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Biomedical subjects

E F Bond

Publications and source records attributed to E F Bond.

30 records · Page 2Linked to original sources
PubMed1976

Improved resolution in cathodoluminescent microscopy of biological material.

This paper continues work reported in an earlier paper on modification of a Cambridge Stereoscan Mk IIA to improve the quality of cathodoluminescent micrographs of biological material. In the work presently described the microscope gun has been offset laterally by 2 mm, to prevent light from the filament passing down through the column to the specimen chamber. The electron beam is brought onto the column axis by deflection coils. This modification effectively eliminates background light in the chamber, and a full parabolic mirror is fitted to maximize light collection. Results for yeasts and wheat seed sections are described.

Microscopy, Electron, Scanning↗
PubMedDate not supplied

Morphine inhibits TRH-induced intestinal transit increases.

The current study examined the effects of intraperitoneal (IP) and intracisternal (IC) administration of the opiate agonist, morphine, and an opioid, central beta-endorphin, on thyrotropin releasing hormone (TRH)-induced small intestinal transit increases. Anesthetized rats, 14-day and older, were studied to determine age-related differences. Results showed that in all age groups IP morphine (2 mg/kg) blocked TRH (15 micrograms)-induced increases in transit of a charcoal bolus. Morphine 1 microgram and beta-endorphin 1 microgram administered IC in 0.6 microliter failed to block TRH (10 microgram)-induced increases in intestinal transit in 14-day-old rats. However both morphine and beta-endorphin 1 micrograms IC blocked TRH-induced increases in adult rats. Dose-response studies demonstrated that higher doses (greater than 1 microgram) of morphine IC were required to block TRH-induced increases in preweaning rats.

Aging↗
PubMedDate not supplied

Interventions for irritable bowel syndrome: a nursing model.

Irritable Bowel Syndrome (IBS) is a common problem affecting a significant portion of the U.S. population. Nurses are involved directly in the planning and implementing of therapeutic interventions for this patient population. Using a Human Response Model, the authors of this article review intervention studies for IBS. This model provides a context for integration of Person (vulnerability) and Environment (risk) factors that may modify the patient's response to a given therapeutic regimen. Human responses are categorized as Physiological, Pathophysiological, and Behavioral/Experiential. Interdisciplinary therapeutic strategies include motility manipulations via pharmacological agents, dietary modifications, and self-care enhancement. Areas for nursing research are described.

Colonic Diseases, Functional↗
PubMedDate not supplied

Gastric emptying and gastric-intestinal transit in rats with varying ovarian hormone status.

Basal and stimulated gastric emptying and gastrointestinal (GI) transit in rats of varying ovarian hormone status were compared to define direct ovarian hormone effects on GI function. Thyrotropin-releasing hormone (TRH) was used to evoke vagal GI motility stimulation. Adult female Sprague-Dawley rats were anesthetized (equithesin), ovariectomized, and implanted with 28-day estrogen (E), progesterone, (P), E+P, or vehicle (V) pellets; males were also studied. On Day 26, fasted rats were anesthetized (urethane). Nonabsorbable 14C polyethylene glycol-4000 in saline was gavaged at t = 0. At t = 5 minutes, TRH or saline was administered intracisternally. At t = 30 or 60 minutes, the GI tract was removed, ligated, sectioned, and counted. Gastric emptying was expressed as 100% minus the ratio of gastric to total counts; GI transit was expressed as geometric center of radioactivity. In saline-treated rats, gastric emptying and GI transit at 60 minutes varied significantly among ovarian hormone-treated groups, with E lower and males elevated. TRH-significantly increased both variables at both times in all groups. Results are consistent with acceleration of upper GI function in the absence of E, possibly contributing to GI symptoms during menopause and late luteal phase.

Animals↗
PubMedDate not supplied

The relationship between psychological distress and gastrointestinal symptoms in women with irritable bowel syndrome.

BACKGROUND: Individuals with irritable bowel syndrome (IBS) are reported to experience more symptoms compatible with psychopathologic disorders, abnormal personality traits, and psychological distress. Conversely, individuals with psychiatric disorders report higher levels of gastrointestinal (GI) symptoms compatible with IBS. Thus, psychological distress may contribute to GI symptoms in individuals with IBS. OBJECTIVES: To examine psychological distress in women with IBS, women with similar GI symptoms but not diagnosed (IBS nonpatients, IBS-NP), and asymptomatic Control women. METHODS: The women (N=97) were interviewed, completed questionnaires, and maintained daily diaries for 2 months. Across-women and within-woman analyses were used to calculate the results. RESULTS: The IBS and IBS-NP groups had a higher percentage of lifetime psychopathology and recalled psychological distress. At least 40% of the women in the IBS and IBS-NP groups had positive relationships between daily psychological distress and daily GI symptoms. CONCLUSIONS: Psychological distress is an important component of the IBS symptom experience and should be considered when treatment strategies are designed.

Adult↗
PubMedDate not supplied

Menstrual cycle factors related to increased gastric contractile response to tube feeding.

Evidence exists that the ovarian hormones have a modulating effect on gastrointestinal (GI) motility, yet details are sketchy and little attention has been paid to the effect that fluctuating hormone levels might have on women who are receiving enteral feedings. This study compared gastric motility indices in response to tube feedings at two points in the menstrual cycle, concurrently measured ovarian hormone levels, and described three potentially related factors (ie, GI symptoms, uterine cramping pain, reports of daily stressors). Intragastric motility responses to enteral feedings were obtained on 28 women (aged 19-37) during menses and midfollicular phases of two menstrual cycles. Intragastric pressure changes were monitored by an open-tipped cannula method at rest, during and after tube feeding (Ensure, 240 ml at 8 ml/min). Serum estradiol and progesterone levels were measured by radioimmunoassay. Women completed a daily diary of symptoms and stressors throughout the two menstrual cycles. Results showed that intragastric pressure amplitudes and frequencies were higher at menses compared with midfollicular recordings. At menses, prefeeding and feeding gastric pressure amplitudes were positively correlated with uterine cramping pain and GI symptoms (ie, nausea). At menses, postfeeding contraction frequencies were also correlated with uterine cramping pain. At midfollicular phase, progesterone levels correlated with gastric motility indices; number of stressors indirectly correlated with gastric motility indices. These data suggest that gastric responses to enteral feeding are influenced by menstrual cycle phase.

Adult↗
PubMedDate not supplied

GI symptoms, function, and psychophysiological arousal in dysmenorrheic women.

In a previous study, gastrointestinal (GI) symptoms and stool characteristics were found to be influenced by menstrual cycle phase. The current study was designed to replicate initial work regarding GI symptoms and stool characteristics and to explore the relationships between GI symptoms, stool characteristics, ovarian hormone levels, and indicators of psychophysiological arousal. Fifty women (dysmenorrheic, N = 22; nondysmenorrheic, N = 28) maintained a daily dairy for recording stool characteristics, GI symptoms, and daily anxiety level. First morning void urine specimens for catecholamine assays and serum samples for ovarian hormone and cortisol determinations were obtained at menses, follicular, and luteal phases. Results showed menstrual cycle-related differences in stool characteristics and report of GI symptoms, with the greatest changes occurring at menses in the total sample. Dysmenorrheic women reported higher levels of all GI symptoms at menses as compared to nondysmenorrheic women. In addition, cycle-related differences in serum cortisol, urine catecholamines, and report of anxiety were also noted, particularly in dysmenorrheic women. However, looser stools and GI symptoms at menses were not correlated with absolute levels of ovarian hormones or indicators of psychophysiological arousal.

Adult↗
PubMedDate not supplied

Intestinal transit and body weight responses to ovarian hormones and dietary fiber in rats.

A two-part experimental design was used to study the effects of ovarian hormone cessation, hormone supplementation, and dietary fiber composition on body weight, appetite, and intestinal transit. In Part 1, effects of ovarian hormone status on body weight and baseline and stimulated intestinal transit were measured in chow-fed rats. Sprague-Dawley rats were ovariectomized (OVX), then injected daily (22 days) with estrogen (E), progesterone (P), the combination (E + P), or placebo. Controls were sham operated and placebo injected. Among OVX rats, E and E + P had the least body weight gain (9%, 6%); placebo and P had the greatest (36%, 34%). In OVX-P, baseline intestinal transit (measured in anesthetized rats as distance traveled by a charcoal marker) was relatively low, but vagal stimulation via centrally administered thyrotropin-releasing hormone evoked an increase significantly larger than that in other groups. In Part 2, experiments probed the interacting effects of ovarian hormone cessation and dietary fiber composition on body weight and baseline intestinal transit. Caloric intake was measured to determine the contribution of altered appetite. Rats were OVX or sham operated, then fed liquid diets with or without dietary fiber (25 days). OVX fiber-fed rats had significantly higher caloric intake, weight gain, and baseline intestinal transit than other groups. Caloric intake did not fully account for group differences. These results demonstrate modulation of GI function by ovarian hormones and dietary fiber.

Animals↗