. Patients were white, primarily male and employed, one-third with graduate education, with a mean age of 54. The nurse sample consisted of 18 registered nurses with cardiosurgical nursing care experience. A 30-item stressor scale was developed: 27 items were derived from literature review and 3 from comments of cardiovascular clinical specialists. Stressfulness of each item was rated on a 5-point scale. A pilot study with seven patients provided information for initial scale refinement. Content validity of the scale has both theoretical and empirical support because of the varied sources used to obtain and validate relevant items for the tool. Homogeneity reliability of the scale was supported by high coefficient alphas. Based on severity of stress ratings, two-way analysis of variance indicated that the cardiothoracic nurses generally rated all items as significantly more stressful for coronary bypass patients than did the patients themselves. Comparisons used by the nurses and the patients in assigning stressfulness ratings are discussed.

Influence of weather on osteoarthritics

This exploratory study examined the effects of selected weather variables on pain and pain-related stress in osteoarthritic subjects. Urban and rural dwelling arthritics who perceived that weather made their symptoms worse and those who did not were surveyed. Some persons with osteoarthritis in urban Chicago were more weather sensitive than their rural counterparts in Grand Forks, North Dakota. Multiple regression analysis showed that precipitation affected degree of pain for urban subjects who identified weather as a pain-generating factor; barometric pressure, relative humidity and sunshine were significant factors influencing pain-related stress. Wind speed correlated with pain and pain-related stress; relative humidity and precipitation correlated with pain-related stress for urban subjects who did not perceive weather as a problem. Specific weather variables were not identified as affecting rural subjects' pain. However, temperature and barometric pressure affected degree of pain-related stress in rural subjects who perceived weather as a problem. Subtle differences between Chicago urban and Grand Forks rural climates are reflected in arthritic subjects' degree of pain and their perception of pain-related stress.

Psychometric evaluation of the Hemodialysis Stressor Scale

This report updates the psychometric information available on the Hemodialysis Stressor Scale. The tool is a 29-item scale that rates the incidence and severity of stressors associated with hemodialysis treatment of end-stage renal disease. Six items are classified as physiologic stressors and 23 as psychosocial stressors. Alpha homogeneity coefficients achieved acceptable standards for reliability. Content validity is demonstrated by the varied sources used to ascertain pertinent items for the scale. Construct validity of the scale was investigated by factor analysis (N = 174). A two-factor solution to evaluate the validity of the physiological-psychosocial dichotomy showed insufficient support for this simplistic dichotomous classification of hemodialysis stressors. A subsequent unrestricted factor solution to explore the multidimensionality of the scale yielded eight factors, but only three were significant, so a three-factor solution was subjected to rotation. The content of the 6 physiological and 9 psychosocial items loading significantly on Factor I characterized this factor as psychobiological; Factor II consisted of 12 psychological and social stressors; Factor III pertained to 8 dependency and restriction stressors. The three-factor solution was seen as the best-fitting solution with this particular data set because it was conceptually clear, informative, and parsimonious.

Quality of life index: development and psychometric properties

The purpose of the study on which this article is based was to assess the validity and reliability of an instrument designed to measure quality of life. Sixty-four items applicable to both healthy subjects and dialysis patients were tested with graduate students (n = 88); six items relative to dialysis were added, and the instrument was administered to dialysis patients (n = 37). Items were based on literature review, which supported content validity. Correlations between the instrument and an overall satisfaction with life question of 0.75 (graduate students) and 0.65 (dialysis patients) supported criterion-related validity. Support for reliability was provided by test-retest correlations of 0.87 (graduate students) and 0.81 (dialysis patients) and Cronbach's alphas of 0.93 (graduate students) and 0.90 (dialysis patients).

The employment potential of hemodialysis patients

This study examined variables that may influence the employment potential of hemodialysis patients. The study group consisted of currently employed (n = 20) and currently unemployed (n = 20) hemodialysis patients. All subjects had been employed before starting dialysis and were currently judged physically able to work by their physicians. No significant differences were found in job satisfaction or job importance before starting dialysis. The groups did not differ on biophysiological status or perception of health. However, a greater number of the unemployed had held jobs requiring heavier physical labor and reported that uremic symptoms prevented them from working. They also encountered more job discrimination due to illness and had a greater loss of career and life goals. No significant differences were found between the two groups in life satisfaction or dependence. In both groups the more independent subjects reported greater satisfaction with life.

Life satisfaction, health control orientation, and illness-related factors in persons with osteoarthritis

The purpose of this study was to assess life satisfaction in osteoarthritics and to explore relationships between that variable and health perception, health locus of control, and illness-related factors. The study group consisted of 160 osteoarthritics from four different types of settings. The osteoarthritics rated their present life satisfaction and recent health as relatively good and were externally controlled in terms of their health beliefs. Present life satisfaction was related to better health perception, internal locus of control, and less joint pain.

Psychometric assessment of the Jalowiec Coping Scale

The Jalowiec Coping Scale consists of 40 coping behaviors culled from a comprehensive literature review, which are rated on a 1- to 5-point scale to indicate degree of use. Twenty judges classified the items to permit analysis of the coping behaviors according to a problem-oriented/affective-oriented dichotomy; 15 problem and 25 affective items resulted. Overall agreement by the judges was 85%, with greater consensus on problem items. Evaluation of stability using a two-week retest interval (N = 28) yielded significant rhos of .79 for total coping scores, .85 for problem, and .86 for affective. With a one-month interval (N = 30) coefficients were .78, .84, and .83, respectively. Alpha reliability coefficients of .86 (N = 141) and .85 (N = 150) supported instrument homogeneity. Content validity is substantiated by the systematic manner of tool development, by the large number of items used, and by the inclusion of diverse coping behaviors. Factor analysis (N = 141) was used to investigate construct validity. A two-factor solution to evaluate the validity of the dichotomous classification showed that 80% of the problem items loaded on Factor I, but only 56% of the affective items loaded on Factor II. To examine this multidimensional aspect, several other factor solutions were explored. Ultimately, the four-factor solution provided the most intelligible conceptual pattern with the least loss of information. Conceptual composition of these factors is discussed, and several tentative labels for each factor are suggested.

Health Beliefs, Adjustment to Illness, and Control of Hypertension

Health beliefs influencing compliance and psychosocial adjustment to illness were compared in two groups of hypertensive patients. Based upon clinical judgments of physicians, 15 controlled and 15 uncontrolled hypertensives made up the study group. Subjects came from a white middle to upper class suburban community and were demographically homogeneous. There was no significant difference between groups in health beliefs affecting compliance, but significant differences were found in several domains related to psychosocial adjustment to illness. Uncontrolled hypertensives showed less illness-related adjustment. They reported significantly greater difficulties in their domestic environments, more disturbances in extended family relationships, and more psychological distress. Less adjustment to illness was significantly correlated with less compliance and with a more complex medication regimen. No relationships were found between compliance and demographic variables, medication variables, or duration of hypertension; nor between adjustment, demographic variables, or illness duration. Clinical assessment of illness-related adjustment problems may help enhance compliance of hypertensive patients.

Nurse practitioner and physician care compared for nonurgent emergency room patients

This experimental field study compared knowledge, satisfaction and compliance in 62 nonurgent emergency room (ER) patients based on whether they were cared for by a nurse practitioner (experimental group) or a physician (control). Data were collected via structured interviews in the ER, two weeks later by phone and three months later by phone, mail and chart review. No significant differences were found between groups in overall short- and long-term compliance scores, appointment-keeping scores for the three-month study period, number of health recommendations recalled, resolution of health problem or satisfaction ratings of ER care. It was also found that: referrals were the recommendation least complied with; 60 percent of appointments were kept; frequent reasons for noncompliance were inconvenience and lack of perceived need; experimental subjects showed greater comprehension of diagnostic recommendations and therapeutic applications, while controls had better knowledge of medications; 77 percent of experimentals were completely satisfied with NP care, as compared to only 48 percent of the controls with MD care; and reasons for satisfaction centered on the quality of care, while reasons for dissatisfaction focused on unresolved problems and slow care.

Validation of two experimental nursing approaches using content analysis

The purpose of this study was to analyze and compare the recorded content of two experimental nursing interventions used in a hypertensive-education program. One intervention was characterized as deliberative or high indirect, the other as task-centered or low indirect. A total of 4,149 nurse-patient interaction units was derived from 62 typed interview transcripts, equally representative of both approaches. Two trained coders categorized the interactions, based upon recurring themes of the teaching content; 24 distinct topical categories were identified. Intercoder agreement above chance for all 4,149 interaction units was k = .68, with confidence limits of 99% +/- .03, p less than .0001. A space-time unit for quantifying the relative amounts of time spent on the various categories also was developed, and analyses were conducted for space-time units as well as interaction units. The main findings showed no definable differences in the frequency of categories or the amounts of time spent in their discussion in the two approaches. These results were contrasted to results obtained when the validity of the nursing approaches was tested previously, and differences between the two interventions in attaining social and health goals were interpreted in light of the findings of the content analysis.

Factors influencing knowledge, attitudes, and compliance of hypertensive patients

Using a factorial design, four aspects of an educational program for 160 hypertensive patients were manipulated: number of meetings, patient responsibility and participation, directiveness of the intervention, and emphasis on negative consequences of uncontrolled hypertension. Validity checks on the manipulations included content analysis of the nurse-patient interaction and interview-based measures of the patient's responsibility, participation, and awareness of dangers. Outcome variables included repeated measures of patient knowledge, assessment by the nurse of patient attainment of identified goals, and reduction of the patient's mean arterial blood pressure. High indirect interventions tended to lead to higher goal attainment, particularly in the psychosocial area. Emphasis on negative consequences tended to promote learning for patients with long standing diagnoses, but to retard learning for recently diagnosed patients. Additional meetings and emphasis on patient responsibility were not helpful alone, but in combination they tended to lead to greater learning. Although as a whole, patients in the program tended to reduce their blood pressures, there were no statistically significant main effects or interaction effects of the educational approach variables on blood pressure reduction.

Stress identification and coping patterns in patients on hemodialysis

The types and severity of stressors and methods of coping with stress were assessed for 35 patients on hemodialysis. Coping was measured with a tested scale and stress was evaluated with a scale developed for the study. Test-retest reliability of the stressor scale was satisfactory (rs = .71). Results indicated that stressors experienced by the hemodialysis patient can be measured with an objective tool; psychosocial stressors have an impact equal to that of physiological stressors. Fluid restriction was ranked as the highest psychosocial stressor and the top physiological stressors were muscle cramps and fatigue. Patients on dialysis for one to three years indicated the greatest amount of stress. Patients used problem-oriented coping methods significantly more than affective-oriented methods (t [34] = 7.06), p greater than .001). Optimism and controlling the situation were the two most common coping methods, and putting the problem out of one's mind and blaming someone else were the least important coping tools.

Learning needs of cancer patients: a comparison of nurse and patient perceptions

The purposes of this study were to discover and compare patients' and nurses' perceptions of the learning needs of cancer patients. Using rating scales, 33 nurses and 27 patients rated the degree of importance of learning 36 informational items, including nutrition, treatment, and diagnostic testing. In addition, nurses and patients ranked six content areas according to: how problematic each area was for the patient; how much knowledge the patient had about each area; and how much the patient wanted information about each area. Results indicated that significant differences existed between nurses' and patients' perceptions of the learning needs of cancer patients. Nurses rated the degree of importance of the 20 general information items significantly higher than did the patients. The rank order of the six content areas for each of three questions by nurses and patients showed nurses ranked dealing with feelings as the most problematic area for patients, while patients ranked this area low.

Stress and coping in hypertensive and emergency room patients

Stressful life events (SLEs) and coping behavior were compared in 25 emergency room patients with nonserious acute illness and 25 newly diagnosed hypertensive patients. Stress was evaluated with a modified Rahe's SLE questionnaire and coping with a rate scale developed by the primary investigator. Results showed that: ER patients reported significantly more (p < .05) SLEs for one year preceding illness onset, although more hypertensives subjectively rated their stress level as high; ER patients experienced significantly more SLEs in personal and social, home and family, and financial categories; hypertensives experienced significantly more health-related SLEs; age was seen as influencing SLEs; hypertensive patients used significantly more problem-oriented coping methods than did ER patients; hypertensives relied more on religion and physical activity in coping than did the ER group; ER patients more often day-dreamed or used their past experience as a guide for coping with stress; each group rated use of drugs as least important in coping; and educational level proved to be a salient variable affecting coping.

Satisfaction with life for patients undergoing hemodialysis and patients suffering from osteoarthritis

Two groups of chronically ill patients, alike in some respects of psychological stress and physical limitations but differing in degrees of physical threat to life because of treatment, were compared in terms of quality of life. Twenty patients undergoing hemodialysis at a satellite center and 20 patients with severe osteoarthritis receiving care at a hospital clinic, ranging in age from 40 to 60 years, were randomly selected and asked to rate themselves on Cantril's self-anchoring scale in relation to pase, present, and future life satisfaction. An ANOVA for simple main effects indicated that patients undergoing hemodialysis viewed present life satisfaction significantly higher, F = 4.81, p less than .05, than did patients with arthritis. Expectation for greater life satisfaction tended to be slightly better for dialysis patients, but not significantly so; past life satisfaction was the same for both groups. Dialysis patients viewed their present life better than past life, whereas arthritis patients had the opposite viewpoint. The increased life satisfaction among dialysis patients may be the result of an increased sense of physical well-being because of the dialysis procedure, and chronic pain may be a factor in the decreased life satisfaction among arthritis patients.

Fungi Associated with Softening of Bisulfite-Brined Cherries

Softening of sound, calcium bisulfite-brined cherries was induced fairly quickly by brining them with cherries rotted by Aspergillus niger, Cytospora leucostoma , and Penicillium expansum , but not with cherries rotted by a variety of other microorganisms, including Alternaria sp., Aspergillus oryzae, Aureobasidium pullulans, Botrytis cinerea, Cladosporium sp., Mucor racemosus, Rhizopus stolonifer , and Sclerotinia fructicola . Rapid softening was correlated with the presence of a bisulfite-stable polygalacturonase, as demonstrated by a cup-plate test. A survey of naturally rotted cherries suggests the involvement of a bark-canker fungus, C. leucostoma , in softening of commercially brined cherries in the Pacific Northwest.