Estimation of tile drainage contribution to streamflow and nutrient loads at the watershed scale based on continuously monitored data

Nitrogen losses from artificially drained watersheds degrade water quality at local and regional scales. In this study, we used an end-member mixing analysis (EMMA) together with high temporal resolution water quality and streamflow data collected in the 122 km² Otter Creek watershed located in northeast Iowa. We estimated the contribution of three end-members (groundwater, tile drainage, and quick flow) to streamflow and nitrogen loads and tested several combinations of possible nitrate concentrations for the end-members. Results indicated that subsurface tile drainage is responsible for at least 50% of the watershed nitrogen load between April 15 and November 1, 2015. Tiles delivered up to 80% of the stream N load while providing only 15-43% of the streamflow, whereas quick flows only marginally contributed to N loading. Data collected offer guidance about areas of the watershed that should be targeted for nitrogen export mitigation strategies.

Genetic diversity of Clostridium perfringens isolated from healthy broiler chickens at a commercial farm

Clostridium perfringens is an important commensal and bacterial pathogen of many animal species. It has particular significance in poultry, where it may cause necrotic enteritis. Our objective was to characterize the population diversity of C. perfringens colonizing healthy birds, and to observe how diversity changed over time. Isolates were obtained from broiler chicken cecal samples in two barns on a single farm, on days 7, 14, 22, 27, 30 and 34 of a single 42-day rearing cycle. Bacitracin was used as a feed additive in one of the barns and withdrawn from the second barn for the duration of the experiment. Each isolate was typed using pulsed-field gel electrophoresis (PFGE) using SmaI restriction endonuclease. A total of 205 cecal isolates from 49 birds were typed, as well as 93 isolates from the barn environment (bedding, drinking water and feces). Eight major PFGE types and 17 subtypes were found in the 298 total isolates. The results show that an optimal sampling strategy would involve a large number of birds, with only a few isolates sampled per bird. The diversity of C. perfringens in this study appears to be low within a single bird, and increases as the bird matures. There was no significant difference in genetic diversity between the two barns. In addition, isolates from fresh fecal samples appear to represent the cecal C. perfringens population accurately, although this was not proven statistically. Antimicrobial susceptibility testing was performed on selected isolates (n=41) representing a cross-section of PFGE types. Based on minimum inhibitory concentration distributions, 95% of the isolates tested were deemed resistant to bacitracin, with a 16 microg/mL breakpoint. Three new cpb2 (beta2 toxin gene) variants were found in the study.

Health care professionals and industry: reducing conflicts of interest and established best practices

The relationship between health care providers and pharmaceutical companies and other commercial interests is ethically complex. The common practice of gift giving takes many forms including free samples, sponsorship of medical education, loan of equipment, and gifts ranging from those of nominal value such as pens to more valuable gifts such as golf outings or dinners. Gift giving is a practice that serves both the recipient and the giver, but, in the medical setting, it raises the question of whether this is to the detriment of patient care. Although health care professionals may believe they are able to ignore influence from commercial interests, human judgment research indicates that decision-makers are generally unaware of biases affecting their decisions. This is an issue of organizational ethics as well. Institutions that allow commercial interests to give some form of gift are allowing the appearance of bias as well as placing the burden of avoiding bias on the individual rather than on the institution. Conflict-of-interest analysis indicates that best practice is to limit or eliminate the influence of commercial interests, ensuring that professionals are better able to exercise their independent objective judgment.

Intraoperative gamma detection of 125I-lanreotide in women with primary breast cancer

BACKGROUND

Somatostatin receptors are present in most human breast cancers. We performed a pilot trial of intraoperative tumor-gamma detection using the radiolabeled somatostatin analog 125I-lanreotide in 13 women with 14 primary breast carcinomas.

METHODS

All patients were given 125I-lanreotide intravenously before surgery. Patients underwent lumpectomy, and postresection margins were evaluated with the gamma probe. Axillary dissection specimens were evaluated ex vivo.

RESULTS

Seven of 13 women had gamma probe-positive or clinically suspicious margins re-excised at the time of lumpectomy. Four of six probe-positive margins were histologically positive, and two of six probe-positive margins were histologically negative; a single clinically suspicious margin was histologically positive. A total of 270 axillary lymph nodes were evaluated ex vivo by gamma probe and histology. McNemar's contingency tests demonstrated a highly statistical correlation between histology and gamma probe counts (P < .0001).

CONCLUSIONS

The overall accuracy of nodal evaluation with 125I-lanreotide/intraoperative gamma detection was 77%; the negative predictive value of this technique was 97%, however. This technique predicted the presence of tumor in 20% of axillary lymph nodes that were negative by routine histology. This technique appears safe and is able to detect positive tumor resection margins and accurately predict axillary lymph node negativity. Further trials of this technique are required to validate its utility.

Integrated ethics for the clinical systems manager

This article describes how clinical systems managers can integrate clinical ethics, management ethics, and the social responsibility of business or organizational leaders (business ethics) to resolve ethical dilemmas they may encounter. Three examples are discussed: policy on use of resources, personnel issues, and managed care and the current backlash against it.

Ethics and the future of health care

Ethical values and beliefs will shape the decisions that shape the future of health care. This can be exemplified by reviewing some of the issues related to developing genetic testing. A good leader recognizes the ethical issues and addresses them explicitly.

Taking on organizational ethics. To do so, ethics committees must first prepare themselves

Healthcare ethics committees which have focused almost entirely on clinical ethics, now need to prepare to deal with organizational ethics, a field that is attracting increasing attention. As they did with clinical ethics, ethics committees members must educate themselves in the demands of the newer field. As before, they must respect the perspectives of the actual decision makers while maintaining an independent framework for analyzing the issues at stake. They must ensure that management is properly represented on the committee if they need guidance from a professional ethicist they should seek one with a strong background in business ethics and social justice. Healthcare organizations are likely to need help with a wide range of ethical issues involving patient services (rationing of resources, for example), business and service plans (mergers and joint ventures, for example), business and professional integrity (conflicts of interest, for example), employee rights and responsibilities (downsizing, for example), and the organization's role in in the community (advocacy and lobbying, for example). To be helpful to the organization, the ethics committee must be prepared to say when cost factors trump other considerations and when they do not. An ethics committee will often be asked to give advice on specific occasions-a proposed new policy, for instance. The most important part of its response is its analysis of the issue. Finally, an ethics committee should view its organization as part of the larger social context.

The prevalence of colonic neoplasia in patients with Barrett's esophagus: prospective assessment in patients 50-80 years old

OBJECTIVE

An association between Barrett's esophagus and colorectal neoplasia has been suggested; however, several studies addressing this issue have reported conflicting results. The purpose of this study, therefore, was to determine the prevalence of colorectal neoplasia in a large group of patients (50-80 yr old; mean, 65 yr) with Barrett's esophagus and compare it with that of a similar group of asymptomatic, average-risk controls.

METHODS

Seventy-nine subjects (71 men, eight women) with well-documented Barrett's esophagus underwent complete colonoscopy (cecum reached), which was performed as part of an initial screening evaluation for enrollment in a prospective study of Barrett's esophagus. The control population (N = 930) is represented by the cumulative results of four recent studies in which screening colonoscopy was performed in asymptomatic subjects of average risk. The age of the two groups were similar.

RESULTS

A total of 38 adenomatous polyps were found in 26 patients in the study group. Three patients (4%) had polyps > 1 cm in size or with villous change, which was similar to the prevalence among asymptomatic controls (5%). The overall prevalence of colon adenomas was 32%, and the prevalence of colorectal cancer was 1% in the Barrett's group. In the control group, 30% had adenomas and 0.5% had cancer.

CONCLUSION

The prevalence of adenomatous polyps, both large and small, in a group of patients (ages 50-80 yr) with well-documented Barrett's esophagus is no different from that in asymptomatic controls. These results do not support the assumption of an association between Barrett's esophagus and an increased risk of colon neoplasia, or justify an aggressive surveillance strategy for colon neoplasia in patients with Barrett's esophagus.

The troubled phlebotomist: training new employees in an ethical organization

V.W. is a day-shift phlebotomist at Sunny View Cancer Hospital, located in a mid-sized southern city. She is a high-school graduate from an underprivileged background who has had no exposure to the hospital environment and has been recently trained "on the job" for her current position. She has been extremely troubled recently and has been unable to report to work because of stress-related symptoms. All of this began when, on a routine phlebotomy sweep one day, an extremely cachectic cancer patient looked her in the eyes and asked her why his blood had to be drawn again, saying that he did not expect to live through the night. What should V.W. do? What should V.W.'s manager do?

"Biospheric medicine" as viewed from the two-year first closure of Biosphere 2

Biosphere 2 is a 3.15-acre, 7-million ft. enclosed ecological space near Tucson, AZ. It contains five wilderness and two domestic biomes (rain forest, savanna, desert, ocean, marsh; agricultural station, living quarters), an original introduction of 3,800 species (approximately 20% extinctions have occurred), and a large basement "technosphere." Sealed inside Biosphere 2 in September 1991, four women and four men, including two of the authors, maintained themselves and the various systems for 2 yr, the longest-sustained "isolated confined environment" period on record. MMPI psychological profile scores for Biosphere 2 crewmembers correlated closely with those reported for astronauts and shuttle applicants. Major medical problems encountered during the 2 yr included adaptation to a low-calorie (1800-2200 kcal.d-1 per person) but otherwise nutritionally adequate diet, with substantial weight loss (18% for men, 10% for women), and a declining oxygen atmosphere (down to 14.2%). Life in a miniworld such as Biosphere 2 may differ substantially from life in a space station or temporary planetary base. These differences include multiple, shifting, sometimes opposing post-launch objectives; complete self-sustenance with recycling of virtually all materials within a highly complex biologic system; retooling of some areas of practical medicine; an attention to "culture" as a social dynamic and how that may influence crew and leadership selection in a societal rather than a quasi-military community. Assuming that long-term planetary colonies must be largely self-sustaining (due to costs of supply over great distances), they must of necessity approach the condition of biospheres. Subject to chaos dynamic (nonlinear dynamic) perturbations, the behavior of complex biospheres will be inherently non-predictable--as opposed to the linear dynamic situation of most space missions--and will require of the inhabitants, including the medical team, a wide range of coping abilities. Under the circumstances, and while strong similarities exist, important differences may serve to distinguish "biospheric medicine" from "space medicine."

Medical futility and life-sustaining treatment decisions

By focusing our attention on the questions of "what are we trying to achieve" and "are we able to do it", the discussion of medical futility has contributed an important dimension to the ethics of treatment decision making near the end of life. It is not simply enough to ask and answer the question of what the patient wants. Healthcare professionals have a responsibility to offer only those life-sustaining efforts that have a reasonable chance of being beneficial. Futility policies should permit treatment-limiting decisions to be made without the agreement of the patient or surrogate at times, but such policies should also provide opportunities to challenge a judgement of futility. Above all, such policies should not be used as a reason to avoid communication. Patients or surrogates need to be informed about what treatments are options and what are not. The futility criterion for limiting treatment should be recognized as a means of contributing to communication and discussion regarding benefits, harms and medical goals. It should not be permitted to bypass such discussions. The recognition of the significance of the concept of futility means that discussion needs to continue at another level as well. The questions of "what are we trying to achieve" and "are we able to do it" are not easily answered. It is especially important, we think, that those who are experienced in working with patients with neurological impairments contribute to the on-going reflection on what constitutes benefit or what is the appropriate use of life-sustaining interventions for such patients.

Procuring organs from a non-heart-beating cadaver: commentary on a case report

Procurement of organs from non-heart-beating cadaver donors raises concerns. Standards for optimal patient care during withdrawal of life-sustaining therapy are evolving and continue to be debated and studied. Consensus on specific procedures and methods has not been attained, however, and protocols for the procurement of organs from patients following the withdrawal of life-sustaining therapies may compromise the evolving standards and harm the patient and the attendant family. In addition, there is little evidence to suggest that such protocols will significantly increase the number of organs procured. "Non-heart-beating cadaver" protocols that do not give comprehensive attention to optimal patient/family care at the time of withdrawal of life-sustaining therapy ought not to be endorsed.