Gastrointestinal symptoms before and during menses in women with IBD

BACKGROUND

It is believed that women with inflammatory bowel disease (IBD) have heightened symptoms around their menses. However, there is little information regarding normative changes and which symptoms emerge in relation to menses.

AIM

To determine the relationship between gastrointestinal and other symptoms and menses in a population-based cohort of women with IBD vs. healthy women.

METHODS

Women enrolled in the University of Manitoba IBD Research Registry who were between 18 and 65 years were mailed a survey. A control group of adult women were recruited through out-patient gynaecology clinics. Participants were asked to consider their menstrual periods in the recent several months and report on symptoms 1-5 days prior to and during the days of their menses.

RESULTS

There were 151 premenopausal women with Crohn's disease (CD), 87 with ulcerative colitis (UC) and 156 premenopausal controls. Mean age of menses onset was similar in all three cohorts and the percentage in each group with regular menstrual periods was similar. Premenstrually, abdominal pain was less commonly reported in UC (36.8%) than CD (51%, P = 0.034) and controls (57.6%, P = 0.002). Premenstrually, and during menses diarrhoea was more commonly reported in CD (47.7% and 59.6% respectively) than UC (26.4% P = 0.001 and 42.5%, P = 0.01 respectively) and controls (24.4%, P < 0.0001 and 28.2%, P < 0.0001 respectively). Premenstrually, women with CD (46%) vs. UC (26%) were more likely to report worsening of their IBD symptoms (P = 0.0007), but there was no difference between CD (47%) and UC (39%) for reporting worsening during menses (P = 0.24).

CONCLUSIONS

Compared to healthy women, women with IBD had similar symptom experiences premenstrually, except that those with CD were more likely to have increased diarrhoea premenstrually. During menses, women with CD or UC were more likely to experience diarrhoea than healthy controls.

Autoshaping as a function of prior food presentations

Young chickens were given 1, 10, 100, or 1000 presentations of grain in a hopper. Subsequently, the key was illuminated before each presentation of grain to study autoshaping of the key-peck response. The number of keylight-grain pairings before a bird first pecked the lighted key was found to be a U-shaped function of the number of prior food-only presentations, with pecks occurring significantly sooner after 100 food-only trials than after any of the other values. Two of five chicks at the 100-trial value pecked on the first illumination of the key. Experiment II showed further that when a series of food-only trials (no keylight) preceded keylight-only trials (no food) 30% of the chicks pecked the illuminated key. Experiment III extended the generality of first-trial pecking to pigeons. After preliminary training with food-only, two of five pigeons pecked on the first illumination of a key. The results suggest a close relationship between autoshaping and pseudo-conditioning.

Kidney exchange programs: attitudes of transplant team members toward living donation and kidney exchanges

INTRODUCTION

Several living donor kidney exchange programs (LDKEPs) have been established throughout the world; however, none have yet achieved the perceived substantial potential for increasing the number of living donor kidney transplants. Over the past 2 years, the Ohio Solid Organ Transplant Consortium (OSOTC) has developed and implemented an LDKEP with a complementary, robust web-based computerized matching program for living donor/recipient pairs. Prior to implementation of the OSOTC LDKEP, attitudes of transplant professionals from each of eight participating kidney transplant programs were surveyed to determined attitudes toward living donation and LDKEP and to identify potential barriers to LDKEP. The state of decision making toward LDKEP was also examined.

METHODS

Transplant professionals were surveyed using an instrument designed to assess attitudes toward living donation and LDKEPs. Most questions were answered on a Likert scale (1 = strongly agree, 5 = strongly disagree).

RESULTS

Respondents agreed that living donor transplantation should be encouraged (mean 1.17 +/- 0.6) and that the laparoscopic donor procedure was preferred (1.36 +/- 0.82). Respondents had largely read about KEPs (2.02 +/- 1.02) but had "thought about participating in KEPs" (2.57 +/- 1.26), or actively sought information (2.87 +/- 1.3) to lesser degrees. Despite this, significant indecisiveness existed regarding participation in LDKEPs (2.73 +/- 1.39).

CONCLUSIONS

Transplant professionals are highly aware of LDKEPs. However, they remain indecisive about LDKEP participation. These results indicate that barriers exist in the transplant community toward LDKEP, and these must be defined to increase LDKEP acceptance and participation.

Influence of Educational Programs on Perceived Barriers Toward Living Donor Kidney Exchange Programs

Living donor kidney exchange programs (LDKEPs) provide significant advantages toward addressing ABO and crossmatch incompatibility in living donor kidney transplantation, however, they have not yet realized their potential. The aim of this study was to examine the effect of an educational conference on perceived barriers toward living donor kidney transplantation and LDKEPs.

METHODS

Between 2002 and 2004, a state-wide living donor/living donor kidney exchange program was established by the Ohio Solid Organ Transplant Consortium (OSOTC). Prior to initiating the OSOTC LDKEP, an educational conference was held and its effect on transplant professional attitudes toward LDKEP barriers were assessed prior to and following the conference using a questionnaire. Questions were answered using a Likert scale (LS) (1 = strongly agree, 5 = strongly disagree).

RESULTS

Forty-eight participants completed questionnaires prior to and following the conference. The conference was judged to increase understanding of KEPs. The complementary web-based computer matching program was also felt to be an important component for the LDKEP. The conference did not affect the state of decision making regarding KEPs, however. Perceived barriers to LDKEPs not influenced by the educational conference included (1) concerns about donor travel costs, (2) concern about potential medical legal problems, (3) lack of perceived superiority of LDKEPs over desensitization protocols, and (4) concern about donation to strangers. Although numeric trends existed for each of these barriers, none were statistically significantly influenced by the education conference.

CONCLUSIONS

These results suggest that interventions other than large scale educational conferences will be needed to address the barriers to LDKEP.

A mesoscale phytoplankton bloom in the polar Southern Ocean stimulated by iron fertilization

Changes in iron supply to oceanic plankton are thought to have a significant effect on concentrations of atmospheric carbon dioxide by altering rates of carbon sequestration, a theory known as the 'iron hypothesis'. For this reason, it is important to understand the response of pelagic biota to increased iron supply. Here we report the results of a mesoscale iron fertilization experiment in the polar Southern Ocean, where the potential to sequester iron-elevated algal carbon is probably greatest. Increased iron supply led to elevated phytoplankton biomass and rates of photosynthesis in surface waters, causing a large drawdown of carbon dioxide and macronutrients, and elevated dimethyl sulphide levels after 13 days. This drawdown was mostly due to the proliferation of diatom stocks. But downward export of biogenic carbon was not increased. Moreover, satellite observations of this massive bloom 30 days later, suggest that a sufficient proportion of the added iron was retained in surface waters. Our findings demonstrate that iron supply controls phytoplankton growth and community composition during summer in these polar Southern Ocean waters, but the fate of algal carbon remains unknown and depends on the interplay between the processes controlling export, remineralisation and timescales of water mass subduction.

The simulated evolution of biochemical guilds: reconciling Gaia theory and natural selection

Gaia theory, which states that organisms both affect and regulate their environment, poses an interesting problem to Neo-Darwinian evolutionary biologists and provides an exciting set of phenomena for artificial-life investigation. The key challenge is to explain the emergence of biotic communities that are capable, via their implicit coordination, of regulating large-scale biogeochemical factors such as the temperature and chemical composition of the biosphere, but to assume no evolutionary mechanisms beyond contemporary natural selection. Along with providing an introduction to Gaia theory, this article presents simulations of Gaian emergence based on an artificial-life model involving genetic algorithms and guilds of simple metabolizing agents. In these simulations, resource competition leads to guild diversity; the ensemble of guilds then manifests life-sustaining nutrient recycling and exerts distributed control over environmental nutrient ratios. These results illustrate that standard individual-based natural selection is sufficient to explain Gaian self-organization, and they help clarify the relationships between two key metrics of Gaian activity: recycling and regulation.

Effects of proline cis-trans isomerization on TB domain secondary structure

The transforming growth factor beta (TGF-beta) binding protein-like (TB) domain is found principally in proteins localized to extracellular matrix fibrils, including human fibrillin-1, the defective protein in the Marfan syndrome. Analysis of the nuclear magnetic resonance (NMR) data for the sixth TB module from human fibrillin-1 has revealed the existence of two stable conformers that differ in the isomerization states of two proline residues. Unusually, the two isoforms do not readily interconvert and are stable on the time scale of milliseconds. We have computed independent structures of the major and minor conformers of TB6 to assess how the domain fold adjusts to incorporate alternatively cis- or trans-prolines. Based on previous observations, it has been suggested that multiple conformers can only be accommodated in flexible regions of protein structure. In contrast, P22, which exists in trans in the major form and cis in the minor form of TB6, is in a rigid region of the domain, which is confirmed by backbone dynamics measurements. Overall, the structures of the major and minor conformers are similar. However, the secondary structure topologies of the two forms differ as a direct consequence of the changes in proline conformation.

An object-oriented data-driven migration model

This research uses object-oriented simulation to derive the migratory patterns of animal populations. These patterns are then compared with the trajectories of aquatic pollutant releases to yield quantitative biological impact assessments. These estimates are more realistic than those based on assumptions of uniform or random distributions of animals in a region--a common approach to this problem. The general migration model (MIGMOD) employs stochastic movement routines driven by biological field data to derive heterogenous migration patterns similar to those observed in nature. This data-driven approach circumvents many of the difficulties involved in migratory modelling from first principles. However, we also discuss the importance of selected causal mechanisms in these models.

EUZONE: simulating the evolution of aquatic ecosystems

In the spirit of contemporary artificial life research, EUZONE provides a virtual laboratory for the emergence of complex ecosystems from simple primitives. However, whereas most alife systems abstract away many real-world environmental constraints, EUZONE employs detailed physical and chemical models in combination with evolutionary algorithms to support the emergence of carbon-based aquatic ecosystems. With an emphasis on plankton-like organisms, this research focuses upon the self-organization and evolution of (a) lower levels of aquatic food webs, (b) Gaian interactions between primitive organisms and their physical environments, and (c) species interactions governed by varying life-history strategies.